Measuring and characterizing force exposures during computer mouse use

Objectives The purpose of this study was to develop and validate a sampling strategy for characterizing the finger force exposures associated with com puter mouse use. Methods Mouse forces were measured from 16 subjects (8 men, 8 women), on 3 separate days, at their actual workstations while they performed (i) their regular work, (ii) a battery of standardized tasks, and (iii) simulated mou se use. Results The forces applied to the mouse did not vary between hours or days. During regular work, the mouse was used 78.0 (SD 40.7) times per hour, acc ounting for 23.7 (SD 9.5) % of the worktime. The mean forces applied to the sides and button of the mouse were low, averaging 0.6 % (0.35 N) and 0.8 % (0.43 N) of the maximal voluntary contraction, respectively. The forces ap plied to the mouse during the standardized tasks differed from the regular work forces; however, there were moderate-to-strong correlations between th e 2 measures. Conclusions With respect to performing exposure assessment studies, the 3 m ajor findings were (i) mouse force measurements should be made while subjec ts perform their actual work in order to characterize the absolute applied force accurately, (ii) the forces applied to the mouse during the performan ce of a short battery of standardized tasks can be used to characterize rel ative exposure and identify computer operators or work situations for which higher forces are applied to the mouse, and (iii) subjects cannot accurate ly simulate mouse forces.