Analysis of Jobs for Control of Cumulative Trauma Disorders

Abstract

Cumulative Trauma Disorders (CTD) such as carpal tunnel syndrome, tenosynovitis, and strains are a common health problem among people who perform repetitive work with their hands. Repeated exertions and movements with certain hand postures, stresses on the surface of the hand and arm, vibrations, low temperatures, and use of gloves all have been identified as factors of CTD. To facilitate identification of these factors, a job analysis procedure based on traditional work measurement techniques was developed. Jobs are first divided into sequences of acts or elements; postures, forces, and other physical factors associated with each element then are determined. This process is facilitated by a video tape system that is used to film the job and can be played back in slow motion. A microcomputer is used to facilitate recording and storage of element sequences. Surface electromyograms of the medial forearm are calibrated and recorded on videotape for estimation of forces exerted with the hand. Finally, recommendations for control of CTD are based on identification of stressful elements.