Computer use and ulnar neuropathy: results from a case-referent study

We aimed to evaluate associations between vocational computer use and 1) ulnar neuropathy, and 2) ulnar neuropathy- like symptoms as distinguished by electroneurography. We identified all patients aged 18-65 years, examined at the Department of Neurophysiology on suspicion of ulnar neuropathy, 2001-2007. We mailed a questionnaire to 546 patients with ulnar neuropathy, 633 patients with ulnar neuropathy-like symptoms, and three community referents per case, matched on sex, age, and primary care centre. From a Job Exposure Matrix we extracted estimates of daily hours of computer use. The analysis was performed by conditional logistic regression.There were a negative association between daily hours of computer use and the two outcomes of interest. Participants who reported their elbow to be in contact with their working table for 2 hours or more during the workday had an elevated risk for ulnar neuropathy (OR=2.16, 95 % CI; 1.06-4.44).The two outcomes were not associated with daily hours of computer use. Findings suggested specific effects of pressure on the elbow, and might be an explanation for the overweight of left-sided outcomes in this primarily right-handed group. Preventive efforts would then be straightforward by providing appropriate arm support for the left arm and elbow.