Which statement is NOT a contraction type described in the material?

Which statement is NOT a contraction type described in the material?

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

Answer: (D)

The key idea is how the muscle changes length while producing force. Concentric contractions happen when the muscle shortens, like lifting a weight. Eccentric contractions occur as the muscle lengthens under tension, such as slowly lowering that weight. Isometric contractions are when the muscle produces force but doesn’t change length at all, like holding a weight steady. Isotonic describes a movement under a constant external load, and it can involve both shortening and lengthening phases. It’s a way to describe the type of dynamic movement, not a separate contraction category. Because the material lists three specific contraction types—concentric, eccentric, and isometric—the term describing a constant-load dynamic action isn’t treated as its own contraction type. That’s why the statement naming isotonic as a contraction type isn’t aligned with the described terms.

The key idea is how the muscle changes length while producing force. Concentric contractions happen when the muscle shortens, like lifting a weight. Eccentric contractions occur as the muscle lengthens under tension, such as slowly lowering that weight. Isometric contractions are when the muscle produces force but doesn’t change length at all, like holding a weight steady.

Isotonic describes a movement under a constant external load, and it can involve both shortening and lengthening phases. It’s a way to describe the type of dynamic movement, not a separate contraction category. Because the material lists three specific contraction types—concentric, eccentric, and isometric—the term describing a constant-load dynamic action isn’t treated as its own contraction type. That’s why the statement naming isotonic as a contraction type isn’t aligned with the described terms.