What type of joint allows for the greatest range of motion?

The ball-and-socket joint allows for the greatest range of motion because it has a rounded end of one bone that fits into a hollow cavity of another bone. This structure enables movement in multiple directions, including rotation, flexion, extension, abduction, and adduction. The design allows the articulating surfaces to move freely in various planes, which is why ball-and-socket joints, such as the shoulder and hip joints, are often referred to as the most mobile type of joint in the human body.

In contrast, hinge joints primarily allow movement in one direction, similar to the motion of a door opening and closing, which limits their range of motion compared to the ball-and-socket joint. Pivot joints allow for rotation around a single axis, further restricting their range of motion to a rotational movement. Ellipsoid joints permit movement in multiple directions but are still constrained compared to the total freedom of movement found in ball-and-socket joints. Thus, the structure and function of the ball-and-socket joint account for its superior range of motion among joint types.