Evaluation of an Electrogoniometer for Wrist Position Measurements

Abstract

In evaluating work tasks, electrogoniometers provide a simple tool for assessing wrist postures and motions. However, crosstalk and zero drift erode the accuracy and reliability of these devices. As a result, a revised biaxial electrogoniometer has been developed specifically designed for measuring wrist posture. The manufacturer claims that it addresses the problem of increased error rates associated with forearm rotation and extreme wrist angles by incorporating a shorter length flexible wire between the two telescopic ends. This study evaluated the electrogoniometer to determine if accuracy and reliability are improved as compared to results of other studies using similar devices and methods. Overall, the revised device significantly reduces crosstalk and zero drift, but it is unclear to what extent the revised device contributed to the reduction in error versus procedural changes, which included recalibration of the device between different levels of pronation and supination of the forearm. Forearm rotation was significant in determining error and zero drift for both flexion/extension and radial/ulnar measurements, and the amount of error and zero drift significantly increased for more extreme wrist angles. Gender, hand length percentile grouping, and order of angle presentation did not significantly affect electrogoniometric readings.