In younger children, related complaints may be tired feet or legs, wanting to be held after being on their feet for a short duration, or reluctance to play or be active on their feet. However, pes plano valgus is often associated with some symptoms. Pes plano valgus is not always symptomatic (painful). While being overweight does not necessarily cause pes plano valgus, it can contribute to these feet being symptomatic (painful). While there are some rare causes of pes plano valgus in children and adolescents, and still other common causes in adults, the cause of pes plano valgus in the majority of children and adolescents is hereditary factors, such as bone and joint alignment, ligament laxity (hyperflexible joints), or a tight calf muscle. Since these latter conditions are identified at birth and treated differently than the more common pes plano valgus, they will not be discussed here. On the other hand, there are two uncommon conditions that are congenital (present at birth) and usually identified at birth – vertical talus (not flexible), and calcaneovalgus (flexible). Keep in mind that most children don’t fully form an arch until age 3-5. Usually, parents don’t become aware of their child’s pes plano valgus until they start walking, or even later. A relatively uncommon form of pes plano valgus can be caused by a tarsal coalition, and is not very flexible or mobile (please see the Kaiser Permanente Santa Rosa Department of Foot and Ankle Surgery’s document about tarsal coalitions for more information). Pes plano valgus is usually flexible, meaning that the joints of the foot and ankle are mobile. A pes plano valgus foot is often maximally pronated. This complex set of position changes between sitting and standing is called pronation of the foot. However, when the person stands, the arch flattens, the ankle rolls in, and the heel rolls out (everts). When sitting, a person with pes plano valgus may have a reasonably well-formed arch. Pes plano valgus feet may require treatment – more on this later. Pes plano valgus is the medical term that refers to an abnormal foot due to a flattened arch, a rolled-in appearance of the ankle, and a heel that appears to be rolled-out from under the ankle. A normal foot with a low arch rarely requires treatment.
The arches of normal feet can be of varying height, so it is possible to have a relatively normal foot with a low arch. The term flatfoot is not a medical term, but is often used to describe a foot with a flattened or lowered arch.