Which of the following is an example of a closed kinetic chain exercise?

A closed kinetic chain exercise involves movements in which the distal segment of the body (i.e., hands or feet) is fixed in space and cannot move freely. This type of exercise typically engages multiple joints and muscle groups simultaneously, promoting functional strength and stability.

In a push-up, the feet are planted firmly on the ground, providing a stable base, while the hands push against a stationary surface. This configuration allows for the engagement of various muscle groups, including the chest, shoulders, triceps, and core, creating a coordinated movement pattern typical of closed kinetic chain exercises.

In contrast, the other options involve open kinetic chain movements, where the distal segment is free to move. For example, in a biceps curl, the hands hold the weight and move independently, and similarly in the machine chest press and seated row, the limbs move while the rest of the body remains stable, but the distal parts are not fixed relative to one another. Therefore, the push-up is the best example of a closed kinetic chain exercise in this selection.