MUSCULOSKELETAL DISORDERS

l

WORK

Edited by

Peter Buckle

MuscuIoskeletaI Disorders at Work

Proceedings of a conference held at The University of Surrey, Guildford

13-1 5 April 1987

Edited by

Peter Buckle The Robens Institute, Guildford

Taylar & Francis London . New York. Philadelphia

1987

UK

USA

Taylor & Francis Ltd, 4 John St, London WC1 N 2ET

Taylor & Francis Inc, 242 Cherry St, Philadelphia, PA 191 06-1 906

Copyright @ Taylor & Francis Ltd 1987

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without permission in writing from the publisher.

British Library Cataloguing in Publication Data Musculoskeletal disorders at work :

proceedings of a conference held at the University of Surrey, Guildford, 13-15 April 1987. 1. Musculoskeletal system-Wounds and injuries 2. Industrial accidents I. Buckle, Peter 617'.47044 RD732

ISBN. 0-85066-381-4

Printed in Great Britain by Ta ylor & Francis (Printers) Ltd, Basingstoke, Hants.

CONTENTS

Introduction

A Review of Epidemiological Research on Risk Factors of Low Back Pain HiZdebrandt, V.

Physical Work Environment and Musculoskeletal Disorders i n the Busdriver 's Profession Kompier, M - , dg Vries, M., van Noord, F . , MuZders, H . , ~rleijman, T. and Broersen, J .

Physical Work Load and Musculoskeletal Disorders i n the Engineering Industry Leino, P. and Hasan, J .

The Spinal Engine and Its Gearbox .

Gmcovetsky , S. and Carbone, A .

Computer-Aided Analysis of Trunk and Shoulder Posture KeyserZing, W.M., Fine, L. J . and Punnett, L.

Arm-lift Strength Variat ion Due t o Task Parameters Kwnar, S.

Portable Microcomputer Based Technique f o r Posture o r Act iv i ty Recording i n the F i e l d CZark, A.G., Brome, K . , MadeZey, R. and Ridd, J.E.

Evaluation of Work P o s t u r e . 1 , A Model f o r Evaluation of Seated Work Tasks EkZund, J. A. E. , Zettergren, S . and Odenrick, P.

2 Contents

Evaluation of Work Postures. 2 . Measurement and Analysis of Work Postures i n the F ie ld Odenrick, P,, EkZund, J .A .E. , Zettergren, S. and Brtengren, R. 56

Evaluation of Work Postures. 3 . Workplace Design f o r Crane Drivers i n a Steelworks Zettergren, S., EkZund, J . A . E. and Odenrick, P. 6 2

One Year.'s Not i f ica t ions of Back I n j u r i e s t o t h e ~ a t i o n a i Society Securi ty Off ice , Especial ly with Respect t o Nature of Cause, Medical Diagnoses and Consequences Josefsen, K., Boss, A.H., Andersen, V , and Biering-Sorensen, F .

An Epidemiologic Study of Postural R i s k Factors f o r Back Disorders i n Industry Punnett, L . , Fine, L.J. and Keyerling, W.M.

Risk f a c t o r s i n Back Pain Porter, R, W.

One Year's Not i f ica t ions of Back I n j u r i e s t o t h e National Social Secur i ty Office. A Demographic Description Andersen, V . , Boss, A. H . , Joszfsen, K. a d Biering-Sorensen, F .

Working Postures and Spinal Diseases among Porphyry Quarrymen CoZombini, D. , Occhipinti, E. , Cristofo Zini, A. and Grieco, A.

Shovel Design and Back Load i n Digging Trenches van der Grinten, M.

S t a t u r e Changes and Psychophysical Ratings Associated with Repet i t ive L i f t i n g Vincent, M . , Buckle, P.W. and Stubbs, D.A,

An Epidemiological Study of Postura l Risk Factors f o r Shoulder Disorders i n Industry Fine, L. J. , Punnett, L. and Keyserling, V . M . 108

I Contents

Neck and Shoulder Complaints Among Sewing-machine Operators . Frequencies and Diagnoses i n Comparison t o a Cont ro l Populat ion ~ Z a d e r , S. , Barch HoZst, U,, DanieZsson, S . , Ferhm, F . , ICaZparnaa, M,, Leijon, K . , Lindh, M*, Markhede, G. and MikaeZsson, B. 110

RSI - The Aus t r a l i an Experience Meyer, R. H. 112

A Review of Research on Repe t i t i ve S t r a i n I n j u r i e s (RSI) Bdmer, G. and BZignauZt, I .

Carpa l Tunnel Syndrome and Associated Risk Fac to r s - A Review

.. E ~ r n e r , J . P. and Buckle, P. W.

Conservat ive Management of Carpal Tunnel Syndrome U t i l i z i n g Pyridoxine Kusdan, M. L.

A Nat iona l S t r a t egy for t h e Prevent ion and Management of RSI ~iddicoat, K. and EZZis, N .

Prevent ion of I n j u r i e s Related t o Physical S t r e s s through In t e rven t i on by Labour I n s p e c t o r s KemZert , K., KiZbom, A., NiZsson, B . , Andersson, R. and BjurvaZd, M .

R e p e t i t i v e S t r a i n I n j u r i e s among Se rv i ce Personnel on North Sea O i l P la t fo rms Waersted, M. and Westguard, R.H.

Tra in ing i n Safe L i f t i n g : Are t h e Methods Taught Used by Workers? St-Vincent, M , , Lor t i e , M. and TeZZier, C.,

T e s t s of Manual Working Capaci ty and t h e P r e d i c t i o n o f Low Back Pain Troup, J. D. G. , Foreman, T. K . , Baxter, C. E. and Brom, D.

Three Dimensional Non-Invasive Assessment of Lumbar Brace Immobil izat ion of t h e Spine Dorsky, S., Buchalter, D . , Kahanovitz, N . and Nordin, M.

The Use 0 5 the ae t t inger Test i n Pre-employment Screening Thompson, D . , Lowerson, A. and ZaZewski, M.

Reducing Upper Limb Strain Injury by Redesign: A Case Study i n the Food Processing Industry Mabey, M.H., Pethick, A. J . , Graves, R.J . and Admns, P. K.

Reducing ~ e p e t i t i v e S t r a i n and Back Pain among Bricklayers Akinmuyom, N. K.

<

Musculoskeletal Disorders among Cargo Handlers Akinmayowa, N. K. and Akintunji , I.

\

An In te rna t iona l Comparison of the Prevalence of RSI among Keyboard Operators and i t s Relat ionship t o Office Work Prac t i ces Barner,, G.

In tegra ted Biomechanical Examination o f the Musculoskeletal System ByfieZd, D.

Comparative Analysis of E l e c t r i c a l Stimulation and Exercises t o Increase Trunk Muscle Strength and Endurance Kahanovitz, N., Nordin, M . , Viola, K . , Yabut, S . , Parnianpour , M. and Mu Zvihi Z 2, M.

The Low-back Pain Prevai l ing among the Freight- container Tractor Drivers in Japan

*

Nakata, M . , ilrishiyama, K. and Watanabe, S.

Introduction of Standing Aids in the Furni ture Industry Nijboer, I. and DuZ, J .

Correlat ion between Dif ferent Tes ts of Trunk Strength Parnianpour, M . , Nordsn, M. , Moritz, U. and Kahanovitz, N .

Development of a P r a c t i c a l Method f o r Workplace Redesign t o Reduce Upper Limb St ra in Injury Pethick, A. J. , Mabey, M. H. and Graves, R. J .

THE LOW-BACK PAIN PREVAILING 'AMONG THE FREIGHT-CONTAINER TRACTOR DRIVERS IM JAPAN

M. NAKATA, K. NISHIYAMA and S. WATANABE

Degartment of Preventive Medicine, Shiga University of Medical Science, Seta, Tsukinowa-cho, Otsu, 520-21 Japan

INTRODUCTION

The containerization of liner freight has been rapidly developing in Japan since 1967, and it amounted to more than two thirds of the export and import freight in the early 1980s. About 5,800 exclusive semi-trailer tractors are active now for domestic ground transport with the 20 'p

or 40 foot-long containers. The only task of tractor drivers is driving, being free from handling of the freight, but many of them complain of low-back pain (LBP).

To make clear the causal factors of this LBP, the vibration measurement of the seat, ergonomical check of the tractors, survey on the working hours and medical examination were carried out.

METHODS

1. Vibration measurements were made on 9 kinds of popularly-used freight-container tractors with or without freight on selected public roads (80km). One heavy duty truck was also measured at the same conditions as a reference. The pick-up was set under the driver's buttocks on the seat.

The time-weighted mean of vibration level was measured according to the weighting method of IS0 2631, and the allowable exposure time was then obtained from the fatigue-decreased proficiency boundary (FDP) and exposure limit (EL) in IS0 2631.

2. Survey on the working hours and distance travelled were

(dB) and its evaluation by fatigue-decreased proficiency boundary (FDP) and exposure limit (EL) of IS0 2631.

Tractor Time Me an Allowable exposure required vibration time (min) (min) level(dB)* FDP EL

and direction

Mean : U 70 9 5 . 0 (X) 120 350 L 75"" 95.5"" ( 2 ) loo** 290""

Truck: U 68 95.7 ( 2 ) 190 480< L 62 95.0 ( Z ) 220 480 <

U : Unloaded condition. L : Loaded condition. * : Mean vibration level and its direction

which make the allowable exposure time the shortest.

* * : Calculated value frox nine X directions, + : Improved A-old motiel.

Low back pain among container tractor drivers 223

calculated from the daily working records of a month of 240 drivers. A more precise time-study was carried out on 6 drivers during 7 days to calculate the mean speed of the tractors in various routes.

From these two studies, the daily vibration exposure time was estimated on each labour day of each driver, which came to a total of 5,163 days.

3. Ergonomical evaluation of the freight-container tractors was made using an ergonomical checklist consisting of 130 items on the matters of getting in and out of the cabin, space size of the cabin, driver's seat, steering wheel, pedals, levers, visual range from the cabin, noise, vibration, condition of the air, some operations performed outside the cabin, etc. The checklist was filled in by 549 drivers.

4. Medical examination, primarily composed of orthopedic examinations and questioning on health conditions, was performed on 231 drivers whose mean age was 38.6 yrs (87% in 30-40 yrs) and whose experience as a tractor driver was 8.8+4.5 yrs on an average. -

RESULTS

1. The vibration of the tractor seat was at a high level in the X direction, equal to or exceeding that in the 2 direction, which is dominant in ordinary vehicles. So, the direction in which the allowable exposure time from the point of view of FDP and EL was the shortest was the X direction in all cases except one (see Table).

The allowable exposure time of each tractor was considerably shorter than that of the heavy duty truck.

2. In more than 90% of the 5,163 work-days, the driving hours (estimated vibration exposure time) exceeded the allowable exposure time from the viewpoint of FDP, and in more than 30% exceeded the allowable exposure time from that of EL.

3. The ergonomical check on the tractors revealed various problems, among which there were many concerned with muscle fatigue, for instance, difficulties in getting in and out of the cabin, narrow foot space of the cabin, unfitness of the driver's seat to the driver's body, difficulties in using pedals and gearshift,steering wheel

2 24 Musculoske le ta l d i s o r d e r s a t work

F i g u r e 1. P o s i t i v e r a t e o f t e n d e r n e s s t e s t o n v a r i o u s m u s c l e s o f t h e r i g h t s i d e o f b o d y . ( T h e r e s u l t s o n t h e l e f t s i d e i s s i m i l a r t o t h i s e x c e p t t h e n a r m u s c l e s . ) S y m b o l s ; s e e F i g u r e 2 .

P o s i t i v e r a t e ( %

S t e r n o m a s t o i d

T r a p e z i u s

Levator scapulae

Rhornbo ide i

I n f r a s p i n a t u s P e c t o r a l i s

B i c e p s b r a c h i i E x t e n s o r s o f

t h e f o r e a r m F l e x o r s o f

t h e f o r e a r m 1st d o r s a l

T h e n a r m u s c l e s

E r e c t o r s p i n a e ( t h o r a c i c ) E r e c t o r s p i n a e ( l u m b a r ) Q u a d r a t u s

lumborum

G l u t e u s m e d i u s

S a c r o - i l i a c j o i n t r e . g i o n

G l u t e u s maximu B i c e p s f e r n o r i s ( u p p e r p a r t ) B i c e p s f e m o r i s ( l o w e r p a r t ) Semimembranosu

P o p l i t e a l f o s s

G a s t r o c n e m i u s

T e n d o c a l c a n e u

Low back pa in among conta iner t r a c t o r d r i v e r s 225

Z i g u r e 2 . P o s i t i v e r a t e ~f t e n d e r n e s s a n d / o r p e r c u s s i o n - p a i n t e s t o n t h e s p i n o u s p r o c e s s e s b y t h e g r a d e o f l o w - b a c k c o m p l a i n t s -

r a t e o f p a i n ( % ) 0 10 20 3 0 40 50 6 0

t I I 1 I I 1

(I)

a, (I) (I) Q)

U 0 k a

m 3 0 C . rl

a m

o m p l a i n t s s c a r c e

t a t e e

226 Musculoskeletal disorders at work

being hard to turn, the necessity of frequently bracing the legs to support the body on severe vibration or shock, etc. All of these were pointed out by more than half of the drivers.

4. Prevailing complaints were dullness or stiffness of the shoulders in 71%, dullness of the neck in 699'0, dullness of the low-back in 6276, LBP in 42%, dullness of the lower limbs in 39% and dullness of the back in 36%.

The rates of complaints of dullness or pain of neck, back, or lower limbs, and disturbance of daily activity were associated with the grade of LBP evaluated from the subjective symptoms.

Orthopedic examination revealed an increased tonus or fatigue sign of muscles of the body trunk and limbs, i.e., a high positive rate of tenderness (see Figure l), percussion pain on the spinous processes (see Figure 2), and poor results in the tests on back and abdominal muscle strength and durability.

These findings were seen mope frequently in the group with subjective symptoms, but also among the group without symptoms in some degree, suggesting the existence of latent LBP cases.

From these findings, the characteristic of the LBP prevailing among the freight-container tractor drivers seems to originate in the accumulated or chronic fatigue mainly extending over a wide area of the erector spinae.

Moreover, that fatigue was recognized as that derived from daily exposure to the severe vibration of the tractor for a long time and ergonomically problematic conditions of the tractor which demand strong muscle power or continuous~static tension of muscles.

REFERENCES

International Organization for Standardization, 1978, Guide for the evaluation of human exposure to whole-body vibration, 2nd edn (IS0 2631-1978 ( E ) ) .

Nakata, M. & Nishiyama, K., 1986, Labor of freight-container tractor drivers and low-back pain: correlation with whole-body vibration exposure. Japanese Journal of Industrial Health, 28, ~341-351.