Final answer:
The best description of scapular upward rotation is when the glenoid fossa rotates superiorly and the inferior scapular angle rotates upward, allowing for upper limb abduction without impingement. The correct option is D.
Step-by-step explanation:
The statement that BEST describes scapular upward rotation is: The glenoid fossa rotates superiorly; the inferior scapular angle rotates upward. Scapular upward rotation is a specific type of scapular movement wherein the glenoid cavity, which is part of the scapula, moves in an upward direction.
This movement is crucial during upper limb abduction, which is the motion of lifting the arm away from the body. In upward rotation, as the glenoid cavity moves up, the medial end of the scapular spine moves downward, allowing for greater range of motion at the shoulder joint without impingement.
Conversely, downward rotation of the scapula occurs during limb adduction and involves the downward motion of the glenoid cavity with upward movement of the medial end of the scapular spine.