The rectus femoris is one of the four heads that form the quadriceps muscle. It originates with the head directed from the inferior anterior iliac spine and with the head reflected from the supra-acetabular groove at the level of the superior margin of the acetabulum. It is inserted into the patella with a tendon common to the other garments.
Unique of the four heads of the quadriceps to act on two joints, with its action it flexes the thigh and extends the leg. It represents one fifth of the total strength of the quadriceps but is essential in walking. In fact, with its contraction it allows the extension of the hip and the flexion (lifting) of the thigh of the non-supporting limb, collaborating in this case with the ileopsoas, sartorius, tensor of the lata and pectoral fascia. He also collaborates (together with the other heads of the quadriceps) in the extension of the leg of the contralateral limb in the rear thrust action.
Its flexor action on the thigh is all the more powerful as the knee is flexed.
It is innervated by the femoral nerve (L2, L4).
ORIGIN Direct head: lower anterior inferior iliac spine. Reflex head: supra-acetabular sulcus (upper margin of the acetabulum) |  |
INSERTION Patella (some fibers form the patellar ligament and fit into the tuberosity of the tibia) | |
ACTION Extends the leg and participates in flexing the thigh | |
| INNERVATION Femoral nerve (L2, L4) |
| Upper limb | Lower limb | Trunk | Abdomen | Articles |
