Development and validation of an electrogoniometric wrist alignment device

This paper reports the development of an instrumented flexible electrogoniometric hand posture corrective device designed specifically for monitoring and controlling the range of motion (ROM) at the hand and wrist. The device, known as the wrist alignment device (WAD), consists of flexible electrogoniometers attached to a Lycra glove and a control box housing the WAD circuitry. The WAD controls the wrist ROM within set limits by means of presetting the joint angle ranges prior to commencing measurements, thereby preventing or reducing extreme wrist ulnar deviation, wrist hyperflexion, and wrist hyperextension. Additionally, the device consists of a window comparator, which allows the joint movement always to remain within the set limits. Where the subject's wrist ROM is outside the presettings, a piezo-buzzer is triggered which alerts the subject to reduce the ROM, thereby ensuring that the joint angles are always kept within the preset angle range. All instrumentation associated with the development of the device underwent calibration. As a device, it has widespread applications within the office and clinical environment. Preliminary results indicate that reliable measurements based on ROM settings can be obtained when using the WAD.