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

The type of muscle contraction that occurs when the muscle shortens under tension is concentric contraction. During concentric contractions, the muscle generates force and shortens in length, which typically happens when performing activities such as lifting weights. This shortening of the muscle pulls on the bones to produce movement at a joint.

In contrast, eccentric contractions involve lengthening of the muscle under tension, as seen when lowering a weight. Isometric contractions occur when the muscle generates tension without changing length, such as holding a weight steady in a fixed position. Passive tension refers to the tension that develops in a muscle when it is stretched without any active contraction occurring. Each type of contraction serves different purposes in movement and stability, but when specifically looking at muscular shortening under tension, concentric is the clear choice.