Navicular drop as a composite measure of excessive pronation.

The measure of navicular drop has been used as an indicator of pronation at the foot. It is defined as the distance the navicular tuberosity moves in standing, as the subtalar joint is allowed to move from its neutral position to a relaxed position. The purposes of this study were to test the reliability of a method to measure navicular drop and to assess the relationships among measures of forefoot to rearfoot position, subtalar joint neutral position, and navicular drop. The results support traditional biomechanical theory but indicate that other factors contribute significantly to navicular drop.