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Workload in lower arm and shoulder when using manual and powered screwdrivers at different working heights

1991; Elsevier BV; Volume: 8; Issue: 3 Linguagem: Inglês

10.1016/0169-8141(91)90034-j

1872-8219

Roland Örtengren, Tony Cederqvist, Mats Lindberg, Bo Magnusson,

Musculoskeletal pain and rehabilitation

Manual screwdriving still plays a significant part in electrical installation work in Sweden and elsewhere in the world. The aim of the present study was to investigate the workload when using manual and battery powered screwdriwers, screws, screwhead types and working postures. Rms detected myoelectric signals were recorded form the forearm and shoulder of ten experienced male wiremen. The applied axial force against the workpiece was recorded with a force transducer. Ratings of perceived exertion and preferred working pace were also recorded. Results were tested statistically by means of ANOVA. The results show that the workload when inserting screws manually is high enough to cause symptoms of overload disorders. Battery-powered scewdrivers reduce the load in the forearm to more favourable levels at all working heights. In the shoulder working height and screw type have greater influence. Axial force and ratings of perceived exertion were significantly lower with TORX type screws. Use of a powered screwdriver consistently increased the work pace. The study also shows that many factors influence the workload and sometimes interact, which must be considered when inserting screws in construction work.