Question

which argument best justifies the importance of scapular rotation during arm abduction?
it reduces the workload on the rotator cuff muscles.
it allows for greater range of motion in the glenohumeral joint.
it enhances mechanical stability by aligning the glenoid fossa with the humeral head.
it is the primary mechanism for achieving overhead arm position.

Explanation:

Scapular rotation (upward rotation) during arm abduction reorients the glenoid fossa to match the movement of the humeral head. This alignment prevents impingement and enables the arm to move through a full, unobstructed overhead range, which is the core functional benefit that justifies its importance. While it supports stability and reduces cuff load, the key justification is enabling maximum glenohumeral motion.

Answer:

B. It allows for greater range of motion in the glenohumeral joint.