Which term best describes inability to activate muscles?

• A. Neuromuscular dysfunction
• B. Functional Excursion
• C. Active Insufficiency
• D. Passive Insufficiency

Answer: (A)

Inability to activate muscles points to an issue with neural input to the muscle—the nervous system’s ability to recruit motor units and trigger contraction. When neural drive is impaired, the muscle may not contract even if the person intends to move, which is described as neuromuscular dysfunction. This differs from mechanical length-tension problems: active insufficiency is when a muscle can’t generate enough force because it’s shortened across joints, and passive insufficiency is when a muscle can’t be stretched enough across joints to allow full ROM. Functional excursion refers to the range over which a muscle-tendon unit can shorten and lengthen during movement, not to activation. So the best term for an activation problem is neuromuscular dysfunction.