How is isotonic/eccentric contraction characterized?

Isotonic contractions involve a change in the length of a muscle while maintaining a constant tension. Eccentric contractions specifically occur when a muscle lengthens under load, such as when lowering a weight or controlling motion against resistance. In this context, option C accurately describes the nature of eccentric contractions; the muscle generates force while it lengthens. This is a critical aspect of eccentric contraction, as it plays a significant role in activities that require deceleration or controlled movement, such as lowering a heavy object or descending stairs. Eccentric contractions are also important for muscle growth and strength training, as they can lead to greater muscle damage and subsequent repair compared to concentric contractions. Understanding this concept is essential for designing effective training programs that leverage the benefits of eccentric movements.