In a prone stander, orientation to gravity influences what?

• A. Influences muscle tone throughout the trunk and extremities
• B. Affects the perception of sensation
• C. Determine the degree of range of motion available
• D. Is a measure of function

Answer: (C)

Gravity acting through the body in a prone stander changes how much movement a joint can achieve in that posture. When the body is oriented against gravity, external load stretches some tissues and tightens others, shifting the length-tension relationship of muscles, ligaments, and joint capsules. This load can limit or permit different joint angles, so the amount of range of motion available in that position depends on how gravity stretches and restrains the tissues around the joints.

While gravity can influence other things like muscle tone or sensory perception in different contexts, the specific factor that determines how far a joint can move in a prone stander is the degree of range of motion available in that posture.