Practical Operation of a Biaxial Goniometer at the Wrist Joint

Abstract

The objectives of this study were (a) to determine errors in wrist angle measurements from a commercially available biaxial electrogoniometer and (b) to develop a calibration routine in order to correct for these errors. Goniometric measurements were collected simultaneously with true angular data using a fixture that allowed wrist movement in one plane while restricting motion in the orthogonal plane. These data were collected in two sets of trials: flexion/extension with radial/ulnar deviation restricted, and radial/ulnar deviation with flexion/extension restricted. During these trials, we studied discrete 30 degrees increments of forearm rotation. The results showed the expected cross talk and zero drift errors during forearm rotation. The application of mathematical equations that describe the effect of goniometer twist resulted in significant error reduction for most forearm rotations. The calibration technique employs both a slope and a displacement transformation to improve the accuracy of angular data. The calibration technique may be used on data collected in the field if forearm rotation is measured simultaneously with the goniometer data.

Wrist electrogoniometry: are current mathematical correction procedures effective in reducing crosstalk in functional assessment?

“…Thus, better correction results are expected in the greater ROM. Furthermore, for functional data, small modifications in ROM, such as 6° found by Buchholz and Wellman 20 , had little impact on the correction of data 7 .…”

“…bone structure, fat, muscle, skin flexibility, which can contribute towards the different ranges of rotation between the sensor enblocks 20 .…”

“…This phenomenon takes place in the wrist joint, for example, when ulnar/radial deviations are recorded during the performance of pure movements of flexion/extension and vice-versa 19 . According to Hansson et al 1,2 and Buchholz and Wellman 20 , the crosstalk in the electrogoniometric recording of the wrist occurs due to the rotation of the forearm, as part of this movement is transferred to the wrist sensors.…”

“…Previous studies have suggested procedures for the correction of errors arising from crosstalk due to sensor rotation 7,20 and for differences between identical sensors 22 . In both cases, there was a reduction in errors.…”

The effect of wrist rests and forearm support during keyboard and mouse use

“…The goniometers were positioned while the participants were sitting, elbows at 90 with their wrist in neutral and forearms in pronation resting on the desk surface. Reference lines were drawn over anatomical landmarks to enable accurate positioning of the goniometers (Bucholz and Wellman, 1997;Biometrics, 1999). Left and right electrogoniometers were calibrated in a neutral position.…”