What type of muscle contraction is characterized by the muscle lengthening under tension?

The type of muscle contraction characterized by the muscle lengthening under tension is eccentric contraction. During an eccentric contraction, the muscle generates force while gradually elongating, which commonly occurs when it is acting against an external force such as gravity. This is frequently observed in activities like lowering a weight or descending stairs, where the muscle must control the descent while being stretched.

Eccentric contractions play a vital role in absorbing shock and preventing injury, as they help to decelerate movements. This type of contraction is crucial in various athletic activities and rehabilitation processes, as it can enhance muscle strength and endurance. Understanding eccentric contractions is essential for designing effective training and rehabilitation programs in biomechanics.