The active abduction view: a new maneuvre in the diagnosis of rotator cuff tears.

The plain film views of the shoulder in the case of a fresh rotator cuff tear are usually normal. Reduction of the space between the under surface of the acromion process of the scapula and the humeral head occurs only in late, neglected cases. A new projection is described, the active abduction view of the shoulder, where in many patients with a complete rotator cuff tear the humeral head is closely apposed to the acromion, obliterating the subacromial space. In such a situation, the medial portion of the torn rotator cuff retracts during active abduction, allowing approximation of the two bones.