Biceps femoris
Last reviewed: 19.11.2021
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The biceps femoris (m.biceps femoris) has two heads - long and short. The long head (caput longum) along with the semitendinous muscle begins on the upper medial surface of the ischial hillock and on the sacro-tubercle ligament, where there is an upper bag of the biceps femoris superior (bursa musculi bicipitis femoris superior). At the level of the lower third of the femur, the long head of the biceps femoris is detached from the semitendinous muscle and connects to the short head, passing into a flat tendon. A short head (caput breve) begins on the lateral lip of the rough line, the upper part of the lateral epicondyle and on the lateral intermuscular septum of the femur. The general tendon of the muscle is directed down the posterolateral side of the knee joint and is attached to the fibular head and the outer surface of the lateral condyle of the tibia. Part of the tendon bundles continues into the fascia of the shin. Between the tendon of the muscle and the fibular collateral ligament there is an inferior subculture bag of the biceps femoris (bursa subtendinea m.bicipitis femoris inferior).
The function of the biceps femoris: along with the other muscles of the posterior group, the thigh extends; flexes the shin in the knee joint; When the knee is bent at the knee joint, it turns outward.
Innervation of the biceps femoris: long head - tibial nerve (SI-SII), short head - common peroneal nerve (LIV-SI).
Blood supply of the biceps femoris muscle: a medial artery, enveloping the femur, perforating the arteries.
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