Which type of exercise involves an extremity remaining in contact with a stationary surface?

The correct answer is closed kinetic chain exercises. In closed kinetic chain exercises, the extremity (such as an arm or leg) is fixed to a stationary surface, which allows for movement at other joints but keeps one part of the body stable. This type of exercise typically involves weight-bearing activities, where the motion of one segment is dependent on the movement of others.

For example, when performing a squat, the feet remain in contact with the ground, allowing the hips and knees to move while providing stability and proprioceptive feedback. Closed kinetic chain exercises are often beneficial for rehabilitating injuries because they often mimic functional movements and engage multiple muscle groups.

In contrast, isometric exercises involve muscle contraction without joint movement, and while they may involve stable positions, they do not specifically focus on the extremity being in contact with a surface. Open kinetic chain exercises, such as leg extensions, allow the extremity to move freely without a fixed point of contact, which is the opposite of closed kinetic chain exercises. Dynamic exercises encompass any movement that involves muscle contraction and joint movement, which may or may not include a fixed point of contact.