Which of the following is NOT a primary motion of the glenohumeral joint?

• A. Flexion
• B. Pronation
• C. Abduction
• D. Internal rotation

Answer: (B)

The shoulder (glenohumeral) joint moves the arm in six primary directions: flexion and extension, abduction and adduction, and internal and external rotation. Pronation, on the other hand, is a rotation of the forearm around the radius and ulna, turning the palm to face downward. That motion happens at the forearm’s radioulnar joints, not at the ball-and-socket shoulder joint. So pronation is not a primary glenohumeral motion, even though you can perform it while the arm is positioned at the shoulder. The other options—flexion, abduction, and internal rotation—are genuine glenohumeral movements.