Contents
Position
- Deep
Origin
- Tuberositas ischiadicum
- Lateral part
Insertion
- Crista intertrochanteric femur
- As well as just inferior to crista intertrochanteric
Main function
- Hip
- Lateral rotation
Secondary function
- Hip
- Adduction
- Pelvis
- Contralateral rotation
Nerve innervation
- Segmental
- L5-S1
- Peripheral
- Plexus sacralis
Arterial supply
- Inferior gluteal artery
- Obturator artery
Palpation
- Patient position
- Prone
- The muscle is deep and is difficult to palpate
- You can palpate the lateral rotator group of which the quadratus femoris is a part of, but it is difficult to isolate the palation of the muscle
- Place your hand just lateral to the sacrum, halfway between SIPS and apex of sacrum
- Ask the patient to flex the knees to 90°
- Give resistance to the patient in a medial rotation direction, so that the patient is giving force towards lateral rotation while you feel for the contraction of the lateral rotator group
- Note that the lateral rotator group also consists of the obturator internus, obturator externus, piriformis, gemellus superior and gemellus inferior. It can be difficult to seperate between these muscles, so be aware that they all will be active during the movement
- Also note that giving too much force can activate the gluteus maximus as well
Strength test
- Patient position
- Sitting with 90° flexion of the knee and the leg hanging freely outside the bench and above the floor
- Place your one hand just lateral to the patient thigh on the side which is to be tested
- Use your other hand to give resistance to the patient
- Place the hand along the medial aspect of the calf and pull the leg into a internally rotated position of the hip so that the patient is giving force towards external rotation
- Note that this test is also testing the quadratus femoris, obturator internus, obturator externus, gemellus superior and gemellus inferior which are all lateral rotators of the hip