|Muscles of the gluteal and posterior femoral regions. Semimembranosus labeled at bottom left.|
|Semimembranosus labeled at bottom right.|
|Gray's||subject #128 479|
|Insertion:||Medial surface of tibia|
|Artery:||profunda femoris, gluteal artery|
|Action:||Hip extension, Knee flexion|
The semimembranosus, so called from its membranous tendon of origin, is situated at the back and medial side of the thigh.
The tendon of origin expands into an aponeurosis, which covers the upper part of the anterior surface of the muscle; from this aponeurosis muscular fibers arise, and converge to another aponeurosis which covers the lower part of the posterior surface of the muscle and contracts into the tendon of insertion.
It is inserted mainly into the horizontal groove on the posterior medial aspect of the medial condyle of the tibia.
The tendon of insertion gives off certain fibrous expansions: one, of considerable size, passes upward and lateralward to be inserted into the back part of the lateral condyle of the femur, forming part of the oblique popliteal ligament of the knee-joint; a second is continued downward to the fascia which covers the Popliteus muscle; while a few fibers join the tibial collateral ligament of the joint and the fascia of the leg.
The muscle overlaps the upper part of the popliteal vessels.
The semimembranosus is innervated by the tibial part of the sciatic nerve.
- LUC semm
- SUNY Labs 14:st-0408
- SUNY Figs 14:01-07 - "Muscles (hamstrings) of the posterior compartment of the thigh."
- SUNY Figs 14:02-06 - "Muscles that form the superficial boundaries of the popliteal fossa."
- Anatomy at Dartmouth knee/surface/surface4
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