This study assessed the effects of a wrist rest for VDT operators via an experimental investigation. Muscular strain associated with the working posture was measured continuously via electromyographic activities (EA) of 8 muscle groups which were involved in the working tasks. The electromyographic measurements yielded a clear systematical effect of the wrist rest while entering text using the 10-finger touch system. Values of the EA – as an indicator of “physiological cost” – were essentially lower with the wrist rest. Working without the wrist rest is at least two times more strenuous than working with it. The differences are statistically highly significant. Less positive and less consistent results were found while working on the prefixed mousepad of the wrist rest. Considering the influence of the working aid on entering text, the results of the subjective assessment after the tests corresponded well with the objectively measured physiological data. Whereas the working aid for entering text was assessed quite positively overall, the integrated mousepad earned a clearly negative rating.