Piriformis syndrome is difficult to diagnose and resistant to therapy. The
existence of piriformis syndrome has been doubted for years. In many instances
it is not even considered as a diagnosis, in others it is ruled out, and in
others yet the symptoms are ascribed to "sciatica" or some other
cause, even if the piriformis is considered as a possible cause. Often the
patient has considered the possibility before the physicians, trainers,
therapists and others have.
Piriformis syndrome may overlap with a variety of other problems including what McCrory et. al. have called a "deep buttock" syndrome. This includes pain in the buttock region, possibly pain in the hamstrings, occasionally pain in the back of the leg that is difficult to locate.
These symptoms of the piriformis muscle dysfunction may be caused by other cllinical entities that include gluteus medius dysfunction, herniated or bulging disks, "sciatica" and other musculoskeletal problems in this area. Scant information is available on piriformis in lay publications, and only a little more in scientific publications. The functioning of the muscle has not been clearly defined and examined in the literature. The location of the muscle does not allow for surface EMG (electromyographical) study. It is quite difficult, if not impossible to place a deep electrode in the muscle for study purposes also.
The anatomical position of the muscle leads one to conclude that it functions in some ways similar to that of the gluteus medius. The major portion of origin of the piriformis is the anterior lateral portion of the sacrum and the insertion is on the upper portion of the femur.
It can be seen that the sciatic nerve passes immediately below the piriformis muscle.
Origin:
Innervation:Piriformis nerve (L5, S1, S2)
Insertion:
Function:
External rotation of the femur (hip)
Some slight extension of the hip, if hip is flexed.
Abduction of the hip, when hip is flexed.
Other External rotators:
Superior gemellus
Obturator internus
Inferior gemellus
Obturator externus
Diagnosis:
The symptoms most often reported are pain when running or walking in the gluteal region. Pain may go down the back of the leg. Dyspareunia is sometimes noted.
Having the patient lie down, flex the knee to 10 - 20 degrees and then have the patient attempt to externally rotate the leg against resistance. Pain may occur with piriformis tendonitis. Direct tenderness will be found in the region of the piriformis tendon over the buttock region.
If there is a positive test to the straight leg lift (causing sciatica like pain), externally rotate the leg to see if this lessens the pain. This could indicate compression of the sciatic nerve by the piriformis.
Be certain to examine the sacroiliac joint also.
Treatment:
Rest is usually recommended. A two to three week break from the sports and activities that cause pain can be very helpful. Relative rest, meaning less intense workouts, and fewer miles is also helpful, and should be used during your return to activity. Like Achilles tendonitis and iliopsoas tendonitis this is a very difficult problem to eliminate.
An approach to treatment should be addressed to determining which of the following possible contributing factors exist and directly working on each of them:
Stretching:
Stretch Piriformis & Abductors
Internal Rotation of the leg stretches.
Seated Leg Cross-Overs
ITB type - side stretch.
Stretching The Hip Flexors:
The "quad stretch" with your leg held backwards like a bow offers some stretch to the anterior hip flexors.
Stretching The Adductors:
Roll legs out with sole of the feet touching.
Stretching The Hamstrings:
Lie on your back. Bring one leg up to your chest. Hold for 30 seconds.
Lower that leg and bring the other leg up to your chest. Hold for 30 seconds.
Bring both legs up to your chest. Hold 30 seconds.
Repeat sequence 3 times.
Strengthening and Stretching
Exercise 1)
While standing left the affected leg. Try to rotate the leg in so that your toes point towards the other leg. Hold ten seconds, repeat 10 times. This is easy to do, and should not aggravate symptoms.
Exercise 2)
After much progress has been made and the patient is relatively asymptomatic, this may be carefully tried. Stand on a 6" platform or step near a rail. The injured leg should be the high side, the uninjured dangles. Bend the upper supported knee slightly, only 10 - 20 degrees and move your body forward. The hip of the upper leg should be higher than that of the lower leg. Move your body forward several inches and then try to move it backwards without touching the lower legs foot to the floor. Owen Anderson has suggested a similar exercise for ITB. It seems well suited to strengthen and stretch many of the external rotators and abductors.
In running, avoid hills and canted surfaces. Shorten your stride and curtail
your speedwork. Also, try a brief rest of a few weeks, while continuuing your
stretching and strenghtening exercises.
Massage Therapy
There have been non-peer reviewed reports of the utility of deep internal massage in women. The piriformis is not in a location easy to reach by this method. It would be found to be deep, posterior and to the side. Kegel exercises have been suggested by some to impact muscles that are adjacent to but functionally quite different than that of the piriformis.
Gentle external massage could be of possible benefit.
References
Beatty RA:"The piriformis musclesyndrome: a simple diagnostic maneuver"Neurosurgery 34(3):512-514,1994
Eibel P:"Pyriformis syndrome" Lancet 2:1220,1987
Jankiewicz JJ, Hennrikus WL, Houkom JA: "The appearance of the Piriformis Muscle Syndrome in Computed Tomography and Magnetic Resonance Imaging" Clin.Orthop. and Rel. Res. 262:205-209, 1991
Papadopoulos SM, McGillicuddy JE, Albers JW:"Unusual cause of piriformis muscle syndrome" Arch.Neurol.47:1144-1146,1990
Pecina M:"Contribution to the etiological explanation of the piriformis syndrome" Acta Anat. 105:181-187,1979
Silver JK, Leadbetter WB. Piriformis syndrome: assessment of current practice
and literature review.
Orthopedics. 1998 Oct;21(10):1133-5.
Sports Med 1999 Apr;27(4):261-74 Nerve entrapment syndromes as a cause of
pain in the hip, groin and buttock. McCrory P, Bell S.
Arch Phys Med Rehabil 2001 Apr;82(4):519-21 Related Articles, Books
Magnetic resonance imaging findings in piriformis syndrome: A case report. Rossi
P, Cardinali P, Serrao M, Parisi L, Bianco F, De Bac S.