Knee orthosis

A knee orthosis comprising:

• a femoral cuff configured for engaging an upper leg of a wearer;
• a tibial cuff configured for engaging a lower leg of the wearer;
• and
• a hinge pivotally connecting the femoral cuff to the tibial cuff, the hinge having a femoral portion connected to the femoral cuff and a tibial portion connected to the tibial cuff, the femoral portion and the tibial portion including corresponding shells engaged with one another and configured to pivot relative to one another about a center of rotation, one of the femoral portion and the tibial portion has at least one guide slot defined in the corresponding shell, and the other of the femoral portion and the tibial portion has at least one pin extending therefrom and received within the at least one guide slot for guiding the pivot of the femoral and tibial portions relative to one another, the at least one pin defining a pin axis intersecting a center of rotation of a knee of the wearer;
• wherein the shells include complementary engagement surfaces facing each other, the complementary engagement surfaces having a non-spherical surface curvature corresponding to a portion of an ellipsoid, the ellipsoid defined by:
• a major axis extending in a sagittal plane;
• a minor axis orthogonal to the major axis;
• a length of the ellipsoid along the major axis being greater than a length along the minor axis;
• and
• revolution around the major axis.

A knee orthosis comprising:

• a femoral cuff configured for engaging an upper leg of a wearer;
• a tibial cuff configured for engaging a lower leg of the wearer;
• a hinge pivotally connecting the femoral cuff to the tibial cuff, the hinge having a femoral portion connected to the femoral cuff and a tibial portion connected to the tibial cuff, the femoral portion and the tibial portion including respective shells engaged with one another and configured to pivot relative to one another about a center of rotation, a first one of the shells including an engagement surface facing a complementary engagement surface on a second one of the shells, the engagement surface and the complementary engagement surface each having a shape corresponding to a portion of an ellipsoid defined by:
• a major axis extending in a sagittal plane;
• a minor axis orthogonal to the major axis;
• a length of the ellipsoid along the major axis being greater than a length along the minor axis;
• and
• revolution around the major axis;
• wherein the length of the ellipsoid along the major axis is greater than the length of the ellipsoid along the minor axis by an amount corresponding to an anteroposterior shift of a center of rotation of the knee.