Physiological, performance, and subjective effects of eight computer input devices at a standing computer workstation

Abstract

This study compared eight non-keyboard input devices in conjunction with a standing fatigue study. The rapid growth in the use of graphical user interfaces (GUI's) has caused an increase in the use of nonkeyboard input devices. Further, the limited amount of literature available on non-keyboard input devices, especially studying standing input device usage, has caused concern about the increased usage. Eight subjects (4 male and 4 female) used each of the eight input devices (IBM Options mouse, Logitech Sensa mouse, Microsoft mouse 2.0, Logitech Trackman trackball, MicroSpeed trackball, Logitech Portable trackball, Glidepoint touch pad, and PC Stylus mouse pen) for two hours on each of two consecutive days. This study used physiological, performance, and subjective measures to determine differences between the input devices. The physiological measures used included the following: finger tip temperature, hand temperature, forearm temperature, arm volume, systolic and diastolic blood pressures, median nerve conduction velocity, and finger tip vibration sensitivity. The performance measure used was a simple tracking test with three different target presentation speeds, Subjective measures included perceived levels of pain and discomfort (body part discomfort survey), a specific input device features survey and an overall ranking. The following measures showed statistical significance for individual input devices: arm volume, all three presentation speed tracking performance tests, the input device features survey, and overall ranking. Further analysis showed significance for input device types (mice, trackballs, and 'others') for all of these measures except arm volume. The other measures taken during the experiment (arm, hand, and finger temperature, systolic and diastolic blood pressure, vibration sensitivity, nerve conduction time, and body part discomfort), while not showing strict statistical significance for the different devices, all indicated trends away from zero and may be indicators of work load or fatigue. Throughout the experiment, mice were shown to be superior to the other input devices in both performance and preference. There was, however, no one mouse clearly better than the rest. The best trackball was the Logitech Trackman, with performance and preference ratings often not significantly different from the mice.