Knee orthosis with helicoidal axis and method of design and fabrication thereof

A knee orthosis comprising:

• a femoral section configured for engaging relative to a femur of a wearer;
• a tibial section configured for engaging relative to a tibia of a wearer;
• a medial hinge configured for pivotally engaging the femoral and tibial sections relative to a knee of the wearer, the medial hinge comprising superposed shells having a shape corresponding to an arc of a sphere which, when viewed from a frontal view, has a lateral-facing concavity, wherein the sphere that defines the shape of the superposed shells of the medial hinge has a first diameter defining the lateral-facing concavity and has a first geometric center extending in 3D space laterally relative to the lateral-facing concavity, the first geometric center being spaced apart from the superposed shells of the medial hinge by the first diameter, and the first geometric center displacing in 3D space as the medial hinge is articulated, wherein the medial hinge defines a medial pivot having a medial pivot axis extending through the first geometric center and moving as the first geometric center displaces in 3D space;
• and
• a lateral hinge configured for pivotally engaging the femoral and tibial sections relative to the knee of the wearer, the lateral hinge comprising superposed spherical shells having a shape corresponding to an arc of a sphere which, when viewed from the frontal view, has a medial-facing concavity, wherein the sphere that defines the shape of the superposed shells of the lateral hinge has a second diameter defining the medial-facing concavity and has a second geometric center extending in 3D space medially relative to the medial-facing concavity, the second geometric center being spaced apart from the superposed shells of the lateral hinge by the second diameter, and the second geometric center displacing in 3D space as the lateral hinge is articulated, wherein the lateral hinge defines a lateral pivot having a lateral pivot axis extending through the second geometric center and moving as the second geometric center displaces in 3D space, further wherein the second geometric center displaces in 3D space independent from the first geometric center such that the lateral pivot axis moves independent from the medial pivot axis;
• wherein the first diameter is different than the second diameter, and the medial pivot axis and the lateral pivot axis do not coincide with one another throughout a full articulation of the knee orthosis about the medial and lateral hinges.