origin: anterior iliac spine, upper half of the iliac notch;
insertion:
-
pes arserinus
(anterior & medial surface of
the body of tibia just below the condyle);
action:
- flexion of the thigh at the hip and flexion of the leg at the knee;
- rotation of the femur laterally as it flexes at the hip and knee;
- when knee is flexed, rotates tibia medially;
- reversed origin insertion action:
- when femur and knee are fixed, flexes the pelvis on the hip and gives
anterior stabilization to the pelvis;
- synergists:
biceps femoris,
semitendinosus,
semimembranous,
gracilis;
nerve supply:
-
femoral,
L2,
L3;
- see
innervation of the lower extremity;
