Evaluation of an Experimental Testing System for Non-Powered Hand Tools

Abstract

During the Eurohandtool Project an experimental testing system for non-powered hand tools was developed for laboratory testing. With this system, it is possible to measure simultaneously (1) the EMG activity of two muscles, (2) the opening angle of hand tool blades by means of a potentiometer and, (3) by means of strain gages, the force transmitted to the handle. The first part of evaluation of the system was to determine its time of warming-up, reliability, linearity and repeatability. This paper concentrates on the second part, during which the aim was to test the measurement system by comparing the forces needed to cut wood of a certain diameter, and the actual force required, as measured by a material-testing system. The correlation between forearm flexor muscle activity and the compression force created by the user was investigated. The evaluation of experimental testing system for non-powered hand tools has shown that there are methods to measure force demand, opening angle and EMG-activity simultaneously. However, it is recommended to make some improvements before this measurement system can be taken into widespread use.