Most runners have experienced a "pain in the butt" at one time or another, and we are not talking about one's spouse or children. Most butt pains come and go, but some persist and worsen over time. The problem is that not all butt pains are created equal. There are many causes of pain in the gluteal area, the more anatomically correct term. Most runners recognize pain in the lower leg near the heel as Achilles tendonitis. However, a pain in the butt is not as easy to diagnose. Many runners self-diagnose their gluteal pain as sciatica, although when pressed to describe exactly what sciatica is, few can do it. Experience has shown us that what most runners call sciatica is actually pain from another source, and the possibilities are many. Gluteal pain may stem from any of the following: muscle problems, (including strains and "trigger points"), piriformis syndrome, sacroiliac joint restrictions, sciatica, and the list goes on. To complicate matters more, many of these problems may occur simultaneously and are not always easy to distinguish from one another. So the next time one of your running buddies tells you that he or she knows the cause of your butt pain, thank them and then think again.

As runners, we tend to associate our injuries to the spot where it hurts because often that is the source of the injury. Unfortunately, that does not always hold true in the gluteal and hip region because of the unique anatomy and number of muscles, nerves, and joints in this region. The cumulative effects of constant and repeated small stresses over a long time can give rise to the same type of injury as a sudden, traumatic stress. The appearance of pain can be subtle at first, an annoyance to your stride, but may proceed to a debilitating level, hobbling every step. Both muscle strains and trigger points may develop in this manner. Muscle strains may occur in a variety of muscles causing butt pain in hamstrings, gluteal muscles, adductors (muscles bringing legs together), abductors (muscles bringing legs apart), or hip rotators, etc.

Trigger points are hyper-irritable spots in contracted muscle tissue that may be activated by a sudden or long-term overload of the muscle. Trigger points tend to accumulate toxins and waste products of muscle metabolism, thereby leading to irritation. They may have localized tenderness, but a more formidable problem occurs when a trigger point refers pain to an area away from the actual spot of irritation. In other words, you may feel pain in your butt in one area while the actual trigger point causing the pain is somewhere else.

Many runners are misdiagnosed with other problems when trigger points are actually the culprit. Trigger points are very adept at developing secondary to other problems like muscle strains, sacroiliac problems, and sometimes just as a result of a hard workout or race. Runners are becoming more aware of trigger points because of articles about them in running publications and increased awareness among health care providers. Massage therapy, chiropractic, and myofascial therapy have all been successful in the conservative treatment of trigger points.

The sacroiliac (or SI) joints are very important joints in the hip and gluteal region for runners. There is one on each side of the body where the lower back meets the hips (see illustration). Smooth movement of both joints is required for efficient running biomechanics and functioning of muscles around the gluteal and hip region. If a restriction (or subluxation) of the SI joint occurs, pain may result from both the irritated joint itself and from surrounding muscles that may be overworked due to the resulting loss of movement. Trigger points and strains can often develop secondary to a sacroiliac problem. SI problems have also been associated with leg length deficiencies (a short leg), which can lead to other injuries. The importance of this joint to smooth, injury-free running cannot be overstated, as can be seen from the examples above. Also, emphasis needs to be placed on treating the cause of the injury, the restricted SI joint, in order to eliminate all of the other potential symptoms and problems.

Piriformis syndrome and sciatica go hand in hand since sciatica in runners is most often caused by a piriformis problem. The piriformis is a small muscle deep in the gluteal region that rotates the leg outward. The sciatic nerve, the largest nerve in the body, passes beneath the piriformis muscle as it provides nerve supply to the lower extremity muscles (see illustration). If the piriformis muscle becomes contracted from overuse or injury, it may press upon the sciatic nerve causing sciatica, the irritation of the sciatic nerve that leads to pain most often felt in the gluteal region and down the leg. Sciatica usually occurs on one side, indicating underlying biomechanical problems. Problems in the lower back, including disc and nerve- root irritation, may also cause sciatica, but these are less common causes for runners. Correcting underlying biomechanical problems and stretching the piriformis muscle will usually alleviate the pain of sciatica.

Although pain in the butt has a variety of sources and can be complicated by overlapping problems occurring at the same time, it is also important to recognize that not all pain is related to our running. Sometimes an underlying illness or health problem can cause a sensation or pain similar to that of a running injury, except that the pain will not usually be associated with the act of running and does not go away with rest. Sounds simple enough, but many times an underlying condition may be obscured due to the normal aches and pains we sometimes experience in our daily training. It is important to be aware of the actual cause of our pain and not just treat the symptoms that result. No matter how trivial the pain may seem, we should always rule out more serious problems when the normal approaches to healing our running injuries are not working. Fortunately, we runners are a healthy lot and our running pains are usually our biggest health concerns. So remember, next time you have a pain in the butt, think again!

Neil McLaughlin, a graduate of St. John's University and New York Chiropractic College, is a certified chiropractic sports physician and member of the ACA and VCA Council on sports Injuries and Physical Fitness. Ron Kulik, the top area finisher in the 1991 Marine Corps marathon (6th, 2:26), is a graduate of Virginia Tech and New York Chiropractic College. Drs. McLaughlin and Kulik practice at the Commonwealth Chiropractic Center of Reston, where they treat many of the top area runners.