The arm has three long bones, one in the upper arm and two in the forearm. Stand with your palms facing forward. Then the radius is on the thumb side, and the ulna is on the pinky side. Tap each bone.
Humerus
The armhumerus Ā· radius Ā· ulna
The bones
š” Memory trick: the ulna is on the same side as your pinky (āuā for the underside, by the pinky). The radius rotates. It is on the thumb side, and it lets you turn your palm.
š· Reference image
A real labeled figure to compare with the interactive above.
Bones of the Upper Limb ā OpenStax, CC BY 3.0 (via Wikimedia Commons)
