Which type of muscle contraction involves shortening of the muscle?

Concentric contraction is a type of muscle contraction in which the muscle shortens while generating force, allowing movement to occur. This form of contraction commonly occurs during activities such as lifting weights, where the muscle fibers actively contract to overcome resistance. For instance, when performing a bicep curl, as the weight is raised, the bicep muscle shortens, facilitating the upward movement of the forearm.

In contrast, eccentric contraction involves lengthening of the muscle while it still generates force, often occurring during the lowering phase of movements. Isometric contraction refers to muscle activation without any change in muscle length, maintaining a static position. Relaxation is the phase where the muscle fibers return to their resting length and do not contribute to movement or force generation. Understanding the dynamics of concentric contractions is essential for designing effective strength training and rehabilitation programs.