Patent ID: 6969364
Filing Date: 2005-11-29
Classification: A61F

Abstract:
1. An orthopedic knee brace for controlling movement of a wearer's knee, comprising: a rigid thigh engaging member; a rigid calf engaging member; a lateral hinge lateral to the wearer's knee, connecting said thigh engaging member to said calf engaging member; a medial hinge medial to the wearer's knee, connecting said thigh engaging member to said calf engaging member, wherein said thigh engaging member and said calf engaging member form rigid connections to said lateral hinge and said medial hinge, wherein said lateral hinge and said medial hinge further comprise a plurality of parallel, concentric, spherical shells; and a plurality of cam follower pins and a plurality of cam slots distributed among said shells, wherein said plurality of cam follower pins engage said plurality of cam slots to rotatably engage said shells, and wherein a side of each of said cam follower pins is shaped to track a path parallel to a side of each of said cam slots in which said pin is engaged, wherein said lateral hinge has a first variable axis of rotation and comprises: a first shell, a second shell, and a third shell in the shape of a segment of a sphere, said first and third shells being concentric and fastened parallel to each other to form a first opening, said first and third shells being fastened to one of said lateral portion of said thigh engaging member and said calf engaging member; said second shell having a first end designed to be inserted into said first opening and a second end fastened to the other of said lateral portion of said thigh engaging member and said calf engaging member, said first and third shells rotatably engaged to said second shell by said plurality of cam follower pins and said plurality of cam slots; wherein said medial hinge has a second variable axis of rotation and comprises: a fourth shell, a fifth shell, and a sixth shell in the shape of a segment of a sphere, said fourth and sixth shells being concentric and fastened parallel to each other to form a second opening, said fourth and sixth shells being fastened to one of said medial portion of said thigh engaging member and said calf engaging member; said fifth shell having a first end designed to be inserted into said second opening and a second end fastened to the other of said medial portion of said thigh engaging member and said calf engaging member, said fourth and sixth shells rotatably engaged to said fifth shell by said plurality of cam follower pins and said plurality of cam slots; wherein said lateral hinge further comprises: a first cam follower pin and second cam follower pin distributed among said shells and extending inside said first opening, said first pin located on said second shell and said second pin located on said third shell; a first cam slot and a second cam slot distributed among said shells to receive said first and second pins, respectively, said first shell comprising said first cam slot and said second shell comprising said second cam slot; and wherein said medial hinge further comprises: a third cam follower pin and a fourth cam follower pin distributed among said shells and extending inside said second opening, said third pin located on said fifth shell and said fourth pin located on said sixth shell; a third cam slot and a fourth cam slot distributed among said shells to receive said third and fourth pins, respectively, said fourth shell comprising said third slot and said fifth shell comprising said fourth slot, whereby, in use, when the wearer's leg is extended, said first variable axis of rotation and said second variable axis of rotation are coincident and in alignment with the wearer's condyles; and wherein said knee brace prescribes asymmetric three-dimensional anatomic motion in six degrees of freedom by actively prescribing flexion and extension, abduction and adduction, internal/external rotation, anterior/posterior translation, medial/lateral translation, and proximal/distal translation between a femur and a tibia of the wearer's leg.