What are typical signs of a shoulder AC joint separation in field assessment?

• A. Pain at AC joint, visible step-off or bump, tenderness over AC joint, pain with cross-body adduction; decreased abduct
• B. Numbness in fingers
• C. Pain in the elbow on flexion
• D. Pain under the scapula

Answer: (A)

AC joint separation shows up with localized signs at the top of the shoulder because the injury involves the ligaments that stabilize the clavicle against the acromion. In the field, you’d look for pain directly over the AC joint, and often a visible step-off or bump where the clavicle sits relative to the acromion. The joint is tender to palpation, and pain is elicited when the arm is moved across the chest (cross-body adduction), which compresses the AC joint and recreates the injury’s pain. Because these ligaments are stressed, lifting the arm away from the body can be painful, sometimes limiting abduction and giving the appearance of decreased ability to abduct. Numbness in the fingers would suggest nerve involvement, pain in the elbow on flexion points away from the shoulder joint, and pain under the scapula indicates other regions or structures being affected.