The Case History

On Part III, the history is where the case is won or lost: the vignette hands you a few words from the patient, and the item asks what you should ask next, what the answer means and which diagnosis it makes likely. In the clinic the same skill decides whether a patient with back pain gets an adjustment, an x-ray or a same day trip to the emergency department. This chapter teaches you to turn a vague complaint into a focused, defensible history that has already narrowed the differential before you lay a hand on the patient.

Section 1The chief complaint and history of present illness

What the history is for

Studies in primary care have shown for decades that the history alone leads to the correct diagnosis in roughly 70 to 80 percent of patients; the physical examination and tests add comparatively little once a good history is in hand. For a chiropractor the history has three jobs. First, it sorts the patient into one of three diagnostic bins: serious pathology (about 1 to 2 percent of spinal pain patients), radicular syndrome (about 5 to 10 percent) and nonspecific mechanical pain (about 90 percent). Second, it generates a short list of hypotheses that the examination will test. Third, it establishes the baseline against which you will judge progress and on which your record stands if the case is ever reviewed.

The standard order is: identifying data, chief complaint (CC), history of present illness (HPI), past medical history (PMH), medications and allergies, family history (FH), personal and social history (SH), and the review of systems (ROS). Part III items test the logic inside each part: which question best discriminates between two diagnoses, which answer is a red flag, and which piece of history is missing.

The chief complaint

The chief complaint is recorded in the patient's own words, with its duration: "Low back pain going down my left leg for three weeks." It should not be a diagnosis ("sciatica" or "subluxation") because a premature label closes the mind. If a patient has several complaints, list them, ask which matters most, and take a separate HPI for each one, because a new symptom (for example, a headache in a patient who came for neck pain) may have a completely different cause.

OPQRST and OLDCARTS

Both mnemonics cover the same ground. OPQRST is Onset, Provocation and Palliation, Quality, Region and Radiation, Severity, and Timing. OLDCARTS is Onset, Location, Duration, Character, Aggravating factors, Relieving factors, Timing and Severity. What matters on the board is not the acronym but what each answer means.

Mechanism of injury

The mechanism is the history's best predictor of which tissue failed and whether a fracture is possible. Ask exactly what happened, the forces and their direction, the position of the body, what the patient felt and heard, and what they could do immediately afterward.

• Flexion with rotation under load (lifting a box and turning) concentrates stress on the posterolateral annulus: classic disc injury.
• Axial load (fall from height onto the feet or buttocks, diving into shallow water) produces compression or burst fractures, most often at the thoracolumbar junction (T11 to L2). A calcaneal fracture from a fall onto the heels travels with a lumbar fracture in about 10 percent of cases, so ask about heel pain and examine both.
• Repetitive hyperextension (gymnastics, football linemen, cricket bowlers, divers) stresses the pars interarticularis: spondylolysis in adolescents.
• Acceleration and deceleration in a motor vehicle collision causes whiplash associated disorders. Ask about direction of impact, whether the head was rotated (worse outcome), headrest height, seat belt and airbag, speed, awareness of the impending impact, and whether symptoms began immediately or the next day.
• Fall on an outstretched hand injures the scaphoid, distal radius, radial head and shoulder.
• Minimal trauma (a cough, stepping off a curb, lifting a grandchild) producing sharp thoracic or lumbar pain in an older or steroid treated patient is an osteoporotic compression fracture until proven otherwise.
• No mechanism at all is itself a finding: insidious pain without an event points away from simple strain and toward degenerative, inflammatory, neoplastic or infectious disease.

The timeline

Duration classifies spinal pain as acute (under 6 weeks), subacute (6 to 12 weeks) and chronic (over 12 weeks, or 3 months). The trajectory matters as much as the duration. Most acute mechanical episodes improve substantially within 2 to 6 weeks; a course that is steadily progressive despite rest and appropriate care is a red flag in itself. Ask about previous episodes, because a recurrent pattern of short mechanical episodes with full recovery between them is reassuring, while a first episode at age 55 or later deserves more caution. Ask what treatment has been tried and with what result: failure to improve after about four weeks of appropriate conservative care is a common trigger for imaging or referral.

Aggravating and relieving factors in more depth

The behavior of pain under load is one of the strongest clues to the pain generator. Flexion intolerance (worse with sitting, bending, lifting, driving, getting out of a chair, morning) fits a discogenic source, because flexion loads the anterior column and pushes nuclear material posteriorly. Extension intolerance (worse with standing, walking, lying prone, reaching overhead) fits the facet joints or stenosis, because extension loads the posterior elements and narrows the canal and foramina. Pain that is worse with cough, sneeze or straining (Valsalva) suggests a space occupying lesion that raises intrathecal pressure on a sensitized root, usually a disc herniation but occasionally a tumor. Pain relieved by sitting or flexing forward and brought on by walking, with leg symptoms, is the hallmark of neurogenic claudication from lumbar spinal stenosis, while leg pain on walking that eases with simply standing still suggests vascular claudication.

Worked examples: turning a vague complaint into a focused history

Section 2Past, family, personal and social history

Why the background history matters

The background history changes pretest probability. The same complaint of thoracic pain means one thing in a fit 25 year old rower and something very different in a 70 year old woman on long term prednisone or a 60 year old man treated for prostate cancer five years ago. Each element below should be asked with a purpose: to raise or lower the probability of a specific diagnosis, or to identify a contraindication to a specific treatment.

Past medical and surgical history

• Prior episodes of the same complaint, how they were treated and how they resolved. Recurrent mechanical episodes predict recurrence; previous good response to manipulation predicts a good response again.
• Prior injuries and fractures, including fragility fractures (wrist, hip, vertebra) that indicate osteoporosis.
• Prior spinal surgery (discectomy, laminectomy, fusion, disc replacement), with dates and levels. Fusion and instrumentation alter technique choice; failed back surgery syndrome changes prognosis; recent surgery with new fever or wound drainage suggests postoperative infection.
• Cancer, at any time. A history of cancer is the single strongest history predictor of malignancy as the cause of back pain (positive likelihood ratio roughly 15). The cancers that most often metastasize to bone are breast, prostate, lung, kidney and thyroid.
• Systemic disease: diabetes (neuropathy, infection risk, delayed healing), rheumatoid arthritis (atlantoaxial instability), inflammatory bowel disease and psoriasis (spondyloarthritis), osteoporosis, connective tissue disorders such as Ehlers Danlos and Marfan syndromes (hypermobility, arterial fragility), cardiovascular disease, kidney stones, and any immunosuppression (HIV, transplant, chemotherapy).
• Down syndrome: atlantoaxial instability in about 10 to 20 percent of patients.

Medications and allergies

Medications both reveal hidden diagnoses and change what you can safely do. Ask about prescription drugs, over the counter drugs, supplements and recreational drugs, and record allergies with the type of reaction.

Family history

Family history raises the probability of conditions with a genetic component. A first degree relative with ankylosing spondylitis or other spondyloarthritis, psoriasis or inflammatory bowel disease supports inflammatory back pain (HLA-B27). A family history of abdominal aortic aneurysm raises AAA risk several fold. Family history of premature cardiovascular disease (a male relative under 55 or a female relative under 65) matters in chest, jaw and arm pain. Ask also about cancer (breast, colon, prostate), osteoporosis and hip fracture in a parent (a FRAX risk factor), scoliosis (adolescent idiopathic scoliosis clusters in families), gout, rheumatoid arthritis, diabetes, migraine, connective tissue disorders and sudden cardiac death in a young relative (relevant to athletes).

Personal and social history

How each piece changes the working diagnosis

Think of each answer as a weight on a scale. Age over 50, prior cancer, unexplained weight loss and failure of a month of care push toward malignancy. Fever, injection drug use, recent infection (urinary tract, skin), immunosuppression, diabetes and recent spinal procedures push toward infection. Older age, osteoporosis, steroids and trauma push toward fracture. Age under 40, morning stiffness, alternating buttock pain, uveitis, psoriasis, inflammatory bowel disease and a family history of spondyloarthritis push toward axial spondyloarthritis. Smoking, hypertension, male sex, age over 60 and family history push toward AAA. A young, active, healthy patient with a clear mechanical onset sits firmly at the benign end.

Section 3Review of systems and red flag questioning

The systematic review of systems

The review of systems (ROS) is a structured head to toe inventory of symptoms the patient may not connect with the chief complaint. Its purpose in a chiropractic case is to find the patient whose musculoskeletal complaint is really systemic or visceral disease, and the patient who has a second problem that needs attention. A written intake questionnaire covers the ground efficiently; the clinician then asks follow up questions about every positive answer and about the systems most relevant to the complaint.

Red flag questions by category

Red flags are features of the history and examination that raise the probability of serious pathology. Individually most are weak; their value lies in combinations and in the strong ones. Know the question to ask for each threat and the urgency of referral if it is positive.

Cauda equina syndrome: the questions you must ask

Cauda equina syndrome results from compression of multiple lumbosacral roots below the conus medullaris, most often by a large central disc herniation at L4 to L5 or L5 to S1, less often by tumor, abscess, hematoma or severe stenosis. The single most sensitive finding is urinary retention (sensitivity about 90 percent); with retention, overflow incontinence follows. Ask every patient with back pain and leg symptoms, in plain words: "Have you had any trouble starting or stopping your urine, or any leaking?" "Any numbness between your legs or around your back passage, for example when you wipe after the toilet?" "Any change in bowel control?" "Any new problem with sexual function?" "Is the leg pain on both sides, or getting worse?" Document both positive and negative answers. Incomplete cauda equina syndrome (altered urinary sensation, reduced saddle sensation, retained control) carries a much better outcome after decompression than the retention stage, which is why the question must be asked early and the patient told to return immediately if any of these symptoms appear.

Vascular and visceral causes from the history

Visceral pain refers to the spine through shared segmental innervation, and its giveaway is that it does not behave mechanically: posture, movement and palpation do not reproduce it, while eating, urination, menstruation or exertion do. Kidney stones cause colicky flank pain radiating to the groin, with restlessness (the patient cannot get comfortable, in contrast to the stillness of mechanical pain) and hematuria. Pyelonephritis adds fever and dysuria. Pancreatitis gives boring epigastric pain through to the back, eased by leaning forward, often after alcohol or a fatty meal. Peptic ulcer on the posterior duodenal wall gives midthoracic pain related to meals. Gallbladder disease refers to the right scapula after fatty meals. Myocardial ischemia refers to the left arm, jaw, neck and interscapular region with exertion, sweating and dyspnea. Aortic dissection causes sudden tearing chest or interscapular pain. Gynecologic disease (endometriosis, ovarian cyst, ectopic pregnancy) causes low back and pelvic pain related to the menstrual cycle; in any woman of reproductive age with low abdominal or back pain, ask the date of the last menstrual period.

Cervical red flags and the vertebrobasilar screen

Before treating the neck, ask about the features of cervical artery dissection and vertebrobasilar insufficiency: recent onset of severe, unusual neck pain or occipital headache (often described as different from any previous headache), especially after minor trauma, sport or prolonged neck extension; and the brainstem symptoms summarized as the 5 Ds and 3 Ns: dizziness, diplopia, dysarthria, dysphagia, drop attacks, ataxia of gait, nausea, nystagmus and numbness (often facial or perioral). Internal carotid dissection may produce an ipsilateral Horner syndrome (ptosis, miosis, anhidrosis) and pulsatile tinnitus. A thunderclap headache (maximal within a minute) suggests subarachnoid hemorrhage. Also ask about features of upper cervical instability: rheumatoid arthritis, Down syndrome, recent trauma, a sense that the head is heavy or unstable, and bilateral paresthesias.

Yellow flags: predicting chronicity

Yellow flags are psychosocial factors that predict persistent pain and disability rather than serious disease. They include fear avoidance beliefs (the belief that movement or work will cause harm), catastrophizing, low mood and depression, anxiety, passive coping (waiting to be fixed), poor sleep, social withdrawal, job dissatisfaction and conflict at work, compensation and litigation issues, and a history of long time off work. Related color flags include blue flags (the worker's perception of the workplace) and black flags (system or contextual barriers such as employer policy or the compensation system). Orange flags denote psychiatric disorders such as major depression or personality disorder that require referral.

Section 4Building differential diagnoses from the history

From pattern recognition to probability

Experienced clinicians reason in two modes. Pattern recognition (fast, intuitive) matches the story to an illness script stored from experience: "young man, lift and twist, leg pain below the knee worse with sitting: disc." Analytical reasoning (slow, deliberate) lists possibilities systematically and weighs evidence for each. Pattern recognition is efficient but vulnerable to cognitive biases; analytic reasoning is the check on it. Good practice is to form an early hypothesis from the pattern and then deliberately ask, "What else could this be, and what must I not miss?"

Pretest probability is the probability of a diagnosis before a test is performed, and it comes chiefly from prevalence in the setting and from the history. A test result moves probability, and the size of that move is captured by the likelihood ratio (LR). A positive LR above 10 or a negative LR below 0.1 produces a large, often decisive shift; LRs of 2 to 5 (or 0.2 to 0.5) produce small but sometimes important shifts; an LR near 1 changes nothing. Every history question is a test in this sense. A history of cancer in a back pain patient carries a positive LR near 15; age over 50 alone carries a positive LR near 2.7; "pain not relieved by bed rest" has an LR barely above 1. A highly sensitive finding, when absent, helps rule a condition out (SnNout); a highly specific finding, when present, helps rule it in (SpPin).

Mechanical versus nonmechanical pain

The first branch point in any spinal differential is whether the pain is mechanical. Mechanical pain changes with posture, movement and load, has a position of relief, can be reproduced on examination, and usually follows a recognizable onset. Morning stiffness is brief (under 30 minutes). Nonmechanical pain is constant or progressive, does not change with position, is often worse at night, and is accompanied by systemic or organ specific symptoms. Nonmechanical pain has three broad sources: systemic disease (tumor, infection, inflammatory arthritis, metabolic bone disease), visceral referral and neuropathic or central pain. A mixed picture is common, for example a mechanical overlay on a metastatic lesion, so a mechanical component never excludes serious disease when red flags are present.

Radicular, referred and central patterns

Separating the distribution of pain is the second branch point. Somatic referred pain arises from a spinal structure (facet joint, disc, sacroiliac joint, muscle) and is felt as a deep, diffuse, poorly localized ache in the same segmental territory, usually not below the knee in the lower limb or below the elbow in the upper. Radicular pain arises from an irritated nerve root and is sharp, shooting or burning, felt in a narrow band, often extends below the knee into the foot, and is usually worse in the limb than in the back. Radiculopathy is the objective loss of root function (dermatomal sensory loss, myotomal weakness, reduced reflex). Myelopathy is cord compression with bilateral symptoms, clumsy hands, gait disturbance and upper motor neuron signs. Visceral referred pain follows the dermatomes of the organ's sympathetic afferents (heart to T1 to T4 and the left arm; gallbladder to the right scapula; kidney to the flank and groin; pancreas to the upper lumbar region). Nociplastic pain (central sensitization) is widespread, disproportionate, with allodynia and hyperalgesia.

Avoiding cognitive traps

• Anchoring: locking onto the first impression (the patient said "I pulled something") and discounting later contradicting facts (weight loss, night pain).
• Premature closure: stopping the search once one plausible diagnosis is found. A disc herniation and a prostate cancer metastasis can coexist.
• Availability bias: overweighting diagnoses seen recently or vividly.
• Confirmation bias: asking only questions that support the favored hypothesis. Deliberately ask a question that would disprove it.

Section 5Communication, special populations and documentation of the history

Asking questions well

Begin with open ended questions ("Tell me about the pain," "What brings you in today?") and allow the patient to speak without interruption for the first minute or two; most patients finish their opening statement in under two minutes, and interrupting early loses information. Then narrow with focused questions ("Where exactly does it go?") and finish with closed questions that confirm or exclude specific features ("Any numbness between your legs?"). Avoid leading questions ("The pain doesn't go down your leg, does it?") and compound questions that ask two things at once. Use facilitation (nodding, "go on"), clarification ("What do you mean by dizzy: is the room spinning, or do you feel faint?"), reflection and summarizing ("Let me check I have this right...") to confirm accuracy. End by asking, "Is there anything else you think I should know?" and "What are you most worried this might be?" The second question often reveals a fear (cancer, paralysis, losing a job) that shapes the patient's recovery.

Clarifying vague terms

Patients use words that mean different things to different people. Dizziness may be vertigo (a spinning illusion, vestibular or brainstem), presyncope (near fainting, cardiovascular or orthostatic), disequilibrium (unsteadiness on the feet, neurologic or proprioceptive) or vague lightheadedness (often anxiety or medication). Numbness may mean loss of sensation, tingling or a feeling of heaviness. Weakness may mean true loss of strength, fatigue or pain inhibition.

Special populations

Interpreters

Family members, and especially children, should not interpret a clinical history except in an emergency: they may filter or omit sensitive information (bladder, sexual or abuse history), lack medical vocabulary and compromise confidentiality. A trained medical interpreter translates exactly and keeps confidentiality. Speak in the first person directly to the patient, and document the language and the interpreter's name or ID, using the same approach for informed consent.

The pregnant patient

Low back and pelvic girdle pain affect more than half of pregnant women, and most is mechanical, related to relaxin mediated ligamentous laxity, weight gain, an anterior shift of the center of gravity and increased lumbar lordosis. The history must still screen for obstetric emergencies. Rhythmic low back pain that comes and goes with tightening of the abdomen may be preterm labor. Vaginal bleeding with constant abdominal or back pain and a rigid uterus suggests placental abruption. Headache, visual disturbance, right upper quadrant or epigastric pain and sudden swelling after 20 weeks suggest preeclampsia; check blood pressure. Fever with flank pain suggests pyelonephritis, which is more common in pregnancy. Unilateral calf pain and swelling suggests DVT, whose risk is several times higher in pregnancy and the postpartum period. In the first trimester, unilateral pelvic pain with spotting raises ectopic pregnancy.

Documenting the history in a defensible record

The record is a clinical, legal and billing document. It must allow another clinician to understand what you found, what you thought and why you did what you did. A defensible history has these features:

• Legible, dated and signed (or authenticated in the electronic record), written at the time of the visit or promptly after.
• Chief complaint in the patient's words with duration; HPI with each OPQRST element; mechanism of injury with specific details (for a collision: direction, speed estimate, seat belt, head position, onset of symptoms).
• Pertinent negatives: "Denies saddle anesthesia, bladder or bowel dysfunction, fever, weight loss, night pain." If it is not written, a reviewer will assume it was not asked.
• Baseline functional status and outcome measures (pain scale, Oswestry or Neck Disability Index, activities the patient cannot do) and the patient's goals, which justify the plan and later demonstrate medical necessity.
• Medications and allergies and relevant comorbidities that modify care.
• Objective, nonjudgmental language: record what the patient said in quotation marks rather than labels such as "malingerer" or "drug seeker."
• Corrections made by a single line through the original entry with the date, time and initials, never by obliterating or rewriting; late entries labeled as such with the current date. Altering a record after a complaint or claim is one of the most damaging things a clinician can do.
• Communication with others (phone calls, referrals, advice to go to the emergency department, refusals) with time and content.

Words worth knowing

The General Physical Examination

A chiropractor is a portal of entry provider, which means you may be the first clinician to see a patient whose back pain is really an aneurysm, whose neck pain is a thyroid mass, or whose headache is a blood pressure of 210 over 125. Part III cases routinely slip a single abnormal vital sign or physical finding into a musculoskeletal story and ask what it means and what you should do next. This chapter teaches the general physical examination as a set of decisions: what to look for, what is abnormal, and how each finding changes management.

Section 1General survey and vital signs in the case

The general survey

The general survey begins as the patient walks in. Note apparent age versus stated age, level of distress (calm, guarding, writhing, unable to sit), body habitus (cachexia, obesity, central adiposity), posture and movement, skin color (pallor, cyanosis, jaundice, flushing), hygiene and dress, speech, affect and alertness. A patient lying perfectly still because any movement hurts suggests peritonitis; a patient who cannot find a comfortable position suggests renal or biliary colic. A patient leaning forward to ease epigastric pain suggests pancreatitis, while leaning forward to ease leg symptoms on walking suggests stenosis. Cachexia with temporal wasting suggests cancer or chronic disease. Jaundice points to liver or biliary disease; pallor to anemia; a malar rash to lupus; a moon face, central obesity and purple striae to Cushing syndrome; a tall slender build with long limbs to Marfan syndrome (aortic root dilation and dissection risk).

Body mass index and anthropometrics

BMI is weight in kilograms divided by height in meters squared. Waist circumference adds information about visceral fat and cardiometabolic risk. Unexplained weight loss of more than about 5 percent of body weight over 6 to 12 months is a red flag for cancer, infection, endocrine disease or depression.

Blood pressure: technique

Measurement errors routinely move blood pressure by 10 mmHg or more, so technique is tested. The patient avoids caffeine, exercise and smoking for 30 minutes, empties the bladder, and sits quietly for 5 minutes with the back supported, feet flat and legs uncrossed. The arm is bare, supported at heart level. The cuff bladder should encircle about 80 percent of the arm circumference and its width should be about 40 percent; a cuff that is too small reads falsely high, one that is too large reads falsely low. Estimate the systolic pressure by palpating the radial pulse as the cuff inflates, then inflate 20 to 30 mmHg above that point to avoid missing an auscultatory gap, and deflate at 2 to 3 mmHg per second. Systolic pressure is the first Korotkoff sound (phase I); diastolic is disappearance (phase V). Take two or more readings and average them, and at the first visit measure both arms, using the higher arm thereafter.

Special blood pressure findings

• Interarm difference above about 15 to 20 mmHg systolic suggests subclavian artery stenosis (subclavian steal), aortic dissection (with tearing pain) or coarctation. A consistent difference over 10 mmHg is also a marker of cardiovascular risk.
• Orthostatic hypotension is a fall of at least 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing. Causes include dehydration, blood loss, antihypertensives and diuretics, autonomic neuropathy (diabetes, Parkinson disease) and prolonged bed rest. It explains dizziness on rising from the treatment table and is a fall risk.
• Leg pressures are normally equal to or slightly higher than arm pressures. Lower leg than arm pressure in a young hypertensive patient suggests coarctation of the aorta (with radiofemoral delay and rib notching on chest radiographs).
• Wide pulse pressure (systolic minus diastolic, normally about 40) occurs in aortic regurgitation, hyperthyroidism, anemia and stiff arteries of aging. Narrow pulse pressure occurs in aortic stenosis, heart failure, tamponade and shock.
• Pulsus paradoxus, a fall of more than 10 mmHg in systolic pressure on inspiration, suggests cardiac tamponade, severe asthma or COPD exacerbation.

Pulse, respiration, temperature and oxygen saturation

Count the radial pulse for 30 seconds and double it if regular, or for a full 60 seconds if irregular, noting rate, rhythm, amplitude and symmetry. Count respirations without telling the patient (for example, while appearing to continue taking the pulse), because awareness changes breathing. Note the breathing pattern: Kussmaul (deep, rapid; metabolic acidosis such as diabetic ketoacidosis), Cheyne Stokes (cycles of crescendo breathing and apnea; heart failure, brain injury) and pursed lip breathing in COPD. Oral temperature is reduced by recent cold drinks and mouth breathing; older adults and immunosuppressed patients may mount little fever despite serious infection.

The sepsis and instability screen

A patient with suspected infection who has two or more of the quick SOFA criteria (respiratory rate 22 or more, altered mentation, systolic blood pressure 100 or less) has a high risk of a poor outcome and needs emergency care. More generally, any combination of hypotension, tachycardia, tachypnea, hypoxemia, fever and confusion signals a physiologically unstable patient who is not a candidate for office treatment that day.

Section 2Head and neck, thorax and lungs

Eyes

Inspect the lids, conjunctivae and sclerae, then test pupils, extraocular movements, visual fields and, when indicated, the fundus. The findings that matter in a chiropractic case are those that indicate neurological, vascular or systemic disease.

Ears, nose and throat

Otoscopy shows a pearly gray tympanic membrane with a cone of light in the anteroinferior quadrant; a red, bulging membrane indicates acute otitis media, and a retracted membrane suggests eustachian tube dysfunction. Hearing is screened with the whispered voice test, then characterized with a 512 Hz tuning fork. In the Weber test, the vibrating fork is placed on the vertex; normally sound is heard equally in both ears. In the Rinne test, the fork is placed on the mastoid until the sound fades, then held beside the ear; normally air conduction is heard longer than bone conduction (a "positive" Rinne).

Unilateral sensorineural hearing loss with tinnitus and imbalance suggests an acoustic neuroma (vestibular schwannoma) and needs MRI. Sudden sensorineural hearing loss is an emergency for steroid treatment within days. In the nose, note septal deviation, polyps and bleeding; in the mouth and throat, look for tonsillar exudate, dental abscess (a cause of jaw and neck pain), leukoplakia and nonhealing ulcers (oral cancer in smokers and drinkers).

Lymph nodes

Palpate the cervical chains systematically: preauricular, postauricular, occipital, submental, submandibular, tonsillar, anterior and posterior cervical, and supraclavicular. Describe each node by size, consistency, tenderness, mobility and whether it is matted. Small (under 1 cm), soft, mobile, tender nodes are usually reactive to infection. Hard, rubbery or fixed, nontender nodes over about 1.5 to 2 cm, nodes that persist beyond 2 to 4 weeks, and any supraclavicular node are suspicious for malignancy. A left supraclavicular node (Virchow node) suggests abdominal malignancy, especially gastric cancer; a right supraclavicular node suggests lung, mediastinal or esophageal cancer. Rubbery, painless nodes with fever, night sweats and weight loss suggest lymphoma.

Thyroid and carotids

Examine the thyroid from behind with the neck slightly flexed, asking the patient to swallow; the gland moves upward with swallowing. A diffusely enlarged gland (goiter) may be hyper or hypothyroid; a single hard nodule, fixation, hoarseness or associated nodes raise suspicion of cancer. Look for systemic signs: hyperthyroidism (tachycardia, atrial fibrillation, fine tremor, warm moist skin, weight loss, proximal weakness, exophthalmos) and hypothyroidism (bradycardia, dry skin, weight gain, delayed relaxation phase of reflexes, carpal tunnel syndrome, myalgia and fatigue). Hypothyroidism is a treatable cause of diffuse muscle pain and carpal tunnel syndrome.

Palpate each carotid separately (never both at once, and gently in older patients because of the carotid sinus reflex) and auscultate with the bell for a bruit, a whooshing sound from turbulent flow that suggests stenosis. An asymptomatic carotid bruit is a marker of atherosclerosis; a bruit with transient ischemic attack symptoms (transient monocular blindness, called amaurosis fugax, hemiparesis, aphasia) requires urgent referral. A murmur from aortic stenosis can radiate to the carotids and must be distinguished.

Thorax and lungs

Examine the chest in the order inspection, palpation, percussion, auscultation. Inspect for shape (barrel chest in emphysema with an increased anteroposterior diameter; pectus excavatum and carinatum; kyphoscoliosis restricting ventilation), use of accessory muscles, intercostal retraction, and symmetry of expansion. Palpate for tenderness, crepitus and tactile fremitus (vibration felt as the patient says "ninety nine"), which is increased over consolidation and decreased over fluid or air. Measure chest expansion at the fourth intercostal space; less than about 2.5 cm suggests restriction (ankylosing spondylitis, chronic lung disease). Percuss comparing side to side: resonance is normal over lung, dullness indicates consolidation or effusion (stony dull), and hyperresonance indicates air (pneumothorax, emphysema). Auscultate with the diaphragm comparing side to side.

Adventitious sounds: crackles (discontinuous; fluid or reopening airways in pneumonia, heart failure, fibrosis), wheezes (continuous, musical; narrowed airways in asthma and COPD), rhonchi (low pitched, clear with coughing; secretions), stridor (inspiratory, high pitched, over the neck; upper airway obstruction, an emergency) and pleural friction rub (creaking with breathing, localized; pleurisy, pulmonary infarction). Pleuritic chest pain that changes with breathing can mimic a rib or costovertebral lesion, so ask whether it also changes with trunk movement and whether there is fever, cough or dyspnea.

Section 3Cardiovascular and peripheral vascular examination

Inspection and palpation of the precordium

With the patient supine and the trunk raised about 30 to 45 degrees, inspect for visible pulsations and palpate the point of maximal impulse (PMI), normally a dime sized tap in the left fifth intercostal space at the midclavicular line. A PMI displaced laterally and downward, or larger than about 2.5 cm, suggests left ventricular enlargement (dilated cardiomyopathy, chronic regurgitation); a sustained, forceful PMI suggests left ventricular hypertrophy (hypertension, aortic stenosis). A thrill (palpable vibration) accompanies loud murmurs of grade 4 or higher.

Auscultation areas and normal heart sounds

Listen with the diaphragm (high pitched sounds: S1, S2, regurgitant murmurs, rubs) and the bell (low pitched sounds: S3, S4, the rumble of mitral stenosis) in each area. S1 is closure of the mitral and tricuspid valves at the start of systole, loudest at the apex. S2 is closure of the aortic and pulmonic valves at the end of systole, loudest at the base. On inspiration, increased venous return to the right heart delays pulmonic closure and S2 splits physiologically; a fixed split that does not vary with respiration suggests an atrial septal defect, and a paradoxical split (widening on expiration) suggests left bundle branch block or severe aortic stenosis.

Extra heart sounds

An S3 (ventricular gallop, "Ken-tuc-ky") occurs in early diastole as blood fills a volume overloaded ventricle. It is normal in children, young athletes and pregnancy but in an adult over about 40 suggests heart failure or severe regurgitation. An S4 (atrial gallop, "Ten-nes-see") occurs in late diastole as the atrium contracts against a stiff ventricle (hypertension, left ventricular hypertrophy, ischemia, aortic stenosis); it is absent in atrial fibrillation. A pericardial friction rub is a scratchy, three component sound heard best with the patient leaning forward; with sharp chest pain eased by sitting up and leaning forward, it indicates pericarditis. An opening snap in early diastole indicates mitral stenosis, and a midsystolic click indicates mitral valve prolapse.

Murmurs

Describe a murmur by timing (systolic or diastolic), location, radiation, intensity, pitch, shape and response to maneuvers. Intensity is graded 1 to 6: grade 1 is barely audible; grade 3 is moderately loud without a thrill; grade 4 has a thrill; grade 6 is audible with the stethoscope just off the chest. Diastolic murmurs are always pathological and require referral. Soft, short midsystolic murmurs (grade 1 to 2) without other findings are often innocent flow murmurs, particularly in children, pregnancy, fever and anemia.

Most murmurs from the right side of the heart get louder with inspiration and most from the left side get louder with expiration. The two murmurs that get louder with Valsalva and standing (which reduce preload) are hypertrophic cardiomyopathy and mitral valve prolapse; nearly all others get softer.

Jugular venous pressure

With the patient reclined at about 45 degrees and the head turned slightly left, identify the highest point of pulsation of the right internal jugular vein. Its vertical height above the sternal angle is normally 3 cm or less (the right atrium lies about 5 cm below the sternal angle, so this corresponds to about 8 cm of water). An elevated JVP indicates raised right atrial pressure: right heart failure, fluid overload, tricuspid disease, pericardial tamponade or constriction, or superior vena cava obstruction. The hepatojugular (abdominojugular) reflux test applies firm pressure over the abdomen for 10 seconds; a sustained rise in the JVP of more than 3 cm supports heart failure. Unlike the carotid pulse, the jugular pulse is not palpable, has a double waveform, is obliterated by light pressure above the clavicle, and changes with position and respiration.

Peripheral pulses and the vascular examination of the limbs

Palpate the carotid, brachial, radial, ulnar, femoral, popliteal, dorsalis pedis (lateral to the extensor hallucis longus tendon on the dorsum) and posterior tibial (behind the medial malleolus) pulses, comparing sides. Grade amplitude on a 0 to 4 scale: 0 absent, 1+ diminished, 2+ normal, 3+ increased, 4+ bounding. An isolated absent dorsalis pedis with a normal posterior tibial pulse may be a congenital variant. Auscultate for bruits over the abdominal aorta, renal, iliac and femoral arteries. Examine the skin for signs of chronic arterial insufficiency (cool, shiny, hairless skin, thickened nails, pallor on elevation, dependent rubor, delayed capillary refill over about 2 seconds, painful punched out ulcers on the toes and heels) and venous insufficiency (edema, brown hemosiderin staining, stasis dermatitis, varicose veins, shallow painless ulcers near the medial malleolus).

The ankle brachial index

The ankle brachial index (ABI) is measured with a handheld Doppler and a blood pressure cuff. With the patient supine for 5 to 10 minutes, measure systolic pressure in both brachial arteries and in the dorsalis pedis and posterior tibial arteries of each ankle. For each leg, divide the higher ankle pressure by the higher of the two brachial pressures.

Vascular versus neurogenic claudication

Both conditions are common in the same age group and they often coexist, so an older patient with leg symptoms on walking needs both a pulse examination and a neurological examination. Acute limb ischemia (an embolus or thrombosis) presents with the 6 Ps: pain, pallor, pulselessness, paresthesia, paralysis and poikilothermia (a cold limb). It is a vascular emergency, with irreversible damage within about 6 hours.

Section 4Breast and axilla, abdomen

Breast and axillary examination

Breast examination is performed with consent, a chaperone where appropriate and clear explanation, and within the scope of practice of the jurisdiction. Inspect with the arms at the sides, raised overhead and pressed on the hips, looking for asymmetry, skin dimpling or retraction, peau d'orange (orange peel skin from lymphatic obstruction), nipple inversion of recent onset, nipple discharge (particularly bloody or unilateral), eczematous change of the nipple (Paget disease of the nipple) and redness. Palpate in a systematic vertical strip pattern from the clavicle to the inframammary fold and from the midaxillary line to the sternum, including the axillary tail, with the patient supine and the ipsilateral arm raised. Then palpate the axillary (central, anterior, posterior, lateral), infraclavicular and supraclavicular nodes.

Breast cancer is the most common source of skeletal metastasis in women and favors the thoracic spine, ribs, pelvis and proximal femur. A woman with a history of breast cancer, even many years earlier, who develops new constant thoracic pain needs imaging.

The abdominal examination

Position the patient supine with the knees slightly flexed and arms at the sides, and examine in the order inspection, auscultation, percussion, palpation; auscultation comes before palpation so that palpation does not alter bowel sounds. Examine the painful area last.

• Inspection: contour (flat, scaphoid, distended), scars, striae, visible peristalsis, pulsation, hernias (ask the patient to raise the head), dilated veins (caput medusae in portal hypertension), and periumbilical (Cullen) or flank (Grey Turner) ecchymosis.
• Auscultation: bowel sounds are normally present every 5 to 15 seconds. High pitched, tinkling or rushing sounds suggest early obstruction; absent sounds after listening for 2 or more minutes suggest ileus or peritonitis. Listen for bruits over the aorta (midline above the umbilicus), renal arteries (just lateral to the midline above the umbilicus; a renal bruit with resistant hypertension suggests renal artery stenosis), iliac and femoral arteries.
• Percussion: tympany over gas, dullness over solid organs and fluid. The liver span at the right midclavicular line is normally about 6 to 12 cm. Dullness at the lowest left intercostal space in the anterior axillary line (Traube space) on inspiration suggests splenomegaly. Shifting dullness and a fluid wave indicate ascites.
• Palpation: light palpation for tenderness, guarding and superficial masses; deep palpation for organs and deep masses. Note voluntary guarding (reduced with distraction) versus involuntary rigidity (board like abdomen in peritonitis).

Organomegaly and aortic palpation

Palpate the liver edge at the right costal margin during deep inspiration; a smooth, tender edge suggests hepatitis or congestion (heart failure), and a hard, nodular edge suggests cirrhosis or metastases. The normal spleen is not palpable; a palpable spleen is enlarged at least two to three times (infectious mononucleosis, leukemia, lymphoma, portal hypertension). In infectious mononucleosis, splenic rupture can follow minor trauma, so contact sport and forceful abdominal or lower thoracic pressure are avoided for at least 3 to 4 weeks. The kidneys are palpated bimanually; an enlarged kidney suggests polycystic kidney disease, hydronephrosis or tumor.

Palpate the abdominal aorta deeply in the epigastrium, slightly left of the midline, placing a hand on each side of the pulsation. A normal aorta is about 2 cm wide; an expansile (pushing the hands apart, not just upward) pulsatile mass suggests an abdominal aortic aneurysm, defined as a diameter of 3 cm or more. Sensitivity of palpation rises with aneurysm size and falls with obesity, so a normal palpation does not exclude AAA in a high risk patient; ultrasound is the screening test (recommended once for men 65 to 75 who have ever smoked). Risk factors are age over 60, male sex, smoking, hypertension, atherosclerosis and family history. Aneurysms over about 5.5 cm, rapidly enlarging aneurysms and any symptomatic aneurysm need surgical evaluation; a tender aneurysm, or back pain with hypotension, suggests leak or rupture and is an emergency. Avoid deep abdominal pressure, and avoid prone lumbar thrust techniques in a patient with a known or suspected aneurysm until it has been assessed.

Special abdominal signs

What abdominal findings mean for the back pain patient

Every patient with thoracolumbar or low back pain that does not behave mechanically deserves an abdominal examination. A pulsatile mass suggests AAA; costovertebral angle tenderness with fever suggests pyelonephritis; epigastric tenderness radiating to the back suggests pancreatitis or a posterior duodenal ulcer; a positive psoas sign with fever and a flexed hip suggests a psoas abscess (often from vertebral osteomyelitis or Crohn disease) that can mimic a hip flexor strain; and a hard, fixed mass or hepatomegaly suggests malignancy. Abdominal wall pain (positive Carnett sign) and costochondral pain are reproduced by palpation and movement, unlike visceral pain.

Section 5Urogenital and rectal findings and putting the exam together

Scope, consent and chaperones

Genital, rectal and breast examinations are sensitive. Whether a chiropractor performs them depends on the law of the jurisdiction, and many practitioners refer them to a medical colleague. Part III expects you to know what the findings mean and when they are needed, particularly for the patient with groin pain, testicular pain or suspected cauda equina syndrome. Whenever such an examination is performed, obtain and document specific informed consent, offer a chaperone, explain each step, provide privacy and draping, and stop if the patient asks.

Hernias

Groin pain in an athlete or laborer may be a hernia rather than an adductor strain or hip lesion. Examine the standing patient, inspecting for a bulge at rest and with coughing or straining. In men, the examining finger invaginates the scrotal skin up to the superficial inguinal ring while the patient coughs.

An incarcerated hernia cannot be reduced; a strangulated hernia has a compromised blood supply and presents with a tense, tender, red bulge, vomiting and signs of bowel obstruction. Strangulation is a surgical emergency.

Testicular and scrotal findings

Scrotal and testicular disease can present as groin, lower abdominal or even low back pain, because the testis is innervated from about T10 to T12 and the scrotum from L1 and the sacral segments. The cremasteric reflex (stroking the upper medial thigh elevates the ipsilateral testis) tests L1 to L2.

Prostate and rectal examination

The digital rectal examination (DRE) is performed with the patient in the left lateral (Sims) position or bending over the table. It assesses anal sphincter tone at rest and on voluntary squeeze, perianal sensation, rectal masses, and in men the prostate. The normal prostate is about the size of a walnut, rubbery, smooth and nontender with a palpable median sulcus.

Rectal tone, saddle sensation and sacral reflexes

When the history raises cauda equina syndrome, the examination must include the sacral segments. Saddle sensation is tested with light touch and pinprick over the perineum, perianal skin, buttocks and posterior upper thighs (S2 to S5 dermatomes); patchy or bilateral loss is significant. The anal wink (superficial anal reflex) is a contraction of the external sphincter when the perianal skin is stroked; it tests S2 to S4. The bulbocavernosus reflex (contraction of the anal sphincter on squeezing the glans or tugging an indwelling catheter) also tests S2 to S4. Reduced resting tone and weak voluntary squeeze on DRE indicate sacral root or conus dysfunction. A post void residual bladder volume over about 100 to 200 mL (by bladder scan or catheter) objectively confirms retention. In a patient with suspected cauda equina syndrome, these findings are obtained in the emergency department as part of the urgent workup; if you cannot perform them, do not delay referral to do so.

Putting the physical examination together

A complete general examination is not performed on every patient. Instead, choose components by hypothesis: the history determines which systems need examination. Every new patient should have vital signs and a general survey. A patient with thoracic pain needs the chest, heart and abdomen examined if the pain does not behave mechanically. A patient with low back pain and red flags needs the abdomen (aorta, kidneys), pulses, a lymph node survey and a neurological examination including the sacral segments if the history suggests it. A patient with neck pain and headache needs blood pressure, a cranial nerve screen and, in older patients, palpation of the temporal arteries.

After the examination, write a problem list that includes every abnormal finding, not only the chief complaint. For each problem, decide one of three paths: treat (within scope, no contraindication), co-manage (treat the musculoskeletal component while another provider manages the other problem, for example a patient with stage 2 hypertension and mechanical neck pain), or refer, with an urgency that matches the risk.

Words worth knowing

The Neuromusculoskeletal Examination of the Spine

On Part III the spinal examination is never asked as a list of eponyms; it arrives as a patient who has already told you a story, and the item asks which test you would do next, what a positive result means, and whether this person can safely be treated. A good spinal examination is short, ordered by hypothesis and honest about what each test can and cannot prove. This chapter works through posture and gait, the cervical, thoracic and lumbopelvic regions, and segmental palpation the way the exam does: one case at a time, from the first clue to a working impression.

Section 1Posture and gait analysis in cases

Why posture and gait come first

Posture and gait are observed before the patient knows the examination has started: as they rise from the waiting room chair, walk down the hall and undress. That unguarded observation is often more honest than any provoked test. A patient who rises using the arms of the chair, walks with a shortened step and leans forward on the counter has told you about pain behavior, lower limb strength and perhaps lumbar stenosis before a single question about the back. The board uses posture and gait as the first clue in a vignette; your job is to translate the finding into a structure and then pick the test that confirms it.

Static posture

Static posture is assessed from behind, from the side and from the front, ideally against a plumb line or grid. From the side the ideal line falls through the external auditory meatus, the cervical vertebral bodies, the acromion, the lumbar vertebral bodies and the greater trochanter, then slightly anterior to the knee joint axis and slightly anterior to the lateral malleolus. From behind it bisects the occiput, follows the spinous processes and the gluteal cleft, and falls midway between the knees and the heels. Departures are described by region and direction, then explained by a mechanism.

• Anterior head carriage places the ear in front of the acromion. Each 2.5 cm of forward displacement roughly adds the weight of the head again to the load on the posterior cervical muscles, which is why these patients complain of suboccipital tension and headache.
• Upper crossed syndrome (Janda) pairs tight upper trapezius, levator scapulae and pectorals with weak deep neck flexors, lower trapezius and serratus anterior, giving forward head, rounded shoulders and scapular winging.
• Lower crossed syndrome pairs tight hip flexors and thoracolumbar extensors with weak abdominals and gluteus maximus, producing anterior pelvic tilt and increased lumbar lordosis.
• Flat back (loss of lordosis) is common with acute disc pain and protective spasm, and late in degenerative disease or after fusion. Sway back shifts the pelvis forward of the line with the thorax behind it.
• A lateral shift (list) of the trunk over the pelvis in acute low back pain usually reflects a posterolateral disc herniation. By convention the shift is named for the direction the shoulders move. A shift away from the painful side is classically associated with a herniation lateral to the nerve root, and a shift toward the painful side with an axillary (medial) herniation, although the rule is not reliable enough to diagnose from.
• Leg length inequality is measured with a tape. Anatomical (true) length runs from the ASIS to the medial malleolus; apparent (functional) length runs from the umbilicus to the medial malleolus. An unequal apparent length with equal true lengths points to pelvic obliquity, muscle imbalance or a lumbar curve rather than a short bone.

Scoliosis screening

From behind, look for shoulder height difference, scapular prominence, unequal space between the arm and the waist (the waist triangle), and a pelvis that is level with a trunk that is not. The Adams forward bend test separates structural from functional curves: the patient bends forward with knees straight and palms together while the examiner sights along the back from behind or in front. In a structural curve the vertebral bodies rotate toward the convexity, carrying the posterior ribs backward and producing a rib hump on the convex side; the spinous processes rotate toward the concavity. A functional (postural or compensatory) curve, for example from a leg length difference or muscle spasm, straightens or disappears in forward flexion and does not produce a rotational prominence. Seating the patient abolishes a curve caused by a short leg.

A scoliometer laid across the prominence measures the angle of trunk rotation. A reading of 5 degrees is the usual screening threshold and 7 degrees corresponds roughly to a Cobb angle of 20 degrees; at or above 7 degrees most guidelines recommend a standing PA radiograph. The most common pattern is a right thoracic curve in an adolescent girl. A left thoracic curve, a painful curve, rapid progression, or neurologic signs (abnormal abdominal reflexes, clonus, cavus foot) raise concern for an underlying cause such as syringomyelia, tethered cord or osteoid osteoma, and call for MRI and referral.

Gait analysis

The gait cycle runs from initial contact of one heel to the next initial contact of the same heel. Stance occupies about 60 percent of the cycle and swing about 40 percent. Each cycle contains two periods of double limb support, each about 10 percent, which disappear in running. Stance is subdivided into loading response, midstance, terminal stance and preswing; swing into initial swing, midswing and terminal swing. The timing matters because each deviation belongs to a phase: foot slap happens at loading response, a Trendelenburg drop at midstance, toe drag and steppage during swing.

Section 2Cervical examination in cases

Order of the cervical examination

Begin with safety, not provocation. Before any test that loads the neck, the history should already have screened for trauma that needs imaging (Canadian C spine rule or NEXUS criteria), inflammatory arthritis or Down syndrome (upper cervical ligament laxity), symptoms of myelopathy, and symptoms of cervical artery dysfunction. Then observe, take active range of motion, test neurologically, and only then use provocative and relieving tests chosen by the working hypothesis. A patient with a fracture risk is imaged first and examined later; a patient with signs of cord compression or dissection is referred, not provoked.

Range of motion

Commonly taught normal active ranges are flexion 50 degrees (chin nearly to chest), extension 60 degrees, lateral flexion 45 degrees and rotation 80 degrees to each side. About half of cervical rotation occurs at C1 on C2, and about half of flexion and extension at the occiput on C1 and in the lower cervical segments. Rotation limited mainly in flexion (the cervical flexion rotation test) isolates C1 to C2 and is a useful sign in cervicogenic headache, where rotation of less than about 32 degrees toward the painful side is considered positive. Record range, the pattern of restriction and what each movement reproduces. Pain on extension and ipsilateral rotation suggests facet or foraminal compression; pain on the opposite side with lateral flexion suggests muscle or ligament stretch. Loss of rotation of less than 60 degrees toward the symptomatic side is one item of the radiculopathy cluster.

Provocative and relieving tests for radiculopathy

No single test makes the diagnosis, which is why the Wainner cluster is so useful. Its four items are a positive upper limb tension test A, ipsilateral cervical rotation of less than 60 degrees, a positive distraction test and a positive Spurling test. With three of four positive the positive likelihood ratio is about 6; with all four it rises to about 30. The upper limb tension test, with its high sensitivity, is the best single test to rule radiculopathy out.

Myelopathy

Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction in older adults and is easy to miss because neck pain may be minimal. Clues are clumsy hands (difficulty with buttons and handwriting), a broad based or spastic gait, generalized rather than dermatomal numbness, and later bladder urgency. Lhermitte sign, an electric sensation down the spine or into the limbs on neck flexion, points to the cord itself: myelopathy, multiple sclerosis, or less commonly tumor or radiation injury. Long tract signs include Hoffmann sign (flicking the distal phalanx of the middle finger produces thumb and index flexion), the inverted supinator sign (tapping the brachioradialis tendon produces finger flexion with a reduced brachioradialis response, implying a C5 to C6 cord lesion), hyperreflexia below the level, clonus and a Babinski sign. A clinical cluster (gait deviation, positive Hoffmann, inverted supinator sign, positive Babinski and age over 45) gives a positive likelihood ratio of about 30 when three of five are positive, while one or fewer positive helps rule it out. Myelopathy is a reason to refer for MRI and surgical opinion and a contraindication to high velocity cervical thrust.

Upper cervical instability and cervical artery dysfunction

Ligamentous laxity at C1 to C2 is a concern in rheumatoid arthritis, Down syndrome, after upper cervical trauma, and with some congenital anomalies such as os odontoideum. Symptoms include a sense that the head is "heavy" or needs holding, occipital pain, paresthesia of the lips or face, and myelopathic signs. The Sharp Purser test is performed seated with slight neck flexion: the examiner stabilizes the C2 spinous process and presses the forehead posteriorly. A sliding sensation or relief of symptoms as the atlas reduces is positive (specificity about 0.96). Alar ligament stress tests feel for immediate C2 spinous process movement with side bending or rotation; delayed movement suggests laxity. These tests should be gentle, and a positive or suspicious finding means flexion and extension radiographs or MRI before treatment, not repeated testing.

Cervical artery dysfunction (vertebral or internal carotid artery dissection) usually presents with unusual, severe neck pain or headache that the patient calls new and different, sometimes after minor trauma, followed hours to days later by ischemic symptoms. The vertebrobasilar warning signs are remembered as the 5 Ds and 3 Ns: dizziness, diplopia, dysarthria, dysphagia, drop attacks, nausea, nystagmus and numbness (often facial or perioral), plus ataxia. Internal carotid dissection may add Horner syndrome, pulsatile tinnitus or cranial nerve palsies. Traditional positional tests (George, DeKleyn, Maigne, Hautant, Underburg) hold the neck in extension and rotation while watching for nystagmus or symptoms. They have poor sensitivity and do not predict who will be harmed, so a negative positional test never clears a patient. Screening rests on the history and a neurologic examination, including cranial nerves, coordination and blood pressure in both arms. A suspected dissection is an emergency referral.

Section 3Thoracic and rib examination in cases

Motion and rib mechanics

The thoracic spine is stiffened by the rib cage, so its motion is small: commonly cited values are flexion about 20 to 45 degrees, extension 25 to 45 degrees, lateral flexion 20 to 40 degrees and rotation 35 to 50 degrees, with rotation greatest in the upper and middle segments where the facets lie in a near coronal plane. Each typical rib articulates with two vertebral bodies at the costovertebral joint and with a transverse process at the costotransverse joint, so a painful rib and a painful thoracic segment are easily confused. Upper ribs move mainly in a pump handle pattern that raises the sternum anteriorly; lower ribs move in a bucket handle pattern that widens the lateral chest. A rib that stops moving early on inspiration is described as held in exhalation, and one that stops early on exhalation as held in inhalation.

Chest expansion is measured with a tape at the fourth intercostal space (the nipple line in men) from full exhalation to full inspiration. Expansion of less than about 2.5 cm is abnormal and, in a young adult with inflammatory back pain, suggests costovertebral involvement by ankylosing spondylitis. Restricted expansion also occurs with pleural disease, obesity, pain and chronic lung disease, so it is interpreted with the history.

Thoracic outlet tests

Thoracic outlet syndrome is compression of the brachial plexus, subclavian artery or subclavian vein at one of three sites: the interscalene triangle (anterior scalene in front, middle scalene behind, first rib below), the costoclavicular space between the clavicle and first rib, and the subpectoral space beneath the pectoralis minor near the coracoid. The plexus and subclavian artery pass through the interscalene triangle, while the subclavian vein passes in front of the anterior scalene. About 95 percent of cases are neurogenic, typically affecting the lower trunk (C8 and T1: ulnar side of the hand and forearm, intrinsic hand weakness). Venous cases (about 3 to 5 percent) present with arm swelling and cyanosis, often in a young athlete after overhead exertion (effort thrombosis, Paget Schroetter syndrome). Arterial cases (about 1 percent) present with coldness, pallor or digital ischemia and are often associated with a cervical rib.

Red flag thoracic pain

Thoracic pain carries a higher pretest probability of serious disease than neck or low back pain. The thoracic spine is the most common site of spinal metastasis (roughly 70 percent of spinal metastases), and many visceral organs refer pain to the interscapular region. Treat thoracic pain as mechanical only when it behaves mechanically: it should change with movement, posture and palpation, and should not be accompanied by systemic or visceral symptoms.

Section 4Lumbar and pelvic examination in cases

Motion and observation

Typical active lumbar ranges are flexion 40 to 60 degrees, extension 20 to 35 degrees, lateral flexion 15 to 25 degrees and rotation 3 to 18 degrees. Watch the quality of motion as much as its range: a painful arc, a deviation to one side during flexion, a reversal of the lumbopelvic rhythm on returning from flexion (the patient "climbs up the thighs" with the hands, a sign of instability or severe pain), and whether repeated movements centralize or peripheralize symptoms. Pain that centralizes, retreating from the leg toward the spine with repeated movement in one direction, predicts a good outcome with directional preference exercise. The modified Schober test marks the lumbosacral junction (the level of the dimples of Venus) and a point 10 cm above it; an increase of less than 5 cm on full flexion indicates restricted lumbar flexion and is a classic finding in ankylosing spondylitis.

The straight leg raise family and the slump

The sciatic nerve and the L4 to S1 roots glide 2 to 6 mm through the foramina as the hip flexes with the knee straight. A herniated disc tethers the root, so stretch reproduces radicular pain. In the straight leg raise (Lasegue) the examiner lifts the straight leg of the supine patient. Reproduction of the patient's radiating leg pain below the knee between about 30 and 70 degrees is positive. Below 30 degrees there is little root excursion, and pain then suggests acute inflammation, hip or sacroiliac disease, or nonorganic behavior; above 70 degrees the root is fully stretched and pain usually comes from hamstrings, the lumbar joints or the sacroiliac joint. Back pain alone or posterior thigh tightness is not a positive SLR.

The sacroiliac joint and the hip

Single sacroiliac tests and static or motion palpation of the joint are unreliable, but a cluster performs well. In the Laslett cluster five provocation tests are used: distraction (anterior gapping, pressure on both ASIS supine), thigh thrust (posterior shear through the femur with the hip flexed to 90 degrees), compression (side lying, pressure down through the iliac crest), sacral thrust (prone, pressure on the sacrum) and Gaenslen (one hip held in full flexion while the other is extended off the table). Three or more positive of five, or two of the first four, gives a sensitivity near 0.9 and specificity near 0.8 for sacroiliac pain. Thigh thrust is the most sensitive single test and distraction the most specific. The cluster is meaningful only when lumbar sources have been reasonably excluded, for example when repeated movements do not centralize the pain. Patrick (FABERE) places the heel on the opposite knee and lowers the flexed, abducted, externally rotated thigh: groin pain implicates the hip, while posterior pain at the joint implicates the sacroiliac joint. Yeoman extends the hip with the knee flexed, prone: sacroiliac pain suggests anterior sacroiliac ligament strain, anterior thigh pain suggests femoral nerve tension, and lumbar pain suggests a lumbar source.

Always screen the hip in "back pain" with buttock or groin pain. Loss of internal rotation is the earliest sign of hip osteoarthritis; groin pain on FADIR (flexion, adduction, internal rotation) suggests femoroacetabular impingement or a labral tear and is very sensitive; pain on the log roll is specific for an intra-articular source; the Thomas test shows hip flexor tightness when the extended thigh lifts off the table; Ely (prone knee flexion that raises the hip) shows rectus femoris tightness; Ober shows iliotibial band tightness. The Trendelenburg sign tests gluteus medius strength.

Nonorganic signs

Waddell signs fall into five categories: superficial or nonanatomic tenderness; simulation tests (low back pain with light axial loading of the head or with passive rotation of the shoulders and pelvis together); distraction (a markedly positive supine SLR but a normal seated SLR during apparent knee examination, the flip test); regional disturbances (giving way or sensory change that follows no root or nerve); and overreaction. Three or more positive categories is significant. The signs indicate psychosocial distress and predict poorer outcome and response to purely physical treatment; they do not prove malingering and do not exclude organic disease. The Hoover test adds evidence about effort: the examiner cups both heels while the supine patient tries to raise the affected leg; a patient who is genuinely trying presses the opposite heel down, and absence of that pressure suggests lack of effort.

Section 5Palpation and segmental examination

Static and motion palpation

Static palpation is performed with the patient still. It assesses skin temperature and moisture, soft tissue texture and edema, muscle tone (hypertonicity, taut bands and trigger points), tenderness, and bony alignment such as a rotated spinous process or a step off. A myofascial trigger point is a tender nodule in a taut band that reproduces a characteristic referred pain pattern and may give a local twitch response or a jump sign. A palpable step off at L5 on S1, with the spinous process above sitting forward, suggests spondylolisthesis.

Motion palpation assesses movement. Intersegmental range is felt as the patient or examiner moves the spine through flexion, extension, lateral flexion and rotation, and the examiner's contact tracks whether each segment moves as much as its neighbors. Joint play is the small, involuntary accessory movement available in a relaxed joint, and is assessed with gentle springing toward the end of passive range. A fixation (hypomobility) is a segment that lacks normal joint play or end range motion. The examiner notes the direction of restriction, which in chiropractic listings guides the line of drive.

End feel

End feel is the quality of resistance at the end of passive range, as described by Cyriax. Each normal joint has a characteristic end feel, and an end feel in the wrong joint or at the wrong point in range is pathological.

Reliability of palpation findings

Palpation is the most chiropractic of all examination skills and the least reliable between examiners, and the board expects you to know the evidence. Reliability is usually expressed with the kappa statistic, where 0 is chance agreement and values above about 0.4 are moderate and above 0.6 substantial. Pain provocation (tenderness on pressure) shows the best interexaminer agreement, typically moderate. Static assessment of soft tissue, and especially of bony position, is poor. Motion palpation for segmental fixation shows interexaminer kappa values near chance in most studies, while the same examiner agrees with himself better (intraexaminer reliability is fair to moderate). Regional range of motion with an inclinometer is reliable. Several practical rules follow: anchor a segmental finding to tenderness, confirm it with a second type of finding at the same level, use the patient's report of familiar pain, and do not stake a diagnosis on a single palpatory impression.

From findings to a segmental diagnosis: PARTS

The PARTS framework organizes the evidence for a segmental dysfunction (the chiropractic subluxation): Pain and tenderness, Asymmetry or misalignment, Range of motion abnormality, Tone, texture and temperature change in the soft tissues, and Special tests (such as provocation or instrumented tests). For third party documentation in the United States, a subluxation demonstrated by physical examination requires at least two of the four PART findings, one of which must be asymmetry or range of motion abnormality. Requiring agreement among several findings at the same level offsets the weakness of any single one.

Words worth knowing

Extremity, Neurologic and Peripheral Vascular Examination

Most extremity and neurologic items on Part III are really localization problems: a patient points to a painful shoulder, a numb hand or a weak foot, and you must decide which tissue, which nerve or which level is responsible, and whether the cause is in the limb, the spine or the blood supply. The tests in this chapter are the tools for that decision. Know how each is done and what it means, but above all know which test to choose next and how much a positive or negative result should change your mind.

Section 1Upper extremity orthopedic examination in cases

The shoulder

Start every shoulder examination by clearing the neck, because C5 radiculopathy, C5 to C6 facet pain and referred visceral pain (the heart, the diaphragm through C3 to C5, the gallbladder on the right, the spleen on the left) all present as "shoulder pain." Pain that does not change with shoulder movement, or that is reproduced by neck movement, is not from the shoulder. Then compare active and passive range. Loss of both active and passive motion, worst in external rotation, then abduction, then internal rotation (the capsular pattern), indicates adhesive capsulitis or glenohumeral arthritis. Loss of active motion with preserved passive motion indicates a weak or torn rotator cuff or a nerve lesion. A painful arc between about 60 and 120 degrees of abduction suggests subacromial impingement or cuff tendinopathy; pain at the top of the arc, from about 160 to 180 degrees, suggests the acromioclavicular joint.

Clusters outperform single shoulder tests. For subacromial impingement, a positive Hawkins Kennedy, a painful arc and weak resisted external rotation together give a positive likelihood ratio of about 10. For a full thickness rotator cuff tear, a painful arc, a positive drop arm and weak external rotation together, especially over age 60, make a tear very likely. A traumatic cuff tear with marked weakness in an active patient is a reason for early orthopedic referral, because repair results are best within weeks.

The elbow

Lateral elbow pain in a person who grips repeatedly is usually lateral epicondylalgia (tendinopathy of the extensor carpi radialis brevis origin). It is reproduced by Cozen test (resisted wrist extension with a fist, elbow extended, forearm pronated), Mill test (passive wrist flexion with elbow extended and forearm pronated), and Maudsley test (resisted middle finger extension). Medial epicondylalgia is reproduced by resisted wrist flexion and pronation, or passive wrist extension with the elbow extended. Ligaments are tested with valgus stress at about 20 to 30 degrees of flexion for the ulnar collateral ligament (throwing athletes) and varus stress for the lateral collateral ligament. The ulnar nerve is assessed with a Tinel sign in the cubital tunnel and the elbow flexion test (full elbow flexion with wrist extension for one to three minutes reproduces ulnar side paresthesia). Lateral elbow pain that also produces aching in the dorsal forearm and weakness of finger extension without sensory loss suggests the posterior interosseous nerve (radial tunnel).

The wrist and hand

Section 2Lower extremity orthopedic examination in cases

The hip

Hip joint pain is felt mainly in the groin and anterior thigh and may refer to the knee, so a child or older adult with "knee pain" and a normal knee needs a hip examination. Lateral hip pain with tenderness over the greater trochanter that is worse lying on that side suggests greater trochanteric pain syndrome (gluteus medius and minimus tendinopathy, with or without bursitis). Buttock pain is more often lumbar, sacroiliac or gluteal than intra-articular. The hip tests most worth knowing were introduced in Chapter 3: loss of internal rotation as the earliest sign of osteoarthritis; FADIR for impingement and labral tears (sensitive, so a negative result helps exclude); the log roll, which is specific for intra-articular pathology because it moves only the joint; FABERE; the Thomas, Ely and Ober tests for flexor, rectus femoris and iliotibial band tightness; and the Trendelenburg sign. Craig test estimates femoral anteversion by rotating the prone hip until the greater trochanter is most lateral; increased anteversion produces in-toeing. The piriformis or FAIR test (flexion, adduction, internal rotation in side lying) reproduces buttock pain in piriformis syndrome.

The knee

The mechanism usually tells you which structure is injured: a noncontact pivot with a pop and rapid swelling (hemarthrosis within two hours) is the classic anterior cruciate tear; a blow to the lateral knee stresses the medial collateral ligament; a dashboard injury or fall onto the flexed knee drives the tibia backward and tears the posterior cruciate; twisting on a loaded, flexed knee tears a meniscus, which swells more slowly over 6 to 24 hours and may lock or catch. Check for effusion first with the bulge (sweep) test for small effusions and patellar ballottement for large ones.

The Ottawa knee rule calls for knee radiographs after acute injury if any one of the following is present: age 55 or older, isolated tenderness of the patella, tenderness of the fibular head, inability to flex the knee to 90 degrees, or inability to bear weight for four steps both immediately and in the examination room (limping steps count as bearing weight).

The ankle and foot

The common inversion sprain injures the anterior talofibular ligament first, then the calcaneofibular ligament. The anterior drawer of the ankle (pull the heel forward with the tibia stabilized, in slight plantar flexion) tests the ATFL, and the talar tilt (inversion stress in neutral) tests the CFL. A high ankle sprain of the distal tibiofibular syndesmosis follows external rotation of the foot, is painful above the joint and recovers slowly; it is reproduced by the squeeze test (compressing the tibia and fibula at midcalf produces distal pain) and the external rotation (Kleiger) test. The Thompson test squeezes the calf of the prone patient: absence of plantar flexion means an Achilles tendon rupture (sensitivity about 0.96, specificity about 0.93), often in a middle aged recreational athlete who felt as if kicked in the heel, sometimes after a fluoroquinolone. Morton neuroma (usually the third web space) gives burning forefoot pain reproduced by squeezing the metatarsal heads, sometimes with a click (Mulder sign). Plantar fasciitis produces first step heel pain with tenderness at the medial calcaneal tubercle, reproduced by passive great toe extension (windlass test). Tarsal tunnel syndrome gives a Tinel sign behind the medial malleolus with burning in the sole.

Section 3Neurologic screening in cases

Root level screening

A neurologic screen of the limbs tests each root three ways: a dermatome (the skin supplied by one root), a myotome (a muscle group supplied mainly by one root) and a deep tendon reflex. Agreement of all three at one level localizes a radiculopathy; disagreement suggests a peripheral nerve, a plexus or a central lesion. Because adjacent dermatomes overlap, sensory loss from a single root is often patchy; motor and reflex findings are more objective.

Muscle strength is graded 0 (no contraction), 1 (flicker), 2 (full range with gravity eliminated), 3 (full range against gravity), 4 (against some resistance) and 5 (normal). Reflexes are graded 0 (absent), 1+ (diminished), 2+ (normal), 3+ (brisk, possibly with spread) and 4+ (with clonus). Diminished reflexes on one side point to a root or peripheral nerve; symmetrically diminished reflexes may be normal or reflect a peripheral neuropathy (ankles first); brisk reflexes with spread, sustained clonus (more than three beats) or pathologic reflexes indicate an upper motor neuron lesion. Reinforcement (the Jendrassik maneuver, pulling clasped hands apart) helps bring out a hard to elicit reflex.

Upper versus lower motor neuron lesions

The upper motor neuron runs from the motor cortex through the internal capsule and brainstem, crosses at the pyramidal decussation of the medulla and descends in the lateral corticospinal tract. The lower motor neuron begins at the anterior horn cell and travels through the root, plexus and peripheral nerve to the neuromuscular junction. A lesion above the anterior horn releases the spinal reflex arc from cortical inhibition; a lesion at or below it interrupts the arc itself.

Pathologic reflexes are the bedside markers of an upper motor neuron lesion. The Babinski sign is extension of the great toe with fanning of the other toes when the lateral sole is stroked from heel to forefoot; it is normal in infants up to about 12 to 24 months. Oppenheim (stroking down the tibial crest) and Chaddock (stroking around the lateral malleolus) elicit the same response. In the upper limb, Hoffmann sign is the equivalent. Superficial reflexes are lost in upper motor neuron lesions and with damage to their own segments: the abdominal reflexes (T8 to T12), the cremasteric reflex (L1 to L2) and the anal wink (S2 to S4).

Cranial nerves and the cerebellum

Cerebellar function is screened with finger to nose and heel to shin (dysmetria and intention tremor), rapid alternating movements (dysdiadochokinesia), tandem gait and observation for nystagmus and scanning speech. Cerebellar signs are ipsilateral to a hemispheric lesion, while midline (vermis) lesions mainly produce truncal and gait ataxia. The Romberg test (feet together, eyes closed) assesses proprioception rather than the cerebellum: a patient who is steady with eyes open but falls with them closed has a dorsal column or large fiber sensory deficit (B12 deficiency, diabetic neuropathy, tabes dorsalis). A patient with cerebellar ataxia is unsteady with eyes open as well.

Section 4Peripheral vascular procedures

Pulses, color, temperature and refill

The peripheral vascular examination begins with inspection and touch: compare color, temperature, hair distribution, skin and nail texture, swelling and ulcers side to side. Chronic arterial insufficiency produces cool, pale, shiny, hairless skin, thickened nails and painful ulcers on the toes and pressure points; chronic venous insufficiency produces edema, brown hemosiderin staining, stasis dermatitis and shallow, less painful ulcers above the medial malleolus. Palpate the radial, brachial, femoral, popliteal, dorsalis pedis and posterior tibial pulses and grade them: 0 absent, 1+ diminished, 2+ normal, 3+ bounding (some scales add 4+). The dorsalis pedis is congenitally absent in a minority of people, so an isolated absent dorsalis pedis with a normal posterior tibial pulse is less meaningful than loss of both. Capillary refill after nail bed blanching should be under about 2 seconds (up to 3 seconds is often accepted in adults and the elderly); a prolonged refill suggests poor perfusion, though cold and dehydration slow it too.

The ankle brachial index

The ankle brachial index (ABI) is the ratio of the higher systolic pressure at the ankle (dorsalis pedis or posterior tibial, measured with a Doppler probe) to the higher of the two brachial systolic pressures. Each leg has its own ABI. It is the standard office test for peripheral arterial disease, with about 90 percent sensitivity and 95 percent specificity at a cutoff of 0.90. Calcified, noncompressible arteries in diabetes and chronic kidney disease falsely raise the ankle pressure, giving a value above 1.40 that hides disease; a toe brachial index is then used.

Vascular versus neurogenic claudication

Leg pain with walking in an older adult has two common causes, and the distinction is a favorite board item because both patients may also have back pain.

Deep vein thrombosis

The classic Homans sign (calf pain on passive dorsiflexion) is neither sensitive nor specific and should not be used to rule DVT in or out. Probability is estimated with the Wells criteria: one point each for active cancer; paralysis, paresis or recent plaster immobilization of the leg; bed rest over 3 days or major surgery within 12 weeks; localized tenderness along the deep veins; swelling of the entire leg; calf circumference more than 3 cm greater than the other side (measured 10 cm below the tibial tuberosity); pitting edema confined to the symptomatic leg; collateral superficial (nonvaricose) veins; and previously documented DVT; minus two points if an alternative diagnosis is at least as likely. A score of 2 or more means DVT is likely and the patient needs same day compression ultrasound; a score below 2 means DVT is unlikely and a negative D-dimer can exclude it. A suspected DVT is never massaged, manipulated or treated with soft tissue work.

Section 5Putting the NMS exam together

Choose tests by hypothesis

An efficient examination is not a checklist of every eponym in the region. By the end of the history you should hold two or three ranked hypotheses, including at least one that must not be missed. Each test is chosen because its result will change that ranking. The usual sequence is: screen for red flags and safety; observe; take active and passive range of motion and resisted testing to identify the tissue type (contractile, inert or neural); do the neurologic screen if there are limb symptoms; then use a small number of provocative or special tests targeted at the leading hypotheses; palpate last, so that tenderness does not color the earlier findings. Stop when the answer is clear enough to act on.

Sensitivity, specificity and likelihood ratios

Sensitivity is the proportion of people with the condition who test positive; specificity is the proportion without it who test negative. A highly sensitive test rarely misses disease, so a negative result rules it out (SnNout): the negative SLR for disc herniation, the negative upper limb tension test for cervical radiculopathy, the Ottawa rules for fracture. A highly specific test rarely labels healthy people, so a positive result rules disease in (SpPin): the crossed SLR, the drop arm test, the pivot shift, Spurling. Predictive values depend on prevalence and so change from one clinic to another, which is why likelihood ratios are more useful.

The positive likelihood ratio (LR+) equals sensitivity divided by (1 minus specificity); the negative likelihood ratio (LR minus) equals (1 minus sensitivity) divided by specificity. An LR+ above 10 or an LR minus below 0.1 produces a large, often conclusive change in probability; 5 to 10 and 0.1 to 0.2 produce moderate changes; 2 to 5 and 0.2 to 0.5 small changes; values near 1 change nothing. A convenient approximation for pretest probabilities between about 10 and 90 percent: an LR of 2 adds about 15 percentage points, 5 adds about 30 and 10 adds about 45; an LR of 0.5 subtracts about 15, 0.2 about 30 and 0.1 about 45.

From complaint to localized lesion

Localization works by asking where one lesion could explain every finding. Weakness and sensory change confined to one root's territory with a matching reflex change localize to the root. Findings that follow a peripheral nerve's map but cross root boundaries localize to the nerve. Findings in more than one root and nerve in one limb suggest the plexus. Bilateral findings with upper motor neuron signs place the lesion in the cord or brain, and a sensory level on the trunk places it in the cord. Stocking and glove sensory loss with reduced ankle reflexes describes a length dependent polyneuropathy (diabetes, alcohol, B12 deficiency, chemotherapy). Fatigable weakness with ptosis and diplopia and normal sensation points to the neuromuscular junction (myasthenia gravis); symmetric proximal weakness with normal sensation and reflexes points to muscle.

Words worth knowing

Imaging Decisions, Protection, Positioning and Report Writing

Part III rarely asks you to name a bone; it asks whether this patient needs a film at all, which view will answer the question, how to keep the dose down, what the image shows, and what you should write and recommend next. Imaging decisions are clinical decisions: a film ordered without a reason exposes the patient and finds incidental noise, while a film not ordered in the patient with red flags misses a fracture, tumor or infection. This chapter teaches the reasoning that connects the history to the right study, the right projection and the right report.

Section 1Indications and contraindications for imaging

The question comes first

Every film should answer a question that will change management. Before ordering, state the question in one line: "Is there a fracture after this fall?", "Is there destructive bone disease in this 68 year old with night pain and weight loss?", "Is there instability after this flexion injury?" If you cannot write the question, or if no possible answer would alter what you do, the film is not indicated. Plain radiographs are excellent for fracture, gross alignment, advanced degeneration, many bone tumors and congenital anomalies. They are poor for disc herniation, nerve root compression, early infection, early metastasis (roughly 30 to 50 percent of trabecular bone must be lost before a lytic lesion shows), ligament injury and soft tissue disease. Knowing these limits is as important as knowing the indications.

Red flags that justify imaging

For spinal pain, current guidelines agree that routine imaging of acute low back pain without red flags is not helpful: findings such as disc degeneration and facet arthrosis are common in people without pain, they do not predict outcome, and early imaging is associated with more procedures, more time off work and no better recovery. Imaging becomes appropriate when the history or examination raises suspicion of serious pathology, or when a patient fails to improve after about 4 to 6 weeks of appropriate care.

Decision rules for cervical trauma

Two validated rules decide whether an alert, stable adult with neck trauma needs cervical imaging. The Canadian C spine rule asks three questions in sequence. First, is there any high risk factor that mandates imaging: age 65 or older, a dangerous mechanism (fall from 3 feet or 5 stairs or more, axial load to the head as in diving, high speed motor vehicle collision over 100 km/h or with rollover or ejection, motorized recreational vehicle, bicycle collision), or paresthesias in the extremities? If yes, image. Second, is there a low risk factor that allows safe assessment of range of motion: simple rear end collision, sitting position in the emergency department, ambulatory at any time, delayed onset of neck pain, or absence of midline cervical tenderness? If none is present, image. Third, can the patient actively rotate the neck 45 degrees left and right? If yes, no imaging is needed; if not, image. The rule has a sensitivity close to 100 percent for clinically important cervical injury. It does not apply to patients under 16, those with a Glasgow Coma Scale below 15, unstable vital signs, acute paralysis, known vertebral disease or prior cervical surgery.

The NEXUS criteria say imaging is not needed if all five are present: no posterior midline cervical tenderness, no focal neurological deficit, normal alertness, no intoxication, and no painful distracting injury. NEXUS is simpler but somewhat less specific than the Canadian rule. In an emergency setting, CT is now the preferred first study for adults who meet imaging criteria, because it is far more sensitive than plain films for fractures; in the chiropractic office, the decision that matters is that the patient needs imaging before any cervical manipulation, and that a high risk patient is immobilized and sent for it.

Extremity decision rules

The Ottawa ankle rules call for ankle radiographs when there is pain in the malleolar zone plus bone tenderness at the posterior edge or tip of either malleolus (distal 6 cm) or inability to bear weight for four steps both immediately and at examination. Foot films are indicated for midfoot pain plus tenderness at the base of the fifth metatarsal or the navicular, or the same inability to bear weight. Sensitivity approaches 100 percent, so a negative rule reliably excludes fracture. The Ottawa knee rule calls for films with age 55 or older, isolated patellar tenderness, fibular head tenderness, inability to flex to 90 degrees, or inability to bear weight for four steps.

When imaging is not indicated

• Acute nonspecific low back or neck pain under about 6 weeks with no red flags.
• Routine films to "find subluxations", to establish a baseline for every new patient, or to document progress in an improving patient. Repeat films need a new clinical question.
• Imaging for reassurance alone, or to satisfy an insurer, when the result would not change care.
• Radiographs when the question is a soft tissue one (disc herniation, cord, ligament, tendon) and the next step would be MRI or ultrasound anyway.

Pregnancy and children

Ask every patient of reproductive age about pregnancy and the date of the last menstrual period before any exposure that includes the abdomen or pelvis, and document the answer. Elective imaging is deferred during pregnancy. When imaging is truly needed, the dose of a single lumbar or pelvic series is well below the threshold associated with fetal malformation (commonly taught as about 50 to 100 mGy); a lumbar series delivers a fetal dose on the order of 1 to 4 mGy. The theoretical concern at low doses is a small increase in childhood cancer risk, so the rule is to avoid unnecessary exposure, prefer nonionizing studies (ultrasound, MRI without gadolinium), and never withhold a necessary study. The older "10 day rule" (elective pelvic exposure only in the first 10 days after menses onset) reflects the same principle.

Children are more radiosensitive than adults because their tissues are dividing and they have more years in which a cancer can develop. Their unfused growth plates, ossification centers and normal pseudosubluxation also make films easy to misread. Image children only for specific indications, use the fewest views, collimate tightly and use pediatric technique factors. Scoliosis follow up should use the lowest dose method available, PA projection and the minimum number of films needed to make treatment decisions.

Section 2Patient protection and positioning

ALARA and the three cardinal principles

ALARA means keeping exposure "as low as reasonably achievable" while still producing a diagnostic image. For the operator, the three cardinal principles are time (minimize it), distance (maximize it) and shielding (use it). Distance works through the inverse square law: intensity is proportional to 1 divided by the square of the distance, so doubling the distance from a source reduces exposure to one fourth. The operator stands behind the control booth barrier, never holds a patient during exposure, and wears a dosimeter badge. The main source of operator exposure is scatter from the patient, not the primary beam.

For the patient, dose is reduced mostly by avoiding unnecessary films, then by technique: tight collimation, adequate filtration, appropriate kVp and mAs, fast image receptors, correct positioning on the first attempt (repeats double the dose) and, where regulations require it, shielding.

Collimation, filtration and shielding

• Collimation restricts the beam to the area of interest. It is the single most effective technical way to reduce patient dose, and because less tissue is irradiated it also produces less scatter, which improves contrast. The collimated field must never be larger than the image receptor, and a visible collimation border on all sides is evidence of good practice.
• Filtration (aluminum in the tube housing, at least 2.5 mm aluminum equivalent total for units above 70 kVp) absorbs low energy photons that would be absorbed in skin without contributing to the image. Compensating (wedge or trough) filters even out density across body parts of unequal thickness, for example the cervicothoracic junction or a full spine film.
• Shielding of the gonads, thyroid and breast has traditionally been taught when these organs lie within or near (about 5 cm) the primary beam and the shield will not obscure the anatomy of interest. Current physics guidance has moved away from routine gonadal and fetal shielding, because modern equipment uses automatic exposure control that may increase dose when a shield enters the field, and shields frequently hide pathology and force repeat films. Follow the regulations that apply where you practice; for the exam, know both the traditional rule and the reason it is changing.

Technique factors

With digital radiography, an underexposed image looks noisy while an overexposed image still looks good because software rescales brightness. This allows dose creep, in which operators drift toward higher exposures without noticing. Watching the exposure index and staying within the manufacturer's target range is the digital version of ALARA.

Standard and supplemental views

Every region has a minimum standard series, and long bones and joints always need at least two views at 90 degrees to each other, because a fracture or dislocation can be invisible in a single plane. For a long bone, include the joints above and below. Supplemental views are added to answer a specific question raised by the history, examination or the standard films.

Section 3Normal radiographic anatomy and variants in cases

Why normal comes first

Most misreads on Part III come from two directions: calling a normal variant disease (and frightening or overtreating the patient) or accepting real disease as normal. The protection against both is a confident picture of normal on each standard view, including the lines and measurements that define alignment, and a short list of variants that are known to mimic pathology.

The lateral cervical film

The neutral lateral is the single most informative cervical view. On it, four smooth, roughly parallel curves should be traced: the anterior vertebral line along the front of the bodies, the posterior vertebral line (George's line) along the back of the bodies, which forms the anterior wall of the canal, the spinolaminar line joining the junctions of the laminae with the spinous processes, which forms the posterior wall of the canal, and the posterior spinous line through the spinous tips. A step in any line suggests translation (subluxation, dislocation, spondylolisthesis), and fanning of the spinous processes suggests posterior ligament disruption.

The other standard views

• APOM: the dens sits centered between the lateral masses of C1, the lateral masses of C1 line up with the articular pillars of C2, and the joint spaces are symmetric. Bilateral overhang of the C1 lateral masses beyond C2 totaling more than about 7 mm suggests a Jefferson burst fracture with transverse ligament rupture. In young children, physiological overhang (pseudospread of the atlas) is normal.
• AP lower cervical: spinous processes in a straight line (a sudden rotational offset suggests unilateral facet dislocation), uncinate processes and uncovertebral joints visible, pedicles and lateral masses symmetric, trachea midline.
• AP lumbar: paired oval pedicles ("owl's eyes") at every level; the interpediculate distance normally widens gradually from L1 to L5. A missing pedicle ("winking owl" sign) suggests lytic metastasis, while widening of the interpediculate distance suggests an intraspinal mass or burst fracture. Psoas shadows, renal outlines, sacroiliac joints and the hips are reviewed in the same film.
• Lateral lumbar: disc heights increase from L1 to L4 to L5; L5 to S1 is often slightly narrower and that alone is not abnormal. George's line should be continuous. The lumbosacral (Ferguson's sacral base) angle averages about 41 degrees (normal range roughly 26 to 57); the lumbar lordosis is measured from the top of L1 to the sacral base.
• Oblique lumbar: the "Scottie dog": nose (transverse process), eye (pedicle), ear (superior articular process), neck (pars interarticularis), body (lamina), front leg (inferior articular process). A collar on the neck is spondylolysis; a decapitated dog suggests spondylolisthesis.
• Thoracic AP and lateral: pedicles at every level, paraspinal lines close to the spine (a bulging paraspinal line suggests hematoma, abscess or tumor), smooth kyphosis about 20 to 40 degrees, and vertebral body heights equal anteriorly and posteriorly (an anterior height loss over about 20 percent suggests compression fracture).

Variants that mimic disease

Section 4Description and interpretation of images

A systematic search

Satisfaction of search, stopping after the first abnormality, is the classic interpretive error. A fixed sequence prevents it. Begin with the label (name, date, side marker, view), confirm the film is adequate (positioning, exposure, the whole region included), and then follow ABCS:

• A, alignment: the curves and lines described above, translation, rotation, scoliosis, listhesis, joint congruity.
• B, bone: each bone's size, shape, outline (cortex continuity) and density (generalized osteopenia or sclerosis, focal lytic or blastic lesions). Count the pedicles. Check the endplates, posterior elements and the edges of the film.
• C, cartilage (joint spaces): uniform versus nonuniform narrowing, subchondral sclerosis, cysts, osteophytes, erosions, calcification of cartilage (chondrocalcinosis), fusion.
• S, soft tissues: prevertebral swelling, paraspinal lines, psoas shadows, abdominal aorta calcification and diameter, renal and gallbladder stones, lung apices, foreign bodies, soft tissue calcification or gas.

Review "hot spots" deliberately: the dens and C1 to C2 on every cervical film, the lung apices, the abdominal aorta (an aortic wall more than 3 cm apart suggests aneurysm), the hips and sacroiliac joints on lumbar films, and the corners of the image where tumors hide.

Describing a bone lesion

Plain film features remain the best way to judge whether a bone lesion is slow growing (usually benign) or aggressive (malignancy or infection). Age is the most powerful clue: a solitary aggressive lesion under 30 suggests a primary tumor such as osteosarcoma or Ewing sarcoma, while over 40 the leading diagnoses become metastasis and multiple myeloma.

1. Location: which bone; axial or appendicular; epiphysis (chondroblastoma, giant cell tumor after physeal closure), metaphysis (osteosarcoma, osteochondroma, nonossifying fibroma), diaphysis (Ewing sarcoma, fibrous dysplasia, myeloma); central, eccentric or cortical; vertebral body versus posterior elements (metastasis destroys the pedicle and body, aneurysmal bone cyst and osteoblastoma favor the posterior elements).
2. Size and number: solitary or multiple; multiple lytic lesions over 40 suggest metastasis or myeloma.
3. Margin and zone of transition: graded with the Lodwick system (below). A narrow zone of transition means slow growth; a wide one means aggressive growth.
4. Matrix: what the lesion produces. Osteoid matrix is cloudlike or ivory dense (osteosarcoma, osteoblastic metastasis); chondroid matrix shows rings and arcs or popcorn calcification (enchondroma, chondrosarcoma); fibrous matrix gives a hazy ground glass density (fibrous dysplasia).
5. Periosteal reaction: solid, thick, uninterrupted new bone means a slow process; interrupted reactions (lamellated "onion skin", spiculated "sunburst" or "hair on end", and the Codman triangle where elevated periosteum is broken through) mean an aggressive process.
6. Cortical breakthrough and soft tissue mass: both indicate aggression.

Writing the report

A report is a legal and clinical document that another provider must be able to act on. A standard structure is:

1. Identifying data: patient name, date of birth, date of study, facility, referring clinician.
2. Clinical history: the question being asked ("fall, midline C6 tenderness, rule out fracture").
3. Views obtained and their quality, including limitations ("C7 obscured by shoulders").
4. Findings: organized by ABCS, describing what is seen in neutral terms (location, size, margin, matrix, periosteal reaction), including pertinent negatives ("no prevertebral soft tissue swelling") and incidental findings.
5. Impression: the conclusion in order of importance: the most significant or most likely diagnosis first, then a short differential, then minor or incidental findings. The impression is what busy readers read, so it must stand on its own.
6. Recommendations: specific and actionable: the next study (MRI, CT, bone scan, swimmer's view, follow up films in a stated interval), laboratory tests (CBC, ESR, CRP, SPEP, PSA), referral (orthopedic, oncology, emergency department) and urgency.

Findings that need action within hours, such as an unstable fracture, cord compression, aggressive lesion, aortic aneurysm or free intraperitoneal air, must be communicated directly (by phone or in person) to the responsible clinician or patient, and the communication (time, person, content) documented. Leaving a critical finding in a report that may not be read for days is a standard of care failure.

Section 5Choosing advanced imaging in cases

Match the study to the tissue and the question

Each advanced study sees a different property of tissue. CT measures X-ray attenuation in thin slices and shows cortical bone in fine detail. MRI maps the behavior of hydrogen protons in a magnetic field and shows water, fat and soft tissue contrast, including marrow, discs, nerves, cord and ligaments. A bone scan (technetium 99m methylene diphosphonate) shows osteoblastic activity and blood flow anywhere in the skeleton. Ultrasound shows tendons, muscles, fluid and vessels in real time without radiation. DEXA measures areal bone mineral density. Choosing well means knowing which property answers the question.

MRI signal basics for case questions

On T1 weighted images fat is bright and water is dark, so T1 is the anatomy and marrow sequence: normal adult marrow is bright from fat, and a dark marrow on T1 means replacement by tumor, infection or edema. On T2 weighted images water is bright, so cerebrospinal fluid, edema, cysts, a hydrated disc nucleus and inflammation are bright; a dark ("black") disc on T2 is a desiccated, degenerated disc. STIR and fat suppressed T2 sequences darken fat so that edema stands out, which is ideal for stress reactions, acute fractures and sacroiliitis. Gadolinium enhancement highlights vascular or inflamed tissue: it separates scar (enhances) from recurrent disc herniation (does not enhance centrally) after surgery, outlines abscesses and characterizes tumors.

A classic pattern contrast: in vertebral osteomyelitis and discitis the disc itself is destroyed and bright on T2, with adjacent endplates eroded and both vertebral bodies showing edema; in metastasis the disc is typically preserved while the body and pedicle are replaced. "The disc crosses the infection, the tumor respects the disc" is a useful board shortcut.

Timing: when each study becomes positive

Plain films lag behind biology. Osteomyelitis takes about 10 to 14 days to produce radiographic bone destruction; stress fractures may not show periosteal callus for 2 to 3 weeks, and some never do; a lytic metastasis must remove roughly a third to a half of trabecular bone before it is visible; scaphoid waist fractures are missed on initial films in a meaningful minority of patients. MRI and bone scan become positive within a day or two. This is why a normal radiograph does not exclude early infection, stress fracture or metastasis in a patient whose history suggests them.

Deciding the next study and how fast

DEXA interpretation

The T score compares the patient with a young adult of the same sex at peak bone mass: minus 1.0 or higher is normal, between minus 1.0 and minus 2.5 is low bone mass (osteopenia), and minus 2.5 or lower is osteoporosis. A fragility fracture of the hip or spine establishes osteoporosis regardless of the T score. The Z score compares the patient with people of the same age and sex and is used for premenopausal women, men under 50 and children; a Z score of minus 2.0 or lower is "below the expected range for age" and should prompt a search for a secondary cause (steroids, hyperparathyroidism, celiac disease, hypogonadism, myeloma). The FRAX tool combines bone density with clinical risk factors to estimate 10 year fracture probability.

Words worth knowing

Clinical Laboratory and Special Studies in Cases

A laboratory value means nothing until it is attached to a patient: a sedimentation rate of 85 mm/h is a curiosity in a healthy 30 year old, and a reason for same week referral in a 74 year old with new headache and jaw pain. Part III tests whether you know which test to order for a given question, what pattern of results points to which disease, and what you do next when a result is dangerous. This chapter works through urinalysis, hematology, serology, chemistries, stool and joint fluid, electrophysiologic studies and the statistics that decide whether a test is worth ordering at all.

Section 1Urinalysis and hematology in cases

The dipstick

A routine urinalysis has three parts: physical (color, clarity, specific gravity), chemical (the dipstick) and microscopic (sediment). It is cheap, fast and screens for kidney disease, urinary infection, diabetes, liver and hemolytic disease, and it is the first test for flank pain that might be renal rather than spinal.

Microscopy: casts and crystals

Casts form in the renal tubules from Tamm Horsfall protein, so a cast localizes disease to the kidney itself. Red cell casts mean glomerulonephritis. White cell casts mean pyelonephritis or interstitial nephritis (they distinguish upper from lower urinary tract infection). Fatty casts and oval fat bodies ("Maltese cross" under polarized light) go with nephrotic syndrome. Muddy brown granular casts indicate acute tubular necrosis. Waxy casts and broad casts mean advanced chronic kidney disease. Hyaline casts are nonspecific and can follow exercise, fever or dehydration.

Crystals help in stone disease: calcium oxalate (envelope or dumbbell shaped) in the most common stones and in ethylene glycol poisoning; uric acid (rhomboid, yellow brown) with gout, high cell turnover and acid urine; struvite or magnesium ammonium phosphate ("coffin lid") with urease producing infection and staghorn calculi; cystine (hexagonal) in the inherited disorder cystinuria.

The complete blood count

Classifying anemia

The MCV divides anemia into three groups, and each group has a short list. In microcytic anemia (MCV below 80), iron deficiency is most common; in an adult man or a postmenopausal woman, iron deficiency means gastrointestinal blood loss (often colon cancer) until proven otherwise, and in a premenopausal woman heavy menses is the usual cause. Iron studies separate the causes: iron deficiency shows low ferritin (the single best test; below about 30 ng/mL is diagnostic in most settings), high TIBC and high RDW; anemia of chronic disease shows normal or high ferritin with low TIBC; thalassemia trait shows normal iron, a very low MCV out of proportion to mild anemia, a normal or high red cell count (Mentzer index MCV divided by RBC below 13) and target cells. Lead poisoning and sideroblastic anemia are rarer causes, with basophilic stippling and ringed sideroblasts.

In macrocytic anemia (MCV above 100), the megaloblastic causes are vitamin B12 and folate deficiency, recognized by hypersegmented neutrophils (6 or more lobes). B12 deficiency (pernicious anemia, metformin, long term proton pump inhibitors, vegan diet, gastric or ileal surgery) causes subacute combined degeneration: loss of vibration and position sense, ataxia and upper motor neuron signs, sometimes before anemia appears; methylmalonic acid and homocysteine are both elevated, whereas folate deficiency raises only homocysteine. Nonmegaloblastic macrocytosis comes from alcohol, liver disease, hypothyroidism, reticulocytosis and medications.

In normocytic anemia (80 to 100), the reticulocyte count decides the direction. High reticulocytes indicate blood loss or hemolysis (raised LDH and indirect bilirubin, low haptoglobin, schistocytes or spherocytes on smear). Low reticulocytes indicate underproduction: anemia of chronic disease, chronic kidney disease (low erythropoietin), early iron deficiency, or marrow infiltration by leukemia, myeloma or metastatic cancer, especially when other cell lines are also low.

White cells and platelets

For a chiropractor these results matter directly: patients on anticoagulants or with thrombocytopenia bruise and bleed more easily, so high velocity and deep soft tissue techniques are modified or avoided, and any unexplained bruising, petechiae, gum bleeding or hemarthrosis is a reason to check a CBC and coagulation profile rather than treat.

Section 2Serology and blood chemistries in cases

Inflammatory markers: ESR and CRP

The erythrocyte sedimentation rate (Westergren method) measures how far red cells fall in an hour; acute phase proteins, mainly fibrinogen and immunoglobulins, neutralize the negative surface charge of red cells so they stack (rouleaux) and settle faster. A common rule of thumb for the upper limit is age divided by 2 for men and age plus 10, divided by 2, for women. ESR rises slowly over days, falls slowly over weeks, and is raised by anemia, pregnancy, age and kidney disease; it is lowered by polycythemia, sickle cells and very high white counts. An ESR above 100 mm/h narrows the field to a few causes: infection (osteomyelitis, endocarditis), multiple myeloma and other malignancy, and giant cell arteritis or polymyalgia rheumatica.

C reactive protein is made by the liver under the influence of interleukin 6. It rises within 6 to 8 hours, peaks at about 48 hours and falls quickly when inflammation resolves, so it tracks response to treatment of infection better than ESR. A standard CRP below about 10 mg/L (1 mg/dL) is usually considered normal; high sensitivity CRP is a separate cardiovascular risk test with much lower cutoffs. Both ESR and CRP are nonspecific: their main value in a back pain patient is as a screen that, when normal, makes infection and many cancers less likely, and when high, demands an explanation.

Autoantibodies and HLA B27

The rule for autoantibodies is that they are ordered to confirm a disease the clinical picture already suggests, not to screen people with nonspecific aches. An ANA ordered for fatigue and diffuse pain without objective findings will be positive in a meaningful number of healthy people and usually leads to more testing and anxiety rather than a diagnosis. Seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic, reactive and enteropathic arthritis) are "seronegative" because RF and anti CCP are negative; HLA B27 and imaging are the relevant tests.

Uric acid

Urate saturates body fluids at about 6.8 mg/dL. Hyperuricemia is far more common than gout and is not treated by itself in an asymptomatic patient. During an acute gout flare the serum urate can be normal (urate shifts into crystals and inflammatory cytokines increase excretion), so a normal level does not exclude gout; the diagnostic test is crystals in joint fluid. Causes of high urate include underexcretion (kidney disease, thiazide and loop diuretics, low dose aspirin, alcohol, especially beer), overproduction (myeloproliferative disease, tumor lysis, psoriasis) and diet (purine rich meat and seafood, fructose sweetened drinks).

Calcium, phosphorus, alkaline phosphatase and the bone pattern

Serum calcium (about 8.5 to 10.5 mg/dL) should be interpreted with albumin, because about 40 percent is protein bound: corrected calcium = measured calcium + 0.8 x (4.0 minus albumin). Hypercalcemia in outpatients is usually primary hyperparathyroidism (high or inappropriately normal PTH); in sick or hospitalized patients it is usually malignancy (PTH suppressed: PTH related peptide from squamous cancers, lytic bone metastasis, myeloma). Symptoms follow "stones, bones, abdominal groans and psychic moans": kidney stones, bone pain, constipation and abdominal pain, fatigue, confusion and depression, plus polyuria.

Alkaline phosphatase (about 40 to 130 U/L in adults) comes mainly from liver and bone. A raised ALP with a raised GGT points to the liver (cholestasis); a raised ALP with a normal GGT points to bone, where it reflects osteoblast activity: growth in adolescents, healing fracture, Paget disease (often very high), osteoblastic metastasis (prostate, breast), osteomalacia and hyperparathyroidism. A bone specific ALP or ALP isoenzymes can confirm the source. ALP is typically normal in multiple myeloma, because myeloma suppresses osteoblasts.

PSA, glucose, kidney and liver tests

• PSA: a prostate specific (not cancer specific) protein. A level above about 4 ng/mL has traditionally prompted evaluation, with age adjusted ranges also in use. It rises with prostate cancer, benign prostatic hyperplasia, prostatitis, urinary retention, recent ejaculation and instrumentation. Screening men 55 to 69 is an individual decision after shared discussion. In a man with back pain and an osteoblastic lesion or a raised ALP, PSA is a targeted diagnostic test, not screening.
• Glucose: diabetes is diagnosed by fasting plasma glucose 126 mg/dL or higher, HbA1c 6.5 percent or higher, a 2 hour oral glucose tolerance value of 200 mg/dL or higher, or a random glucose of 200 mg/dL or higher with classic symptoms. Prediabetes is a fasting glucose of 100 to 125 mg/dL or HbA1c of 5.7 to 6.4 percent. Diabetes matters musculoskeletally because of adhesive capsulitis, peripheral neuropathy, Charcot joints, diffuse idiopathic skeletal hyperostosis and infection risk.
• Kidney panel: BUN (about 7 to 20 mg/dL) and creatinine (about 0.6 to 1.2 mg/dL), with eGFR calculated from creatinine, age and sex. A BUN to creatinine ratio above 20 suggests prerenal azotemia (dehydration, heart failure, GI bleeding). Chronic NSAID use, dehydration and diuretics can all injure the kidney; an eGFR below about 30 changes the choice of anti inflammatory drug and contrast agent.
• Liver panel: ALT is more liver specific than AST; AST to ALT ratio above 2 suggests alcoholic liver disease; very high aminotransferases (in the thousands) suggest acute viral, toxic (acetaminophen) or ischemic hepatitis. A cholestatic pattern raises ALP, GGT and conjugated bilirubin. Low albumin and a prolonged PT indicate reduced synthetic function.
• Creatine kinase: raised in muscle injury, inflammatory myopathy (polymyositis, dermatomyositis), statin myopathy, hypothyroidism and rhabdomyolysis (very high CK with dark urine that is dipstick positive for blood but shows few red cells).
• TSH: the first test for thyroid function; hypothyroidism causes myalgia, carpal tunnel syndrome, fatigue and raised CK.

Section 3Stool analysis and joint fluid analysis

Occult blood and colorectal cancer screening

Stool tests appear on Part III mainly through colorectal cancer screening, iron deficiency anemia and inflammatory bowel disease that travels with spondyloarthritis. Average risk adults are screened from age 45 to 75. Options include colonoscopy every 10 years, an annual fecal immunochemical test (FIT), a multitarget stool DNA test with FIT every 1 to 3 years, or CT colonography or flexible sigmoidoscopy every 5 years. Any positive stool test requires a follow up colonoscopy; repeating the stool test is not acceptable.

Two connections with the musculoskeletal system deserve emphasis. First, reactive arthritis follows enteric infection with Salmonella, Shigella, Campylobacter or Yersinia (and genitourinary Chlamydia) by 1 to 4 weeks, often in HLA B27 positive people, with asymmetric lower limb arthritis, enthesitis, conjunctivitis and urethritis. Second, about 1 in 5 patients with Crohn disease or ulcerative colitis has an enteropathic arthritis: peripheral arthritis that tracks bowel activity, or sacroiliitis and spondylitis that run independently of it.

Synovial fluid analysis

Aspiration of an effusion (arthrocentesis) is the single most informative test for an acutely swollen joint, and for an acute monoarthritis it is mandatory, because septic arthritis destroys cartilage within days and has a meaningful mortality. Fluid is sent for cell count and differential, crystal examination under compensated polarized light, Gram stain and culture. Glucose, protein and LDH add little. Normal synovial fluid is clear, pale yellow, viscous (forms a long "string") and contains fewer than about 200 white cells per µL.

Crystal examination uses a red compensator. Monosodium urate crystals in gout are needle shaped and strongly negatively birefringent (yellow when aligned parallel to the slow axis of the compensator, blue when perpendicular). Calcium pyrophosphate crystals in pseudogout (CPPD disease) are rhomboid or rod shaped and weakly positively birefringent (blue when parallel). Calcium hydroxyapatite crystals are too small to see without special stains. Crystals and infection can coexist, so a fluid with crystals and a very high count is still cultured and the patient may need antibiotics until results return.

Gram stain is positive in only about half of septic joints, so a negative stain never excludes infection; culture of synovial fluid is positive in most nongonococcal cases. In gonococcal arthritis synovial cultures are often negative; the diagnosis is made by nucleic acid testing of urethral, cervical, rectal and pharyngeal specimens and blood cultures, in a young adult with migratory polyarthralgia, tenosynovitis and pustular skin lesions.

Section 4Electrophysiologic recordings

ECG basics

The electrocardiogram records the summed electrical activity of the heart from 12 viewpoints (six limb leads in the frontal plane and six precordial leads in the horizontal plane). Standard paper runs at 25 mm per second, so one small (1 mm) box is 0.04 s and one large (5 mm) box is 0.20 s; vertically, 10 mm equals 1 mV. For a regular rhythm, heart rate is 300 divided by the number of large boxes between consecutive R waves (1 box 300, 2 boxes 150, 3 boxes 100, 4 boxes 75, 5 boxes 60, 6 boxes 50). For an irregular rhythm, count the QRS complexes in a 10 second strip and multiply by 6.

The P wave is atrial depolarization; the PR interval (start of P to start of QRS, normally 0.12 to 0.20 s) is mostly delay in the AV node; the QRS complex is ventricular depolarization (normally under 0.12 s, usually under 0.10); the ST segment should be at the baseline and represents the plateau of ventricular action potentials; the T wave is ventricular repolarization; the QT interval, corrected for rate (QTc), is normally under about 0.44 s in men and 0.46 s in women. A systematic read covers rate, rhythm, axis, intervals, P wave and QRS morphology, ST segments and T waves.

Dangerous patterns

EEG

The electroencephalogram records cortical electrical activity from scalp electrodes. Its main indications are suspected seizures and epilepsy classification (interictal spikes and sharp waves; generalized 3 Hz spike and wave in childhood absence epilepsy), unexplained altered consciousness or encephalopathy (diffuse slowing, triphasic waves in hepatic encephalopathy), suspected nonconvulsive status epilepticus, sleep disorders (as part of polysomnography) and confirmation of brain death in some protocols. A normal interictal EEG does not exclude epilepsy, since a single routine study captures abnormalities in only about half of people with the disorder; sleep deprivation and repeated or prolonged recordings raise the yield. EEG has no role in the routine evaluation of headache, dizziness without loss of consciousness, or syncope that is clearly vasovagal.

Nerve conduction studies and needle EMG

Electrodiagnosis is an extension of the neurological examination. Nerve conduction studies stimulate a nerve and record either a sensory nerve action potential (SNAP) or a compound muscle action potential (CMAP), measuring latency, amplitude and conduction velocity. Normal velocities are roughly 50 m/s or faster in the arms and 40 m/s or faster in the legs. Demyelination slows conduction, prolongs distal latencies and F waves and can produce conduction block, while amplitudes are relatively preserved. Axonal loss reduces amplitude with near normal velocity. Needle EMG samples muscle at rest and during contraction: fibrillation potentials and positive sharp waves at rest indicate denervation (or active myopathy); large, long duration, polyphasic motor units with reduced recruitment indicate chronic denervation with reinnervation; small, short, polyphasic units with early recruitment indicate myopathy.

The location of the lesion relative to the dorsal root ganglion is the key to radiculopathy. The sensory cell body sits in the DRG within or just outside the foramen. A root lesion (disc, foraminal stenosis) is proximal to the DRG, so the sensory axon remains connected to its cell body and the SNAP is normal even when the patient has numbness. Plexus and peripheral nerve lesions are distal to the DRG and reduce the SNAP. Timing matters too: fibrillations appear in paraspinal muscles after about 1 to 2 weeks and in limb muscles after about 3 to 6 weeks, so EMG done in the first 2 to 3 weeks after onset can be falsely normal. The ideal time to study a suspected radiculopathy is about 3 weeks or later.

Section 5Ordering and interpreting tests wisely

Start with the question and the pretest probability

Every test should answer a specific question, and its result should be able to change what you do. The value of a result depends as much on the pretest probability (how likely the disease was before testing, from prevalence, history and examination) as on the test itself. A positive result for a rare disease in a low risk patient is more often a false positive than a true one; a negative result in a high risk patient may not lower the probability enough to stop.

Sensitivity, specificity and predictive values

• Sensitivity = true positives divided by all who have the disease: how often the test is positive in disease. A highly sensitive test, when negative, rules the disease out (SnNout).
• Specificity = true negatives divided by all who do not have the disease: how often the test is negative in health. A highly specific test, when positive, rules the disease in (SpPin).
• Positive predictive value = true positives divided by all positives: the chance a positive result is right. Negative predictive value = true negatives divided by all negatives. Predictive values change with prevalence: as prevalence falls, PPV falls and NPV rises, even though sensitivity and specificity stay the same.
• Likelihood ratios combine sensitivity and specificity and do not depend on prevalence. LR+ = sensitivity divided by (1 minus specificity); LR minus = (1 minus sensitivity) divided by specificity. Multiply the pretest odds by the LR to get the posttest odds.

Applied examples from earlier chapters: the straight leg raise is sensitive (about 90 percent) but not specific for lumbar disc herniation, so a negative SLR helps rule it out while a positive SLR proves little; the crossed SLR is specific (about 90 percent) but insensitive, so a positive crossed SLR strongly supports herniation. An ESR of 20 mm/h or more has moderate sensitivity for cancer as a cause of back pain, but because cancer causes well under 1 percent of back pain in primary care, a raised ESR alone produces many false positives; it is most useful combined with clinical red flags.

Serial and parallel testing

Testing in series (a sensitive screening test first, then a specific confirmatory test only in those who screen positive) maximizes specificity and limits cost: ANA then anti dsDNA; FIT then colonoscopy; ESR and radiographs then MRI. Testing in parallel (several tests at once, any positive counts) maximizes sensitivity and speed and suits urgent situations such as the hot joint (cell count, crystals, Gram stain and culture together) or suspected spinal infection (CBC, ESR, CRP and blood cultures together).

Which test answers which question

Cost and harm

Tests are not free of harm. False positives lead to further tests, procedures and anxiety (a cascade); incidental findings ("incidentalomas") lead to follow up imaging and sometimes to surgery that offers no benefit; labeling a patient with a disease marker they do not need to know about can change how they behave; radiation and contrast carry their own risks; and money spent on low value testing is unavailable for useful care. Normal ranges are set to include 95 percent of healthy people, so in a panel of 20 independent tests, a healthy person has roughly a 64 percent chance of at least one "abnormal" result. Order the test that answers the question, interpret it in light of the pretest probability, and act on the result.

Words worth knowing

Clinical Impression I: Musculoskeletal and Neurologic Presentations

Diagnosis or clinical impression is the single heaviest content area on Part III, and nearly every case in the other areas ends with the same silent question: what does this patient have? This chapter teaches you to read a musculoskeletal or neurologic vignette the way an experienced clinician does, by spotting the one or two clues that separate a common mechanical problem from its dangerous look alike, naming the most likely diagnosis, and knowing which alternative must not be missed and how fast to act on it.

Section 1Neck pain and headache presentations

Reading a neck pain vignette

Part III neck cases are built around three questions. First, is this local mechanical pain, pain from a nerve root, or a disorder of the spinal cord? Second, is there a red flag (trauma with instability risk, cancer, infection, inflammatory disease, vascular injury)? Third, does the headache, if present, come from the neck or from somewhere more dangerous? The examination items in the vignette are chosen to answer those questions, so read them as deliberately placed clues.

Mechanical neck pain (nonspecific neck pain, facet or myofascial dysfunction, sprain or strain) is the most common answer. It is pain in the posterior neck, sometimes into the upper trapezius or interscapular area, that changes with posture and movement, eases with rest, and is accompanied by restricted, painful segmental motion and local tenderness. The neurologic examination is normal. Facet pain tends to be unilateral, worse with extension and rotation toward the painful side, with referral in predictable maps (C2 to C3 to the suboccipital area, C5 to C6 to the base of the neck and upper trapezius, C6 to C7 to the scapula). Arm symptoms, when present, are vague and do not follow a dermatome.

Cervical radiculopathy is irritation or compression of a nerve root, most often by a posterolateral disc herniation in younger patients and by uncovertebral and facet osteophytes narrowing the intervertebral foramen in older ones. The pattern is arm pain that is often worse than the neck pain, following a dermatome, with paresthesia, and sometimes a myotomal weakness and a reduced reflex. Relief with the hand placed on top of the head (shoulder abduction relief sign) is a classic clue. Because cervical roots exit above the vertebra of the same number, a C5 to C6 disc affects the C6 root. C6 and C7 are the most commonly affected roots.

The examination cluster that best supports radiculopathy is the one described by Wainner: a positive upper limb tension test A (median nerve bias), cervical rotation toward the affected side of less than 60 degrees, a positive distraction test and a positive Spurling test. When three of the four are positive, the probability of radiculopathy rises substantially; when all four are positive, the positive likelihood ratio is about 30. The ULTT A alone has high sensitivity (around 0.97) and is good for ruling out, whereas Spurling has high specificity (around 0.9) and is good for ruling in.

Cervical spondylotic myelopathy is compression of the cord, usually by a combination of disc bulge, osteophytes and a buckled ligamentum flavum in a congenitally narrow canal, typically in patients over 50. It is the classic must not miss diagnosis disguised as neck stiffness. The patient describes clumsy hands (dropping things, difficulty with buttons and handwriting), numb hands that do not follow a dermatome, and an unsteady, broad based gait; neck pain may be mild or absent. Signs are upper motor neuron signs: hyperreflexia, a positive Hoffmann sign, inverted brachioradialis reflex, sustained clonus, a Babinski sign, and difficulty with tandem gait. Lhermitte sign (electric sensation down the spine with neck flexion) may be present. Cook's clinical prediction rule uses five items: gait deviation, positive Hoffmann, inverted supinator sign, positive Babinski and age over 45; three or more positive strongly rules in myelopathy. The management consequence is important: high velocity cervical manipulation is contraindicated, MRI is indicated, and the patient is referred for a spine surgical opinion, urgently if deficits are progressing.

Whiplash associated disorders

Acceleration and deceleration injuries are graded with the Quebec Task Force scale, and the grade drives both imaging and management decisions.

Whether a trauma patient needs radiographs before any treatment is decided with the Canadian C spine rule. Any high risk factor (age 65 or older, a dangerous mechanism such as a fall from 3 feet or five stairs, an axial load, a high speed or rollover collision, or extremity paresthesias) mandates imaging. If no high risk factor is present, a low risk factor (simple rear end collision, sitting position in the emergency department, ambulatory at any time, delayed onset of neck pain, or absence of midline tenderness) allows the clinician to test active rotation; if the patient can rotate 45 degrees to each side, imaging is not required. The rule has a sensitivity close to 100 percent for clinically important injury.

Headache: primary types

Most headaches in a chiropractic office are primary headaches, and the board expects you to name them from their features.

The flexion rotation test is performed supine with the neck fully flexed to isolate C1 to C2, then rotated passively to each side. Normal rotation is about 44 degrees each way; a reduction to about 32 degrees or less, or a difference of more than 10 degrees between sides, supports C1 to C2 dysfunction and cervicogenic headache.

Red flag headaches and cervical artery dissection

The SNOOP mnemonic organizes the danger signs: Systemic symptoms or disease (fever, weight loss, cancer, immunosuppression), Neurologic signs or symptoms (confusion, focal deficit, papilledema), Onset sudden (thunderclap, peak within a minute), Older age at onset (new headache after 50), and Pattern change (progressive, positional, triggered by Valsalva, exertion or sex, worse on waking). Each flag points to specific diagnoses.

Cervical artery dissection is a tear of the intima of the vertebral or internal carotid artery, allowing an intramural hematoma that can narrow the lumen or send emboli. Its incidence is low (about 2 to 3 per 100,000 per year), but its early symptom is neck pain and headache, which is why patients with an evolving dissection seek chiropractic care. The board expects you to recognize it before treatment. Vertebral artery dissection causes unilateral posterior neck and occipital pain, often described as unlike any previous pain, followed (sometimes days later) by posterior circulation ischemia: the 5 Ds and 3 Ns (dizziness, diplopia, dysarthria, dysphagia, drop attacks; nausea, numbness, nystagmus) plus ataxia. Internal carotid dissection causes anterolateral neck, face or periorbital pain, an ipsilateral partial Horner syndrome (ptosis and miosis without anhidrosis, because facial sweating fibers travel with the external carotid), pulsatile tinnitus, and later anterior circulation signs (hemiparesis, aphasia, monocular vision loss). Risk factors include recent minor trauma, connective tissue disease, migraine, recent infection and hypertension.

Current understanding is that a dissection already in progress explains most cases in which stroke follows a visit. Premanipulative positional tests (such as the George or DeKleyn tests) have poor sensitivity and do not reliably detect at risk patients; the protection is a careful history for the dissection pattern, a cranial nerve and cerebellar screen, and blood pressure. If the clues are present, the impression is suspected dissection, manipulation is withheld and the patient goes to the emergency department.

Section 2Thoracic and chest wall presentations

The central question: wall or viscus?

Thoracic pain cases test one skill above all others: telling pain that comes from the spine, ribs and chest wall from pain that comes from the heart, lungs, aorta, esophagus, stomach or gallbladder. Viscera share segmental innervation with the thoracic dermatomes, so visceral pain is felt in the body wall. The clue is not the location but the behavior: musculoskeletal pain is reproduced by movement, posture, palpation and joint loading, while visceral pain is linked to exertion, eating, breathing in a nonmechanical way, or comes with autonomic and systemic symptoms. Remember that palpation tenderness does not exclude a myocardial infarction; about 1 in 7 patients with acute coronary syndrome has some chest wall tenderness, so the whole picture matters.

Musculoskeletal thoracic diagnoses

Thoracic segmental and costovertebral dysfunction causes sharp, localized paraspinal or interscapular pain, often after a twisting or lifting movement or a night of awkward sleep. It may wrap partway around the chest along the rib, and it catches with deep inspiration, coughing, rotation or lying on the affected side. There is tenderness over the costotransverse joint, painful rib springing and restricted segmental motion.

Costochondritis causes anterior chest wall pain with tenderness at multiple costochondral junctions (usually the second to fifth), without swelling, in an adult; it is a diagnosis of exclusion in anyone with cardiac risk. Tietze syndrome is similar but with visible swelling, typically at a single upper costal cartilage (second or third) in a younger patient. Slipping rib syndrome involves the hypermobile 8th to 10th ribs, with a clicking or popping sensation and a positive hooking maneuver. Intercostal muscle strain follows coughing or a sudden twist and is focal.

Thoracic disc herniation is uncommon and usually at T8 to T12. It may cause band like radicular pain around the chest or abdomen, or, because the thoracic canal is narrow and the cord has a watershed blood supply, a myelopathy with leg spasticity, a sensory level and bladder symptoms. Any sensory level on the trunk is a cord problem and needs MRI.

Osteoporotic compression fracture is the classic must not miss musculoskeletal diagnosis in an older patient. The vignette typically describes a woman over 65, or a patient of any age on long term corticosteroids, with sudden midthoracic or thoracolumbar pain after minimal trauma (bending, lifting a grocery bag, sneezing, stepping off a curb), severe pain on standing and walking that eases lying down, and percussion tenderness over a spinous process. Height loss of more than 4 cm (or more than 2 cm in a year) and a fixed kyphosis suggest prior fractures. The next step is radiographs; a wedge with an intact posterior cortex is a stable fracture that can be managed conservatively with modification of care, whereas posterior cortex involvement, neurologic signs or a fracture above T7 in an older patient raises concern for a pathologic fracture from metastasis or myeloma. Spinal manipulation of the fractured segment is contraindicated.

Herpes zoster (shingles) is reactivation of varicella zoster virus in a dorsal root ganglion. Its trap is the prodrome: for 2 to 5 days the patient has burning, stabbing or itching unilateral pain in a thoracic dermatome before any rash, which looks like a rib or a radicular problem. Clues are the strictly unilateral band that stops at the midline, allodynia (pain to light touch of clothing), age over 50 or immunosuppression, and sometimes malaise. Then a cluster of vesicles on an erythematous base appears in the dermatome. Antiviral therapy works best within 72 hours of rash onset, so refer promptly; ophthalmic zoster (vesicles on the tip of the nose, Hutchinson sign) is an eye emergency. Postherpetic neuralgia is pain persisting 90 days or more after the rash.

Visceral mimics

Acute coronary syndrome (unstable angina and myocardial infarction) produces pressure, tightness or heaviness behind the sternum, often radiating to the left arm, jaw or between the scapulae, provoked by exertion or emotion and accompanied by dyspnea, diaphoresis, nausea or lightheadedness. Women, older adults and people with diabetes more often present with atypical symptoms: dyspnea, fatigue, epigastric discomfort or interscapular pain alone. Stable angina lasts a few minutes and resolves with rest or nitroglycerin; pain at rest or lasting more than 15 to 20 minutes is an emergency. The chiropractor's job is to recognize the pattern, call emergency services, keep the patient at rest, and (absent allergy or bleeding risk) aspirin may be advised per local protocol.

Aortic dissection causes sudden, tearing or ripping chest pain radiating to the interscapular back, at maximum intensity at onset, in a patient with hypertension, Marfan syndrome or a bicuspid aortic valve. Clues are a blood pressure difference of more than 20 mm Hg between arms, a pulse deficit, a new diastolic murmur of aortic regurgitation, or neurologic deficits. It is an emergency.

Pulmonary embolism presents with sudden pleuritic chest pain, dyspnea, tachycardia, sometimes hemoptysis, in a patient with risk factors: recent surgery or immobilization, long travel, pregnancy or estrogen use, cancer, or a swollen painful calf. Spontaneous pneumothorax occurs in a tall thin young man or a patient with emphysema: sudden unilateral pleuritic pain, dyspnea, reduced breath sounds and hyperresonance on the affected side. Pneumonia and pleurisy give pleuritic pain with fever, cough and crackles or a friction rub. A Pancoast tumor at the lung apex produces shoulder and medial arm pain (C8 to T1), hand intrinsic weakness and Horner syndrome in a smoker; it is often first treated as a thoracic outlet or cervical problem.

Section 3Low back and pelvic presentations

Triage first

About 90 percent of low back pain is nonspecific mechanical pain, roughly 5 to 10 percent is radicular, and only 1 to 2 percent is serious pathology (fracture, cancer, infection, cauda equina syndrome, inflammatory disease, aneurysm or visceral disease). Board vignettes over represent the last group, so read every low back case for its red flags before you name a mechanical diagnosis.

Disc herniation and radiculopathy

Lumbar disc herniation peaks in the 30s to 50s and about 95 percent occur at L4 to L5 or L5 to S1. A posterolateral herniation compresses the traversing root (the lower number): an L4 to L5 disc affects L5, and an L5 to S1 disc affects S1. A far lateral (foraminal) herniation compresses the exiting root (the upper number), so an L4 to L5 far lateral disc affects L4. Pain is worse with sitting, bending, coughing and sneezing (raised intradiscal and intrathecal pressure), and the patient may lean away from the side of the lesion (antalgic list).

The straight leg raise is positive when it reproduces leg pain below the knee between about 30 and 70 degrees. It is sensitive (about 0.9) but not specific; the crossed SLR (raising the well leg reproduces pain in the affected leg) is highly specific (about 0.9) and suggests a large or sequestered fragment. The slump test is slightly more sensitive. A positive femoral nerve stretch (prone knee bend) points to L2 to L4 roots. Centralization of symptoms with repeated movements predicts a good prognosis.

Cauda equina syndrome

Cauda equina syndrome is compression of multiple lumbosacral roots below the conus, usually by a large central L4 to L5 or L5 to S1 disc herniation, and less commonly by tumor, abscess, hematoma or severe stenosis. The clues are saddle anesthesia (perineum, buttocks, inner thighs), urinary retention with overflow incontinence (the most consistent finding, about 90 percent), fecal incontinence or reduced anal tone, sexual dysfunction, and bilateral or alternating sciatica with progressive leg weakness and reduced ankle reflexes. Back pain alone with any new bladder or perineal change is enough to act. This is a surgical emergency: send the patient to the emergency department for same day MRI, because outcomes are best when decompression occurs within about 48 hours, before retention is established. Conus medullaris syndrome (T12 to L1) causes more symmetric, early sphincter dysfunction with mixed upper and lower motor neuron signs and less pain.

Stenosis, spondylolisthesis and the sacroiliac joint

Central lumbar stenosis results from disc bulge, facet hypertrophy and ligamentum flavum thickening, usually at L4 to L5, in patients over 60. Its hallmark is neurogenic claudication: bilateral buttock and leg aching, heaviness or numbness provoked by standing and walking (extension) and relieved by sitting or flexion (the shopping cart sign). The best history items are relief with sitting and absence of pain when seated; a wide based gait and a positive Romberg add specificity. Lateral recess and foraminal stenosis give unilateral radicular pain with similar positional behavior.

Spondylolisthesis is forward slippage of one vertebra on the one below. Isthmic spondylolisthesis follows a pars interarticularis fracture (spondylolysis), almost always at L5 on S1, in adolescents who repetitively hyperextend (gymnasts, divers, football linemen, cricket bowlers). Degenerative spondylolisthesis is due to facet arthrosis with an intact pars, occurs typically at L4 on L5, is more common in women over 50, and often causes stenosis. Clues are extension pain, hamstring tightness, and a palpable step off (above the slipped level in isthmic slips, because the posterior arch stays behind; at the slipped level in degenerative slips). The Meyerding grade (I under 25 percent, II 25 to 50, III 50 to 75, IV 75 to 100, V spondyloptosis) is discussed with imaging.

Sacroiliac joint pain is felt below L5 over the PSIS and buttock, sometimes into the posterior thigh, rarely below the knee. No single test is reliable, but the Laslett cluster (distraction, compression, thigh thrust, sacral thrust, Gaenslen) is useful: three or more positive of the five gives a positive likelihood ratio of about 4, especially when centralization is absent. Pregnancy and the postpartum period, leg length difference, and trauma (falls onto the buttock) are typical stories.

Inflammatory back pain and the mimics

Inflammatory back pain (ASAS criteria) is chronic back pain beginning before age 40, insidious in onset, improving with exercise but not with rest, with pain at night that improves on getting up; four of these five features give a sensitivity of about 77 percent and specificity of about 92 percent. Supporting clues are alternating buttock pain, enthesitis (heel), uveitis, psoriasis, inflammatory bowel disease, a family history, a good response to NSAIDs, raised CRP and HLA B27. The spondyloarthropathies are covered in Chapter 8; the impression step here is to recognize the pattern and refer for rheumatologic evaluation rather than treating it as mechanical pain for months.

Visceral and vascular causes of back pain are nonmechanical: pain that does not change with position or activity, night pain, colicky pain, and pain with systemic symptoms. Abdominal aortic aneurysm (men over 65, smokers, hypertension, family history) may cause deep back, flank or abdominal pain and a pulsatile, expansile mass above the umbilicus; a widened aortic shadow or curvilinear calcification on a lateral lumbar film is a clue. A symptomatic or tender aneurysm, or pain with hypotension and syncope, means rupture or impending rupture: call emergency services. An asymptomatic aneurysm of 3.0 to 5.4 cm is referred for surveillance; 5.5 cm or more, or growth over 1 cm per year, is referred for repair. Avoid forceful lumbar manipulation and deep abdominal work in known aneurysm. Renal colic (writhing, colicky flank pain radiating to the groin with hematuria), pyelonephritis (fever, flank pain, costovertebral angle tenderness), pancreatitis, and gynecologic or prostate disease are discussed with visceral referral in Chapter 8.

Section 4Extremity presentations

How extremity vignettes are built

Extremity cases almost always give you three things: the patient's age, the mechanism (overuse, a specific traumatic event, or insidious onset), and one discriminating examination finding. Combine them and the diagnosis usually falls out. Always ask two further questions: could this be referred from the spine or a viscus (neck for shoulder pain, hip for knee pain, heart or diaphragm for left shoulder pain), and does it need imaging before treatment?

Rules that decide imaging

The Ottawa ankle rules call for ankle radiographs when there is pain in the malleolar zone and any of: bone tenderness along the distal 6 cm of the posterior edge or tip of the lateral malleolus, bone tenderness along the distal 6 cm of the posterior edge or tip of the medial malleolus, or inability to bear weight for four steps both immediately and in the office. Foot radiographs are needed for midfoot pain with tenderness at the base of the fifth metatarsal or the navicular, or inability to bear weight. Sensitivity is close to 100 percent, so a negative rule safely avoids imaging. The Ottawa knee rule calls for a film after acute knee injury in a patient aged 55 or older, with isolated patellar tenderness, fibular head tenderness, inability to flex to 90 degrees, or inability to bear weight for four steps.

Section 5Neurologic presentations

Localize first, then name

Neurologic vignettes reward the habit of localizing the lesion before guessing a disease. Weakness, sensory change and reflexes together place the problem in the brain, cord, root, plexus, peripheral nerve, neuromuscular junction or muscle.

Peripheral neuropathy and entrapment

Diabetic polyneuropathy is the most common neuropathy: symmetric burning or numbness starting in the toes, loss of vibration (128 Hz tuning fork) and of 10 g monofilament sensation, and absent ankle reflexes. Loss of protective sensation means daily foot inspection and podiatry referral because of ulcer risk. Other causes to name from clues are vitamin B12 deficiency (vegan diet, metformin, proton pump inhibitors, gastric surgery, pernicious anemia; posterior column loss with a positive Romberg and macrocytosis), alcohol, hypothyroidism, chemotherapy, and Guillain Barre syndrome, which is an ascending symmetric weakness with areflexia over days, often 1 to 3 weeks after a diarrheal or respiratory illness. Guillain Barre is an emergency because of respiratory failure.

Common entrapments are median nerve at the carpal tunnel (thenar weakness, sensory loss on the radial three and a half digits sparing the thenar eminence, because the palmar cutaneous branch passes above the tunnel), ulnar nerve at the cubital tunnel (little and ulnar ring finger numbness including the dorsal hand, interossei weakness, Froment sign) or at Guyon canal (dorsal ulnar hand spared), radial nerve at the spiral groove (wrist drop, "Saturday night palsy," triceps spared), common peroneal at the fibular head (foot drop with weak eversion, sensory loss on the dorsum, from leg crossing or rapid weight loss), and the lateral femoral cutaneous nerve at the inguinal ligament (meralgia paresthetica: burning anterolateral thigh with no weakness, tight belts, obesity, pregnancy). Distinguish peroneal palsy from L5 radiculopathy: L5 also weakens inversion (tibialis posterior) and hip abduction, and often brings back pain.

Multiple sclerosis, stroke and TIA, Parkinson disease

Multiple sclerosis is a demyelinating disease of the central nervous system, usually in women aged 20 to 40. Episodes are separated in time and space: optic neuritis (painful monocular vision loss with pain on eye movement), internuclear ophthalmoplegia, transverse myelitis, sensory loss, Lhermitte sign, fatigue, and the Uhthoff phenomenon (worsening with heat such as a hot shower). Examination shows upper motor neuron signs. Refer for MRI (periventricular, juxtacortical, infratentorial and cord lesions) and neurology.

Stroke is sudden focal deficit: face droop, arm drift, speech change (BE FAST: balance, eyes, face, arm, speech, time). Middle cerebral artery strokes affect the face and arm more than the leg, with aphasia if dominant; anterior cerebral artery strokes affect the leg; posterior circulation strokes cause vertigo, ataxia, diplopia, dysarthria and crossed signs (ipsilateral face, contralateral body, as in Wallenberg lateral medullary syndrome). Thrombolysis is time limited, so call emergency services and note the time last known well. A TIA resolves, usually within an hour, without infarction; it is a warning, with stroke risk highest in the first 48 hours, so it needs same day emergency evaluation. Amaurosis fugax (a curtain over one eye for minutes) is a carotid TIA.

Parkinson disease is loss of dopaminergic neurons in the substantia nigra, usually after 60. The cardinal signs are bradykinesia plus rest tremor (4 to 6 Hz pill rolling, reduced with action), rigidity (cogwheel or lead pipe) and later postural instability. Early clues include asymmetric onset, micrographia, hypomimia (masked face), reduced arm swing, a soft voice, constipation, loss of smell and REM sleep behavior disorder. The gait is shuffling and festinating with en bloc turning and freezing. Contrast essential tremor: a bilateral action and postural tremor, often familial, improved by alcohol, with head or voice involvement and no bradykinesia. Patients with Parkinson disease are at high risk for falls and osteoporotic fractures.

Vertigo and dizziness

Start by asking what "dizzy" means (spinning vertigo, presyncope, disequilibrium) and then sort by timing and trigger.

The Dix Hallpike test takes the seated patient quickly into supine with the head turned 45 degrees to one side and extended about 20 degrees over the table edge; a positive test is vertigo with upbeating torsional nystagmus toward the lower ear after a short latency, lasting under a minute and fatiguing on repetition. The HINTS examination (Head Impulse, Nystagmus, Test of Skew) is used in continuous vertigo: an abnormal head impulse, unidirectional nystagmus and no skew is reassuring (peripheral), while a normal head impulse, direction changing nystagmus or a skew deviation (any one "INFARCT" finding) suggests stroke, with sensitivity higher than early MRI.

Words worth knowing