What best describes eccentric muscle contraction?

Eccentric muscle contraction is characterized by the lengthening of the muscle while it is under tension. This occurs when a muscle produces a force to control the descent of a load or to perform a controlled movement, such as lowering a weight or descending stairs. During this type of contraction, the muscle fibers are activated and generate tension, yet they elongate instead of shortening. This elongation often happens in opposition to an external load, which is greater than the force being produced by the muscle.

Understanding eccentric contractions is essential for trainers as they play a critical role in activities involving movement control and can contribute to muscle strengthening and injury prevention. Muscles typically undergo eccentric contraction during actions such as walking downhill or controlling the speed of a lift, which helps in building muscle strength and endurance through controlled, lengthening contractions.