Pectineus muscle

At a glance

English

Pectineus muscle

Latin (TA2)

Musculus pectineus

System

Muscle

Region

Lower limb

Side

Paired, left and right

About the pectineus muscle

Pectineus is a short, flat, quadrangular muscle high on the front of the medial thigh. Its name refers to the comb-like pecten of the pubis from which it arises. It is the most superior and most anterior of the adductor group, lying between iliopsoas laterally and adductor longus medially, and with them it makes up the femoral triangle's floor.

It takes origin from the pectineal line (pecten) of the superior pubic ramus, between the iliopubic eminence and the pubic tubercle, and from a narrow strip of bone just anterior to it. The fibres pass downwards, backwards and outwards and end on the femur's pectineal line, the ridge leading from the lesser trochanter down to the linea aspera. Behind the muscle lie the hip capsule, obturator externus and adductor brevis, with the obturator vessels between them. In front, separated by the fascia lata, run the femoral artery and vein.

Its position between the flexors and the adductors is reflected in a double nerve supply. The femoral nerve, the nerve of the anterior thigh, always supplies it and is often the only source. In a minority of people an accessory obturator nerve also enters its deep surface, and the obturator nerve proper may send it a twig too. For this reason the muscle is counted by some with the anterior compartment and by others with the medial one.

Pectineus flexes the hip and adducts the thigh, and it can add slight medial rotation. Its flexing role is the stronger, so it works with iliopsoas when the thigh is brought forwards, as in walking, and with the adductors when the legs are drawn together. Blood reaches it mainly from the medial circumflex femoral and obturator arteries. Strain of this muscle is one cause of pain in the groin in kicking sports.

Attachments, action and supply

Origin

Pectineal line (pecten) of the superior pubic ramus and the bone just in front of it.

Insertion

Pectineal line of the femur, below the lesser trochanter.

Action

Flexes and adducts the thigh at the hip; may assist medial rotation.

Nerve supply

Femoral nerve (L2, L3), sometimes with the accessory obturator or obturator nerve.

Blood supply

Medial circumflex femoral artery and obturator artery, with small branches of the femoral artery.