Figure 3
From: Classification of the height and flexibility of the medial longitudinal arch of the foot
Feiss line with the foot in subtalar neutral position. The foot was in its subtalar neutral position and the landmarks (1-3) are used to measure Feiss line. 1 head of first metatarsal bone; 2 navicular tuberosity; and 3 centre of the medial malleolus. A line between landmark 1 and 3 was drawn and the perpendicular distance between landmark 2 and line 1 to 3 was measured. With the foot in a weightbearing position, the measurements were repeated, and the navicular tuberosity was marked again.