What best differentiates mobility from flexibility?

• A. Mobility is the static length of muscles; flexibility is joint stability.
• B. Flexibility is the range of motion of muscles and connective tissue; mobility includes control and movement within joints.
• C. Flexibility is strength around joints; mobility is ROM of bones.
• D. Mobility is the amount of time to move; flexibility is intensity.

Answer: (B)

Mobility is about how well a joint can move through its full range with control, stability, and coordinated muscle action. Flexibility is about how far the muscles and connective tissues can lengthen to allow that range. So flexibility describes the passive or tissue-based range of motion, while mobility adds the ability to actively move through that range with proper control.

For example, you might have good hamstring flexibility if the tissues can lengthen enough to reach a certain position. But if you can’t actively move through the hip and knee joints with good control and alignment during a squat, your hip mobility is limited. The distinction hinges on tissue length versus controlled, functional movement within the joint.