Lower limb
Quadratus Femoris
Musculus quadratus femoris
- Origin
- Lateral border of the ischial tuberosity
- Insertion
- Intertrochanteric crest of the femur (quadrate tubercle)
- Function
- External rotation of the hip; stabilizes the femoral head in the acetabulum
- Innervation
- Nerve to quadratus femoris (sacral plexus, L4-S1)
- Movement & chain
- Part of the deep external rotator group of the hip along with piriformis, the obturators and the gemelli, active in pelvic stabilization during the stance phase of gait.
- Palpation
- Deep between ischial tuberosity and intertrochanteric crest; palpable inferior to gluteus maximus border during resisted external rotation.
- Clinical
- Ischiofemoral impingement syndrome (narrowing of the space between ischial tuberosity and lesser trochanter causing quadratus femoris muscle edema and buttock pain).
- Segmental innervation
- L4-S1.
- In clinical practice
- Frequent repositioning to prevent trochanteric and heel pressure ulcers; ensure hip dislocation precautions in total hip arthroplasty patients.
- Region in the model
- Lower limb