What is the term for a muscle contraction that occurs while the muscle is under constant tension but not changing length?

The term for a muscle contraction that occurs while the muscle is under constant tension but not changing length is known as an isometric contraction. In this type of contraction, the muscle generates force without any movement occurring at the joint, meaning that while the muscle is engaged, its length remains unchanged. This is important in numerous exercises and rehabilitation practices, including Reformer Pilates, where stability and control are critical for maintaining proper alignment and engagement of muscles during various movements.

In contrast, isotonic contractions involve a change in muscle length, either through shortening (concentric contraction) or lengthening (eccentric contraction), which does not align with the definition of a contraction under constant tension. Understanding the different types of muscle contractions, such as isometric, isotonic, concentric, and eccentric, is essential for effective practice and teaching in disciplines like Pilates, as each type of contraction has different applications and benefits for strength training and muscle control.