Certain muscle activities (e.g. static muscle activities for prolonged periods of time) and resultant movement patterns may be associated with the development of cumulative trauma disorders. Currently, there is no simple, well-defined measure to discern if a muscle is performing a static or dynamic activity. In this paper, we present the results of a simple study designed to investigate whether the standard deviation (SD) of sEMG is an effective method of identifying muscle dynamicity. Participants completed two separate tasks with a desktop touchscreen deviceone requiring static muscle movements and the other to elicit dynamic movements while we measured muscle activity. The SD was more was more varied (M = 4.8 .4% MVC) during the dynamic task compared to the Static task (M = 2.5 0.2% MVC). Participants muscles had a lower Mean (exertion) (M = 7.3 0.8% MVC) in the dynamic task compared to the Static task (M = 11.6 1.1% MVC). This interaction of measure and task was significant, F(1,18) = 72.23, p < .001, 2 = 0.80. Thus standard deviation of sEMG was found to be a valid measure of muscle dynamicity.
name of conference
Proceedings of the Human Factors and Ergonomics Society
