Get a Grip: Analysis of Muscle Activity and Perceived Comfort in Using Stylus Grips of Touchscreen Tablet Computer

The design of handwriting instruments has been based primarily on touch, feel, aesthetics, and muscle exertion. Previous studies make it clear that different pen characteristics have to be considered along with hand–instrument interaction in the design of writing instruments. This should include pens designed for touch screens and computer based writing surfaces. Hence, this study focuses primarily on evaluating grip style’s impact on user comfort and muscle activity associated with handgrip while using a stylus-pen. Surface EMG measures were taken approximate to the first dorsal interosseous, extensor digitorum, and flexor carpi radialis of three participants while they performed writing, drawing, and point-and-click tasks on a tablet using a standard stylus and three grip options. Participants were also timed and surveyed on comfort level for each trial. The preliminary subjective measures indicate that the use of grips is perceived as more comfortable than standard stylus use alone. We hypothesize that EMG results that are being analyzed, will correlate with user comfort and muscle activity will transfer from increased fine muscle activity to increased gross muscle activity with grip use. Results of the study should be applicable in improving the stylus grip design of tablet computers.