Direct Measurement Error Identification and Reporting for Upper Extremity Exposure Assessment

Abstract

Electrogoniometers currently represent the most feasible way of obtaining direct measurements of wrist and forearm posture and motion in varied work environments. Researchers have shown that a significant amount of error may be present in the recordings from these instruments (Buchholz and Wellman, 1997; Armstrong et al., 1993). This study showed that even with “state of the art” correction methods, wrist flexion/extension and wrist deviation duration measurements may still vary by as much as 100% plus or minus the measured result in the 95% confidence interval. Forearm extreme posture duration intervals were equal to or less than 40% of the calculated values. Wrist flexion/extension and forearm rotation repetition measurements were more accurate, giving confidence intervals plus or minus less than 25% of the resulting values. Wrist deviation repetition confidence intervals were wider, at plus or minus 100% or greater and generally including zero. These results highlight the need to address accuracy when reporting measurements of the upper extremities and to promote further research into the development of accurate measurement methods.