Which term describes the protective nervous system tone, contracture, guarding of muscle?

• A. Passive tension
• B. Mobility
• C. Guarding
• D. Active tension

Answer: (D)

Guarding captures the involuntary, protective tightening of muscles that a nervous system uses to shield injured tissues. When a area is irritated or damaged, the muscles around it contract reflexively to splint the region and limit movement. This increased tone can become a sustained contraction (a form of contracture) and leads to diminished range of motion, which is exactly what is described by protective nervous system tone, contracture, and guarding of the muscle.

Passive tension refers to the tension felt in a muscle that is being stretched without active contraction, which doesn’t involve a protective reflex. Active tension is the force produced by deliberate muscle contraction, which is voluntary. Mobility describes the ability to move, not the protective muscle response.