FLEXIBLE ELECTROGONIOMETERS - KINESIOLOGICAL ADVANTAGES WITH RESPECT TO POTENTIOMETRIC GONIOMETERS

Unlike conventional potentiometric goniometers, flexible electrogoniom eters do not suffer from any alignment problems with respect to the jo int axis. We hypothesized that flexible goniometers provide more valid measurements in that they avoid some biomechanical pitfalls. With bot h devices simultaneously we measured the movements of dorsal flexion o f the ankle and flexion of the knee in three healthy subjects. In the various subjects, this comparison showed that the flexible goniometers signalled ankle excursion greater by 19-40% with the foot remaining i n neutral position or being simultaneously pronated, and lower by 10-2 1% with the foot being simultaneously supinated. At the knee the flexi ble goniometers signalled a flexion greater by 24-32%, with respect to potentiometric goniometers. Biomechanical considerations support the validity of records taken with flexible goniometers, potentiometric me asures being biased by (a) multijoint, multiplane motions underlying f oot dorsal flexion, and (b) multiaxis motion underlying knee flexion R elevance In measurements of angles between adjacent body segments, fle xible goniometers should be preferred to potentiometric goniometers de spite their higher cost. Flexible goniometers not only are more practi cal: more importantly, they provide a valid measure of relative orient ations in one plane, regardless of the number and different concurrent motions of the underlying joints.