When to worry about shoulder pain with an AC joint injury

The acromioclavicular joint joins the collarbone to the top of the shoulder blade. A fall or direct blow can irritate or stretch its supporting ligaments, causing pain on top of the shoulder, tenderness, swelling, and difficulty lifting the arm across the body. A visible bump may occur, but the severity cannot be judged from appearance alone.

Rest from lifting, contact activity, and movements that sharply increase pain. Support the arm if that is comfortable, and use cold wrapped in a cloth for short periods if it helps swelling. Keep the elbow, wrist, and fingers moving, while avoiding forceful shoulder motion. Arrange follow-up to review movement, strength, and the need for rehabilitation.

Seek prompt assessment if pain or swelling is increasing, the shoulder shape changes after injury, or you cannot lift the arm. Urgent care is appropriate for a cold or pale hand, new tingling or numbness, major weakness, chest symptoms, or severe pain after a fall. Persistent pain or reduced function also deserves review.

Ask which movements are safe, whether the joint appears stable, and how long support or activity limits should continue. Discuss rehabilitation exercises, work or sport restrictions, and whether imaging is useful for your injury pattern.