Exposure-Response Relationships for Force and Repetition, and CTS

Abstract

Carpal tunnel syndrome (CTS), though widely investigated, remains a troubling and costly disease for both employers and workers. Recent studies have consistently shown that combinations of force and repetition are occupational risk factors for CTS. However, it remains unclear which of these two factors is primarily responsible for the increase in risk. This study uses pooled prospective data to compare exposure-response relationships for peak force and several measures of repetition, including the integrated measure of peak force and hand activity level, the ACGIH TLV for HAL. Results suggest that peak force acts as an independent risk factor for CTS, while repetition is only a risk factor if the exertions are “forceful”. Thus, it appears that applied hand/wrist force is the dominant occupational physical exposure risk factor for CTS.