Development of a force sensing walker for rehabilitation

The purpose of this study was to design and develop an instrumentation configuration suitable for determining upper extremity forces during walker-assisted gait. To accomplish these goals a finite element model of a conventional aluminum tube walker was constructed and the structural cross-talk in frame members was fully described for orthogonal loading conditions. Results from the study were used to locate strain gage sensors on the structure such that independent measurements of unilateral band loads could be determined. The instrumentation configuration is presented along with preliminary data illustrating system output. Integration of this system with an upper extremity kinematic model is also discussed. Complete description of upper extremity kinetics during walker-assisted gait may provide insight into rehabilitative treatment strategies. Characterization of the demands placed upon the upper extremities and assessment of patient stability may influence walker design parameters (height, width, weight) and recommended procedures for use (foot placement, hand location, motion sequence, and feedback loading control).