Influence of the long term use of a computer on median, ulnar and radial sensory nerves in the wrist region

Repetitive microtrauma or overuse injuries may often affect upper extremities of the long term computer users. The aim of this study was to compare sensory nerve conduction velocities (SNCV) for median, radial and ulnar nerves in the wrist of computer users with the same parameters in controls who do not use computers regularly. Twenty one male computer users (age: mean (M) = 28.3 years +/- standard deviation (SD) = 7.5 years) and 21 male control subjects (age: M +/- SD = 24.1 +/- 4.6 years) were recruited for the study. Limb length and the perimeters of the dominant arm and forearm were measured for each subject. The neurophysiological study consisted of measuring sensory nerve conduction of the median, ulnar and radial nerves. The sensory conduction velocities of both median and ulnar nerves were significantly delayed in the dominant arm of the computer users compared to the controls. In addition, sensory conduction velocity of the median nerve was significantly delayed in the dominant extremity of the computer users compared to their non-dominant extremity. This study shows that computer users have a tendency toward developing median and ulnar sensory nerve damage in the wrist region. Mechanism of delayed SNCV in the median and ulnar nerves may be due to sustained extension and ulnar deviation of the wrist during computer mouse use and typing. Reduced SNCV changes were more apparent on the dominant side of the median nerve. This may indicate the increased neural deficits related to an increased use of the dominant side. Further investigation is needed to determine how to reduce potential risk factors at this stage in order to prevent development of median or ulnar neuropathy in the long term computer users.