Full-length lower extremity radiograph shows how to measure anatomical medial proximal femoral angle (aMPFA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal tibial angle (mLDTA), femur-tibial angle (FTA) and hip-knee-angle-axis (HKA-A). The hip-knee-ankle angle is a measure of lower limb alignment and defined as the angle between the mechanical axes of the femur and the tibia.