Instrumented Shoes for Measuring Ground-Reaction Force of Persons with Stroke in Level Walking, Stair Ascending and Descending

Abstract

Analysis of foot-floor reactions during one’s locomotion can be helpful for clinical diagnosis of his dynamic stability, walking ability, and balancing performance. The objective of this study is to design a pair of instrumented shoes to measure ground-reaction forces of persons with stroke in their level walking, stair ascending and descending. This study integrates a pair of instrumented shoes and a microprocessor-controlled data logger to build a portable system for measuring vertical foot-floor reaction forces. The instrumented shoes consist of 14 load cells, adjustable shoe modules, and signal conditioning circuits. The system is capable of synchronizing with a video recorder and continuously acquiring data up to 2h under a 100 Hz sampling rate. Plantar forces of 5 healthy adults and 6 persons with stroke were measured in their level walking, stair ascending and descending up to 10min. Their temporal and spatial gait parameters were calculated using analysis software programmed by LabVIEW. The instrumented shoes have 0.08 % and 1.72 % averaged static error and dynamic error, respectively, and were proved to equip with portability, high resolutions, and long operation time. Significant group differences were found in force waveforms, COP loci and bilateral symmetry of temporal and spatial gait parameters. Furthermore, the force waveforms and COP loci seems to accordingly reflect the severity of participants with stroke. Experiment results show the system is capable of acquiring foot-floor reaction forces for both normal and pathological gaits and can derive adequate parameters for clinical diagnosis.