Semi-membranous muscle

Semimembranous muscle , m. Semimembranosus, is located along the medial edge of the posterior surface of the thigh . The outer edge of the muscle is covered by m. Semitendinosus, which leaves here an imprint in the form of a longitudinal wide sulcus. The inner edge of the muscle is free. The muscle originates from a flattened, powerful tendon from the ischial tuberosity.

Going down, the muscle passes into a flat tendon, which then gradually narrows and rounds, and, circling the medial epicondyle, is directed to the anteromedial surface of the tibia . In this place the tendon becomes wider and divides into three bundles. The inner bundle, located horizontally, terminates on the medial condyle of the tibia, the middle fascicle also reaches the medial condyle, passing into the fascia that covers the popliteal muscle; The outer bundle, approaching the capsule of the knee joint , passes into the oblique popliteal ligament. At the point of divergence of the tendon, a synovial pouch of the semimembranous muscle is formed into separate bundles, bursa m. Semimembranosi.

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

Innervation: n. Tibialis (LIV-LV; SI).

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