Normal range of spinal mobility

Transcription

1 Ann. rheum. Dis. (1971), 3, 381 Norml rnge of spinl mobility An objective clinicl study J. M. H. MOLL1 AND V. WRIGHT2 From the Rheumtism Reserch Unit, University Deprtment of Medicine, the Generl Infirmry t Leeds, nd the Royl Bth Hospitl, Hrrogte Progressive loss of spinl mobility is generlly ccepted s one of the crdinl fetures of nkylosing spondylitis. The importnce of this sign is emphsized by its inclusion s clinicl criterion for the dignosis of nkylosing spondylitis t recent interntionl symposium held in 1966 in New York (Bennett nd Wood, 1968). At this conference it ws recommended tht to be of dignostic significnce spinl mobility should be restricted in three plnes (nterior flexion, lterl flexion, nd extension). Interprettion of this criterion, however, hs proved difficult nd unstisfctory for severl resons: (1) The widespred current prctice of ssessing mobility by reltively crude subjective methods hs overshdowed more ccurte mesurement of spinl movement by objective techniques. (2) Of the vilble objective methods, few re free from t lest one mjor disdvntge, such s rdition hzrd (Wiles, 1935; Tnz, 1953; Jonck nd vn Niekerk, 1961), specil instrumenttion (Dunhm, 1949; Goff nd Rose, 1964; Loebl, 1967), or inconvenience to the ptient (Troup, Hood, nd Chpmn, 1968). Furthermore, these techniques hve invribly been limited to spinl mesurement in the sgittl plne lone. (3) The rbitrry grding of mobility s 'norml' or 'bnorml', in the bsence of recognized rnge of normlity, is clerly uncceptble. (4) No correction hs been mde previously for the effect of ge nd sex on these movementsfctors which Mcre nd Wright (1969) hve recently shown to be n importnt source of dignostic error. The principl object of this pper, therefore, is to present for the first time rnge of norml vlues for spinl mobility mesured in three plnes of movement by mens of objective clinicl methods. It is envisged tht this will not only enhnce the ccurcy of dignosing nkylosing spondylitis but will lso help to differentite this condition from disorders of the lumbr disc- clinicl problem encountered more often thn is generlly pprecited. Clinicl mteril The popultion studied ws obtined by consecutive smpling of cliniclly nd rdiologiclly norml reltives of ptients with psoritic rthritis during fmily study of this disese. A totl of 237 subjects (119 mles nd 118 s) comprised the 'norml' group in which ll ges between the second nd ninth decdes were represented. Methods The objective clinicl methods employed to mesure spinl mobility hve been developed recently t the Rheumtism Reserch Unit t Leeds. The method to mesure nterior flexion hs been reported previously (Mcre nd Wright, 1969) nd detils of the methods to mesure lterl flexion nd extension will form the substnce of seprte communictions (Moll nd Wright, 1971, b). Mesurements of nterior spinlflexion This is modifiction of technique originlly described by Schober (1937). Three mrks were inked on the skin overlying the lumbo-scrl spine with the subject stnding erect (Fig. 1). The first mrk ws plced t the lumboscrl junction which is represented by the spinl intersection of line joining the dimples of Venus. Further mrks were inked 5 cm. below nd 1 cm. bove the lumbo-scrl junction. The subject ws then sked to bend forwrd nd touch his toes nd the new distnce between the upper nd lower mrks ws mesured. The distrction between these two mrks hs (1) Senior Registrr in Rheumtology nd Physicl Medicine, Oxford/Reding res (formerly Reserch Assistnt, University of Rheumtism Reserch Leeds) Unit, (2) Professor of Rheumtology Accepted for publiction Mrch 16, 1971

2 382 Annls of the Rheumltic Diseses () F i G. 2 Mesuremnent of thorco-lumbr llterl flexioni. F I1. 1 Mesurement of nterior spinl flexion by modifiction of Schober's method (Mcre nd Wright, 1969). been found in seprte study to correlte very closely (r-- 97) with nterior flexion mesured rdiologiclly (Mcre nd Wright, 1969). Mesurement of lterl spinl flexion With the subject stnding erect, two mrks were inked on the skin of the lterl trunk (Fig. 2). The upper mrk represents the intersection of horizontl line through the xiphisternum with the coronl line. The lower mrk represents the intersection of horizontl line through the highest point on the ilic crest with the coronl line. The distnce between these two mrks ws mesured in centimetres. The subject ws then sked to bend sidewys s fr s possible by sliding the hnd down the homolterl thigh. At the end of this movement the distnce between the two mrks ws gin mesured. A seprte study hs reveled tht the difference between the first nd second mesurements correltes resonbly closely (r = 79; P < 1) with lterl thorco-lumbr flexion mesured rdiologiclly (Moll nd Wright, 1971). Mesurement of spinl extension The lndmrks for this mesurement were the sme s those used to mesure lterl spinl flexion. A simple plumb-line ws constructed. This consisted of pointed weight suspended by thred pproximtely 2 cm. long. The point of the plumb-line ws suspended to coincide with the lower mrk nd the thred held t the upper mrk (Fig. 3). To fcilitte the mnipultion the subject ws sked to stnd erect with hnds on hed. Without support he ws instructed to bend over bckwrds s fr s possible without flexing the knees. During this movement the distnce trversed by the plumb-line pointer ws mrked on the skin of the flnk nd mesured in centimetres. This distnce hs been found to correlte stisfctorily (r = 75; P < 1) with thorco-lumbr extension mesured rdiologiclly (Moll nd Wright, 1971b). Results Distribution of spinl mesurements Histogrms constructed to show the distribution of spinl mesurements reveled Gussin pttern for ech plne of movement (Figs 4, b, c), thus providing firm supporting evidence for the 'normlity' of the popultion surveyed.

3 Norml rnge of spinl mobility 383 FIG. 3 Mesurement of thorco-lumbr extension. Norml rnge ofspinl mesurements A complete set of norml vlues for ech plne of spinl movement is presented in Tble I (overlef). The men + 1 nd rnge of mobility re shown for ech decde, mle nd dt being tbulted seprtely. A digrmmtic summry of these observtions is shown in Figs 5, b, nd c (overlef). The verticl lines t ech decde represent the norml rnge of spinl movement (men ± 2 ). Reference to these digrms revels the following importnt fetures: (1) An initil increse in men mobility from the 15 to 24 decde to the 25 to 34 decde ws followed by progressive decrese with dvncing ge. This ge-dependent pttern ws observed in both sexes nd in ll three plnes of mesurement. The mgnitude of the ge effect in decresing spinl mobility ws clculted from the following: Mgnitude of ge effect (%) = mximl-miniml men mesurement x 1 mximl men mesurement Tble II (overlef) shows tht ge lone my reduce spinl mobility by s much s 23 to 52 per cent. The dignostic significnce of this mrked effect will be discussed lter. (2) The sctter (±2 ) of spinl mobility vried considerbly between decdes but in ech ge group this ws mrked. The wide rnge of norml mobility ws observed in ech plne of movement. (3) Fig. 6 (overlef) revels sex difference t ech 3 ( 2 - +' 1-_ ] -'O e 3 mle I.3 E I *. mle mle Z2 FIG. 4 FIG. 4b FIG. 4c S 4 5 m:7 8 Spinl flexion (cm.) 9K Lterl flexion (cm.) Extension (cm.) Norml distribution of nterior spinl flexion, by sex. Norml distribution ofleft lterl spinlflexion, by sex. Norml distribution of spinl extension, by sex.

4 384 Annls of the Rheumtic Diseses Tble I Norml thorcolumbr spinl movement Flexion Lterl flexion to right Lterl flexion to left Extension E c x 4, D - - H U Thorco-lumbr spinl movements, by ge nd sex Age (yrs) Sex No. of subjects Men (cm.) Rnge Men (cm.) Rnge Men (cm.) Rnge Men (cm.) Rnge M F M F * * *46 1* *66 1*7 1* M F M F ' Age group (yers) I i ] E " ,), E 8 u 6- H4. 2- IT T -ri..t. mle M F M F M F * FIG. 5 Thorco-lumbr nterior flexion in norml mles nd s: men flexion = 2 plotted ginst ge. FIG 5 b Thorco-lumbr lterl flexion to left ( ) nd right --- -) in norml mles nd s: men _ 2 plotted ginst ge. FIG. 5c Thorco-lumbr extension in norml mles nds: men extension 2 plotted ginst ge. decde in ll three plnes of movement. It is interest- wheres in lterl flexion the converse obtined. The ing to note tht in the cse of nterior flexion nd mgnitude of the mobility difference between the extension mle mobility exceeded mobility, sexes hs been clculted from the following: Mgnitude of sex effect in nterior overll men (ll decdes) mle mobility-overll men mobility flexion nd extension (%) overll men mle mobility Mgnitude of sex effect _ overll men (ll decdes) mobility-overll men mle mobility in lterl flexion (%) overll men mobility 1 L- -ME CH 1t ]

5 Norml rnge of spinl mobility 385 Tble II to ge Plne of mesurement Percentge reduction ofspinl mobility due Per cent. reduction of spinl mobility M Anterior flexion Extension Lterl Left flexion Right Tble III shows tht spinl mobility differed by 7 to 11 per cent. between the sexes. Tble III Percentge reduction of spinl mobility due to sex difference Plne of mesurement F Per cent. reduction of spinl mobility Anterior flexion 1 (F<M) Extension 7 (F<M) Lterl Left 11 (F>M) flexion Right 11 (F>M) Discussion The present study ws prompted by the widespred prctice of subjective mesurement nd rbitrry interprettion of certin interntionl criteri for the clinicl dignosis of nkylosing spondylitis. In n ttempt to improve this sitution, it ws oonsidered importnt not only to use objective methods to mesure spinl mobility in severl plnes but lso to estblish rnge of norml vlues for these movements. A reported feture of considerble importnce is the striking decrese in spinl mobility with dvncing ge. This observtion hs both dignostic nd prognostic significnce. Although the mjority of ptients with nkylosing spondylitis present before the ge of 3 yers, number experience their first symptoms in middle ge or even lter (Shrp, 1965). It is importnt, therefore, when considering this disese in the elderly, to llow for the effect of ge to void flse positive dignosis. Prognosticlly, if the progressive diminution of mobility with incresing ge is not considered, the effect due to this in spondylitic subject my be scribed to the progress of the disese rther thn to the progress of nture. Another ge-dependent feture of dignostic significnce concerns the dely in pek spinl 8 b 4-2- FIG. 6 8 (6) *. ~~~~~~mle Age group (yers) Men rnge of movement, by sex nd ge group (A) Anterior flexion. (B) Extension. (C) Right nd left lterl flexion. mobility until the decde following tht in which spondylitis most frequently presents, i.e. between the ge of 15 nd 24 yers (Mson, 1964). As nonspondylitic bck pin nd rdiologicl chnges mimicking scro-iliitis (Rogers nd Cleves, 1935) re reltively common t this decde, wreness of this phenomenon is clerly importnt in order to void dignostic error. An importnt prcticl ppliction of the mesurement of bck movement in three plnes (nterior flexion, lterl flexion, nd extension) concerns the frequent difficulty in differentiting nkylosing spondylitis from disorders of the lumbr disc. It hs been reported tht limittion of mobility in spondylitis usully ffects ll plnes of spinl movement in contrst with the pttern of involvement in cute lumbr disc lesions in which lterl flexion is often spred (Biley, 196). The common prctice of limiting exmintion of spinl mobility to mesurement of nterior flexion in spondylitis surveys my thus led to the erroneous inclusion of ptients with disorders of the lumbr disc (Lwrence, 197). The clinicl prdox in which mle mobility exceeded mobility in the sgittl but not the coronl plne defies simple explntion. An rtefctul effect rising from morphologicl differences, such s nrrower wist nd broder pelvis in the, ws considered. More likely, however, is the

6 386 Annls of the Rheumtic Diseses possibility tht the phenomenon represents rel effect bsed on musculo-skeletl peculirities sufficient to outweigh the usul biologicl tendency towrds mle predominnce. Summry (1) New objective clinicl methods hve been pplied to study of spinl mobility in norml popultion. (2) Spinl movement hs been mesured in three plnes-nteriorflexion, lterl flexion, nd extension. (3) A rnge of norml vlues hs been reported for ech plne of mobility, bsed on mesurements from 237 norml subjects in fmily study. (4) The distribution of mesurements in ech plne of spinl movement followed Gussin (norml) pttern. (5) The pttern of norml mobility plotted ginst ge reveled n initil increse in movement from the 15 to 24 decde to the 25 to 34 decde followed by progressive decrese with dvncing ge. (6) Spinl mobility ws found to diminish by s much s 5 per cent. between youth nd old ge. The dignostic implictions of this ge-dependent effect hve been discussed. (7) A considerble sctter of spinl mobility ws demonstrted t ech decde nd the importnce of regrding norml mobility in terms of wide rnge of vlues ws emphsized. (8) A sex difference ws observed in ech plne of movement. Mle mobility exceeded mobility in nterior flexion nd extension. Femle mobility exceeded mle mobility in lterl flexion. We should like to thnk Mrs E. W. Dvey for technicl help nd Mrs B. Antcliffe nd Mrs B. Gordon for secretril ssistnce. We re lso indebted to the lrge number of psoritic rthritis probnds who llowed us to study their reltives. Finncil support from the West Riding Medicl Trust is grtefully cknowledged. References BAELEY, H. (196) 'Demonstrtion of Physicl Signs in Clinicl Surgery', 13th ed., p Wright, Bristol. BENNETT, P. H., AND WOOD, P. H. N. (editors) (1968) 'Popultion Studies of the Rheumtic Diseses', Proc 3rd lt. Symp., New York, 1966, Int. Congr. p Ser., No Excerpt Medic Foundtion, Amsterdm. DUNHAM, W. F. (1949) Brit. J. phys. Med., 12, 126 (Ankylosing spondylitis: mesurement of hip nd spine movements). GOFF, B., AND ROSE, G. K. (1964) Rheumtism, 2, 63 (The use of modified spondylometer in the tretment of nkylosing spondylitis). JONCK, L. M., AND NIEKERK, J. M. VAN (1961) S. Afr. J. Lb. clin. Med., 7, 67 (A roentgenologicl study of the motion of the lumbr spine of the Bntu). LAWRENCE, J. S. (197) Ann. rheum. Dis., 29, 559 (Discussion t the Heberden Society). LOEBL, W. Y. (1967) Ann. phys. Med., 9, 13 (Mesurement of spinl posture nd rnge of spil movement). MACRAE, I. F., AND WRIGHT, V. (1969) Ann. rheum. Dis., 28, 584 (Mesurement of bck movement). MASON, R. M. (1964) In 'Textbook of the Rheumtic Diseses', ed. W. S. C. Copemn, 3rd ed., p Livingstone Edinburgh. MOLL, J. M. H., AND WRIGHT, V. (1971) 'Objective clinicl mesurement of lterl thorco-lumbr flexion'. In preprtion. -~ -~(1971b). 'Objective clinicl mesurement of the thorco-lumbr extension'. In preprtion. ROGERS, M. H., AND CLEAVES, E. N. (1935) J. Bone. Jt Surg., 17, 759 (The dolescent scro-ilic joint syndrome). SCHOBER, P. (1937) Munch. med. Wschr., 84, 336 (Lendenwirbelsule und Kreuzschemerzen) (The lumbr vertebrl column nd bckche). SHARP, J. (1965) In 'Progress in Clinicl Rheumtology', ed. A. St. J. Dixon, p Churchill, London. TANZ, S. S. (1953) Amer. J. Roentgenol., 69, 399 (Motion of the lumbr spine: roentgenologic study). TROUP, J. D. G., HOOD, C. A., AND CHAPMAN, A. E. (1968) Ann. phys. Med., 9, 38 (Mesurements of the sgittl mobility of the lumbr spine nd hips). WILEs, P. (1935) Proc. roy. Soc. Med., 26, 647 (Movements of the lumbr vertebre during flexion nd extension).