Pectineus
A short flat muscle at the very top of the inner thigh, doing hip flexion and adduction in equal measure.
- Type
- Muscle
- Region
- Thigh
- Standard name
- m. pectineus
- Origin
- Pecten pubis — the ridge on the superior ramus of the pubis
- Insertion
- Pectineal line of the femur, between the lesser trochanter and the linea aspera
- Actions
- hip flexionhip adduction
- Verify
- TA2 2627 TA98 A04.7.02.025
What it is
A small, flat, quadrangular muscle at the top of the inner thigh, forming part of the floor of the femoral triangle. It runs from the pubic ridge down and back to a short line on the upper femur, just below the lesser trochanter.
It sits between the hip flexors in front and the adductors below, and it is usually classified with the adductor group while behaving like a member of both.
Its nerve supply reflects that ambiguity: it is normally supplied by the femoral nerve like the hip flexors, and sometimes additionally by the obturator nerve like the adductors. Few muscles straddle two groups this literally.
What it does
Flexes the hip and adducts it, roughly equally. Bringing the thigh forward and inward at once — the movement of crossing one leg over the other — is close to its pure action.
What loads it
Hip flexion and adduction under load, shared with iliopsoas and the adductor group. Nothing loads it distinctively.
What is commonly got wrong about it
Which group it belongs to. Sources file it as an adductor, as a hip flexor, or as both, and none of them are wrong — the muscle genuinely does both jobs and its innervation is genuinely variable between people.
That "hip flexor tightness" is one muscle. The front of the hip contains iliopsoas, rectus femoris, sartorius, tensor fasciae latae and this muscle, all crossing it. A stretch reaches several at once, and a sensation of tightness does not identify which.