Posterior Thigh Muscles Flashcards
What is the origin of the semitendinosus?
Ischial tuberosity
Where does the semitendinosus insert?
Medial surface of superior part of tibia
What is the innervation of the semitendinosus?
Tibial division of sciatic nerve (L5, S1, S2)
What action does the semitendinosus perform?
Extend thigh; flex leg and rotate it medially when knee is flexed; when thigh and leg are flexed, can extend trunk
What is the origin of the semimembranosus?
Ischial tuberosity
Where does the semimembranosus insert?
Posterior part of medial condyle of tibia; reflected attachment forms oblique popliteal ligament (to lateral femoral condyle)
What is the innervation of the semimembranosus?
Tibial division of sciatic nerve (L5, S1, S2)
What action does the semimembranosus perform?
Extend thigh; flex leg and rotate it medially when knee is flexed; when thigh and leg are flexed, can extend trunk
What is the origin of the biceps femoris?
Long head- ischial tuberoisty
Short head- linea aspera and lateral supracondylar line of femur
Where does the biceps femoris insert?
Lateral side of head of fibula; tendon is split at this site by fibular collateral ligament of kne
What is the innervation of the biceps femoris?
Long head:
tibial division of sciatic nerve (L5, S1, S2)
Short head:
common fibular division of sciatic nerve (L5, S1, S2)
What action does the biceps femoris perform?
Flexes leg and rotates it laterally when knee is flexed; extends thigh (e.g., when starting to walk)
