Origin
Anterior head—anterior inferior iliac spine
Posterior head—ilium above acetabulum
Insertion
Patella, then by patellar ligament to tuberosity of the tibia
Actions
Extends leg at knee joint, flexes thigh
Nerve
Femoral nerve (L2–L4)
Note
This muscle is used when thigh flexion and leg extension are needed together, such as in kicking a football. In walking, the quadriceps prevent the knee from flexing during heel strike and early support phase
