Which statement correctly differentiates mobility from flexibility?

• A. Mobility is static ROM; flexibility is strength
• B. Mobility is bone density; flexibility is nerve conduction
• C. Mobility and flexibility are identical
• D. Flexibility is the range of motion of muscles and connective tissue; mobility includes control and movement within joints.

Answer: (D)

Mobility versus flexibility hinges on active control. Flexibility is the passive range of motion that soft tissues—muscles, tendons, ligaments, and joint capsules—can span when stretched. Mobility, on the other hand, is the ability to move through that range with coordination, stability, and neuromuscular control inside the joint.

So the statement that flexibility is the range of motion of muscles and connective tissue, while mobility includes control and movement within joints, captures the distinction: flexibility describes tissue extensibility, and mobility includes the active, controlled movement within that range. The other ideas mix in unrelated or incomplete concepts—mobility isn’t just static ROM, flexibility isn’t about strength, and neither bone density nor nerve conduction defines these terms.