Eccentric activation produces internal torque when the joint moves in which relation to the muscle's action?

Eccentric activation produces internal torque when the joint moves in which relation to the muscle's action?

• A. Perpendicular to the muscle's action
• B. Opposite the muscle's action
• C. In the same direction as the muscle's action
• D. Not related to muscle action

Answer: (B)

Eccentric contraction means the muscle is activated while lengthening, so the force it generates tends to oppose the movement caused by the joint under external load. When the joint moves opposite to the muscle’s action, the muscle’s internal torque acts to slow and control that motion. For example, lowering a weight with the elbow flexors: the biceps lengthen while still active, the elbow extends due to gravity, and the biceps produce torque that resists that extension. So eccentric activation produces internal torque when the joint moves opposite to the muscle’s action.

Eccentric contraction means the muscle is activated while lengthening, so the force it generates tends to oppose the movement caused by the joint under external load. When the joint moves opposite to the muscle’s action, the muscle’s internal torque acts to slow and control that motion. For example, lowering a weight with the elbow flexors: the biceps lengthen while still active, the elbow extends due to gravity, and the biceps produce torque that resists that extension. So eccentric activation produces internal torque when the joint moves opposite to the muscle’s action.