Flatfeet in kids:
The longitudinal arch of the foot extends from just in front of the heel to the ball of the foot. The arch is highest on the medial (great toe) side of the foot and minimal on the lateral (little toe) side. There is great variation in arch height between normal people. Many people are born with greater laxity than average in the ligaments of their body. When a toddler starts walking, the parents may notice a flattened arch appearance. In most cases, this is a totally benign condition called flexible flatfoot. When the child’s leg dangles when seated, the arch appears normal. This condition usually requires no treatment, other than occasionally issuing arch supports, if there is pain reported. I recommend Achilles stretching exercises in nearly all such cases.
Most people simply continue the foot shape of their youth into adulthood. Discomfort associated with their feet is usually best treated with a cushioned, mildly corrective support, coupled with more Achilles stretching. However, there is a group of adults who develop a progressively worsening flatfoot deformity during their adult years. These people require a more aggressive approach, in most instances. There are several structures contributing to the support of the arch. If one of these structures becomes deficient, whether through previous trauma, or just age related degenerative change, the repetitive stress of walking can overload the remaining supports, leading to painful, profoundly flat foot. If discovered early, aggressive support of the arch with a custom molded arch support may suffice. In other cases, the support must be extended up above the ankle level to be effective, an ankle-foot orthosis. In more advanced cases, surgical intervention may be the only viable option.