Pectineus muscle

The pectineus muscle is a flat, quadrangular muscle, situated at the anterior part of the upper and medial aspect of the thigh.

Action
It is one of the muscles primarily responsible for hip flexion. It also adducts and medially rotates the thigh.

Innervation
Innervation is by the femoral nerve (L2 and L3) and occasionally a branch of the obturator nerve.

Origin and insertion
It arises from the pectineal line of the pubis and to a slight extent from the surface of bone in front of it, between the iliopectineal eminence and tubercle of the pubis, and from the fascia covering the anterior surface of the muscle; the fibers pass downward, backward, and lateralward, to be inserted into a the pectineal line of the femur which leads from the lesser trochanter to the linea aspera.