Before discussing ideal footwear for children, consider normal foot development. The alignment of a child’s foot and lower extremity changes in the early years. Sitting and crawling improves core strength, then they start to stand, cruise, walk, and finally run. Bones get longer and change shape. Due to the intrauterine position , newborns have a high arches, bowlegged limbs, and often in-toeing of the feet. Gravitational pull is strong enough to almost reverse this, and by age 4 children typically have a pronated foot and knock-kneed limbs. As activity increases, individual muscles get stronger. Due to continued gravitational pulls and the powerful developing muscles of children, this seemingly “malalignment” adjusts back to what would seem normal for an adult by the time they are 7–8 years old.

Here’s an important point to keep in mind—a child’s foot is not a miniature version of an adult’s foot . In early development, a child’s foot is widest across the toes. If our population wore shoes that were designed with this functional shape from birth, then most adults would also have feet with the widest part across the toes, and the toes would be perfectly aligned with the metatarsals (long bones in midfoot). Most of a child’s developing foot is composed of cartilage, which is gradually replaced by bone. If the cartilage is deformed by badly shaped or rigid shoes, the bones will take on the deformed shape. It’s vital that kids’ shoes allow enough room for natural growth, until the foot bones mature. This doesn’t happen until ages 18–19 for girls and 20–21 for boys. Simply put, inflexible, poorly shaped shoes are potentially harmful—they restrict the natural movement and development of the foot.

Bony alignment changes are a healthy, normal, part of human development. Care must be taken when prescribing braces or devices, which may have the affect to create misalignment later in childhood. Pediatricians and podiatrists now realize that there is no single best leg alignment and to allow natural development.

The widest part of newborn’s foot is not the ball of the foot, but their toes. Adult feet in modern societies don’t look the same. The narrow toe boxes in footwear have changed the alignment of our feet, just like braces were once widespread to change the alignment of the legs. Culturally a pointy shoe looks normal as does the foot shape accommodating this look. Children’s shoes are often shaped to this last and thus change shape. This was demonstrated over 100 years ago in a seminal paper by Hoffman.

Children’s shoes are often too stiff to allow natural movement. Materials used in the construction of adult shoes are reproduced for kids weighing a fraction as much. Children do not have the physical weight to flex these shoes. A child’s foot is designed to move, and the specific strengthening of muscles aligns the bones and joints. Adults who have grown up barefoot or in minimal sandals developed very robust healthy feet with strong muscular attachments to stabilize the foot. The modern shoe-wearing adult’s foot does not typically have the same strength and stability.

We are all born barefoot and if allowed to run, jump, and bound in our barefeet as children, we develop the “magic human spring,” which starts at the foot [Lieberman]. When we begin to walk and run in stiff and cushioned shoes the spring gets smaller, and then with injury we are often told to run in a supportive shoes (spring getting smaller), and then with further injury we are advised to run in the supportive shoes and orthoses (spring getting smaller still).

The body will seek to find motion and impact reduction at other joints when not available at the necessary joint (the foot). In western societies we have a greatly disproportionate burden of lower back pain and injury, knee and hip replacements, and impaired general mobility with aging. We detrain our spring and these joints take the load. These conditions are nonexistent in barefoot societies who walk more than we do. Can we retrain all the adults? Maybe, with patience and a progressive re-adaptation, but it may take years. Once you are walking with a cane or walker, the chances are slim.

As a family and sports physician, I firmly believe that children should play in their bare feet or in activity shoes that complement natural foot development and proper biomechanics of movement. Runners, walkers, coaches, and the medical community are all awakening to the benefits of allowing proper natural foot motion to occur in all of our daily activities. Proponents of natural running consider that the smartest design developed for human movement and injury-free activity is the human foot itself and the critical need to enhance balance.

Pediatric footwear until recently have been marketed by the shoe companies to parents, educators, and health care professionals to prepare our kids for shoes they are marketing for adults to wear. The modern shoe industry and its marketing effectively convince parents that when running, a child should wear miniature versions of traditional adult running shoes; almost all of which have elevated heels, extreme cushioning, and some form of motion control technology. Many dress and casual shoes for children are also stiff and overly supportive.

The APMA (American Podiatric Medical Association) [1] parent flyer states that parents should “Select a shoe that’s rigid in the middle. Does your shoe twist? Your shoe should never twist in the middle.” It also however states that, “Step three does not apply to toddlers shoes. For toddlers, shoes should be as flexible as possible.”