Biomechanical Measurement of Painful Wrist by Flexible Electro-goniometry
Wrist pain is a common complaint in hand clinics. More and more computer programmers, typists and TV game addicts sustained wrist pain because of cumulative trauma disorders. The general wrist examinations only record statically the terminal wrist range in flexion/extension and ulna/radial deviation. To evaluate the functional range of motion of an injured joint during motion is very significant for clinical application in pain prevention and treatment determination. Flexible electro-goniometry offers a convenient method to investigate joint kinematics in clinical environment. The flexible electro-goniometer consists of a central strain gauged flexible shim with two end sensors attached to the shim for detecting relative motion between these two ends. The patient can comfortably wear the flexible electro-goniometer while performing their daily activities without any hindrance. This study attempted to measure the functional range of wrist motion by flexible electro-goniometer and provide a biomechanical model for clinical application.
This study recruited thirteen subjects with wrist pain of different causes. The flexible electro-goniometer was worn on the dorsal aspect of the wrist and forearm to detect the angle changes in wrist motion. The subject was asked to perform wrist flexion-extension, radial-ulnar deviation as well as clockwise/anti-clockwise circumduction movements under three forearm positions (pronation, neutral position, and supination). The painful points and ranges during movement were also marked simultaneously. After completing the regular treatment, one subject was assessed for improvement in ranges of motions. The angular data were plotted to show the range and loci of the wrist motion for biomechanical analysis. The circumduction index (CI) was introduced to represent the size of the wrist circumduction. The results showed the various characteristics of the pain points during wrist motion of the different diagnosis groups. The CI value of the subject improved very much in the follow-up measurement. This study demonstrates the current method is useful in clinical application and may lead to an efficient investigation protocol for wrist evaluation, treatment and biomechanical interpretation.