Which term describes a muscle that provides movement through contraction?

Which term describes a muscle that provides movement through contraction?

• A. isometric
• B. eccentric
• C. concentric
• D. isotonic

Answer: (D)

Movement happens when a muscle changes its length as it contracts under a load. Isotonic describes contractions that make a joint move because the muscle changes length under a steady load. In isotonic contractions the muscle can shorten (concentric) to lift a load or lengthen (eccentric) to control a movement. Isometric contractions generate tension without any change in length, so there is no movement. So, describing a muscle that provides movement through contraction fits isotonic, since that term covers contractions that produce joint movement by changing muscle length under load.

Movement happens when a muscle changes its length as it contracts under a load. Isotonic describes contractions that make a joint move because the muscle changes length under a steady load. In isotonic contractions the muscle can shorten (concentric) to lift a load or lengthen (eccentric) to control a movement. Isometric contractions generate tension without any change in length, so there is no movement. So, describing a muscle that provides movement through contraction fits isotonic, since that term covers contractions that produce joint movement by changing muscle length under load.