Research on detection method for abnormal gait using three-dimensional thigh motion analysis with inertial sensor

Recently, rehabilitation systems for stroke patients have been developed using engineering technology. Because the abnormal movements caused bystroke differ greatlyamong patients, the rehabilitation effects using these novel systems may not be consistent or stable. Therefore, objective and quantitative evaluation of the motor function before rehabilitation is important for everypatient. This studyaimed to develop an easymethod for clinical use, which detects abnormal gait movements using an inertial sensor. In the motor measurements using the inertial senor, there was a difference between the anatomical coordinate system constructed from the sagittal and frontal planes, and the coordinate system calculated using the inertial sensor for use to express movement, ，which affected the measured results. Therefore, in this study, we developed a novel method to detect gait abnormalityusing vector loci that displaythigh movements, which does not require calibration of the coordinate system. Using the proposed indexes, the gait movements of 26 healthy subjects and 7 hemiplegic subjects were analyzed. The results using the proposed indexes demonstrated the feasibility of detecting abnormal movements of hemiplegic subjects, indicating the usefulness of the proposed indexes. © 2019, Japan Soc. of Med. Electronics and Biol. Engineering. All rights reserved.