What type of contraction occurs when a muscle contracts but does not produce movement?

• A. Isometric
• B. Isotonic
• C. Isokinetic
• D. Concentric

Answer: (A)

When a muscle contracts but there’s no movement at the joint, the muscle is doing isometric work. The muscle tenses and generates force, but its length doesn’t change, so the joint angle stays the same. This happens in static holds or bracing actions, like pressing your hands together as hard as you can or staying in a fixed posture against resistance.

Other types involve the muscle shortening or lengthening to create movement. If the muscle shortens while contracting, that’s a concentric (isotonic) action and movement occurs. If the muscle lengthens under tension, that’s an eccentric action with movement too. Isokinetic contractions involve constant movement speed, usually with special equipment. Since the scenario specifies no movement, the isometric contraction is the best fit.