i- 1

Clinical Biomechanics 1989; 4: 25-33

Clinica/ and functional examination of the

spine in ,-1- working

. communities:

occurrence of alterations, in the male

control-----,group

E Occhipinti PhE)

D Colombina PhD, G Molteni PhD

Olga Menoni RPT, S Boccardi PhD, A Grieco PhD

Research Unit E.P.M. (Ergonomics of Posture and Movements), Clinica del Lavoro

"Luigi Devoto", Milano, Italy

Summary

The paper reports the results obtained by applying a clinical method for the study of spina) disease as described elsewhere

l in a contro) group of 200 male subjects, strati -

fied for age, who had not been exposed to classically accepted occupational risk indi -catore- for spina/ disorders. For each age class the following data are supplied: frequency of cervata/ thoracic and lumbar d isease ; frequency of sco lios is and dissymmetry of lower limbs; mean values and range of mobility parameters for the varicus spina] . regione. The possible application are discusseti

Relevance

The values presented here, obtained from a structured examination, provide a set of age-related reference values for males in light industry. They form a basis for compari-son with other male occupational groups, to assess the effects on these variables from work-related demands on the spine.

Key Words: Spine, Mobility, Occupational medicine, Back pain, Clinical examination

Introduction

It is common practice in occupational medicine that

possible work-induced impairment be studied alongside

assessment of the risk fattore. In the case of manual hand-

ling and of incorrevi work postures, such study is of

necessity aimed at morphological and functional

alterations of the locomotor system.

To this aim, we have described and validated a method

for the clinical and functional examination of the loco-

motor system and of the spine in part icularl-

2. The signs

and symptoms observed by this method are organized,

according to standardized criteria, for classification finto

Submitted: li May 1987 Accepted: 19 May 1988 Correspondence and reprint requests io: Dr E Occhipínti, CEMOC, via Villasaute, li. 20100 Milan, Italy

@ 1989 Butterworth & Co (Publishers) Ltd 0268-0033/891010025-09$03.00

different p ic tures o f c l inica l– funct ional spondy-

loarthropathy. In generai, this means the presente of a

regional spinai disorder, probably degenerative, shown

by anamnesis, clinical procedures and functional impair -

ment, independent from the radiologica) pitture.

The application of the method in working communi-

ties does, however, require appropriate reference data,

on the basis of which a more exhaustive analysis of the

group results can be made.

The aim of this research was to establish such refer -

ence data and parameters for males by studying a group

of subjects not exposed to occupational postura/ hazards,

such as prolonged fixed postures (both sitting and

standing), manual materia/ handling and whole body

vibrations during their lifetime. In this context, brief

notes will be provided regarding the clinical method used.

(1 95

r26 Cl in . Biomech. 1989; 4 : No 1 It should be noted

that 'pre l iminary studies of the reproduceability of

-the method regarding qualiative vari ables (Le. the

classification of positive anamnesis) and

quantitative variables ariables (Le. the measurement of trunk movements) showed good intra- and inter-observer re-produceability of the variables observed'.

Figure 1. Frontal piane behind the scol iosometer: observation of the patient facing the instrument.

Figure 2. Measurement of thoracic kyphosis and lum-

bar lordosis with flexicurve.

Measurement of some anthropometric parameters:

The anthropometric parameters chosen are those that have a functional role in the generai aims of the clinical examination, especially for spinai mobility assessment. Among them, length of lower limbs is routinely meas- ured in order to check leg length inequality. e

ence ot a nb-Vúmp suggestive of-a-strutturai scoliosis is C considered. Then the thoracic kyphosis and lumbar lor-dosis angles are calculated by means of a flexicurve placed alono, the spine between C7 and the beginning of the intergluteal fold (Figure 2). The double curve (tho-racic kyphosis and lumbar lordosis) thus obtained is then transferred to a suitably sized sheet of paper. The inver-sion point of two curves and the points of maximum kyphosis and lordosis are identified; by drawing lines from the inversion point and from the ends of the curves to the respective maximum points, the angles are ob-tained (Figure 3).

i

Metho'ds

Clinical àamination,

The examination used consisted of six basic parts,outlíned below.:

..Physiological' and occupational anamnesis: It is of fúnd,àmental importante to assess the presente of

._past and_ présent exposures to the mechanical factors Which,àt work or at home, overload the spine.

Diseáse . history_.

Diseasès which have occurred in the last 12 months are particular.", int erést. -The area;-tadiation, characteristics

and tempo ral pattéms 1 of the dis'~ase are recorded. Even-

ìsabilíties'.--ìnduéed by the disease are also investi-

P -é~ciìC,A réshol .'~cr_iténa—allòw assessment of the —.,--_ —— ! óf the d is as-e`:`with—wy'iew to the dia-nostic

classificatiorì .1 ( S" VEANAMNà1S

Occhip in t i e t a l : Spina i examinat ion in work ing c o m

muni t ies 27

Figure 4. Measurement of head extension by incli -nometer.

Assessment of mobility:

The following movements are examined separately: ex-

tension, flexion, lateral inclination (side-bending) and

rotation, respectively, for the cervical and thoraco-lum-

bar spine.

For the cervical spine, passive movements are exam-

ined (subject prone or supine with fixed shoulder) using

an inclinometer (Figure 4) with the exception of the lat-

eral inclination when a goniometer is used. For the tho-

raco-lumbar spine active movements are evaluated with

the pelvis fixed, estimating the linear measurements and

Figure S. Measurement of rotation angle of the spine (cervical spine excluded).

their transformation finto angular values, except for rota-

tion when a goniometer is used (Figure 5).

The flexion angle is measured using the following

parameters: a) Height from suprastemal notch to bed

surface (with the subject seated and perfectly upright); b)

Height from suprastemal notch to bed surface (with pa-

tient flexed holding the pelvis stili).

The right and left inclination angles'are calculat ed

usingthe following two parameters: a) Height from C, to

e Height 7

bed surface (with patient perfectly upright) (Figure 6); b)

Figure 6. Measurement of distance between C, and seating piane with patient in upright seated position.

MAXIMUM KIPHOSIS

INVERSION POINT

MAXIMUM LORDOSIS

Figure 3. Cálculation of dorsal lumbar, lordosis.angle -(p). -- -

kyphosis angle (a) and

28 Clin. Biomech. 1089; 4: No 1

Figure 7. Measurernent of distante between C, and seating surface with patient bending sideways.

Figure 8: Procedure to calculate the flexion and incli -nation angle of the spine (cervical spine excluded).

Height to bed surface (with patient bending right

ght from C7

and left) (Figure 7).

The above parameters are used in the trigonometrical

formula shown in Figure 8 to calculate the flexion and

inclination angles. The extension angle is measured us-

ing the following parameters: a) Distance between the

suprastemal notch and the centre of the line that joins the

ASIS (with patient supine on the bed); b) Distance (with

patient prone and forehead resting on the bed) between

suprastemal notch and surface of the bed; c) Distance

between suprasternal notch and bed surface (with spine

beni backwards).

The above parameters are used in the trigonometrical

formula shown in Figure 9 to calculate the extension

angle. It should be noted that in the different trigonom-

etrical formulas presented there exists a slight discrep-

ancy between A and Al. Nevertheless, as a preliminary

test of reproduceability, the method was demonstrated to

be statistically satisfactory, whilst that was not the case

when the measurements avere taken with the goniome-

ter3.

It is obvious that the angles measured in this way are

not equivalent to those taken from X-rays. They are,

therefore, considered indices of the flexibility of the

thoraco-lumbar spine along the sagittal and frontal e sagitta

In the study of spine mobility it should be noted

whether the patient feels any pain during movement.

classification:

To facilitate standardized analysis of the results, an origi-

nai classification procedure was developed, based on

clinical and functional features (Table 1).

The classification procedure! is derived from a combi-

natila of the various anamnestic, tic, clinical—morphological z:

Figure 9. Procedure to obtain the extension angie of the sp ine (cervical sp ine excluded) from lengths A—B—C.

A- A'

B- A.sina a - arc sin SIA'

6 - 90*-a

A=A'

à =90' C-E2A'. sin a a -%

a r t t a n

( C -B ) A'

Occhipinti et al: Spina, examination in working communities 29

Table 2. Criteria for assessnierit of cervical, thoracic and lumbar mobility

Movements Reduced mobility Painful mobility

Cervical region

Thoracic region

Lumbosacral region

Flexion Extension Right inclination Left inclination Right rotation Left rotation

Right rotation Left rotation

t inclination Right nc— Left inclination

Flexion * Extension

Right inclination

Left inclination

4 out of 6 reduced

3 out of 4 reduced or 2 main movements reduced

3 out of 4 reduced or

2 main movements reduced

out of 6 painful

3 out of 4

painful 2 main movements painful

3 out of 4

painful or 2 main movements painful

. Main movements of regions

Table 3. Head and trunk movements: reference values per age class, in males *

Segments

Parameter 16-25

min—max 26-35

min—max

36-45

min—max

46-55

min—max

Head Flexion 55-98 54-94 49-88 47-85 Extension 35-77 31-72 29-66 26-68 Right inclination 38-66 36-63 34-62 32-57 Left inclination 40-65 38-62 35-60 33-58 Right rotation 74-101 69-97 65-97 60-99

Left rotation 76-98 69-98 66-95 61-93

Trunk Flexion 33-56 30-54 30-53 31-54 Extension 19-37 15-33 14-31 13-30 Right inclination 27-46 25-44 23-43 22-39 Left inclination 26-47 24-44 23-43 23-39 Right rotation 34-68 29-69 28-61 25-58

Left rotation 32-67 27-69 29-61 24259

* Movement values < or > minimum and maximum reference values are considered 'reduced' and 'increased'

and clinical—functional variables in three separate pic-

tures that are not necessarily connected by a single linear

process. These three pictures are clinical—functional

spondyloarthropathy of first, second and third deRree.

The thoracic spine is treated separately in the procedure

since, from the point of view of clinical—functional al-

terations, it behaves differently from the other vertebral

regions.

For flexion, extension, inclination and rotation of head

and trunk, and for the parameters `thoracic kyphosis

anale' and 'lumbar lordosis angle', the values corre -

spondina to the 5th and to the 95th percentiles of the

distributions were calculated.

Values for mobility parameters were treated separately

in four aie classes, since a-e is an influencino,

factor; data

Table 4. Thoracic kyphosis and lordosis angle: refer -ence values for 16-55 years age group, in males *

Minimum Maximum

15

12 30 ---Tó identify reference values for some of the

parameters studied, the data collected in several studies

on adult male subjects were suitably selected and

statistically analysedI'.

Thoracic kyphosis

Lumbar lordosis

* Angle values < or > minimum and maximum refer -ence values are considered 'reduced' and 'increased'

. 1 — _ —

30C1ín,B3íOme7ch.<~1989; 4: No 1

on the angles of the sàgittal curves of the spine were, however, treated independently of age. In faci age, in our data, had no effect on these parameters, at least for the age group considered here.

Table 3 gives the reference values for the head and trunk movements in males. Table 4 shows the reference values for the thoracic kyphosis and lumbar lordosis angles in males. According to these values, for an indi -vidua) diagnosis, the angles may be classif ied as ' re -duced' or 'increased'.

;«C

*

S A P ®s o j.;TOT SAP

r

x C E R V I C A L S A P

5G-

30. The g roup examined

In the present study, the clinical method previously il -lustrateti was applied to a control group of male subjects in order to achieve the following:

a) Estimate the frequency of clinical–functional cervi-cal, thoracic and lumbosacral spondyloarthropathy in four age classes (15-25, 26-35, 36-45, 46-55 years) of male subjects not exposed to occupational postural hazards;

b) Identify mean values and confidence interval of the mean of the various articular-mobility parameters stud-ied within these age classes.

Such data are necessary in order to make comparisons with similar data obtained in investigations on workers exposed to occupational postural hazards, even though a verification of the aetiolo g ical basis of the risk factors under study will require lon g itudinal epidemiologica) studies. Other aspects considered here were the occur -rence of scoliosis and dissymmetry of lower limbs in the aduli population.

Two preliminary conditions were established for the choice of characteristic for the control group: a) stratifi -cation into four age classes (16-25, 26-35, 36-45, 46-55 years); b) inclusion of subjects who had not, either pres -ently or in the past, been employed in jobs involvine exposure to risk factors such as prolonged fixed (both sittine, and erect) postures, manual lifting, moving or transport of load or whole-body vibrations.

The size of the control group was established in rela -tions to the variability of the spinai mobility parameters, so as to keep the 95% confidence interval of the mean of these parameters to 5 degreees5-1. The size of the sample that adequately guaranteed the aims of the study was calculated to be 50 subjects for each a ge class, i.e. a total of 200 subjects6.

In this sample size the confidence limits for the fre -quency (f) of pathological cases under study were f- 0.14 according to the formula used to calculate these limits, and in the most unfavourable circumstances where f=

0.509.

Data analysis

The statistica) analyses have been carried out takin a into

account the following points':

a) Absolute frequency and percentage (f) of qualitative

'/-THORACIC SAP

5c

so

Figure 10. Per cent frequency of cl inical functional cervical , thoracic, lumbosacral spondyloarthopathy (SAP), by age classes, in the male control group. Cases are reported by grade and as a whole.

variables (in particular diagnosis) and estimation of relative confidence limits (1) for each a ge class, according to the formula:

1 =f + 1.96 [f x

b) Mean, standard deviation and 95% conf idence interval of the mean of quantitative parameters (in particular amplitude of movements of cervical, thoracic and lum-

Table 5. Per cent frequency (95% confidence limits) of cervical, thoracic and lumbar spondylarthropathy in four age groups of the male population not exposed to occupational postural risk

Age class

Spondylar- 16-25 thropath

26-35 35-45 46-55

cervical 12 10 32 40

(3-21) (1.7-118-3) (19.1-44-9) (12.2-32-8)

Thoracic 8 10 18 24

(0.5-15-5) (1.7-18-3) (7.4-28-6) (12.2-35-8) Lumbosacral 6 12 28 50

(0-12) (3-21) (15.6-40-4) (32.2-63-8)

15-25 26-35 36-45 45

LUMBO - SACRAL SAP

AGE GROUP

26-35 36-45 45 AGE

GROUP

Occh ip in t i e t a l : Spina/ examinat ion in work ing c O mmunit íes 31 -

Table 6. Head movements: Imean value (*), standard deviation (in brackets) and 95% confidence interval of the -

mean, by age class in ,che contro) group. F test value and relative leve) of significante s hown for each parameter

Age class

Head 16-25 26-35 36-45 46-55 F

movements n=50 n=50 n=50 n=50

Flexion 74.1(11-75) 73.8(11-8) 67.7(11-05) 64.4(11-65) 8 . 2 8—

70.8-77-4 70.4-77-2 64.3-71-7 61.1-67-7

Extension 56.4(11-l) 48.8(10-7) 44.7(11-43) 43.1(11-76) 13.85***

53.2-59-6 45.8-51-8 41.4-48-0 39.8-46-4

Right 51.6(9-01) 49.0(7-45) 45.1(7-01) 43.8(5-6) 14.24***

inclination 49.1-54-1 46.0-51-1 43.1-47-1 42.2-45-4

Left 51.9(6.55) 50.0(7-21) 46.8(6-87) 43.7(5-32) 15.46***

inclination 50.0-53-8 48.0-52-0 44.9-487 42.2-45-2

Right 87.1(4-92) 86.3(5-42) 83.5(7-17) 81.2(9-91) 7. 1 -

rotation 85.7-88-5 84.8-87-8 81.5-83-5 78.4-84-0

Left 88.5(3-81) 87.4(4-78) 84.1(7-41) 81.6(7-92) 12.72***

rotation 87.4-89-6 86.7-88-7 82.0-86-2 79.4-83-8

20

***P < 0.0001

bar spine) for each age class; confidence intervals avere

calculated by the formulati:

i inC ,uP X

+ tn. . 0-05 x sHn

c) Analysis of 2 x 4 tables or i the prevalente, according

to age, of pathological. cases; calculation of the relative e

Figure 11. Per cent frequency of scoliosis, by age classes and as a whole, in the male contro) group.

40.

16-25 26-35 36-45 46-55 AGE GROUP

Figure 12. Per cent frequency of leg dissymmetry, by age classes and as a whole, in the male control group.

chi-square to test the existence of significative statistica)

differences.

c) One-way analysis of variante (ANOVA) for the quantica

tive parameters in relations to the four age classes.

Results

Figure 10 shows, by means of histograms, the observed

per cent frequency of subjects with 'clinical-functional

cervical, thoracic and lumbosacral spondyloarthropathy'

for each of the age classes considered. The cases of

spondyloarthropathy are reported by -rade (I, 11, III)

according to our classification, and as a whole. These

data and the relative 95% confidente limits for estima-

tion of the occurrence of the disease studied in similar

populations are shown in more detail in Table 5. Consid-

ering the per cent frequencies of pathological cases inde-

pendently of the degree, it cari be observed that they tend

to increase with increase in age; ;the increase is minima)

for the thoracic re-ion, but becomes more evident for the

cervical region and even more marked for the lumbosac-

ralre-ion; For -both the cervical and the lumbosacral._..., cri

reons, thè differente between a ge classes in frequency

of norma) and pathological cases was statistically signifi -

cano (x2 = 18

.3 for the cervical region, x

2 = 31

.8 for the

lumbar region; p <0.001).

Figure 11 shows the per cent frequency of the cases of C scoliosis observed in the four age classes, and within the

entire control group. The frequency of cases of scoliosis,

TOT 19%

16% N, 20% 22%

TOT 54% 54%

56%

48%

30.

la

16-25 26-35 36.45 46.55 AGE GROUP

32 Clin. Biomech. '1989; 4: No 1

Table 7. Trunk m.overrie.n.t: mean value (*), standard deviation (in brackets) and 95% confidence interval of the mean, by age class in the control group. F test value and relative leve] of significante shown for each parameter

Age class

Trunk 16-25 26-35 36-45 46-55 F

movements n=50 n=50 n=50 n=50

Flexion 45.4(6-28) 42.7(5-86) 41.7(5-91) 41.11(7-08) 3.23*

43.2-47-1 41.0-44-4 40.0-43-4 40.1-44-1

Extension 28.8(4-36) 27.3(4-12) 25.5(4-87) 23.6(5-11) 11-74***

27.6-30-0 26.1-28-5 24.1-26-9 22.2-25-0

Right 36.5(5-0) 33.6(4-86) 30-.5(6-44) 30.6(4-88) 14.28***

inclination 35.1-37-9 32.2-35-0 28.7-32-3 29.3-32-0

Left 36.7(4-77) 34.4(5-22) 32.4(5-16) 31.5(5-45) 10-03***

inclination 35.4-38-0 32.9-35-9 30.9-33-9 30.0-33-0

Right 53.8(8-29) 54.5(9-31) 50-0(9-44). 45.3(9-95) 10.26***

rotation 51.5-56-1 51.9-57-1 47.3-52-7 42.5-48-1

Left 51.6(9-23) 53-7(9-0) 50.5(8-97) 45

.6 (10.04) 6.82***

rotation 49.0-54-2 51.2-56-2 48.0-53-0 43.0-48-2

P5 0.05

" ' p < 0 . 0 0 1

which were all slight (between 10 and 15° of convexity), n 1

is somewhat high (on avera

ge 54%, with 95% confidence

limits of 47.1-60-9) and, as was to be expected, there

were no substantial differences between the different age

classes.

Figure 12 shows, for age classes and in the control

group as a whole, the frequency of subjects with leg dis-

symmetry greater than 1 cm. In this case, too, the fre -

quencies observed are certainly not negli

gible and are

independent of age.

Tables 6 and 7 report, for the four age classes and for

the cervical and the thoraco-lumbosacral spine, respec-

tively, the following data regarding joint mobility para-

meters (angles of flexion and extension, left and right

inclination, left and right rotation): a) mean angle value;

b) standard deviation; c) 95% confidence interval of the

mean for estimation of the mean value of this feature in

the generalpopulation; d) the value of F and the relative

leve] of significante.

Discussion

A method for the clinical-functional examination of the

spine was devised by us. It was applied to a group of male

subjects, stratified by age, who were not exposed to

occupational postura] risks, in order to provide referente

data in epidemiologica) studies.

firm conclusione are not

possible. Moreover, in this specific case, the limited

numbers of the sub-groups

gave rather avide

confidence limits. It follows that, in the present state of

knowledge, only marked differences in the occurrence of

the diseases examined between the exposed and the

control groups may be judged as significant. C -tr

On the other hand, comparisons for spine mobility will

be much more detailed, since the values of the standard

error of the mean of the relative parameters were generally more restricted.

In addition to the above remarks, some practical

ad-vice will be appropriate on how the groups of

exposed subjects should be selected, so that, even with

the above limits, the comparisons meet the minimum

requirements in order to be valid.

a) The groups

of exposed male subjects should be strati fied

according to the saure age classes as those proposed

here; each age class musi comprise no lese than 50

subjects. If the age class is not sufficiently large it is

preferable to omit it from the comparison; an

alternative is to use the overall rate for all aees and

compare it with an expected rate obtained with the

indirect standardization method. 1

b) It should first be checked that no marked selection

phenomena exist within the group for the disease under

study; selection phenomena may occur either when the

job is not assigned to subjects who, when recruited,

already suffered from spinai disease, or when subjects who

Occhipinti et al: Spina/ examination in working communities 33

a r e m o v e d f r o m t h e i r j o b fo I l o w i n g a d i a g n o s i s o f

spond y loa r th ropa thy a t . a pe r iod i c hea l th check . Both

these phenomena would lead to an underestimation of the

occurrence of the disease in the group under study.

c ) I t i s ad v i s a b l e tha t t he g r oups und er s tud y i nc lud e

subjects who have been employed on the job for at least 5

year s , so a s to guar antee tha t ther e has been adequat e

time for any disease to develop.

d ) I t i s p re fe rab l e to exc lude sub ject s who avere pr ev i -

ously employed for more than 5 years altogether on jobs

involving hazards for the spine.

The purpose of this select ion is to ensure that any in -

creased occurence of a d i sease be at tr ibuted to one and

not many jobs . On the other hand , i t shou ld be remem -

bered that , besides the jobs which involve a sana le r isk

for the sp ine , there are some which involve more than

one risk factor (e. - . (1) vibrations and static postures for

heavy vehicle drivers; (2) postures with the trunk f lexed,

l i f t ing of load and , commonly, t ractor vibrat ions in agr i -

cultural work, etc .) . In these cases, the hi eher occurence

of d i sease wh ich may be observed i s gener i ca l l y a t t r ib -

u ted to the job and i t i s not poss ib le to d i s t in gu ish the

proportion due to_ each hazard.

References

1 Colombini D, Occhipinti E, Grieco A, Boccardi S, Menoni O. Posture lavoro e artropatie. Metodi di

indagine e principi di prevenzione. Ed Comune di Milano 1986; 63-91

2 Colombini D, Occhipinti E, Molteni G, Menoni O, Boccardi S, Grieco A. Esame Clinico-Funzionale del Rachide in collettivita lavorative: metodo e criter i diagnostici. Medicina Clinica e Termale 1987; 1: 6-17

3 Colombini D, Occhipinti E, Menoni O, Grieco A. Ulteriori esperienze su un nuovo metodo per la valutazione dei rischi e dei danni connessi con le posture di lavoro. Med Lav 1981; 2: 128-61

4 Occhipinti E, Colombini D, Molteni G, Menoni O, Boccardi S, Grieco A. Messa a punto e validazione di un questionario per lo studio delle alterazioni del rachide in collettivita' lavorative. Med Lav 1988 (in press)

5 Occhipinti E, Colombini D, Menoni O, Grieco A. Alterazioni del rachide in popolazioni lavorative. 2: Valori di riferimento della motilita' della colonna vertebrale per soggetti maschi adulti. Med Lav 1985; 6: 509-15

6 Armitage P. Statistica medica. Milano: Feltrinelli Editore, 1975

7 Occhipinti E, Colombini D, Menoni O, Grieco A, Motilità del rachide in soggetti maschi adulti: valori di riferimento per classi di età (unpublished data)

8 Colombini D, Occhipinti E, Menoni O, Bonaiuti D, Grieco A. Posture di lavoro incongrue e patologia d e l l ' appar a to locom otore . M ed Lav 1983 ; 74 : 198-210

9 Spiegel MR. Statistica. Collana Schaum. Milano: Etas Libri Editore, 1976

10 Ticchiarell i L. Combxa P, Belli S, Grandolfo M, Verdecchhia A, Bertazzi PA, Duca PG, Marchi M. Introduzione alla biometria in igiene e medicina del

lavoro. Roma: rapporto ISTISAN 84/20, 1984