BACKGROUND: Screwdrivers are a standard tool in all metal and wood processing jobs.
To prevent work-related injuries in the upper extremities, an ergonomic and safe design of the tool is indispensable.
OBJECTIVE: In this comparative ergonomic study, the ergonomic quality of various screwdriver handles from European manufacturers, which exhibited decisive differences in the design aspects “shape”, “dimension”, “material” and “surface”, was tested.
METHODS: Twenty-one male right-handed test subjects had to carry out different screw-driving tests. Before and after the tests, the subjects had to assess specific criteria of the handles such as handling, design features and material. Furthermore, they were asked to express potential physical complaints in the fingers, hand and forearm with respect to intensity and occurrence. In order to reveal possible model-specific differences in operational performance and in muscle strain, maximum exertable torque measurements were carried out, and the associated electromyographic activity (EA) of four muscles involved in different screw-driving tasks was measured via surface electromyography.
RESULTS: The results from the determined EA data and the users’ subjective perceptions while handling the screwdrivers, showed a great impact of the design features “shape”, “dimensions”, “material” and “surface”.
CONCLUSIONS: Only those screwdrivers designed according to appropriate ergonomic criteria enable a high operational performance with reduced physiological costs that have to be paid by the muscles.
