title: Supernumerary humeral heads of the biceps brachii muscle revisited.
abstract: Supernumerary humeral heads of the biceps brachii muscle were found in 27 (15.4%) of 175 cadavers. They were bilateral in five cadavers and unilateral in 22 (8 left, 14 right), giving a total of 32 examples in 350 arms (9.1%). Depending on their origin and location, the supernumerary heads were classified as superior, infero-medial, and infero-lateral humeral heads. Previous studies were reviewed using this classification. The infero-medial humeral head was observed in 31 of 350 (9%) arms and was therefore the most common variation. The superior humeral head was observed in five (1.5%). The infero-lateral humeral head was the least common variation, observed only in one (0.3%) of 350 arms. A biceps brachii with three heads was observed in 27 of 350 (7.7%) arms and with four heads in five (1.4%) arms.
authors.affiliation: Unit of Anatomy and Embryology, School of Medicine, Autonomous University of Barcelona, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Rodríguez-Niedenführ
authors.forename: Teresa
authors.initials: T
authors.lastname: Vázquez
authors.forename: David
authors.initials: D
authors.lastname: Choi
authors.forename: Ian
authors.initials: I
authors.lastname: Parkin
authors.forename: José R
authors.initials: JR
authors.lastname: Sañudo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001132:Arm / Q000033:anatomy & histology*; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000098:blood supply / Q000294:innervation