Hindfoot alignment measurement on a long axial view of the hindfoot. Hindfoot alignment(b) was measured as the angle between the anatomical axis of the tibia (long white line) and the axis of the calcaneus (yellow line). The tibia mid-diaphyseal axis was determined by the extending line through two mid-diaphyseal points (30 mm apart) that bisect the tibia. The calcaneal axis was presented by the extending line of two points: one of the points is the 40 % mark of a horizontal line7 mm from the most distal part of the calcaneus (divided into 40 %:60 % ratio), the other point is the bisecting point of a horizontal line 30 mm from the most distal part of the calcaneus