Providing Training Enhances the Biomechanical Improvements of an Alternative Computer Mouse Design

OBJECTIVE The purpose of this study is to determine if an alternative mouse promotes more neutral postures and decreases forearm muscle activity and if training enhances these biomechanical benefits. BACKGROUND Computer mouse use is a risk factor for developing musculoskeletal disorders; alternative mouse designs can help lower these risks. Ergonomic training combined with alternative input devices could be even more effective than alternative designs alone. METHODS Thirty healthy adults (15 males, 15 females) performed a set of computer mouse tasks with a standard mouse and an alternative mouse while an electromagnetic motion analysis system measured their wrist and forearm postures and surface electromyography measured the muscle activity of three wrist extensor muscles. Fifteen participants received no training on how to hold the alternative mouse, whereas the remaining 15 participants received verbal instructions before and during use of the alternative mouse. RESULTS The alternative mouse was found to promote a more neutral forearm posture compared with the standard mouse (up to 11.5 degrees lower forearm pronation); however, pronation was further reduced when instructions on how to hold the mouse were provided. Wrist extensor muscle activity was reduced for the alternative mouse (up to 1.8% of maximum voluntary contraction lower) compared with the standard mouse, but only after participants received instructions. CONCLUSION The alternative mouse design decreased biomechanical exposures; however, instructions enhanced this potential ergonomic benefit of the design. APPLICATION User knowledge and training are important factors when effectively implementing an alternative ergonomic device.