I know that weakness in several different muscles that can cause scapular winging. How can I tell what weakness is causing my scapular winging?

The clinical presentation of an individual with scapular winging typically includes report of posterior shoulder pain that may radiate down the arm or up the neck. The pain can either be associated with an event or insidious in nature. The individual may experience loss of range of motion into forward flexion or abduction, weakness and a sensation or clicking or catching of the shoulder joint with movement. A skilled clinician will look at scapular position at rest and identify any scapular dyskinesia present with active range of motion of the shoulder or weight bearing on hands in a push up type position. A patient with serratus anterior palsy with exhibit winging at rest and may have pain at rest in periscapular muscles that are attempting to compensate for the weak serratus. Winging is typically accentuated in a wall push up position. If trapezius palsy is involved, wasting or atrophy of the muscle will be visible at the neckline and shoulder drooping will be present. Weakness will be present in overhead positions and winging will become apparent with resisted abduction or external rotation. Winging associated with rhomboid dysfunction is the most difficult to identify. Patients may report medial scapular pain and demonstrate mild winging at rest that increases as they lower their arms from forward flexion.