In closed-chain exercises, what happens to the distal end of the working body segment?

In closed-chain exercises, the distal end of the working body segment is in a fixed position and contacts an immovable surface. This is a defining characteristic of closed-chain movements, which typically involve exercises where the feet or hands are stationary against a surface, such as the ground or a wall.

When the distal end is fixed, the movement of the proximal segment takes place, and this results in the activation of multiple muscle groups and joints. The stabilization provided by the fixed point allows for more functional strength development and better coactivation of muscle groups, which can enhance joint stability. Additionally, this type of exercise tends to mimic real-life activities more closely, as many movements in daily life involve the limbs being anchored while the body moves.

In contrast, the other options describe scenarios that do not align with closed-chain exercises. For instance, when the distal end moves freely in space or has the ability to move toward or away from the center, it generally indicates an open-chain exercise, where the limb is not fixed. This distinction is crucial for understanding the mechanisms of movement and the applications of different training strategies in fitness.