Long head of biceps femoris
Caput longum musculi bicipitis femoris
- Related terms: Long head; Biceps femoris: Long head; Biceps femoris : Long head; Biceps femoris - Long head; Biceps femoris Long head; Biceps femoris (Long head)
Definition
The long head of the biceps femoris is one of the two heads of the biceps femoris muscle, which is part of the hamstring muscle group. The long head originates from the ischial tuberosity, sharing a common tendon with the semitendinosus muscle. The fibers of the long head form a fusiform belly, which passes obliquely downward and lateralward across the sciatic nerve to end in an aponeurosis which covers the posterior surface of the muscle, and receives the fibers of the short head.
The long head of the biceps femoris has a complex structure, consisting of a tendinous part proximally and a muscular part distally. The muscle fibers of the long head are arranged in a pennate architecture, which varies along its length, with shorter fascicles and larger pennation angles distally compared to proximally.
References
1. This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
2.Descriptive Anatomy of the Insertion of the Biceps Femoris Muscle.Tubbs RS, Caycedo FJ, Oakes WJ, Salter EG.Clinical Anatomy (New York, N.Y.). 2006;19(6):517-21. doi:10.1002/ca.20168.
3.Muscle Architecture Variations Along the Human Semitendinosus and Biceps Femoris (Long Head) Length.Kellis E, Galanis N, Natsis K, Kapetanos G.Journal of Electromyography and Kinesiology : Official Journal of the International Society of Electrophysiological Kinesiology. 2010;20(6):1237-43. doi:10.1016/j.jelekin.2010.07.012.
4.Three-Dimensional Geometry of the Human Biceps Femoris Long Head Measured in Vivo Using Magnetic Resonance Imaging.Schache AG, Ackland DC, Fok L, Koulouris G, Pandy MG.Clinical Biomechanics (Bristol, Avon). 2013;28(3):278-84. doi:10.1016/j.clinbiomech.2012.12.010.
