A, Patient with asymmetric pes planus. B, Talus slides distally, medially, and plantarward with loss of posterior tibial tendon and probable insufficiency of plantar calcaneonavicular ligament. C, Long-standing deformity. Achilles tendon contracture exacerbates heel valgus. D, In sitting position, when asked to hold foot in plantarflexion-inversion after being placed there passively by examiner, patient unconsciously used anterior tibial tendon. Also note increased supination (forefoot varus relative to longitudinal axis of calcaneus).