A Gait Retraining Feedback System Based On The Wearable Knee Adduction Moment Measurement

Knee adduction moment is a key parameter that links with the severity of knee osteoarthritis and it is important for the treatment of patients with knee osteoarthritis.However,assessment of the knee adduction moment is commonly accomplished through the motion capture systems and stationary force plates in a gait laboratory.It is less accessible for the purpose of treating an ordinary knee osteoarthritis patient.The aim of this study is to develop a gait retraining feedback system that can be used to estimate the knee adduction moment for the gait training and the daily recovery of knee osteoarthritis patients.In order to realize the real-time assessment of knee adduction moment,a wearable sensor system for knee adduction moment measurement is primarily proposed in the sensor system.And on this basis,a corresponding wearable gait retraining feedback system is designed for the use of the treatment of knee osteoarthritis.In this wearable sensor system,six pressure sensors distributed under foot and one motion sensor located on the foot are used for the wearable knee adduction moment measurement and gait retraining feedback.The six pressure sensors are designed to collect the pressure data of typical pressure part of the foot during walking.We established a neural network model to calculate the knee adduction moment based on the pressure data acquired from the sensors and the reference knee adduction moment captured in a gait laboratory.The motion sensor is used to detect the posture of foot and collect the data of foot progression angle during walking.The judgment of foot progression angle can be usedas the signal of the vibrator controlled by the motion sensor and finally manage to retrain the gait.In order to validate the feasibility of the gait retraining feedback system based on the wearable knee adduction moment measurement method,three experiments were conducted.The first experiment compared the calculated knee adduction moment and the reference knee adduction moment.With the result of the correlation coefficient of the two curves above 0.9 and the error below 0.4,we can prove that the designed wearable knee adduction moment measurement method is practicable.The second experiment is the comparison of the knee adduction moment between different gaits.The result indicates that the designed wearable sensor system can distinguish different gait.The final experiment of gait feedback for the patients is mainly analyzed and the result shows that the gait retraining system can have a real-time influence on the gait and can be used to train the walking gait to reduce the knee adduction moment.