During which exercise type is the distal segment free to move?

In open-chain exercises, the distal segment is free to move, which allows for isolated movement of a limb against resistance. This type of exercise typically involves movements where the hand or foot is not fixed to an object and can move through a range of motion independently. Examples include leg extensions or bicep curls, where the extremity moves through space and is not anchored.

This characteristic is crucial because it enables greater emphasis on particular muscle groups and joint motions while minimizing involvement from other muscles or joints. This isolation can be beneficial for rehabilitation purposes or for targeting specific areas of strength development. In contrast, closed-chain exercises involve the distal segment being fixed in place, typically leading to more functional movement patterns that recruit multiple muscle groups and joints working together. Isometric exercises maintain muscle tension without joint movement, and dynamic resistance involves both concentric and eccentric contractions, which may or may not involve a fixed distal segment.