A study of knee brace locking timing and walking pattern detected from an FSR and knee joint angle

Many factors affect biomechanics of lower limbs during walking, including the gate state and the according pressure distribution of feet. However, such relationship between the pressure distribution and the gate status has not been taken into account in detail to analyze lower-limb kinematics and kinetics during walking. In this study, a sensor system with force sensing resistors (FSR) was developed to measure plantar pressure of feet and impulse acting on each joint to do characteristic analysis of plantar pressure of feet and lower-limb kinematics. Comparing to force plates and a motion capture system, the FSR sensing system can give the detail trace of the ground reaction and the pressure distribution of feet. The system is designed to be used for online monitoring and control of a lower-limb biomechanical device like a knee brace. Several target points of plantar are decided as characteristic ones with pilot tests. Then pattern matching between the pressure distribution and the lower-limb kinematics is investigated. Also, plantar pressure patterns are compared knee joint angle for analyzing precious walking patterns. In the paper, to reduce impact value during walking suggests knee brace locking timing detection through the FSR sensing and knee joint angle.