Lateral Flange - An increase in height of the orthosis on the lateral side of the foot starting lateral to the heel and continuing distally at variable length usually not beyond the fifth metatarsal head.   The height is variable to the prescription, but no higher than just inferior to the lateral malleolus.  An increase in the height of the orthosis on the lateral side of the foot starting lateral to the heel and continuing distally at variable length beyond the 5th metatarsal base and usually not beyond the 5th metatarsal head.