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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 ?
AM = posterior portion of adductor magnus, C = cervical, ES = erector spinae, F = female, GM = gluteus maximus, GMed = gluteus medius, M = male, QL = qua- dratus lumborum, S = subject, SM = semimembranosus, T = thoracic.
Gluteal bolge duzeyinde siyatik sinir yaralanmalarinda, semitendinosus, semimembranosus ve biseps femoris (kisa ve uzun baslari) ile tibial ve peroneal sinir innervasyonlu kaslarda bulgulara rastlanir.
The upper triangle is bounded medially by the semimembranosus muscle and overlying semitendinosus tendon.
The hamstrings comprise three large muscles, namely semitendinosus, semimembranosus and biceps femoris which originate from the ischial tuberosity.
The posterior thigh houses the hamstring group (semitendinosis, semimembranosus, and biceps femoris), which flex the knee, extend the hip, and tilt the pelvis posteriorly.
2011), and they indicate that the H-FABP transcript abundance in semimembranosus and longissimus dorsi muscles of all the researched breeds (Duroc, Pietrain, Pulawska, Polish Large White, and Polish Landrace) of all onto genesis stages (60-, 90-, 12, 50, 180- and 210-d-old) do not exhibit any siginificant changes.
The muscles actuating the model were right medial gastrocnemius (MEDGAS), tibialis anterior, vastus lateralis (VASLAT), semimembranosus (SEMI-MEM), adductor magnus (AMAG1), gluteus medius (GMED1), gluteus maximus (GMAX1), and erector spinae (ESPINAE).
Four "stimulating" (positive) electrodes were placed on the motor points of the semitendinosus, semimembranosus, long head and short head of the biceps femoris (to locate the motor points, the method previously described for the quadriceps was used).
The separate muscles become distinguishable 2 to 10 cm distal to the ischial tuberosity, with the semimembranosus splitting off first.
In the first experiment, three different bovine muscles, Longsissimus-dorsi (LD), Semimembranosus (SM) and Psoas-major (PM) were cut into steaks and placed on display for seven days.
1995), obturator internus (Testut, 1899), semitendinosus and semimembranosus muscles (Bergman et al, 1984; Le Double, 1884) have also been described as attaching to the sacrotuberous ligament (Figure 3 and 4).
The hair on hind legs was removed and the skin of the hind legs sterilized with 75% ethanol, then the whole semitendinosus (ST) and semimembranosus (SM) muscles on the right and left were dissected using scalpels, respectively.