Which joint has the greatest range of motion and involves the greatest number of movements?

The knee is primarily a modified hinge joint that allows flexion and extension with limited rotation, giving it far fewer movement directions than the shoulder.

The glenohumeral joint permits flexion, extension, abduction, adduction, internal rotation, external rotation, and circumduction, giving it the largest movement repertoire of any joint. Its shallow glenoid socket relative to the large humeral head maximizes mobility at the cost of inherent bony stability. No other joint in the body combines this number of movement directions with this degree of total arc.

The hip is also a ball-and-socket joint with similar movement types, but its deeper acetabular socket provides greater bony stability and restricts total range of motion compared to the shoulder.

The ankle is a hinge-type joint mainly limited to dorsiflexion and plantarflexion with minor inversion and eversion, making its range of motion and movement variety significantly less than the shoulder.