Fig. 3From: The impact of limb loading and the measurement modality (2D versus 3D) on the measurement of the limb loading dependent lower extremity parametersMeasurement of 3D HKA. a A sphere was fitted to the femoral head to determine the hip joint centre. b The knee joint centre was located midway between the tibial eminences. c The ankle joint centre was calculated as the centre of mass of all points of the articular surface of the distal tibia and fibula. d Schematic marked the measurement of 3D HKA. A line connecting the HJC and the KJC and a second line connecting the KJC and the AJC were projected to the frontal plane to measure 3D HKABack to article page