| Pectineus | |
|---|---|
 The pectineus and nearby muscles | |
 Structures passing behind theinguinal ligament (pectineus visible at bottom right.) | |
| Details | |
| Origin | Pectineal line of thepubic bone |
| Insertion | Pectineal line of thefemur |
| Artery | Obturator artery |
| Nerve | Femoral nerve, sometimesobturator nerve |
| Actions | Thigh -flexion,adduction,external rotation |
| Identifiers | |
| Latin | musculus pectineus |
| TA98 | A04.7.02.025 |
| TA2 | 2627 |
| FMA | 22440 |
| Anatomical terms of muscle | |
Thepectineus muscle (/pɛkˈtɪniəs/, from the Latin wordpecten, meaning comb)[1] is a flat, quadrangularmuscle, situated at theanterior (front) part of the upper andmedial (inner) aspect of thethigh. The pectineus muscle is the most anterioradductor of the hip. The muscle's primary action iship flexion; it also produces adduction and external rotation of the hip.
It can be classified in themedial compartment of thigh[2] (when the function is emphasized) or theanterior compartment of thigh (when the nerve supply is emphasized).[3]
The pectineus muscle arises from thepectineal line of thepubis and to a slight extent from the surface of bone in front of it, between theiliopectineal eminence andpubic tubercle, and from the fascia covering the anterior surface of the muscle; the fibers pass downward, backward, and lateral, to be inserted into thepectineal line of the femur which leads from thelesser trochanter to thelinea aspera.
The pectineus is in relation by its anterior surface with the pubic portion of thefascia lata, which separates it from thefemoral artery andvein and internalsaphenous vein, and lower down with theprofunda femoris artery.
By its posterior surface with thecapsule of the hip joint, and with theobturator externus andadductor brevis, theobturator artery andvein being interposed.
By its external border with thepsoas major, thefemoral artery resting upon the line of interval.
By its internal border with the outer edge of theadductor longus.
Obturator foramen is situated directly behind this muscle, which forms one of its coverings.[4]
It forms part of the floor of thefemoral triangle.
The lumbar plexus is formed from the anterior rami of nerves L1 to L4 and some fibers from T12. With only five roots and two divisions, it is less complex than the brachial plexus and gives rise to a number of nerves including the femoral nerve and accessory obturator nerve. The pectineus muscle is considered acomposite muscle as the innervation is by thefemoral nerve (L2 and L3) and occasionally (20% of the population) a branch of theobturator nerve called theaccessory obturator nerve. When it is present, the accessory obturator nerve innervates a portion of the pectineus muscle, entering the muscle on its dorsomedial aspect. The greater nerve to the muscle is the femoral nerve. Unlike the obturator accessory nerve, the femoral nerve is always present and provides the sole innervation for the pectineus muscle in over 90% of cases. The muscle is also innervated by the accessory obturator nerve in the 8.7% of cases in which the nerve occurs.[5]
Its primary functions are contributing tohip flexion and hipadduction. Secondarily, it alsointernally rotates the thigh.[6]
This article incorporates text in thepublic domain frompage 472 of the 20th edition ofGray's Anatomy(1918)
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