Which term describes agonist contracting while antagonist relaxes to allow movement?

Which term describes agonist contracting while antagonist relaxes to allow movement?

• A. Co-contraction
• B. Isometric stabilization
• C. Reciprocal inhibition
• D. Mechanical advantage

Answer: (C)

Reciprocal inhibition is at work when the muscle that is doing the moving (the agonist) contracts while the opposing muscle (the antagonist) relaxes to allow the movement. This neural mechanism lets the joint move smoothly because the antagonist lengthens without resisting the action. Co-contraction would mean both muscles contract together, which stabilizes the joint but prevents movement. Isometric stabilization is a static hold with no joint motion. Mechanical advantage refers to leverage, not the neural pattern of muscle activation.

Reciprocal inhibition is at work when the muscle that is doing the moving (the agonist) contracts while the opposing muscle (the antagonist) relaxes to allow the movement. This neural mechanism lets the joint move smoothly because the antagonist lengthens without resisting the action.

Co-contraction would mean both muscles contract together, which stabilizes the joint but prevents movement. Isometric stabilization is a static hold with no joint motion. Mechanical advantage refers to leverage, not the neural pattern of muscle activation.