Winging of the scapula.

Common neurogenic causes of scapular winging are serratus anterior, trapezius and rhomboid palsy. Deformity is minimal in serratus anterior palsy (long thoracic nerve); winging is accentuated by forward elevation and pushing with outstretched arms. In trapezius palsy (spinal accessory nerve), the shoulder droops and winging is accentuated by arm abduction at the shoulder level. Rhomboid weakness (dorsal scapular nerve or C5 root) is best demonstrated by slowly lowering the arms from the forward elevated position.