The piriformis is a muscle that originates from the anterior (or front) part of the sacrum and inserts into the greater trochanter (the large “bump” on the outside of the upper thigh) of the femur. Its action is mainly to externally rotate (or “turn out”) the femur and hip.
The sciatic is a bundle of nerves composed of nerves from the lower spine (~levels L4-S3) and usually runs it course under the piriformis. Interestingly, it is believed that in roughly fifteen percent of the population, the sciatic nerve actually goes through the piriformis muscle.
Piriformis syndrome occurs when the piriformis is overly contracted, shortened, or tight and puts pressure on the sciatic nerve. The result of this is typically (the proverbial) “pain in the butt” and possibly down the back of the thigh, and sometimes pain that radiates into the low back.
Now, the question remains: “Why is the piriformis overcontracted, shortened, or tight in the first place?”. Well, realize that there are basically two muscles that cross and thus stabilize the sacroiliac (or pelvic) joint on either side. These are the gluteus maximus (or buttock muscle) and the piriformis. Typically when I encounter a patient with piriformis syndrome, I find the gluteus maximus to be under-functioning; i.e.: neurologically inhibited. As a result, the piriformis seems to be left to do the job of stabilizing the sacroiliac joint on its own. Obviously, by design, it was meant to have the help of the gluteus maximus muscle, and without it the piriformis may reflexively over-contract or shorten to give the most support possible. The result is then excessive pressure or irritation to the sciatic nerve. Bear in mind that there can certainly be other causes of piriformis tightening or contraction, however the example just mentioned seems to be the norm in what I’ve encountered.
Standard treatment is generally aimed at stretching the piriformis, in addition to deep massage and perhaps anti-inflammatory medication.
Typically, I’ll look to the reasons behind gluteus maximus muscle inhibition if I find that is the major cause of the tight piriformis. This can include pelvic joint dysfunction, ligament laxity in the pelvic joints, lumbar (low back) and sometimes cervical (neck) spine joint dysfunction, lower extremity (hip, knee, ankle, and/or foot) dysfunction, and in some instances nutritional deficiencies.
I aim to address the cause of the piriformis dysfunction in the first place. I have many patients who do not stretch their piriformis and still do not have piriformis syndrome; so we can be certain that the cause of piriformis syndrome is not a lack of stretching. If it was, everyone who didn’t stretch that muscle would have piriformis syndrome. Don’t get me wrong, stretching is often indicated, however my point is that the cause of the tightness needs to be addressed or this problem will generally recur and perhaps cause other complications.
There may also be a problem with an inhibited priformis on the opposite side or inhibited internal hip rotators contributing to or causing the problem. Because of the inter-relatedness of all parts of the body, there can be any number of primary causes for this condition. This article is meant to be a general introduction into the problem, so I’ll leave it there.
All in all, the muscles that support the pelvis should be evaluated for dysfunction. And the alignment and motion of the pelvic joints and lumbar spine need to be restored. Specialized treatment for ligaments, tendons, and fascia (connective tissue) may also be required. A home stretching and strengthening program may be given to help support the treatment, while helping prevent a future recurrence. Nutritional supplements designed to increase healing and reduce inflammation may also be of benefit.
Strangely enough, doctors used to doubt that piriformis syndrome even existed, but that thinking seems to be obsolete now . Dr. Janet Travell, John F. Kennedy’s doctor certainly believed in the occurrence of piriformis syndrome; as she has been reported to say that it was more common than spinal disc herniations (or “slipped disc”) as a cause of back pain.
Dr. Robert D’Aquila – NYC Chiropractor – Applied Kinesiology