Семимембранозды бұлшық еті: анатомия және функциясы

One of the three hamstring muscles, the most medial: posterior compartment of thigh

The semimembranosus muscle (,/s//ɛ//m//i/,/m//ɛ//m//b//r//ə//'//n//oʊ//s//ə//s///) is the most medial of the three hamstring muscles in the thigh. It is so named because it has a flat tendon of origin. It lies posteromedially in the thigh, deep to the semitendinosus muscle. It extends the hip joint and flexes the knee joint.

The semimembranosus muscle, so called from its membranous tendon of origin, is situated at the back and medial side of the thigh. It is wider, flatter, and deeper than the semitendinosus (with which it shares very close insertion and attachment points). The muscle overlaps the upper part of the popliteal vessels.

The semimembranosus muscle originates by a thick tendon from the superolateral aspect of the ischial tuberosity. The tibial part of the sciatic nerve is also responsible for innervation of semitendinosus and the long head of biceps femoris.

The semimembranosus muscle may be reduced or absent, or double, arising mainly from the sacrotuberous ligament and giving a slip to the femur or adductor magnus.

The semimembranosus muscle extends (straightens) the hip joint. It also flexes (bends) the knee joint. It also helps to medially rotate the knee: the tibia medially rotates on the femur when the knee is flexed. It medially rotates the femur when the hip is extended. The muscle can also aid in counteracting the forward bending at the hip joint.

The semitendinosus muscle may be dry needled.