Force and frequency in manual handling tasks are known risk factors for work related upper arm disorders. Three force levels and three frequencies are used to define the external load in a pinching task. The effects of these external loads on subjective and objective responses are studied. Subjective ratings poorly reflect the levels of external load. EMG variables P50 en P10 of the prime mover muscle seem useful variables in evaluating the effects of task frequency above a certain threshold in task frequency. P90 of the prime mover muscle is useful in evaluating the effects of external forces. It can be concluded that the P50 does not reflect the differences in force levels in tasks with low intensities.
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References
1.
ArmstrongT.J.BuckleP.FineL.J.HagbergM.JonssonB.KilbomA.KuorinkaI.A.A.SilversteinB.A.SjogaardG.Viikara-JunturaE.R.A.1993, A conceptual model for work-related neck and upper-limb musculoskeletal disorders, Scandinavian Journal of Work, Environment and Health (19), 73–84.
2.
BrogmusG.E.SorockG.S.WebsterB.S., 1996, Recent trends in work-related cumulative trauma disorders of the upper extremities in the United States: an evaluation of possible reasons, Journal of Occupational and Environmental Medicine, (38–4), 401–411.
3.
ChaffinD.B.AnderssonG.B.J.MartinJ.M., 1999, Occupational Biomechanics, Whiley & Sons, New York.
4.
CherniakM.G., 1996, Epidemiology of occupational disorders of the upper extremity, Occupational Medicine: State of the Art Reviews, (11–3), 513–530.
5.
JensenB.R.GardeA.H., 1998, Forearm muscle load and external force during repetitive work, in: KumarS. (ed), Advances in Occupational Ergonomics and Safety, IOS press, Amsterdam.
6.
JensenC.NilsenK.HansenK.WestgaardR.H., 1993, Trapezius muscle load as a risk indicator for occupational shoulderneck complaints, Int. arch. Occup. Environ. Health, (64), 415–423.
7.
JonssonB., 1978, Kinesiology - witj special reference to electromyographic kinesiology. Contemp. Clin. Neurophysiol. (34), 417–428.
8.
KumarS.LecheltE.C., 1999, Comparative resolution of metabolic and psychophysical variables in discriminating between small-difference low-demand lifting tasks, International Journal of Industrial Ergonomics, (24), 61–71.
9.
KurppaK.Viikari-JunturaE.KuosmaE.HuuskonenM.KiviP., 1991, Incidence of tenosynovitis, peritendinitis and epicondylitis in a meat processing factory, Scandinavian Journal of Work, Environment and Health, (17), 32–37.
10.
OttenF.BongersP.HoutmanI., 1998, De kans op RSI in Nederland. Gegevens uit het permanent onderzoek leefsituatic 1997, Maandbericht Gezondheidsstatistiek, (17–11), 5–19.
11.
SchüldtK.EkholmJ.Harms-RingdahlKArborcliusU.P.NemethG., 1987, Influence of sitting postures on neck and shoulder EMG during arm-hand work movements, Clinical Biomechanics (2), 126–139.
12.
SilversteinB.A.FineL.J.ArmstrongT.J., 1987, Occupational factors and the carpal tunnel syndrome, American Journal of Industrial Medicine, (11), 342–358.
13.
SilversteinB.A.FineL.J.ArmstrongT.J., 1986, Hand-wrist disorders in industry, British Journal of Industrial Medicine, (43), 779–784.
14.
SmutokM.A.SkrinarG.S.PandolfK.B., 1980, Exercise intensity: subjective regulation by perceived exertion, Arch. Of Physical Med. Rehab., (61), 569–574.
15.
VeierstedK.B.WestgaardR.H.AndersenP., 1993, Electromyographic evaluation of muscular work pattern as a predictor of trapezius myalgia, Scandinavian Journal of Work, Environment and Health, (19), 284–290.
16.
VeierstedK.B.WestgaardR.H.AndersenP., 1990, Pattern of muscle activity during stereotyped work and its relation to muscle pain, Int. Arch. Occup. Environ. Health, (62), 31–41.
17.
WestgaardR.H.JansenT.JensenC., 1996, EMG of neck and shoulder muscles: the relationship between muscle activity and muscle pain in occupational settings, in: KumarS.MitalA. (eds), Electromyography in ergonomics, Taylor and Francis, London, 227–258.
