Conduction studies along the accessory, long thoracic, dorsal scapular, and thoracodorsal nerves

Latencies to the trapezius (upper and lower portion), serratus anterior, latissimus dorsi and rhomboid muscles were evaluated in 66 subjects. There was a significant relation between latencies and conduction distances to the rhomboid, to the trapezius and to the serraturs anterior muscles but not to the latissimus dorsi muscle, probably due to differences in the organization of the endplate regions in the muscles in question.