The elbow is a hinge joint. It connects the further end of the humerus and the nearest ends of two lower-arm bones: the ulna and radius. The elbow flexes and extends the forearm, and rotates the ...

Medically reviewed by Jennifer Steinhoff, MD The humerus is your upper arm bone. It is the longest bone in the upper part of ...

Skeletal muscle is joined to bones. Its cells contract ... which is just a fancy way of saying two muscles that pull in opposite directions. For example, in your arm, your biceps and triceps ...