Exam Skill of the week The Feiss Line Test evaluates the medial arch of the foot for pes planus. The examiner marks the head of the first metatarsal bone, the navicular tuberosity, and the center of the medial malleolus. A line is drawn connecting the head of the first metatarsal to the medial malleolus. In a normal foot, the navicular tuberosity lies along this line. If the navicular mark falls slightly below the line, it indicates pes planus. Diagnostic characteristics are not known. Read: htt