An Analyzing Method for Finger Motion of Mobile Phone Operation

摘要

Recent reports have indicated increasing repetitive strain injury (RSI) in association with increased text messaging and e-mail use by mobile phone users. RSI symptoms can cover a wide range, from fatigue and physical weakness to sensory paralysis. The forms of RSI apparent in this case with use of mobile phones are carpal tunnel syndrome and tendonitis. The reduced size of mobile phones ensures that key input requires increased use of the thumb. The purpose of the present research was to clarify the characteristics of movement of the thumb during the operation of mobile phones, in order to provide proposals for future design modifications to such devices. As no established methods currently exist for measuring load applied to tendons, electromyography was employed to measure the load applied to the muscles of the thumb. Electromyography of the thenar eminence, long abductor muscle of thumb, and short abductor muscle of thumb revealed a dramatic reaction in the thenar eminence.