Development of a knee brace with a locking mechanism and its locking control to reduce applied load to the knee

A knee brace with a locking mechanism has been designed and tested for leg muscles to reduce the applied load to the knee during walking on a flat surface. The system function consists of locking leg movement at the “heel strike” phase of walking cycle. The user can not bend his knee more than the locking angle from this phase and the brace supports excessive load applied to his knee so as to minimize the muscles strength. The mechanism is designed to be unlocked at beginning of the “toe off” phase and the user is allowed to bend his knee freely and continues a new walking cycle. The locking control depends on two signals, one is from the four foot pressure sensors attached to the bottom of the foot and the other is from a high precision potentiometer attached to the knee joint to measure the knee angle. EMG sensors are attached to six different muscles of the user's leg to measure the effort during the walking cycle. The EMG data of the user's leg muscles with activating the locking knee brace are measured and compared with those without locking by walking experiments.