Semimembranosus

OriginIschial tuberosityInsertionMedial surface of shaft of tibiaActionsFlexes and slightly medially rotates leg; after flexion, extends thighNerveTibial portion of sciatic nerve (L5, S1, S2)NoteDuring walking or running, the hamstrings are used to slow down the leg...

Semitendinosus

OriginIschial tuberosityInsertionMedial surface of shaft of tibiaActionsFlexes and slightly medially rotates leg; after flexion, extends thighNerveTibial portion of sciatic nerve (L5, S1, S2)NoteDuring walking or running, the hamstrings are used to slow down the leg...

Biceps Femoris

Origin Long head—ischial tuberosity, sacrotuberous ligament Short head—linea aspera, lateral supracondylar ridge, lateral intermuscular septum InsertionLateral side of head of fibula and lateral condyle of tibiaActionsFlexes leg, long head also extends thighNerve Long...

Quadratus Femoris

Origin Lateral border of ischial tuberosity Insertion Below intertrochanteric crest (quadrate line) Actions Laterally rotates thigh Nerve Branch from sacral plexus (L5, S1) Note

Obturator externus

Origin Outer surface of superior and inferior rami of pubis and ramus of ischium surrounding obturator foramen Insertion Trochanteric fossa of femur Actions Laterally rotates thigh Nerve Obturator nerve (L3, L4) Note

Obturator Internus

Origin Pelvic surface of obturator membrane and surrounding bones (ilium, ischium, pubis) Insertion Common tendon with superior and inferior gemelli to medial surface of upper border of greater trochanter Actions Laterally rotates thigh Nerve Nerve from sacral plexus...