<prompt> All are true regarding pes planus except:There is collapse of medial longitudinal archThe heel becomes valgus and foot pronates at the subtalar-mid complex jointJacks test differentiates between flexible and rigid deformityOne of the common type of tarsal coalition is calcaneonavicular it is autosomal recessive  <response>: PES PLANUS FLAT FOOT Flat foot refers to obliterated medial longitudinal arch Heel is often in valgus called as planovalgus Pes Planus is of 2 types: Differentiated by Jacks test Flexible: Disappears on non-weight bearing. Management is conservative Rigid: Due to congenital veical talus or RA or infection or tarsal coalition or tibialis posterior dysfunction. They often require surgical intervention Tarsal Coalition is autosomal dominant fusion of tarsal bones talocalcaneal, calcaneonavicular and talonavicular 