What is the first sign of rotator cuff injury during physical examination?

The first sign of a rotator cuff injury during a physical examination is typically pain with active shoulder abduction. This occurs because the rotator cuff is primarily responsible for the stabilization and movement of the shoulder joint, particularly in shoulder abduction. When a rotator cuff injury is present, the patient may experience pain when actively trying to lift their arm away from the body due to inflammation or injury to the muscles and tendons in the rotator cuff.

Active shoulder abduction requires muscular contributions from the supraspinatus, one of the key rotator cuff muscles, making it a sensitive indicator of rotator cuff pathology. When this function is compromised, it is often one of the earliest and most notable findings on examination. Other signs, such as weakness during shoulder flexion or pain during passive range of motion, typically become more apparent as the condition progresses or as the injury worsens. Therefore, the presence of pain upon active abduction serves as an early and reliable sign of rotator cuff injury.