Anne was running the White Rock marathon in Dallas in 2007. It was a cold, wet day, and by mile 18, she had a "cramp" in her hamstring and into her butt. It continued to get worse and worse as it got colder and colder. First she described that her fourth toe went numb, then the entire bottom of her foot. By the time she got to mile 24, she relates being freezing, wet, miserable, and could not feel her left foot or calf! Quit? Never! It's not even in her vocabulary....Although her running friends that were doing their best to drag her to the finish kept encouraging her, Anne was convinced she had somehow severed her sciatic nerve with the muscle spasm in her butt! What was going on? Piriformis syndrome!
Anne had just experienced a very rude introduction to her piriformis muscle. This muscle arises from the sacrum, passes through the sciatic notch (an opening in the pelvic bone) and attaches to a bony prominence on the side of the thigh bone (greater trochanter). The piriformis muscle acts in outward rotation of the hip. The sciatic nerve exits the spinal cord and passes through the notch in front of the piriformis (in some people the nerve actually passes right through the muscle).
What went wrong that day around White Rock Lake? Anne irritated her piriformis muscle by getting tired (because her pre-race training had been, when she was being honest with herself, less than adequate), which caused her to overpronate, and then she coupled that with running on uneven surfaces and progressively colder temperatures which caused Anne to tighten all of her muscles shivering anyway! As the piriformis became inflamed, it swelled and compressed the sciatic nerve, which caused her foot to become progressively numb.
Most piriformis injuries are caused by overuse or by forced rotation of the hip caused by running on uneven surfaces. You can also irritate your piriformis by falling on your butt and having a direct blow! Pain can usually be elicited early in piriformis syndrome with direct palpation or stretching of the muscle. Anne describes pain enough to jump off the massage table pain when her piriformis was palpated for a month after the marathon!
Why me? Look at your training schedule and you may see an answer. Anne did! Worn out orthotics and not enough miles coupled with an unusually cold day! Other factors come into play like tight hip adductor muscles and excessive pronation. If your adductors are tight, the piriformis has to work harder to abduct the hip before it can help in outward rotation. Also, when your foot excessively pronates (or rolls in) when pushing off, your whole leg rotates inward and the piriformis acts to externally rotate your hip and has to work overtime every time you push off.
Can I keep running with piriformis syndrome? Yes and No. In the early stages, you can run; if you continuously stretch before and after, as well as making sure you warm up the piriformis before running. Decrease your mileage at least 30-50%, slow down and avoid hills and speed work as well as uneven surfaces. If you are finding that the muscle pain is causing you to alter your gait, slow down and start therapy before you end up with another injury. Think of it this way, as the piriformis tightens, the pelvis is actually pulled upward which gives you a functional leg length discrepancy. This can cause major biomechanical injuries to your other foot and leg! In other words, piriformis tightness in the left hip can cause arch or knee pain in the right leg!
What else could it be? The best answer to piriformis syndrome is to get a true diagnosis from a sports medicine physician. Lumbar spine injuries like a herniated disc or degenerative arthritis as well as a pelvic stress fracture can mimic piriformis syndrome. A complete physical exam should highlight the culprit muscle and x-rays or even an MRI may be needed to rule out other possible causes.
Piriformis syndrome is treated with physical therapy, pelvic manipulation, tons of stretching, anti-inflammatories, functional orthotics or shoe inserts to align your gait, deep tissue massage and manipulation, and even the dreaded cortisone shot to the butt in some cases. Very few people need surgical release of the muscle for complete relief of symptoms.
After Anne experienced piriformis syndrome, I bet she will never joke about a pain in the butt again! Be smart! Maintain your core strengthening routine, wear your orhtoics if you pronate excessively, stretch your hip adductors, and strengthen your abductors to ward off the dreaded piriformis syndrome!