Design and feasibility study of instrumented shoes for level walking and stair ambulation

Analysis of foot-floor reactions during locomotion is helpful for clinical diagnoses of dynamic stability, walking ability, and balance. This study integrated a pair of instrumented shoes and a microprocessor-controlled data logger to build a portable system for measuring vertical foot-floor reaction forces. A series of tests was performed to validate the accuracy of the instrumented shoe system in measuring ground-reaction forces (GRFs) of individuals during level walking, and stair ascent and descent. Plantar forces of 5 healthy young (HY) adults and a stroke patient (SP) with good mobility were measured continuously during level walking, stair ascent and descent for up to 10 min. Their temporal and spatial gait parameters were calculated. The SP exhibited substantially longer stride time, and double support and single support periods during stair ambulation than the HY group. Furthermore, the SP demonstrated bilaterally asymmetrical force waveforms, center of pressure (COP) loci and temporal gait parameters. Experimental results indicate that the proposed shoe system can acquire accurate GRF data for an extended period. Based on GRF data, the system can generate data for temporal gait parameters, and GRF waveform and cyclogram patterns for clinical diagnosis of pathological gaits.