Ergonomic comparison of operating a built-in touch-pad pointing device and a trackball mouse on posture and muscle activity

This study examined the effects of operating a built-in touch-pad pointing device and a trackball mouse on participants' completion times, hand positions during operation, postural angles, and muscle activities. 8 young men were asked to perform a cursor travel task on a notebook computer using both 60- and 80-cm high table conditions. Analysis showed that the trackball mouse significantly decreased completion times. Participants selected a hand position farther from the table edge and larger elbow angle for the trackball mouse than for the built-in touch-pad pointing device. Participants' neck, thoracic, and arm angles, or splenius capitis, trapezius, deltoid, and erector spinae muscle activities were not significantly affected by the devices, but table height significantly affected participants' completion times, hand positions, and postural angles.