Piriformis muscle injury

Findings

Pain in the buttock and towards the greater trochanter at its posterior aspect, where it is tender to palpation. There may also be reffered pain towards the anterior hip, the lateral aspect of the thigh and the knee.However, sometimes the referral of pain is along the inside of the thigh to the knee. Weakness of external rotation of the hip; resisted external rotation of the hip may be painful.

Cause

A tear or strain of the external rotators and hip stabilizers, usually at the insertion on the greater trochanter, although the whole muscle may be involved and may be part of the hip external rotator group that is causing the problem.

Treatment

a) Treatment to calm inflammation, such as ultrasound or laser, and cortisone injections to the insertion. Occasionally injecting the origin may help.

b) Massage techniques to organize scar tissue, such as frictions to the insertion.

c) Stretching of piriformis into internal rotation to prevent scar contraction. Place the affected leg in the "figure-of-four" position and then pull the leg an pelvis together, to flex the hip towards the chest.

d) Isometrics to resist external rotation of the hip- for scar organization and strength.

e) Balancing on one leg without allowing the trochanter to stick out, with the femur in varus. Holding a half squat on one leg, but ensuring the pelvies does not swing forwards on the ipsilateral side, which happens if the piriformis and external rotators are weak and therefore cannot maintain the external rotation of this hip.

f) Orthotics will help limit internal rotation of the hip during function, and thus reduce the work required by the piriformis.

Sports

The running athlete mus learn to run "tall" by stabilizing the pelvis, and not allowing the pelvies and hip to collapse into internal rotation during heel strike and lift off(core training may help). "Running tall" can be achieved only by strengthening and using the external rotators of the hip.

In golf, hitting into a closed left hip may cause a problem - open out the left foot.

This muscle group is extremely important for hip stability and it has to be rehabilitated emphatically.

"Concise guide to sports injuries, 2^nd edition",Churchill Livingstone, Malcolm T.F. Read,  foreword by Bryan English