The biceps femoris

The biceps femoris muscle , m. Biceps femoris, is located on the lateral edge of the posterior surface of the thigh . In the muscle, there are two heads, long and short.

The long head, caput longum, starts from the ischial tuberosus as a small flat tendon; Short head, caput breve, - from the lateral lip of a rough line throughout the lower half of the thigh. At the beginning of the long head is the upper bag of the biceps femoris, bursa m. Bicipitis femoris superior. Both heads, joining, form a powerful abdomen, which, going down, passes into a long narrow tendon.

The latter, circling the posterior lateral epicondyle, is attached to the head of the fibula . Part of the bundles, moving horizontally, is fixed to the edge of the upper articular surface of the fibula, and the part, moving slightly downwards, is woven into the fascia of the shank. Between the tendon of the muscle and the fibular collateral ligament lies the lower pad of the biceps femoris, bursa subtendinea m. Bicipitis femoris inferior.

Function: unbends the hip, bends the shin, rotating it outward.

Innervation: the long head is from n. Tibialis and n. Ischiadicus (SI-SII), short - from n. Peroneus communis and n. Ischiadicus (LIV-LV, SI).

Blood supply: aa. Circumflexa femoris medialis, perforantes, poplitea.