Piriformis

Shown above is the pain pattern for the piriformis muscle. Pain may be "referred" to the pelvis and hips. The referred pain is primarily to the sacroiliac region, the buttock, over the posterior hip and sometimes over the proximal two-thirds of the posterior thigh.

Activities Which Aggravate the Pain
Prolonged sitting with the legs in external rotation allows the piriformis muscles to shorten. Foot slips, OB-GYN procedures and twisting sideways while trying to lift heavy objects also contribute to this injury.

Positions that Aggravate Pain from this Muscle
Sitting in one position for prolonged periods. Crossing the injured (painful) thigh over the opposite knee. This may cause pain to run down the back of the leg. Bowel movements may be painful. This figure shows where the muscle is located in the body and how it is attached to the bones of the body.

Anatomy Facts - Piriformis

Muscle Action
For external rotation and also hip abduction when hip flexed to 90 degrees.

Muscle Origin
Arises from the anterior surface of the sacrum.

Muscle Insertion
Inserts on the greater trochanter by means of a rounded tendon.

Muscle Innervation
The first and second sacral nerves. The painful muscle has spots of tenderness called trigger points. These are shown in the next figure.

Trigger Point Locations - Piriformis

You can find your own trigger points by using your thumb or finger to press on the spots shown in the picture. They are not difficult to find. Or you can ask a friend or family member to help you. Press firmly in a step-by-step manner until you find the exact spot that is tender. That is the trigger point.

By pressing firmly on the trigger point, and holding that pressure for several seconds, you will discover the pain lessens dramatically. In fact there are devices that can help you do this. We recommend a device called a "TheraCane" that can be purchased at many stores such as Sammons Preston Medical Equipment that has a mail order catalogue that can be contacted at 1 800 323-5547. The TheraCane is their item # 5244. The TheraCane can use be purchased at many local pharmacies.

Unfortunately this technique, known as acupressure, or shiatsu, provides only temporary relief. Some physicians inject drugs like Novocaine into trigger points, but these offer only temporary relief as well, and can cause scar tissue in the muscle.

Isometric Contraction Testing - Piriformis

A painful muscle will become more painful if it is forcefully contracted (flexed). Use this picture to test this for yourself with the assistance of a friend or family member.

Follow these Directions
Sit on an armless chair while your assistant places his or her hands on the outside of each of your knees. Attempt to spread your legs apart while your assistant prevents you from doing so.