Prosthetic leg with knee braking function

摘要

There is provided a prosthetic limb having a flexible knee brake function, which is designed such that it can be mechanically detected which part of the foot the load of the wearer is imposed on. In a thigh prosthetic limb ( 10 ), a joint upper member ( 12 ) including a knee plate ( 120 ) and a joint lower member ( 14 ) including a base bracket ( 22 ) integral with the frame ( 140 ) are operated to bend the knee. In the housing member ( 24 ), there are provided not only a knee axis but also a hydraulic brake circuit. There is a link mechanism ( 50 ) which allows a small relative motion between the housing member ( 24 ) and the base bracket ( 22 ) on the main body part side. The link mechanism ( 50 ) has an instantaneous center between the toe and the heel part of the prosthetic limb. This instantaneous center serves as a sensing point and detects which part of the foot the load of the wearer is imposed on by distinguishing a first case in which the wearer's load is imposed on the heel and a second case in which the wearer's load is imposed on the toe. Based on the detection result made by the link mechanism ( 50 ), the hydraulic brake circuit is controlled so that a flexible knee braking operation can be made.