Three studies (see citations below in Military performance section) of military recruits have shown no evidence of increased injury, or foot problems, due to flat feet, in a population of people who reach military service age without prior foot problems. However, these studies cannot be used to judge possible future damage from this condition when diagnosed at younger ages. They also cannot be applied to persons whose flat feet are associated with foot symptoms, or certain symptoms in other parts of the body (such as the leg or back) possibly referable to the foot. Children
Studies have shown flat feet are a common occurrence in children and adolescents. The human arch develops in infancy and early childhood as part of normal muscle, tendon, ligament and bone growth. Flat arches in children usually become high arches as the child progresses through adolescence and into adulthood. Children with flat feet are at a higher risk of developing knee, hip, and back pain. A 2007 randomized controlled trial found no evidence for the efficacy of treatment of flat feet in children either from expensive prescribed orthotics (i.e. shoe inserts) or less expensive over-the-counter orthotics. As a symptom itself, flat feet usually accompany genetic musculoskeletal conditions such as dyspraxia, ligamentous laxity or hypermobility. Diagnosis
Since children are unlikely to suspect or identify flat feet on their own, it is important for adult caregivers to check on this themselves.
Treatment may include foot gymnastics or other exercises as recommended by a podiatrist or physical therapist. In cases of severe flat feet, orthoses should be used through a gradual process to lessen discomfort. Over several weeks, slightly more material is added to the orthosis to raise the arch. These small changes allow the foot structure to adjust gradually, as well as giving the patient time to acclimatise to the sensation of wearing orthoses. In some cases, surgery can provide lasting relief, and even create an arch where none existed before; it should be considered a last resort, as it is usually very time-consuming and costly. A minimally-invasive surgical intervention involving a small implant is also available. The implant is inserted into the sinus tarsi and prevents the calcaneus and talus from sliding relative to each other. This prevents the sinus tarsi from collapsing and thus prevents the external symptom of the fallen arch from occurring. Athletic performance
The effects of flat feet fall under two categories, which are asymptomatic and symptomatic. Individuals with rigid flat feet tend to exhibit symptoms such as foot and knee tendinitis, and are recommended to consider surgical options when managing symptoms. Individuals with flexible flat generally exhibit asymptomatic effects in response to their flat feet.According to AAP news and journal gateway, being flexibly flat-footed does not impede athletic performance.It is generally assumed by running professionals (primarily including some physical trainers, podiatrists, and shoe manufacturers) that a person with flat feet tends to overpronate in the running form.