 Secondary to serratus anterior palsy, a winged scapula is also caused by trapezius and rhomboid palsy involving the accessory nerve and the dorsal scapular nerve, respectively.Though the most common causes of a winged scapula is due to serratus anterior palsy, and less commonly trapezius and rhomboid palsy, there are still other circumstances that present the ailment.These incidences include direct injuries to the scapulothoracic muscles (i.e.