Rectus femoris is one of the anterior thigh muscles forming part of the quadriceps femoris complex. It originates from two sites:
- straight head: from the anterior inferior iliac spine
- reflected head: from a groove superior to the acetabulum
Passing inferiorly, muscle fibres converge with those of the vasti muscles to form the quadriceps tendon that inserts into the patella. Via the ligamentum patellae, the quadriceps muscles indirectly insert into the tibial tuberosity.
Rectus femoris is innervated by the posterior division of the femoral nerve (L3,4).
It acts to extend the leg at the knee joint. Also, rectus femoris is the only part of the quadriceps group to cross the hip joint where it acts to flex the thigh.