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sem·i·mem·bra·no·sus (mus·cle)

deep hamstring muscle of posterior (flexor) compartment of thigh; origin, tuberosity of ischium; insertion, medial condyle of tibia and by membrane to tibial collateral ligament of knee joint, popliteal fascia, and via its reflected tendon of insertion (oblique popiteal ligament) lateral condyle of femur; action, flexes knee and rotates leg medially when knee is flexed; and contributes to the stability of extended knee by making capsule of knee joint tense; nerve supply, tibial.
Synonym(s): musculus semimembranosus [TA]


Etymology: L, semi + membrana, membrane
one of three posterior femoral muscles. Situated at the back and medial side of the thigh, it originates in a thick tendon attached to the tuberosity of the ischium and inserts into the horizontal groove on the medial condyle of the tibia. The tendon of insertion passes some fibers laterally and upward to insert on the lateral condyle of the femur and form part of the oblique popliteal ligament behind the knee. The tendon of insertion forms one of the two medial hamstrings. The muscle is innervated by several branches of the tibial part of the sciatic nerve, containing fibers from the fifth lumbar and the first two sacral nerves. The muscle functions to flex the leg, to rotate it medially after flexion, and to extend the thigh. Compare biceps femoris, hamstring muscle, semitendinosus.
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posterior thigh muscle
  • origin lateral part of ischial tuberosity

  • insertion into groove on posteromedial surface of medial condyle of tibia, oblique popliteal ligament of knee joint and the fascia covering popliteus

  • nerve supply tibial nerve

    action as semitendinosus, i.e. hip extensor and knee flexor; internal leg rotation when knee is flexed

References in periodicals archive ?
14] Edema and fatty infiltration scores were calculated in the gluteus maximus and thigh muscles (vastus intermedius, vastus medialis, vastus lateralis, rectus femoris, biceps femoris, semitendinosus, semimembranosus, adductor magnus, sartorius, long adductor, and gracilis).
02 (c) LD, longissimus dorsi; GM, gluteus medius; BF, biceps femoris; TB, triceps brachii; SM, semimembranosus.
8 cm medial to lateral, while the more lateral semimembranosus tendon footprint is crescent-shaped and measures 3.
Popliteal cyst, or Baker's cyst, is caused by a one-way valvular mechanism of the slits between the medial head of the gastrocnemius muscle and the semimembranosus muscle [5].
Popliteal fossa (10) is a triangular area bounded by semitendinosus and semimembranosus tendons medially, biceps femoris muscle laterally and popliteal crease inferiorly.
The fibres of the posterior part of the ligament are short and incline backward as they descend; they are inserted into the tibia above the groove for the Semimembranosus.
The popliteal fossa contains 6 of the numerous bursa of the knee; the bursa beneath the medial head of the gastrocnemius muscle and the semimembranosus tendon is most commonly involved in the formation of a popliteal cyst.
It has been suggested that knee flexion increases activation of the semimembranosus and popliteus cause posterior translation of both the medial and lateral meniscus respectively, potentially dislodging meniscal tissue.
The researchers conducted the study using two beef cuts--the trimmings and semimembranosus muscle--MTG, ground almonds and other necessary ingredients for the formulation.
For additional hip extension, the posterior region of the adductor magnus and the semimembranosus were stimulated bilaterally with intramuscular electrodes in four subjects.
Three muscles that are known collectively as the hamstring muscle cover the posterior thigh consisting of the semitendinosus, the semimembranosus, and the biceps femoris muscles that have a tendency to get shorten.