A STRESS STRENGTH INTERFERENCE MODEL FOR PREDICTING CTD PROBABILITIES

A model for predicting the incidence rate of carpal tunnel syndrome (C TS) for a given job, was developed using known biomechanical data, mec hanical properties of human tendons and reliability engineering techni ques to simplify the problem. In addition, time-dependent stress-stren gth interference theory was used to quantify the stress on the tendons during a job cycle, based on wrist position and grip strength and to estimate the tendon failure rate (or CTS incidence) for a given job. H igher failure probabilities were predicted for greater wrist deviation s, for higher grasp forces, for females as compared to males, for wris t extension as compared to wrist flexion, and for two-fingered pinches as compared to four-fingered grasps. The predictions closely matched previously reported CTS incidence rates for a poultry thigh boning tas k.