Upper extremity impairment in workers performing repetitive tasks.

A series of subjective and objective measures were chosen to determine impairment of upper extremity function in 157 workers performing repetitive tasks. Workers were asked to respond to questions regarding their perception of the presence or absence of numbness, pain, weakness, or swelling in their upper extremities. Objective tests consisted of the measurement of grip strength, pinch strength, Semmes-Weinstein monofilament sensory responses, vibrometer responses, neurometer measurement, and the presence or absence of Tinel's or Phalen's signs. These measures were considered collectively to estimate the overall levels of impairment of each individual. Overall findings show that 55 percent of workers examined had impairment scores of 2 or more and 75 percent had scores of 1 or more. Significant differences were found in impairment ratings between job types. Those jobs requiring the highest repetition with the least rest per cycle had the highest impairment ratings. Workers that rotated jobs had impairment scores significantly less (p less than 0.005) than the average of workers performing single-task jobs. We conclude that cumulative trauma disorders are more prevalent than originally believed and that the disorder is best examined from an overall functional impairment perspective.