summary Flexible Pes Planovalgus, also known as Flexible Flatfoot, is a common idiopathic condition, caused by ligamentous laxity that presents with a decrease in the medial longitudinal arch, a valgus hindfoot and forefoot abduction with weight-bearing. Diagnosis can be made clinically with a foot that is flat with standing and reconstitutes with toe walking, hallux dorsiflexion, or foot hanging. Treatment is usually observation, and stretching with majority of cases resolving over time. Rarely, surgical management is indicated for patients with progressive deformities that do not resolve with nonoperative management. Epidemiology Incidence unknown in pediatric population 20% to 25% in adults Etiology Pathoanatomy generalized ligamentous laxity is common 25% are associated with gastrocnemius-soleus contracture Classification Hypermobile flexible pes planovalgus (most common) familial associated with generalized ligamentous laxity and lower extremity rotational problem usually bilateral associated with an accessory navicular correlation is controversial Flexible pes planovalgus with a tight heel cord Rigid flatfoot & tarsal coalition (least common) no correction of hindfoot valgus with toe standing due limited subtalar motion Presentation Symptoms usually asymptomatic in children may have arch pain or pretibial pain Physical exam inspection foot is only flat with standing and reconstitutes with toe walking, hallux dorsiflexion, or foot hanging valgus hindfoot deformity forefoot abduction motion normal and painless subtalar motion hindfoot valgus corrects to a varus position with toe standing evaluate for decreased dorsiflexion and tight heel cord Imaging Radiographs indications painful flexible flatfoot to rule out other mimicking conditions rigid flatfoot recommended views required login to view 6 more bullets optional login to view 4 more bullets findings Meary's angle will be apex plantar login to view 1 more bullet Differential Tarsal coalition Congenital vertical talus Accessory navicular Treatment Nonoperative observation, stretching, shoewear modification, orthotics indications login to view 2 more bullets techniques login to view 5 more bullets Operative Achilles tendon or gastrocnemius fascia lengthening indications login to view 1 more bullet calcaneal lengthening osteotomy (with or without cuneiform osteotomy) indications login to view 2 more bullets technique login to view 6 more bullets Prognosis Most of the time resolves spontaneously