the piriformis muscle muscles, piriformis

Great sciatic notch

Ischiel tuberosity

Greater trochanterRecurrent

inguinel branch ofperoneal nerve

Greater tuberosity

Nvoc crest

Peroneal nerve

Sciatic nerve

The piriformis muscle Muscles, piriformis

BERNARD A. TiJ'OORTEN, B.S., D.o.Tucson, Arizona

Because of the far-reachingmanifestations of the piriformismuscle syndrome, knowledge of it willenhance the physician's skill indiagnosing and treating low-backdisorders. The piriformis is the mostprominent of the lateral musclerotators in the gluteal regionand the one most commonly injured.Contracture may result in pressure onthe peroneal and sciatic nerves.Osteopathic manipulative therapy isdirected toward stretching the muscleto relieve its contracture and toestablish freedom of internal andexternal rotation of the thigh.Such therapy is effective in 90 to 95per cent of cases of thissyndrome.

According to Edwards,' the piriformis syn-drome is a neuritis of branches of the sciaticnerve, caused by pressure of an injured orirritated piriformis muscle (Fig. 1). Readingthe article in which this statement occurs madeit evident that the piriformis syndrome wasresponsible for many failures in treating low-back disorders. The purpose of this paper is todiscuss this syndrome and thereby help othersto avoid this pitfall.

The osteopathic musculoskeletal lesion com-plex in man is caused by his inherent weak-

ness in maintaining an upright position witha musculoskeletal system not completelyevolved from quadruped stance. The frame ofHomo sapiens would be supported best by afour-cornered base similar to a cantileverbridge. The biped stance is our major weight-bearing stress. 2 The pelvic girdle, in particu-lar, bears the greatest part of this stress ac-commodation. The pelvis is the foundation ofthe human structure on which the rest of thespinal support is balanced.

Life is characterized by motion and balance.Lack of motion and imbalance are the precur-sors of death at the cellular, tissue, or organlevel or of the entire organism. Life at itssimplest level involves one of two motions—secretion or contraction. Since cellular group-ings form complex organ systems, made up oftissues and organs, man is a delicate balanceof multiple motion systems: Pulmonary-res-

Fig. 1. Muscles and nerves of the posterior right ex-tremity. Adapted from ref. 1, p. 89.

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-01%ViimitpObliquus abdominis

externus

Gluteal fascia

Gluteus maximus

Gluteus medius

Piriformis

Gemellus superior

Ischial tuberosity

Ouadratus femoris

Gluteus maximus

Adductor minimus

Fascia late

II

Obturatorinternus

Gemellusinferior

Grecilis Adductor magnusAdductor longue

Wopsoas

Obturetor internu

Symphysis pubis

Serf orius

Fig. 2. Gluteal muscles, posterior aspect. Adapted fromAtlas of human anatomy, by J. Sobotta, edited byJ. P. McMurrich. G. E. Stechert & Co., New York,1927, vol. 1, p. 223.

Fig. 3. Muscles of the true pelvis and the medial sideof the thigh. Adapted from Atlas of human anatomy,by J. Sobotta, edited by J. P. McMurrich. G. E. Stechert& Co., New York, 1927, p. 224.

piratory, cardiovascular, gastrointestinal, mus-culoskeletal, cerebrospinal fluid, and extra-cellular motion systems.

According to Korr,3 a new concept hasarisen regarding the physiologic mechanism.This concept, quite contrary to the older one,concerns the primary tissue. It was oncethought that internal organs of special func-tion were the primary tissues in the body.However, Korr stated that all body motions,such as those involved in walking, skipping,running, playing, working, and talking, areperformed by the musculoskeletal system. Theinternal organs of special function are merelysupportive.

This paper deals with but a small segmentof the pelvic musculature. More specifically,it considers the effect which contracture ofthe piriformis muscle has upon the remainderof the primary tissue.

By definition, a syndrome is a set of relatedsymptoms. These symptoms, for simplicity,may be divided into subjective complaints andobjective signs.

Anatomy of the gluteal musculatureTo arrive at the diagnosis of piriformis syn-drome and to treat this imbalance effectively,one must understand the anatomy of thistissue (Figs. 2 and 3). The piriformis muscleis a flat muscle, pyramidal in shape, whichlies almost parallel to the posterior margin ofthe inferior border of the gluteus medius

muscle.4 It is situated partly within the pelvisagainst its posterior wall, and partly at theback of the hip joint. It arises from the frontof the sacrum by three fleshy digitations, at-tached to the portions of the bone between thefirst, second, third, and fourth anterior sacralforamina, and to the grooves leading from theforamina. A few fibers also arise from themargin of the greater sciatic foramen, andfrom the anterior surface of the sacrotuberousligament. The muscle passes out of the pelvisthrough the greater sciatic foramen, the up-per part of which it fills, and is inserted by arounded tendon into the upper border of thegreater trochanter behind, but often partlyblended with, the common tendon of the in-ternal obturator and the gemelli.

The piriformis rotates the thigh laterally,abducts it, and, to some extent, extends it.The nerve supply is one or two branches fromthe second sacral nerve or the first and secondsacral nerves.

The piriformis muscle is one of ten musclesof the gluteal region that function together toproduce stability of motion in the pelvis foun-dation on which the body is supported andbalanced. The other nine muscles of the glutealregion are the gluteus maximus, gluteus me-dius, gluteus minimus, tensor fasciae latae,obturator internus, gemellus superior, gemel-lus inferior, quadratus femoris, and obtura-torius externus.

Seven of these muscles are lateral rotators

Journal AOA/vol. 69, October 1969 151/79

Quadratus lumborum

Psoas minor

Quadratus lumborum

Interfransversalislateralis

Ligamentumiliolumbale

Psoas major

Iliacus

PiriformisObturator externus

The piriformis muscle

of the thigh, including the piriformis, whichis the major lateral rotator. Three of thesemuscles, the gluteus medius, the gluteus min-imus, and the tensor fasciae latae, are medialrotators.

The ventral surface of the piriformis mus-cle faces the rectum, the sacral plexus, andthe hip joint. The piriformis is covered dor-sally by the gluteus maximus muscle. It liesbetween the gluteus medius and superior ge-mellus muscles. The sciatic nerve usually pass-es into the thigh between the piriformis andthe superior gemellus. The superior glutealnerve and vessels pass dorsally above the su-perior margin of the piriformis, the inferiornerve and vessels pass below its inferior mar-gin!'

The piriformis muscle is rarely absent, butit is subject to several anatomic variations.Its origin may extend to the first sacral orthe fifth sacral vertebra and to the coccyx.The piriformis may be fused with the gluteusmedius or minimus muscles, or more rarelywith the superior gemellus muscle. Its tendonof insertion may be fused with that of thegluteus medius or the obturator internus mus-cle. Grant 6 reported that, in 12.2 per cent of418 limbs studied, the peroneal nerve perfo-rated the piriformis muscle, dividing it intoupper and lower parts. Rarely it is perforatedby the tibial nerve or even by the sciatic nerve.

Beneath the piriformis muscle lie branchesof the peroneal nerve and deep to this thesciatic nerve. Together these nerves supply theinnervation to the extremity. A mild pressureimposed upon these two nerves by a contrac-tion or contracture of the piriformis musclemay cause irritation, first, on the peronealnerve and secondly, with greater involvement,on the sciatic nerve. By the difference of symp-toms the degree of piriformis involvementmay be discerned.

Fig. 4. Psoas, iliacus, and quadratus lumborum.Adapted front ref. 5, p. 547'.

An allopathic proctologist is reported tohave accidentally cured a complaint of long-standing pelvic and lower extremity pain whileperforming rectal massage. It is more thanprobable that this rectal massage, done post-operatively, relieved the contracture of thepiriformis muscle, thereby relieving the symp-toms of which this patient complained.

From a study of Figure 4, it is obvious thatthrough high posterolateral digital massagethe piriformis muscle may be reached andrelieved of its contracture.

Kopell and Thompson stated that,

The sciatic nerve is vulnerable to an entrapment neu-ropathy as it crosses over the sciatic notch in leavingthe pelvis. . . .A well known anatomical variation isthe passage of the whole or part of the sciatic trunkthrough or over the pyriformis muscle. When a por-tion of the nerve goes through the muscle, the lateraldivision—the part of the nerve that forms the peronealtrunk—usually pierces the muscle. . . .A neuropathybased on direct external trauma at the sciatic notchis uncommon because of the protection afforded bythe overlying gluteal musculature.'

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Regional injury can result from posterior dis-location of the femoral head. Aside from thetrauma caused by penetrating objects such asbullets or shrapnel, probably the most fre-quent injury is that from intramuscular in-jection in the buttock.

Falling on a hard object while in the sittingposition can injure the sciatic nerve. Suddenupward pressure not only can injure the nervebut may pull it down against the sciatic notch.This kind of injury may also cause a herniateddisk from local concentration of forces.

Entrapment of the peroneal nerve by acontracture of the piriformis muscle causingpersistent irritation is a common finding inmany patients with chronic low-back disorders.

Chronic and severe contracture of the piri-formis muscle produces symptoms of sciaticneuralgia and/or neuritis concomitant withinguinal and posterolateral hip symptoms.

Etiologic factorsThe causative factors of injury or irritationto the piriformis muscle with resultant syn-drome production are as follows:

1. Postural stress.—One-leg standing; sit-ting cross-legged, especially ankle crossed overknee; automobile operation, the right leg kepton the accelerator for extended periods inlateral rotation; and sitting on one foot, ap-parently a common habit of younger patients.

2. Acute trauma.—Fracture of the femoralneck; fall or near fall; jumping short dis-tances; sudden stops or starts, as in playingtennis; and direct injuries to the pelvis fromfalls or sitting on pointed objects.

3. Insidious trauma.—Sleeping with one leglaterally flexed; entering and leaving an auto-mobile on one leg; obstetric or urologic pro-cedures in stirrups under general anesthesia;and coital positions.

4. Infection.—Arthritis, tuberculosis, and

malignant bone lesions frequently cause thepiriformis to contract abnormally. Inflamma-tory reactions to injury, such as Legg-Perthesdisease, are very commonly associated entities.

5. Malformation.—Sacral and innominatebone deformities, unilateral coxa vara; dislo-cation of articulations; weak foot with dimin-ished support; simple, unequal development;and epiphyseal injury before maturity.

structural diagnosisThe following are signs of the piriformis syn-drome:

1. Pain in the area of the femoral head andthe greater trochanter.

2. Pain in the inguinal area.3. Local tenderness over the piriformis mus-

cle and tendon.4. Splay-foot attitude, unilateral.5. Sacroiliac joint pain, opposite side.6. Radiation of sciatic pain, usually only to

the knee.7. Pain unrelieved by a change in position.

The patient feels best while on his feet andmoving; he cannot sit, stand, or lie comfort-ably.

8. The prime and foremost persistent ex-ternal or lateral rotation with limitation ofmedial rotation. Pain produced in the hip bymedially rotating the extremity.

9. Shortness of the affected extremity.10. Localized pain with pressure over the

piriformis muscle and tendon.11. Pain and limitation of motion at the

tenth and eleventh dorsal vertebrae.12. Tension in the area of the third and

fourth dorsal vertebrae.13. Pain and limitation of motion at the

second cervical vertebra, on the opposite side.14. A concomitant atlanto-occipital lesion

on the same side, caused by the shortness ofthe affected leg.


Fig. 5. Note lack of internal rotation of right ex-tremity.

TreatmentOsteopathic manipulative therapy will provideeffective management in 90 to 95 per cent ofthe cases of the piriformis syndrome. Thetreatment is directed toward stretching thepiriformis muscle to relieve its contractureand to establish freedom of internal and ex-ternal rotation of the thigh. According toHazzard,8

The principle of exaggeration of the lesion is one thatmay be applied to the treatment of many bony luxa-tions. It consists in so manipulating the parts as totend to further increase their malposition, and in thenapplying pressure to them in such a direction as toforce them back toward normal position at the sametime as the part in question is released from its con-dition of exaggeration.

This motion tension release loosens adhe-sions, relieves entrapment of the nerves, andgains the benefit of the natural recoil of thestructures from their exaggerated position.

In piriformis exaggeration treatment, theleg and thigh are flexed and externally rotatedand held for 1 or 2 minutes, then internal ro-tation is accomplished. This frequently re-lieves the adhesions in the gluteal muscle andthe piriformis specifically.

According to Tasker,9

The pyriformis muscle may contract and compressthe sciatic nerve in its course through the sciaticforamen. The physician holds the pelvis to the tableby pressing on the anterior superior spine of the ilium.The thigh is then strongly adducted.

Another method of relieving the contracture

of the piriformis muscle is to place the patienton his unaffected side with his knees flexedand his thighs perpendicular to the body. Thephysician places his elbow upon the tendonof the piriformis muscle (just posterolateralto the greater trochanter) and gradually ap-plies a steady pressure of 20 to 30 pounds. Thefoot is abducted simultaneously to internallyrotate the thigh and put the piriformis muscleon a stretch. This procedure is continued for1 or 2 minutes or until spasm is alleviated. Itis then repeated two or three times. The pa-tient is again placed in a supine position andmotion testing for improvement of internalrotation is done.

The second phase of the treatment is per-formed with the patient supine. The affectedleg is flexed (leg on thigh, thigh on or nearabdomen) and the knee and distal thigh areadducted and the leg and foot abducted as thethigh and leg are slowly extended. This pro-cedure is repeated two or three times to in-crease internal rotation and stretch of thepiriformis muscle. The pelvis is then balancedand the sacroiliac and lumbosacral articula-tions are normalized. The secondary lesionsare then corrected in the lower and upperdorsal spine and, lastly, the upper cervicalarea.

It is a peculiar side effect that the pelvis andleg length imbalance is corrected by this piri-formis procedure. It is also unusual that anattempt to fix the second cervical segment andto balance the pelvis on routine manipulativeprocedures is ineffective until the piriformiscontracture is released.

Symptoms of the piriformis involvementare present in many patients with low-backproblems, and many of them seek osteopathichelp, specifically for these symptoms.

Secondary effects of the piriformis syn-drome are chronic, stress-induced, and mi-

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grainous headaches; mental confusion; visualdistortion; pronounced limping gait; and tem-porary or permanent work incapacitation.

Osteopathic chemotherapeutic managementof the piriformis syndrome includes manymodalities used to enhance the holding effectof manipulation on the more severe and chron-ically recurring cases. Primary in these chemo-therapies is injection of procaine into thetrigger area. Travell and Kinzler" definedthe trigger area as a small hypersensitive re-gion from which impulses bombard the cen-tral nervous system and give rise to referredpain.

Adams" stated,

Pain, in its severer forms, as for example trigeminalneuralgia, migraine, or the various colics, is one ofthe heaviest crosses the human race has to bear. . . .persistent pain, whether mild or severe, over weeks,months, or years can produce serious and far-reachingsequelae, which affect the patients' work, play, andsleep, alter their personalities, and produce changes inevery phase of their daily lives.

Until recent years physicians as a whole tended tominimize the importance of persistent pain, particu-larly if the cause was not readily apparent.

In discussing the paper by Adams, Barrett"said, "The sympathetic nervous system is adominant factor in pain; except for directnerve trauma, ischemia, or localized hypoxia,it is probably the basis of most pain."

The injection of 2 per cent procaine intoaccurately located trigger points has, in gen-eral, brought relief to patients suffering fromchronic pain or atypical neuralgias. Chronicpain or atypical neuralgia is caused by irrita-tion of peripheral sympathetic fibers foundin the subcutaneous tissue, muscles, fascia ofmuscles, about blood vessels, and in peripheralnerves, attachment of muscles and bony struc-tures and in para- and interspinous vertebralligaments. The atypical neuralgia, occurringin backache, causes the alarm reaction withstress that depletes the adrenal cortex.

Fig. 6. Direct pressure applied to piriformis tendon byoperator's left elbow and simultaneous internal rota-tion of thigh with patient's right leg used as lever.

To continue relief derived from procaineinjections, patients are advised to stop theuse of alcohol and to supplement their dietswith vitamins and minerals. Procaine injec-tions of trigger areas and osteopathic manipu-lative management seem to keep the patientsmore symptom free, happy, and content.

Another means of relieving pain and con-tracture of muscles is to spray the trigger areawith ethyl chloride. The ethyl chloride sprayblocks the trigger mechanism and breaks up,by temporary blocking, the referred pain.This local blocking procedure is a symptomatictreatment that does not affect the cause of thepain but only interrupts the pain-trigger-paincycle.

Using a combination of procaine and long-acting cortisone for injections of trigger areasand directly into the tendon-muscle junctionof the piriformis muscle will, in many in-stances, cause relaxation of contracture andavert referred pain for hours, days, and, some-times, weeks if the trigger area is accuratelylocated and blocked.

Acupuncture has been used for more than5,000 years by the Oriental peoples and, to alesser extent, in this country, but with gen-erally good response. A fine stainless steel pinis pierced into the trigger area (deep to in-hibit, shallow to stimulate). After the triggerzone has been located with a skin resistanceelectronic technique and the trigger has beencarefully pinpointed, it is punctured. Func-


Fig. 7. Internal rotation of thigh with patient in su-pine position and right leg again used as lever.

tion is then improved and referred pain isdiminished or abolished."

Proteolytic enzymes, administered orallyand parenterally, have been used in treatingthe piriformis syndrome with little or no ef-fect. Symptoms persist after discontinuanceof such therapy. Other non-hormonal anti-in-flammatory medications have been institutedwith little, if any, effect on the syndrome.Strong narcotics and analgesic agents provideeffective pain relief for short periods. How-ever, side effects prove to be too great for con-tinuance.

Physical modalities other than manipula-tion which have been used in the treatmentof the syndrome, for the most part, have hadlittle success. Unilateral traction, in the hos-pital and at home, has been unsuccessful. Ul-trasonic therapy has been unsuccessful whenused alone, and precise evaluation of its worthas adjunctive treatment is difficult. Ultrasoundtherapy is useful for dispersing deep triggerzone injections of procaine combined withlong-acting cortisone.

Diathermy has given some relief by increas-ing circulation to the area, but its effect hasbeen of short duration. Application of hot,moist packs relieves the pain caused by con-tracture for 3 to 4 hours and appears to be areasonably good means of preparing the tis-sues for manipulative therapy.

Frequently the patient gives a poor descrip-tion of his pain, and symptoms are vague in

the area of the posterolateral hip and downthe tensor fasciae latae muscle. However,when pressure is placed on the piriformismuscle patients frequently say, "That's thespot." Just as frequently they add, "No oneelse has found that before you. How did youknow where it was?"

The structural problems most commonlyconfused with the piriformis contracture aresacroiliac and lumbosacral lesions. It is truethat one or both of these lesions can occursimultaneously with piriformis contracture,but when this happens symptoms often recursoon after manipulative correction and nor-malization of the low-back imbalances. Fre-quently, the recurrence is caused by lack ofnormalization of the piriformis muscle. A sim-ple technique to exclude the piriformis syn-drome is testing of internal and external rota-tion of the femoral heads by rotation of thefeet internally and externally with the patientin the supine position.

Pathologic conditions producing similarsigns and conditions of objective pain areherniated disk; lumbosacral spondylolisthesis;osteoarthritis of the lumbar spine, the pelvis,and femoral heads; rheumatoid arthritis;gouty arthritis; prostatitis; prostatic malig-nancy; uterine retroversion; carcinoma of theuterus or ovary; obstipation; and cystitis.Other conditions may be present, but theseare the ones most commonly observed.

In a discussion of back pain in French'sDifferential Diagnosis, it is stated that "thecause may be found in any of the main groupsinto which pain in the back may be divided.""The groups are as follows:

1. Spinal. (This term includes all of theskeletal structures of the back.)

2. Pyrexial. Backache may be associatedwith fever caused by diseases such as influ-enza, undulant fever, and smallpox.

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3. Visceral. There may be referred painfrom internal organs which is produced bysuch diseases as appendicitis, pyelitis, hyper-nephroma, uterine disorders, prostate disor-ders, and malignancies in the pelvic viscera.

4. Neurologic. Central nervous system dis-orders such as meningitis, subarachnoid hem-orrhage, poliomyelitis, and syringomyelia maycause backache.

5. Psychologic. In the female dull backacheis frequently psychogenic, being cause by anx-iety and unhappiness. Physical fatigue whenassociated with depression and frustrationmay be responsible.

Case reportsCase 1A 41-year-old white housewife presented her-self for treatment of acute right low-backand hip pain which resulted from riding in atruck with a broken spring in the seat. Ex-amination of the pelvis revealed a shortenedright leg with external rotation and limitedinternal rotation. The patient was unable tosit or stand or lie down comfortably. The painwas alleviated with walking, but not entirely.

Two treatments directed toward the piri-formis contracture restored normal pelvic mo-tion and balance and the patient was symptomfree.

Two recurrences—one, 3 months later, andthe other 7 months later—were treated with alittle less rapid recovery. The second recur-rence was complicated with a migraine head-ache caused by left-sided lesion of the secondcervical vertebra which responded after thethird treatment.

Case 2A 51-year-old male livery stable operator camein for treatment of an acute left wry neck.

Fig. 8. Procedure similar to that shown in Figure 7 forinternal rotation of thigh with right leg used as leverallowing the physician to stand upright. In this pro-cedure care should be taken to avoid injuring themedial meniscus, which is guarded in the procedureshown in Figure 7.

Two or three hours after unloading 10 tonsof baled hay, the patient started to have painin the upper left neck with limitation of rota-tion to the left side.

Examination showed the right leg to beshortened, with external rotation and lockingand tenderness down the right lateral thigh.Three treatments normalized the pelvis andrelieved the stiff neck.

It was interesting to note that the wry neckwas not relieved by manipulative therapy tothe neck and upper back until the piriformiscontracture was alleviated.

Case 3A 52-year-old white male school teacher wasadmitted to the hospital for gallbladder sur-gery. Two weeks after the patient was dis-charged, he experienced severe pain in theleft neck. The patient gave a history of injuryto the neck during a high school football game.This had been compensated for during theintervening years but had occasionally pro-duced discomfort. The stress of the cholecys-tectomy was sufficient insult to render the oldfootball injury acute. On examination, theright hip showed the typical signs of piri-formis contracture with shortening and ex-ternal rotation. After 16 office visits, three tofour times a month, the pelvis was balanced


Fig. 9. Normalization of C2 on side opposite piriformisinvolvement. The cervical lesion was directly caused bythe piriformis contracture.

and the left side of the neck corrected. Thestructure was considered normalized and com-pensated at this time.

Case 4A 64-year-old plumber presented himself withpain in the left hip and left leg which he hadinitially experienced after slipping in a ditchsome 6 years previously. The pain recurredfor no known reason and was quite severe. Thepatient was symptom free after the third officevisit. He is now treated at monthly intervalsto maintain his functional balance.

Case 5A 71-year-old retired white man presentedwith symptoms of leg cramps. On structuralexamination, the patient was found to havesymptom-free pelvic imbalance and right piri-formis syndrome. He was placed on a regimenof oral calcium and vitamin D and given gen-eral osteopathic manipulative treatments.After the third visit, the leg cramps were con-trolled and the piriformis syndrome was eradi-cated. The patient claimed that not only hadhis leg cramps disappeared but he also sleptbetter and was relieved of chronic constipationand occasional dull headaches—a prime exam-ple of long-standing, symptom-free piriformissyndrome that was well compensated.

Case 6A 54-year-old white, male carpenter com-

plained of headaches over the left eye andright sciatic pain to the knee. No history ofrecent injury was elicited. Four manipulativetreatments, directed toward the piriformiscontracture, eliminated the sciatic pain andheadaches.

Case 7A 29-year-old white secretary presented withsymptoms of chronic sinusitis and right low-back pain.

She had seen other doctors and had hadmuch medical treatment.

At the age of 15 years, she had sustainedan injury to the pelvis, while playing softball.Sliding into third base she had suffered severeexternal rotation of the right leg. A ligamen-turn teres fracture of the right femoral headwas evident. Continued osteopathic care atsemi-monthly intervals, for the past 5 years,has maintained this patient free of symptomsother than minor low-back pain and minimalsinus congestion.

Case 8A 52-year-old white, male furniture storeowner, presented with symptoms of rightbrachial neuralgia and duodenal ulcers. Thepatient refused all medical care, other thanvitamins and antispasmodics. He was an ad-vocate of health foods and natural methodsand wanted osteopathic manipulative therapyin its purest form. Examination of this patientshowed, aside from the upper dorsal and middorsal lesion, a compensated and symptom-freeright piriformis syndrome. After four treat-ments the symptoms of the brachial neuralgiaand ulcers of the duodenum disappeared, andthe patient now occasionally has right hip andleg pain and left neck pain, under stress of hisbusiness. These symptoms did not occur priorto treatment.

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The patient was told that correct motionand balance, with occasional pain from stress,is better than a compensated structural im-balance that is symptom-free. The piriformissyndrome, in this case, accounted for the dor-sal lesion that caused the sympathomimeticduodenal ulcer production. Whether one shouldtrade an upset stomach for a pain in the hipis a moot question.

Case 9A 55-year-old white, retired business execu-tive presented with a complaint of low-backpain and right hip and leg pain. On examina-tion, the patient was found to have osteoar-thritis in the lumbar spine and sacroiliacs anda piriformis syndrome on the right side. Thepiriformis syndrome was caused by the pa-tient's repeated left body rotation in playinggolf. Two treatments resolved the syndrome.The one recurrence required only one addi-tional manipulative treatment.

Case 10A white, female accountant presented herselfat my office in the spring of 1960. She was 46years old at the time and had a menopausalsyndrome. Routine care was given to minimizeher hormonal imbalance, thyroid deficiency,and calcium depletion. Routine osteopathic ma-nipulative treatment was rendered at monthlyintervals until the patient flew to Michiganto drive back a new automobile. On her returntrip, she contracted influenza, and halfwayhome her left hip produced intense pain andsciatic radiation to the toes.

Immediately after her arrival, the patientwas hospitalized with fever, pulmonary con-gestion, and general debility. She was ex-tremely agitated and unable to walk becauseof the pain in the left hip. After 5 days oftreatment with sedatives, muscle relaxants,

Fig. 10. Normal internal rotation of right lower ex-tremity achieved by correction of the piriformis syn-drome.

and antibiotics, the patient was able to returnhome. However, she still experienced left sci-atic pain and severe left hip pain. An activecourse of manipulative treatment was insti-tuted three to five times a week with poorresults. Consultation was requested and theconsultant's diagnosis was contracture of thepiriformis muscle, in concurrence with mydiagnosis. Manipulative care was continuedfor a period of several months and ultrasoundtherapy, administration of corticosteroids,and trigger injections of procaine and long-acting cortisone were utilized. Gradual im-provement resulted in 5 months, with 2 weekslost from work. The patient is seen at monthlyintervals and active medical treatment to theleft piriformis muscle is no longer necessary.The syndrome now is controlled by osteopathicmanipulative therapy to maintain pelvic bal-ance and motion.

Summary and conclusionsThe piriformis syndrome is a complex withfar-reaching manifestations. It is entirelywithin reason to assume that the piriformismuscle is analogous to a trigger mechanisminasmuch as its referred pain pattern is con-cerned. Knowledge of the piriformis musclesyndrome enhances the osteopathic physician'sskill in diagnosing and treating low-back dis-orders.

Ten muscles in the gluteal region functiontogether to produce stability of motion in the


The piriformis muscle

pelvis, on which the body is supported in bal-ance. Seven of these muscles are lateral ro-tators of the thigh and three are medial rota-tors. Of the seven lateral muscle rotators thepiriformis muscle is most prominent and theone most commonly injured by overstretchingand direct trauma producing contracture andlateral fixation of the femoral mechanism inthe acetabulum.

The most common rotational strain positionmay be that involved in the operation of anautomobile, where the right leg assumes aposition of unsupported lateral rotation on theaccelerator. Perhaps the second most commonpositional stress is that produced by sittingwith the ankle crossed on the opposite knee.

The peroneal and sciatic nerves lie beneathor sometimes pass through the substance ofthe piriformis muscle. Mild pressure uponthese nerves produced by contraction of thepiriformis may cause irritation, pain, and mal-function, as well as a complicated syndrome.

The sciatic nerve and peroneal nerve arevulnerable to entrapment neuropathy as theycross over the sciatic notch leaving the pelvis.Fascial connections from the pelvic fascia thatenvelopes the bony, muscular, neurologic, andvisceral components play an important role inthe integrity of the pelvis in health and mag-nify the pathologic response in disease and in-jury.

The frequency of the piriformis syndromeis far too great to ignore in general practice.

Osteopathic manipulative therapy resolvesa large per cent of these piriformis syndromes,but 5 to 10 per cent require chemotherapy

or surgical therapy.It is my opinion that all physicians who

wish to dedicate themselves to the disciplineof osteopathy should, at least, orient theirthinking to the musculoskeletal system.

1. Edwards, F. 0.: Pyriformis syndrome. In Academy of AppliedOsteopathy year book 19622. Theobald. P. K.: Structural study of the postural complex. InAcademy of Applied Osteopathy year book 19583. Korr, I. M.: The neuromusculoskeletal system as the instrumentof life. Scott Memorial Lecture presented at the Seventy-SecondAnnual Convention and Scientific Seminar of the American Osteo-pathic Association. San Francisco. October 30. 19674. Gray, H.: Anatomy of the human body, edited by C. M. Goss.Ed. 25. Lea & Febiger, Philadelphia. 19485. Schaeffer. J. P., Ed.: Morris' Human anatomy. Ed. 11. TheBlakiston Co.. New York, 19536. Grant, J. C. B.: Cited by Schaeffer, ref. 5.7. Kopell, H. P.. and Thompson, W. A. L.: Peripheral entrapmentneuropathies. Williams & Wilkins Co.. Baltimore, 1963, p. 558. Hazzard, C.: The practice and applied therapeutics of osteopathy.Ed. 2. Journal Printing Co., Kirksville, Mo., 1901. p. 119. Tasker, D. L.: Principles of osteopathy. Ed. 5. Bireley & ElsonPrinting Co., Los Angeles, 1926, p. 56810. Travell, J., and Rinzler, S. H.: The myofascial genesis ofpain. Scientific exhibit. Postgrad Med 11:425-34, May 5211. Adams, R. C.: Diagnostic and therapeutic nerve block. JAMA146:801-3, 30 Jun 5112. Barrett. R. H.: In discussion of ref. 1113. Moss, L.: Acupuncture and you. A new approach to treatment,based on the ancient method of healing. Elek Books Ltd., London.196414. Douthwaite, A. H., Ed.: French's Index of differential diag-nosis. Ed. 7. John Wright & Sons Ltd., Bristol, England, 1954, p.533Schwab, W. A.: Principles of manipulative treatment. The lowback problem. XV. Statistics and summary. In Academy of AppliedOsteopathy year book 1965, vol. 2Selye, H.: The physiology and pathology of exposure to stress. Atreatise based on the concepts of the general-adaptation-syndromeand the diseases of adaptation. Acta, Inc., Medical Publishers,Montreal, 1950

Presented in partial fulfillment of the requirements for fellow-ship in the Academy of Applied Osteopathy, 1968.

Dr. TePoorten, Route 5, Box 774, Tucson, Arizona 85718.

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the piriformis muscle muscles, piriformis

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