Which term describes the resistance to movement when a joint is moved passively?

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

Answer: (C)

Passive tension is the resistance that comes from non-contractile structures when a joint is moved without the muscle actively contracting. Think of the tendons, ligaments, joint capsule, and the stretched parts of the muscle-tendon unit providing a stretch-like resistance as the examiner moves the joint. This distinguishes it from active tension, which is the force produced by muscles during voluntary contraction.

To tie in the other terms: mobility is the overall ability to move a joint through its available range; flexibility refers to how far a muscle group can lengthen to allow that range; and active tension is the force generated by the muscle when it shortens or contracts. An example is a clinician passively moving a knee; the resistance felt is passive tension. If the person were to actively straighten the knee against resistance, the added effort would be active tension.