Which joint type is exemplified by the hips and shoulders?

• A. Hinge joint
• B. Pivot joint
• C. Saddle joint
• D. Ball-and-socket joint

Answer: (D)

Movements of joints are shaped by how the bones fit together. A ball-and-socket joint has a spherical head of one bone fitting into a cup-shaped socket of the other, which gives it the widest, multidirectional range of motion—forward and backward, side to side, and rotational movement. The hips and shoulders fit this pattern, so they allow many directions of movement and circumduction. In contrast, a hinge joint moves mainly in one plane (like opening and closing), a pivot joint rotates around a single axis, and a saddle joint allows two directions with more limited rotation. That's why the hips and shoulders are classic examples of ball-and-socket joints.