What type of muscle contraction occurs when the muscle lengthens under tension?

The term that describes a muscle contraction occurring while the muscle lengthens under tension is eccentric contraction. This type of contraction typically happens when the muscle is forced to elongate while it is still generating force. For example, during the lowering phase of a squat, the quadriceps muscle lengthens while controlling the descent of the body, which signifies an eccentric contraction.

Eccentric contractions are essential for various movements and play a crucial role in activities that involve controlled movement and deceleration. They are also known to contribute to muscle strengthening and injury prevention, as they can enhance the muscle's ability to withstand stress. Understanding this type of contraction is vital in designing effective training programs, as it focuses on the muscle's capability to absorb force and manage load during dynamic movements.