Just like many parts in the rest of their bodies, infants are born without completely ossified bone structures in their feet. It takes times for these structures to become complete, stable, and strong enough to allow for weight bearing and mobility. There is also an additional fat pad that runs along the medial longitudinal arch that serves to protect these structures during development.
When kids do start to learn to walk at around age 1, and for the first few years after, it is quite normal for them to have relatively flat feet. More technically, beginner ambulators typically walk with pronated arches and everted, or valgus, heels. When kids initially learn to stand on their feet, it is common and perfectly normal for them to do so in 6 degrees rearfoot valgus. But this number should decrease progressively as they get older. These flat feet and the fat pad generally transition to a more “normal” appearance and position by age 4-5.
These are normal developmental processes, but there are issues and delays that affect many children and their ability to ambulate. It is imperative to recognize and treat causes of abnormal pediatric flat feet in order to prevent future deformity and disability.
For example, “developmental flatfoot” describes an excessively pronated flexible flatfoot in a pediatric patient under 6 years old. The patient’s foot will not function adequately and affect their posture, leading to future problems if unrecognized. In addition to skeletal deficits in children, one should be aware of genetics, sensory disorders, gross motor delays, and low muscle tone. All of these factors may affect a child’s ability to ambulate effectively.
Normal/Average Pediatric Foot Development
- A child begins to walk around age 1 (average between 10-14 months). At this time, up to 6 degrees rearfoot valgus is normal
- Valgus decreases by about 1 degree per year- at age 6 the heel should be vertical
- By age 13 the foot takes on its final “adult-like” position, with possible rearfoot varus of ~4 degrees.
Growing pains are an unfortunate but expected part of childhood and adolescence. Knowing when and where growing pains are felt can help determine when they can be “powered through” and when additional examination may be needed.
Growing pains occur in the legs, particularly the calves, knees, and thighs. They occur at rest, usually at night, not during physical activity. If a child is complaining of pain during activity, in other areas such as their feet, or seems to avoid activities, the cause is likely not your average growing pains. In these cases, children should be examined for potential foot pathology.
Children who have excessively flat feet, or those that do not progress normally have the potential to experience myriad future issues relating to posture and mobility.
Let’s look at what an overly pronated foot will cause:
- Calcaneal eversion when weight bearing
- A plantarflexed and adducted talus
- Internal rotation of the tibia and femur
- An overstretched posterior tibialis, deltoid ligament, plantar fascia, etc
- Overall an unstable foundation, compromising the rest of the kinetic chain
Looking at the foot type of the parents and family members can give clues as to whether the child is on the path to having flat feet throughout their lives. If this is the case, early orthotic intervention can prevent future issue. This will be especially helpful if there is family history of lower limb and foot problems.
When should children be considered for orthotic therapy?
Here are some guidelines:
- Abnormal foot posture is causing symptoms
- Abnormal weight bearing patterns for the age
- Excessive flat feet beyond the normal developmental parameters
- Changes in gait associated with flat feet
Orthotic therapy in children can be incredibly effective as their feet are constantly growing and can adapt well to extra control and correction. As well, for a myriad of reasons, children tend to be compliant patients when it comes to orthotics. In general, for a pediatric flat foot, orthoses include a deep heel cup, medial and lateral flanges, and often a skive or conservation medial rearfoot posting. The posting for a child should not attempt to bring them back to neutral, only to their age specific heel alignment. Because they will likely outgrow their orthotics within a year or two, take advantage of the serial treatment approach.
Pediatric orthotics are a common and conservative way to manage lower limb related issues. Recognizing when a child is outside their age related development and following preventative measures will help secure them a stronger, better functioning body throughout childhood and into adolescence and adulthood.