Pectineus
Thigh · Lower Limb
The pectineus is a flat, quadrangular muscle at the upper medial thigh, lying at the junction between the anterior and medial muscle groups. It arises from the pectineal line, or pecten pubis, of the superior pubic ramus and inserts on the pectineal line of the femur, just inferior to the lesser trochanter. It adducts and flexes the hip. Its innervation is usually from the femoral nerve (L2, L3), although it occasionally receives a branch from the obturator nerve, reflecting its transitional position between the two compartments.
Origin, Insertion, Action & Nerve
Origin
Pectineal line (pecten pubis) of superior pubic ramus
Insertion
Pectineal line of femur (inferior to lesser trochanter)
Action
Adduction and flexion of hip
Nerve
Femoral nerve (L2, L3); occasionally obturator nerve
Attachments explained
The Pectineus is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.
Origin
Pectineal line (pecten pubis) of superior pubic ramus
Insertion
Pectineal line of femur (inferior to lesser trochanter)
Action & function
When the Pectineus contracts, it produces the following movement: Adduction and flexion of hip.
As part of the Thigh group of the Lower Limb, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.
Nerve supply & clinical relevance
The Pectineus receives its nerve supply from the Femoral nerve (L2, L3); occasionally obturator nerve. This nerve carries fibres from spinal segment(s) L2, L3.
Because a muscle can only contract when its nerve is intact, injury to the Femoral nerve or to its spinal roots (L2, L3) can weaken or paralyse the Pectineus, impairing the movements it normally produces (adduction and flexion of hip). This is why knowing the innervation is central to localising nerve lesions in clinical practice.
How to study the Pectineus (the OIANS method)
Study the pectineus as the bridge muscle between the hip flexors and the adductors, which explains why it does both jobs. Running from the pecten of the pubis to the pectineal line of the femur, its short oblique fibres pull the thigh toward the midline and forward, giving it its combined adduction and flexion action.
Use its dual nerve supply as the memorable detail: it is normally on the femoral nerve (L2, L3) but can also receive an obturator branch, a fact that mirrors its position on the boundary between the anterior and medial compartments. That transitional supply is the exam-worthy feature that sets it apart from the pure adductors.
Frequently asked questions
Where is the Pectineus located?
The Pectineus is a muscle of the Thigh group, located in the Lower Limb.
What is the origin of the Pectineus?
Pectineal line (pecten pubis) of superior pubic ramus
What is the insertion of the Pectineus?
Pectineal line of femur (inferior to lesser trochanter)
What movements does the Pectineus produce?
Adduction and flexion of hip
What nerve supplies the Pectineus?
Femoral nerve (L2, L3); occasionally obturator nerve
Is the Pectineus free to study in OIANS?
The Pectineus is always free to browse. Its full origin, insertion, action and nerve details are open to everyone in the Muscle Directory. Quiz and Flashcard practice for the Lower Limb is part of the one-time Lifetime upgrade, though; only the Upper Limb decks are free to test yourself on.
Related muscles
Study the Pectineus
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