The quadratus femoris is a flat, square muscle running horizontally from the ischial tuberosity to the posterior intertrochanteric crest, the most inferior of the six deep external rotators. It is the external rotator most vulnerable to compression between the ischial tuberosity and the lesser trochanter in ischiofemoral impingement syndrome, a condition increasingly recognised as a cause of posterior hip and buttock pain, especially in women.
| Origin | Lateral border of the ischial tuberosity |
|---|---|
| Insertion | Quadrate tubercle on the posterior intertrochanteric crest of the femur |
| Nerve Supply | Nerve to quadratus femoris (L4, L5, S1) |
| Blood Supply | Inferior gluteal artery |
| Actions | External rotation of the hip; Adduction of the hip; Stabilises the posterior hip joint |
|---|
Its horizontal fibre direction makes it a pure external rotator and adductor of the hip, working with the other short external rotators to stabilise the posterior hip capsule and resist internal rotation during weight-bearing activities.
Ischiofemoral impingement syndrome, where the quadratus femoris is compressed between the ischial tuberosity and the lesser trochanter during hip extension, produces posterior hip and buttock pain that is reproduced by the ischiofemoral impingement test of hip extension with adduction. MRI shows quadratus femoris oedema and fatty infiltration in established cases. The condition is more common in women because of their wider pelvis and is associated with coxa valga and prior hip replacement.
The quadratus femoris can be approached with deep pressure applied between the ischial tuberosity and the greater trochanter just below the piriformis level with the hip in neutral, but deep gluteal fat limits reliable palpation.
Compression of the quadratus femoris between the ischial tuberosity and lesser trochanter during hip extension and adduction, producing posterior hip pain reproduced by the ischiofemoral impingement test and confirmed by MRI showing muscle oedema.
