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

The type of muscle contraction that occurs when the muscle lengthens while under tension is known as eccentric contraction. During an eccentric contraction, the muscle fibers generate force while elongating, which commonly happens when a muscle is actively resisting an external force that exceeds the force the muscle can exert. This type of contraction is frequently observed in activities where muscles must decelerate a movement or control motion, such as when lowering weights or descending stairs. Eccentric actions are crucial for various physical activities and play a significant role in muscle growth, as they can lead to greater muscle damage that stimulates repair and strengthens muscle fibers.

Understanding eccentric contractions is important for athletes and individuals engaged in resistance training, as they can contribute to improved strength and control over movements.