Multiaxis controlled motion knee brace with a four bar joint and method

Abstract

A knee brace has a pair of femoral and tibial links and a four bar joint mechanism by which a lateral side one of the femoral links is pivotally connected to a lateral side one of the tibial links and a four bar joint mechanism by which a medial side one of the femoral links is pivotally connected to a medial side one of the tibial links. Each of the joint mechanisms comprises an inner, padded, pivot plate and an outer pivot plate, each of end of which is pivotally connected at a single point to a respective one of the femoral and tibial links. Furthermore, the pad on the inner pivot plate of the medial side joint mechanism carries a spherically cupped femoral condyle pad by which the brace, generally, and the joint mechanism, specifically, can be properly positioned relative to the knee of the wearer. The locations of the pivot points for the pivot plates on the links are set in accordance with parameters which are designed to produce a multiaxis motion of a reference point which will constrain the tibia to slide rearwardly relative to the femur in an initial range of flexion of the knee from a straight leg position and then to rotate relative thereto along an arcuate path. Additionally, the angle between imaginary lines through the pivots of each pivot plate is caused to be greater than a predetermined minimum value which will insure that the joint mechanism has sufficient strength not to break apart in use due to loads which are imposed horizontally across the knee joint.