The elbow is a uniaxial hinge joint. The movements of this joint are described as flexion and extension. Flexion is bending the elbow, as in the lifting part of a biceps curl, and extension is straightening the elbow, as in lowering the weight in a biceps curl. In sport and exercise, flexion and extension at the elbow often occurs in conjunction with flexion and extension or abduction and adduction at the shoulder. For example, in the chin-up, the elbow flexes and the shoulder extends as the body is lifted upward. The forearm radioulnar joint can rotate both internally and externally (also called pronation and supination, respectively). In pronation (internal rotation) from the anatomical position, the radius rotates over the ulna. Supination (external rotation) returns the radius to its normally lateral position.

Click on a thumbnail below to examine flexion and extension at the elbow.

Click on a thumbnail below to examine pronation and supination at the elbow.

Now let's move to the wrist.