Other Systems and System Interactions

Most patients who walk into a physical therapy clinic bring more than a sore knee or a weak hip: they bring diabetes, thyroid disease, a cancer history, a pregnancy, a pelvic floor problem or a medication list that changes how they respond to exercise. The exam rewards the therapist who notices these other systems, adjusts the plan safely and recognizes when pain is coming from an organ rather than a joint. This chapter covers the metabolic, endocrine, gastrointestinal, genitourinary, oncologic and immune content of the outline, then ties it together with medical screening and the drugs that matter most for exercise, falls and healing.

Section 1Metabolic and endocrine disorders

Diabetes mellitus

Type 1 diabetes is autoimmune destruction of pancreatic beta cells, producing absolute insulin deficiency; onset is usually in youth, and the patient depends on insulin for life. Type 2 diabetes combines insulin resistance in muscle, liver and fat with a gradual failure of insulin secretion; it is strongly linked to obesity and inactivity and is treated with activity, diet, oral or injectable agents and, later, insulin. Gestational diabetes appears during pregnancy and raises the mother's later risk of type 2 disease. The usual diagnostic values are a fasting plasma glucose of 126 mg/dL or higher, a 2 hour oral glucose tolerance value of 200 mg/dL or higher, a random glucose of 200 or higher with symptoms, or an HbA1c of 6.5% or higher. Prediabetes is a fasting glucose of 100 to 125 mg/dL or an HbA1c of 5.7 to 6.4%. A normal fasting glucose is roughly 70 to 99 mg/dL.

Exercise is a cornerstone of diabetes care. A single bout increases glucose uptake by contracting muscle through an insulin independent pathway (translocation of GLUT4 transporters to the cell membrane), and regular training improves insulin sensitivity for 24 to 72 hours after each session. The general recommendation is at least 150 minutes per week of moderate aerobic activity spread over at least 3 days, with no more than 2 consecutive days off, plus resistance training 2 to 3 days per week and flexibility and balance work, especially in older adults.

Glucose safety around exercise

The therapist checks glucose before exercise in any patient who uses insulin or an insulin secretagogue (a sulfonylurea such as glipizide or glyburide, or a meglitinide), because these drugs can drive glucose too low once muscle uptake is added. Metformin, the DPP-4 inhibitors, GLP-1 receptor agonists and SGLT2 inhibitors rarely cause hypoglycemia on their own. Commonly taught thresholds appear below and in Figure 11.1.

Sources differ slightly; for the exam, below 70 is stop and treat, below 100 is snack first for insulin users, and above 250 with ketones is stop.

Hypoglycemia, hyperglycemia and complications

Hypoglycemia (glucose below 70 mg/dL) comes on quickly. Adrenergic signs come first: shakiness, sweating, pallor, tachycardia, anxiety and hunger, followed by neuroglycopenic signs such as headache, confusion, slurred speech, poor coordination, seizure and loss of consciousness. Beta blockers can hide the tremor and tachycardia, leaving sweating as the main clue. A conscious patient receives 15 to 20 g of fast carbohydrate (the "rule of 15"); an unconscious patient receives nothing by mouth and the therapist activates emergency services (glucagon may be given by trained responders). Hyperglycemia develops over hours to days: polyuria, polydipsia, fatigue, blurred vision and, in diabetic ketoacidosis (mostly type 1), fruity breath, nausea, abdominal pain and deep rapid Kussmaul respirations. Hyperosmolar hyperglycemic state occurs mostly in older adults with type 2 disease, with extreme glucose, dehydration and confusion but little ketosis.

Avoid injecting insulin into a limb about to be exercised, avoid exercising at peak insulin action, keep fast carbohydrate at hand, and watch for delayed hypoglycemia after long sessions. Complications drive much of physical therapy care: peripheral neuropathy (loss of protective sensation on the 5.07 Semmes Weinstein monofilament, which delivers 10 g), autonomic neuropathy (orthostatic hypotension, silent ischemia, blunted heart rate response), retinopathy, nephropathy, peripheral arterial disease and poor wound healing. Proliferative retinopathy rules out heavy lifting, Valsalva and head down positions. Patients with neuropathy need daily foot checks and proper footwear; weight bearing exercise is allowed without active ulcers. Diabetes also raises rates of adhesive capsulitis, trigger finger, carpal tunnel syndrome and Charcot neuroarthropathy.

Thyroid disease

Thyroid hormone sets the basal metabolic rate. Hypothyroidism (most often Hashimoto thyroiditis) causes fatigue, cold intolerance, weight gain, constipation, dry skin, bradycardia, depression and slowed relaxation of deep tendon reflexes. The musculoskeletal picture includes proximal muscle weakness and cramping, myalgia, elevated CK, carpal tunnel syndrome from soft tissue swelling, and joint stiffness that can mimic arthritis. Hyperthyroidism (most often Graves disease) causes heat intolerance, weight loss, tremor, anxiety, tachycardia and atrial fibrillation, exophthalmos in Graves disease, and a proximal myopathy affecting the hip and shoulder girdles. Long standing hyperthyroidism accelerates bone loss. A severe crisis (thyroid storm) produces fever, marked tachycardia and delirium and is a medical emergency.

Untreated hyperthyroidism raises resting heart rate and arrhythmia risk, so intensity stays low until the patient is euthyroid; untreated hypothyroidism blunts heart rate response and exercise tolerance. Once levels normalize, standard prescription applies.

Adrenal disorders

Cushing syndrome is cortisol excess, usually from long term corticosteroid medication. Features include central obesity with thin limbs, a rounded face, purple striae, fragile skin with easy bruising, hypertension, hyperglycemia, proximal steroid myopathy, osteoporosis and poor wound healing; exercise stresses proximal strengthening, weight bearing and skin protection during transfers. Adrenal insufficiency (Addison disease when primary) causes fatigue, weakness, hypotension and, in primary disease, hyperpigmentation. Stress or abrupt withdrawal of long term steroids can trigger an adrenal crisis (shock, vomiting, abdominal pain), an emergency.

Osteoporosis

The World Health Organization criteria use the dual energy x-ray absorptiometry T score: normal is −1.0 or above, osteopenia (low bone mass) is between −1.0 and −2.5, and osteoporosis is −2.5 or below. A fragility fracture of the hip or spine establishes osteoporosis clinically regardless of the T score. Risk factors include female sex, age, white or Asian ancestry, low body weight, family history, smoking, excess alcohol, inactivity, early menopause, long term glucocorticoids, hyperthyroidism, rheumatoid arthritis and some anticonvulsants. Vertebral compression fractures are the most common osteoporotic fracture; many are silent and show up as height loss and increasing thoracic kyphosis.

Exercise prescription combines progressive resistance training, weight bearing impact as tolerated, balance training to prevent falls, and posture and spinal extensor strengthening. The key precaution is to avoid loaded spinal flexion, especially flexion combined with rotation (sit ups, toe touches, golf swings without modification, lifting with a rounded back), because anterior vertebral body loading drives wedge fractures. High risk patients learn hip hinging and log rolling. Hip protectors, home hazard reduction and vision checks reduce fall related fractures.

Obesity and metabolic syndrome

Body mass index (kg/m²) classifies adults: 25 to 29.9 overweight, 30 or higher obese, and 40 or higher class III obesity. Metabolic syndrome is three or more of abdominal obesity, high triglycerides, low HDL, high blood pressure and high fasting glucose. Exercise for weight loss favors larger volumes (about 200 to 300 minutes per week) using low impact modes such as cycling and aquatic exercise. Check equipment weight limits, use an adequately sized blood pressure cuff (a small cuff falsely raises the reading), and watch for heat intolerance and sleep apnea.

Section 2Gastrointestinal and genitourinary conditions

Gastrointestinal referral patterns

The viscera have sparse, poorly localized afferent supply that enters the spinal cord at the same segments as somatic structures, so organ disease can present as musculoskeletal pain (Section 4 develops this further). Gastrointestinal pain clues are a relationship to eating, bowel movements or swallowing; associated nausea, vomiting, bloating, heartburn, melena (black tarry stool from upper GI bleeding) or hematochezia (bright red blood); and pain that does not change with posture or movement.

The psoas sign is pain in the abdomen or groin with resisted hip flexion or passive hip extension, suggesting an inflamed structure (appendix, abscess) lying on the psoas. The obturator sign is pain with passive internal rotation of the flexed hip. Both can make abdominal disease look like a hip problem. Inflammatory bowel disease (Crohn disease and ulcerative colitis) is associated with enteropathic arthritis, sacroiliitis and ankylosing spondylitis, so a young adult with inflammatory back pain and chronic diarrhea deserves a question about both.

Renal and urologic referral

Kidney pain (pyelonephritis, stones) is felt in the flank and costovertebral angle; a moving ureteral stone causes colicky pain radiating from flank to groin. Bladder pain is suprapubic, and prostate disease refers to the low back, sacrum and perineum. Fever, dysuria, hematuria, frequency and pain unchanged by spinal motion are the clues; a man over 50 with new back pain and urinary hesitancy or nocturia needs prostate screening.

The pelvic floor

The pelvic floor is a muscular hammock: the levator ani (puborectalis, pubococcygeus and iliococcygeus) and the coccygeus form the pelvic diaphragm, and a superficial layer of perineal muscles lies below. It supports the pelvic organs, keeps the urethra and anal canal closed during rises in abdominal pressure, relaxes for voiding and defecation, contributes to sexual function, and works with the diaphragm, transversus abdominis and multifidus to stabilize the trunk. Innervation is mainly from S2 to S4 through the pudendal nerve and direct sacral branches. Dysfunction may be underactive (weak, poorly timed, after childbirth or with aging) or overactive (high tone, often painful, with dyspareunia, urinary urgency, constipation and pelvic pain). Overactive muscles need downtraining, relaxation, breathing and manual therapy before strengthening; strengthening a high tone pelvic floor can worsen symptoms.

Urinary incontinence

Continence requires a bladder that stores at low pressure, a urethral closure system that stays shut under load, intact neural control and the ability to reach a toilet in time. Each type of incontinence fails a different part of that system (Figure 11.2).

Pelvic floor muscle training is first line treatment for stress and mixed incontinence. The patient first learns to isolate the muscles (squeeze and lift without breath holding, gluteal squeezing or bearing down), aided by cues, palpation by a pelvic health therapist or surface EMG biofeedback. Training combines endurance holds (toward about 10 seconds) and quick flicks, typically 8 to 12 repetitions three times daily for at least 12 weeks, progressed from gravity minimized positions to standing and function. Men after prostatectomy benefit as well. Pelvic organ prolapse causes pressure and a bulge that worsens through the day; pelvic floor training, avoiding straining and physician pessary fitting help.

Pregnancy

Pregnancy raises blood volume about 40 to 50%, cardiac output 30 to 50% and resting heart rate 10 to 20 beats per minute, while blood pressure dips in the second trimester. The hormone relaxin, along with estrogen and progesterone, increases ligament laxity. The center of mass moves anteriorly and superiorly, lumbar lordosis and thoracic kyphosis often increase, and the base of support widens. Common musculoskeletal problems are low back pain, pelvic girdle pain (posterior pelvic pain and symphysis pubis dysfunction, provoked by single leg loading, stairs and rolling in bed), carpal tunnel syndrome from fluid retention, diastasis recti abdominis, and leg cramps. A diastasis is a separation of the rectus abdominis at the linea alba; a gap of more than about 2 cm (often described as two fingerbreadths) during a partial curl up is the usual threshold. Management stresses transversus abdominis and pelvic floor activation, splinting with the hands during curl ups, and avoiding straining and full sit ups until the gap and tension improve.

Healthy pregnant women without contraindications are encouraged to accumulate at least 150 minutes per week of moderate intensity aerobic activity, plus strength training. Because heart rate responses vary, intensity is guided by the rating of perceived exertion (about 12 to 14 on the 6 to 20 scale) or the talk test. Important modifications: avoid prolonged supine positions after the first trimester (the uterus compresses the inferior vena cava, causing supine hypotension; use left side lying or a wedge), avoid contact sports and activities with high fall risk, avoid scuba diving, avoid exercise in heat with overheating, stay hydrated, and avoid prolonged Valsalva.

Pregnancy is a hypercoagulable state, so unilateral calf pain and swelling must be treated as possible deep vein thrombosis. Severe headache, visual changes, epigastric pain and sudden swelling of the face and hands with high blood pressure suggest preeclampsia, which needs urgent medical attention.

Postpartum care

After vaginal delivery, walking, pelvic floor contractions and gentle abdominal work can begin within days. After a cesarean delivery, the patient splints the incision when coughing, log rolls out of bed and avoids lifting more than the baby for several weeks. Return to running is usually deferred until at least about 12 weeks and until she can walk, hop and jog in place without leakage, heaviness or pain. Screen for incontinence, prolapse, diastasis, de Quervain tenosynovitis from infant care, and postpartum depression.

Section 3Oncology and immune conditions

Cancer and its treatments

Exercise before, during and after cancer treatment reduces cancer related fatigue, preserves strength and fitness and improves quality of life. Survivors are advised to avoid inactivity and work toward about 150 minutes per week of moderate aerobic exercise plus resistance training twice weekly, adjusted to treatment phase, blood counts and symptoms. Cancer related fatigue is not relieved by rest; graded aerobic exercise is among its best supported treatments.

Laboratory values that guide exercise

Before each session with a patient on active chemotherapy or after transplant, the therapist reviews the complete blood count. Normal values and the commonly taught exercise thresholds are summarized here and in Figure 11.3. Thresholds vary among institutions and published guidelines, so the exam usually tests the direction of the decision rather than an exact cutoff; when in doubt, consult the medical team.

Bone metastasis, spinal cord compression and other oncologic emergencies

Breast, prostate, lung, kidney and thyroid cancers most often spread to bone, along with multiple myeloma, which arises in the marrow. Bone metastases cause deep, constant pain that is often worse at night and with weight bearing, and they create pathologic fracture risk, especially in the proximal femur, humerus and vertebrae. Patients with known lytic lesions avoid heavy resistance, high impact and end range twisting through the affected bones; resistance is applied proximal to lesions, and weight bearing status follows the physician's orders. Malignant spinal cord compression presents with progressive back pain followed by weakness, sensory level and bowel or bladder changes and is an emergency. Hypercalcemia of malignancy causes fatigue, weakness, confusion, constipation and polyuria. Superior vena cava syndrome (facial and arm swelling, dyspnea, distended neck veins, often from lung cancer) and neutropenic fever (temperature of about 38.0 to 38.3 °C or higher with a low ANC) also require immediate referral.

Lymphedema

Lymphedema is accumulation of protein rich interstitial fluid caused by impaired lymphatic transport. Primary lymphedema results from congenital lymphatic malformation; secondary lymphedema, far more common in practice, follows lymph node dissection, radiation, trauma, infection or venous disease (worldwide, filariasis is a major cause). After breast cancer treatment, risk rises with axillary lymph node dissection (compared with sentinel node biopsy), regional radiation, obesity, infection and higher numbers of nodes removed. The International Society of Lymphology stages are: stage 0 latent (impaired transport, no visible swelling, possible heaviness), stage I pitting edema that subsides with elevation, stage II swelling that does not resolve with elevation, with fibrosis developing and pitting becoming harder to elicit, and stage III lymphostatic elephantiasis with skin changes such as papillomas and hyperkeratosis. A positive Stemmer sign (inability to pinch and lift a fold of skin at the base of the second toe or finger) supports the diagnosis.

Limb volume is measured with circumferential tape measures (a difference of about 2 cm, or about 10% volume, is a common threshold), water displacement or perometry. Complete decongestive therapy has an intensive phase (manual lymphatic drainage, multilayer short stretch bandaging, exercise, skin care) and a maintenance phase (compression garments, self drainage, exercise). Short stretch bandages give low resting and high working pressure. Gradually progressed resistance exercise does not increase lymphedema risk and is recommended. Contraindications to drainage and compression include acute cellulitis, acute DVT, decompensated heart failure and, for compression, an ankle brachial index below about 0.5.

HIV

HIV infects CD4 T lymphocytes; a CD4 count below 200 cells per microliter defines AIDS (normal is about 500 to 1,500). With antiretroviral therapy, therapists mainly see peripheral neuropathy, myopathy, metabolic syndrome, cardiovascular disease, neurocognitive disorder and deconditioning. Aerobic and resistance exercise are safe and do not lower CD4 counts. Standard precautions suffice unless an opportunistic infection such as active tuberculosis requires airborne precautions.

Rheumatologic disease

Autoimmune and inflammatory joint diseases share morning stiffness, systemic signs and flares, and they differ from osteoarthritis in pattern and pathology.

During an acute flare of rheumatoid arthritis the goals are protection and maintenance: rest of inflamed joints, resting splints, gentle active or active assisted ROM once or twice daily to prevent contracture, isometrics rather than resistance through range, energy conservation and joint protection education (use larger joints, avoid sustained grips and positions of deformity). Between flares, aerobic conditioning and progressive strengthening are encouraged; aquatic exercise in warm water is well tolerated. Because of atlantoaxial instability, cervical manipulation and end range cervical techniques are contraindicated, and new symptoms such as occipital headache, paresthesia or gait change in a patient with long standing rheumatoid arthritis need prompt medical evaluation. Long term corticosteroid use adds osteoporosis and skin fragility.

Other rheumatologic conditions: systemic lupus erythematosus (young women; malar rash, photosensitivity, nonerosive polyarthralgia, renal disease, Raynaud phenomenon); ankylosing spondylitis (young men; inflammatory back pain better with exercise, sacroiliitis, reduced chest expansion, HLA-B27; extension, posture and breathing exercise); systemic sclerosis (skin thickening and contractures); polymyalgia rheumatica (older adults; shoulder and hip girdle stiffness with high ESR, linked to giant cell arteritis, which threatens vision); gout (urate crystals, hot first MTP joint); and fibromyalgia (widespread pain and central sensitization, best managed with graded aerobic exercise and education).

Section 4Medical screening and differential diagnosis

Why screening is a core skill

Under direct access, the physical therapist is often the first clinician a patient sees. The examination therefore includes a systems review and a review of systems (fever, chills, night sweats, unexplained weight loss, fatigue) to decide whether the problem fits physical therapy, needs referral alongside therapy, or needs immediate medical care. Screening is not diagnosing disease; it is recognizing when the pattern does not fit a neuromusculoskeletal cause.

How visceral pain behaves

Visceral afferents travel with sympathetic nerves and converge on the same dorsal horn neurons as somatic afferents from skin and muscle at the same segment. The brain, more used to signals from the body wall, projects the pain to the somatic dermatome: this is referred pain. The diaphragm, innervated by the phrenic nerve (C3 to C5), refers to the shoulder, so irritation of its undersurface by blood, bile or an inflamed organ produces shoulder pain. Visceral pain tends to be deep, aching or colicky, poorly localized, and not reproduced or changed by movement, palpation or position, although some musculoskeletal screening tests can still look positive. It often comes with systemic signs and a link to organ function (eating, voiding, breathing, exertion, menstrual cycle).

Red flags

Red flags raise suspicion of serious pathology, and clusters matter more than single items. The best supported single flag for spinal malignancy is a previous history of cancer. Others: age over 50 with new pain, unexplained weight loss, constant pain unrelieved by rest or position, night pain, fever and night sweats, immune suppression or IV drug use, trauma in someone with osteoporosis, long term steroids, failure to improve in about a month, and progressive neurologic deficit.

Deciding what to do

Screening ends in one of three decisions. Treat when the findings fit a neuromusculoskeletal problem. Treat and refer (or refer and communicate) when there is a concurrent medical issue that needs attention but the patient is stable, for example newly found hypertension or a suspicious skin lesion. Refer immediately (activate emergency services or send to the emergency department) when life, limb or neurologic function is at risk: signs of myocardial infarction, stroke, pulmonary embolism, cauda equina syndrome, acute spinal cord compression, septic shock or a symptomatic aneurysm. The exam often asks which finding most warrants referral; choose the one that signals the most serious and time sensitive condition. Documentation should record the findings, the decision and the communication with the physician.

Vital signs are part of every screen. Resting blood pressure of 180/110 mm Hg or higher is commonly given as a reason not to begin exercise and to refer; a resting heart rate above about 120 beats per minute, an oxygen saturation below about 88 to 90%, or an oral temperature at or above about 100 °F (37.8 °C) with systemic symptoms also stop or delay treatment. Blood pressure categories in adults are: normal below 120/80, elevated 120 to 129 systolic with diastolic below 80, stage 1 hypertension 130 to 139 or 80 to 89, and stage 2 hypertension 140/90 or higher; a value above 180/120 is a hypertensive crisis.

Section 5Pharmacology for physical therapists

What the exam expects

The exam tests consequences, not dosing. Ask of every drug: does it change heart rate or blood pressure, cause sedation or orthostasis, affect bleeding, bone, muscle, tendon or skin, or change glucose and electrolytes?

Cardiovascular drugs

Beta blockers (metoprolol, atenolol, carvedilol, propranolol) block beta 1 receptors in the heart, lowering resting and exercise heart rate, contractility and blood pressure. Cardioselective agents act mainly on beta 1; nonselective agents (propranolol) also block beta 2 receptors in the airways and can provoke bronchospasm in people with asthma. Because heart rate rises less with workload, target heart rate formulas based on age predicted maximum are invalid; use the rating of perceived exertion (about 11 to 14 on the 6 to 20 scale), the talk test, or a heart rate range from an exercise test performed on the medication. Beta blockers also mask the tachycardia of hypoglycemia, can cause fatigue and orthostatic hypotension, and are important to take consistently, since abrupt withdrawal can cause rebound tachycardia and angina.

Calcium channel blockers: dihydropyridines (amlodipine) cause peripheral edema and flushing; verapamil and diltiazem also slow heart rate. ACE inhibitors (-pril) cause dry cough, and both they and angiotensin receptor blockers (-sartan) can cause hyperkalemia and dizziness. Loop and thiazide diuretics cause hypokalemia (weakness, cramps, arrhythmia), dehydration and orthostatic hypotension. Nitroglycerin causes headache and hypotension, so the patient sits to take it; the usual teaching is one sublingual dose every 5 minutes up to three, with emergency services called if pain is not relieved after the first dose. Digoxin toxicity causes nausea, visual halos, confusion and arrhythmias, more likely with hypokalemia. Statins can cause myalgia and, rarely, rhabdomyolysis (severe pain, weakness, dark urine), which needs urgent referral.

Anticoagulants and antiplatelet drugs

Warfarin blocks the vitamin K dependent clotting factors (II, VII, IX, X) and is monitored by the INR (target usually 2 to 3). Heparin and low molecular weight heparin are injected; the direct oral anticoagulants (apixaban, rivaroxaban, dabigatran) need no INR monitoring; aspirin and clopidogrel are antiplatelet drugs. All raise bleeding risk: avoid aggressive deep tissue work and manipulation when bleeding risk is high, prevent falls (a head strike needs medical evaluation because of intracranial hemorrhage risk), and watch for bruising, hematuria, melena, hemarthrosis and unusual headache.

A patient with a new DVT may usually begin walking once therapeutic anticoagulation is established, per the physician, because early ambulation does not raise pulmonary embolism risk.

Anti-inflammatory and immune modifying drugs

NSAIDs inhibit cyclooxygenase; they cause gastrointestinal bleeding, kidney injury, fluid retention, higher blood pressure and cardiovascular risk, and may slow bone and soft tissue healing. Black stools or epigastric pain on NSAIDs warrant referral. Acetaminophen has no anti-inflammatory action, and overdose causes liver failure.

Corticosteroids used long term cause osteoporosis, steroid myopathy (proximal weakness), fragile skin, delayed healing, hyperglycemia, hypertension, infection risk, avascular necrosis of the femoral head and adrenal suppression. Repeated local injections can weaken tendons. Methotrexate and biologic agents (such as TNF inhibitors) suppress immunity and can reactivate tuberculosis.

Pain, sedation and the nervous system

Opioids cause sedation, dizziness, constipation, orthostatic hypotension and, at high doses or with other sedatives, respiratory depression; they raise fall risk and can mask pain during exercise. Sessions needing full participation can be timed near peak effect (about 30 to 60 minutes after an oral dose) if the patient is alert. Overdose shows pinpoint pupils, slow breathing and unresponsiveness: activate emergency services, and naloxone may be given.

Antispasticity drugs: baclofen (GABA-B agonist; sedation and weakness, and abrupt withdrawal, especially from an intrathecal pump, causes seizures, hallucinations and high fever), tizanidine (sedation, hypotension, liver toxicity), dantrolene (acts on muscle; generalized weakness, liver toxicity) and botulinum toxin (local effect for about 3 months; pair with stretching, casting and antagonist strengthening). Benzodiazepines and muscle relaxants for spasm cause sedation and falls in older adults.

Levodopa with carbidopa brings wearing off and peak dose dyskinesia over time; schedule therapy in the "on" period, about 45 to 90 minutes after a dose, and watch for orthostatic hypotension. Antidepressants (especially tricyclics) and antiepileptic drugs cause dizziness and falls. Fluoroquinolones (ciprofloxacin, levofloxacin) raise the risk of Achilles tendon rupture, especially in older adults taking corticosteroids.

Diabetes and other endocrine drugs

Exercise should avoid the peak of rapid acting insulin (about 1 to 2 hours after injection) and regular insulin (about 2 to 4 hours). Sulfonylureas cause hypoglycemia; SGLT2 inhibitors cause dehydration; GLP-1 receptor agonists cause nausea and weight loss that includes muscle, which resistance training helps protect. Excess levothyroxine causes hyperthyroid signs and bone loss. Oral bisphosphonates require the patient to stay upright for 30 to 60 minutes after the dose; rare effects include osteonecrosis of the jaw and atypical femoral fracture, which may present as thigh pain.

Medications, aging and falls

Older adults clear drugs more slowly and often take five or more (polypharmacy). Sedative, anticholinergic and blood pressure lowering drugs raise fall risk; the therapist checks orthostatic vitals, screens fall risk and reports new dizziness or confusion after a medication change.

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