After a fall on the shoulder with superior shoulder pain, passive shoulder horizontal adduction reproduces the pain. Which ligament is MOST likely injured?

• A. Coracohumeral
• B. Coracoclavicular
• C. Inferior glenohumeral
• D. Superior glenohumeral

Answer: (B)

Cross-body (horizontal) adduction stresses the acromioclavicular joint. If that maneuver reproduces pain after a fall on the shoulder, it points to an AC joint injury. The coracoclavicular ligaments (the conoid and trapezoid) are the key stabilizers that attach the clavicle to the coracoid and prevent vertical displacement of the clavicle at the AC joint. When these ligaments are injured, as in AC joint separation from a fall, pain is elicited by activities that compress or shear the AC joint, such as horizontal adduction.

The other ligaments listed stabilize the glenohumeral joint rather than the AC joint, so they’re less likely to be the primary injured structure in this scenario.