Which contraction occurs when the joint angle changes with the muscle length lengthening, such as lowering a weight?

Which contraction occurs when the joint angle changes with the muscle length lengthening, such as lowering a weight?

• A. Isometric
• B. Eccentric
• C. Concentric
• D. Plyometric

Answer: (B)

The key idea is controlling movement while the muscle lengthens under tension. When you lower a weight, the joint angle changes as the muscle length increases while it still generates force to slow the descent. This active lengthening is called eccentric contraction. It’s different from concentric contraction, where the muscle shortens to lift a load, and from isometric contraction, where the joint angle doesn’t change. Plyometric refers to a training method involving rapid stretch-shortening cycles, not the basic contraction type in a controlled lowering. So the described scenario is eccentric contraction.

The key idea is controlling movement while the muscle lengthens under tension. When you lower a weight, the joint angle changes as the muscle length increases while it still generates force to slow the descent. This active lengthening is called eccentric contraction. It’s different from concentric contraction, where the muscle shortens to lift a load, and from isometric contraction, where the joint angle doesn’t change. Plyometric refers to a training method involving rapid stretch-shortening cycles, not the basic contraction type in a controlled lowering. So the described scenario is eccentric contraction.