Mobility / Joint ROM refers to movement available at joints and is influenced by structures such as ...

• A. Bone, joint capsule, scars, arthritis, and previous injuries.
• B. Muscle strength only.
• C. Metabolic rate.
• D. Respiratory function.

Answer: (A)

Mobility and joint ROM are limited by the structures surrounding a joint, not just by how strong the muscles are. The bones set the basic shape and travel path of the joint; the joint capsule and associated ligaments control stability and how far the joint can move before tension or restraint occurs. Scar tissue from past injuries can form adhesions that restrict sliding and glide within the joint, and arthritis alters the joint surfaces and causes pain and stiffness that reduce ROM. Previous injuries often leave lingering stiffness or altered mechanics, further limiting movement. Because these structural and tissue factors directly constrain how far a joint can move, the option that includes bone, joint capsule, scars, arthritis, and prior injuries best captures what influences ROM. Muscle strength matters for moving through ROM, but it doesn’t by itself determine the available ROM; metabolic rate and respiratory function don’t directly set joint range of motion.