Instrumented parallel bars for three-dimensional force measurement.

This paper describes the modification and instrumentation of standard parallel bars to allow for the measurement of applied forces on both horizontal bars in three dimensions. This measurement system has been used in the development and evaluation of functional electrical stimulation (FES) devices for standing and gait restoration in paralyzed patients. Real-time measurement of forces applied by the upper body of the patient to the parallel bars is of use in the evaluation of FES stimulation patterns (or automatic controllers of stimulation). Such measurements are useful in the redesign of stimulation patterns and/or stimulation controllers.