Measurement of the Mechanical Energy Absorption in the Hand and Arm Whilst Using Vibrating Tools

Abstract

The mechanical energy absorption in the human hand and arm during exposure to simulated vibration from five common types of hand-held tools within the frequency range of 5 to 1500 Hz, has been directly measured and indirectly determined. The study was carried out on ten healthy subjects, five males and five females. A special handle was used during the measurements. The influence of various experimental conditions, such as vibration level, vibration direction and grip force were also studied. The results show that the energy absorption depends upon the frequency spectra of the tools. The differences between the amount of absorbed energy for the hand-held tools correspond to a factor 3.1 although the frequency weighted acceleration is equal. Furthermore, the results show that experiments conducted with different exposure directions have a significant influence on the amount of absorbed energy. On the other hand, the grip force has only a minor influence. The results also show that it is possible to theoretically calculate the amount of absorbed energy by using the vibration characteristics for the hand-held tool and the mechanical characteristics of the hand and arm.