The muscular anatomical variations of the thoracic member are recorded in a series of 180 subjects. Two muscles are supernumerary: a bilateral accessory coraco-brachialis and a unilateral accessory palmaris longus. Two muscles have additional tendons: the extensor carpi radialis brevis and the extensor digitorum.
Behets Wydemans, C., & Dhem, A. (1986). [Anatomical variations at the level of the muscles of the arm]. Archives d’anatomie, d’histologie et d’embryologie normales et expérimentales, 69, 111-117. https://hdl.handle.net/2078.5/206665 (Original work published 1986)