Winging of the Scapula
Winging of the scapula, or scapula alata, is a failure to hold the medial border of the scapula against the rib cage when pushing forward with the hands. It is most easily observed by asking the patient to push or press against a wall or the examiner’s hand while observing the scapula which lifts away from the posterior chest wall.
Winging of the scapula may be a consequence of weakness of the serratus anterior muscle, usually due to a neuropathy of the long thoracic nerve of Bell, but sometimes as a consequence of brachial plexus injury or cervical root (C7) injury. It may also be of myopathic origin, as in facioscapulohumeral dystrophy.
Weakness of trapezius, particularly the middle trapezius muscle, may also cause winging of the upper part of the scapula, more prominent on abduction of the arm, when the superior angle of the scapula moves farther from the midline. Hence spinal accessory (XI) nerve palsy enters the differential diagnosis.