January 2011

THINKING SMALL: Making strides in children’s footwear

With few studies from which to draw evidence, the design and fitting of children’s footwear has long been as much art as science. But that’s starting to change.

By L.W. Barnes

It was my first trip to buy shoes for my then-toddler son. He had just started walking with the aid of helping hands, and as I stared out at a sprawling display of shoes inside a high-end children’s shoe department, I felt utterly confounded. Some of the shoes felt soft, others were hard-soled and stiff, many were akin to moccasins. I was assaulted by all manner of colors and patterns and styles, each one different from the next. Massaging my eyes, I wanted to only to leave.

I didn’t know the first thing about selecting the right shoe or fit, and the answers I got from the in-store fitters weren’t much of a lift up. One salesman suggested I buy a pair of seemingly well-made, expensive shoes at least a full size larger than my son’s foot and “stuff the toe with paper” to make the purchase last longer. “My mother used to do it,” he offered, trying to be helpful.

Over the following year I asked around: the pediatrician, fellow moms, a sage grandmother or two. But no one could tell me, with any amount of certainty, exactly how a shoe was supposed to a fit a growing child.

And perhaps it’s no surprise. Because after a century of putting shoes on children, industry experts say there is still no standardized approach to pediatric footwear.

Studies have been done to examine different parts of the growing foot, looking at stressors and the impacts of certain kinds of shoes, or simply no shoes at all. Nevertheless, when the topic of children’s shoes comes up — the ongoing debate about exactly how to position a child’s foot in a shoe as it grows and what kind of shoe to use, hackles rise. Like religion and politics, children’s footwear and the question of whether shoemakers are influencing growing feet in a positive or negative way, has become a topic best avoided in certain company.

“It’s a tremendous controversy,” said Paul Scherer, DPM, a clinical professor at the College of Podiatric Medicine at Western University of Health Sciences in Pomona, CA. “Although we’ve been making shoes for children for more than 100 years, we didn’t have the answers. No one has known for sure what was going on with children’s feet.”

That is until now, Scherer will tell you. OK, maybe questions remain, but there appears to be a clearer picture than ever before. That’s thanks largely to the emergence of dynamic pressure sensor technology and a recent multiphase biomechanics study, funded by a leading children’s shoe manufacturer, utilizing that technology to better understand the effects of footwear at the important learning-to-walk stage of a child’s development.

The study, funded by Stride-Rite, was conducted at the Leon Root, M.D. Motion Analysis Laboratory at Hospital for Special Surgery. According to Scherer, who is an investigator, this independent study is the most heavily funded and in-depth research conducted on children’s footwear within the industry to date, collecting the most data on children’s feet in the history of podopediatrics.

The price of poor fit

We parents put shoes on children today to keep them warm, dry and safe. But research suggests that shoes, from the most flexible to the stiffest, influence children’s feet as they grow. It is a child’s first steps, doctors say, that determine their gait pattern – good or bad –into adulthood. Unlike some other parts of the body, the bones in the feet continue to develop well into a child’s early teen years. All the more reason that shoes – the right shoes and the right fit – are an essential part of podiatric development. Even at a tender age, the wrong shoe is a recipe for the onset of juvenile foot deformity, according to two recent European studies (see “Kids’ shoes come up short.”)

Figure 1. The child's bone structure is barely developed and very incomplete as they learn to walk. (Provided by the Hospital for Special Surgery.)

A December study of 858 preschool children conducted by the Medical University of Vienna found that the majority of children wore shoes that were too short. In addition, they found a significant relationship between shoe length and hallux valgus angle, with the relative risk of lateral hallux deviation increasing as children’s toes approached their shoe tips. Those findings were published in the online journal BMC Musculoskeletal Disorders.

And a Swiss study presented at the annual meeting of the American Academy of Orthopaedic Surgeons in 2009, found that about half of the 248 children surveyed were wearing outdoor shoes that were either too small (52.8 %) or too big (13.3 %). Although the study did not analyze the association between shoe fit and hallux valgus angle, it did find that 79.7% of 153 children had hallux valgus angles of 5º or more. An angle of more than 15º is typically considered clinically abnormal. This value was exceeded in 3.3% of children in the study. The problem, researchers said, was largely caused by shoes that were advertised to be a certain size but turned out to measure smaller.

Without enough space in the front of the shoe, children don’t have adequate toe movement forward as they step. Make a shoe too big and the flex point of the shoe will not match up with the flex point of the foot.

Experts advise that the tip of a child’s big toe should be between 10 mm to 12 mm from the shoe’s inside tip while weight bearing. They also warn against shoes that are marked “wide” but in reality do not have a wider sole, just more material sewn onto the shoe. Ask most parents if they are aware of these fitting facts and they will tell you “no.”

Kristi Hayes, CPed, a certified pedorthist and the president of the Pedorthic Footcare Association, said that most children wear the wrong size footwear largely because few people are qualified to fit shoes.

Many in the industry warn against using hand-me-downs for small children, a common practice among parents who don’t realize how detrimental an incorrect shoe size can be on their children’s soft bones. The sole of a shoe, practitioners say, develops its own memory. And any gait anomalies the primary wearer had will be passed on to the next recipient.

What does that mean? If I pronate, for example, wearing a pattern into the sole of my shoes, and then pass those shoes on to a friend, that person may begin to walk differently. So think long and hard, some say, before asking a friend to literally walk a mile in your shoes.

So what do children’s feet need? A literature review published by German researchers in the July 2008 issue of Foot & Ankle Surgery and an Australian study of 437 children aged seven to 12 presented at the 2005 meeting of the International Society of Biomechanics both arrived at similar conclusions: children’s feet differ in anatomy from adult’s feet and should have shoes that meet their own needs.

Those needs were addressed specifically in the study conducted at the Hospital for Special Surgery in New York, in conjunction with podiatric physicians and scientists from the Temple University School of Podiatric Medicine (TUSPM) and the California College of Podiatric Medicine (CCPM). The goal was to understand how footwear and its design can affect the gait, stability and plantar loading throughout the different stages of learning to walk.

Begun in 2008, the study included 15 early walkers (nine to 24 months old) and relied on pressure mats, newly-designed sensors that were applied to the children’s feet and slow-motion video to examine children barefoot and in four shoe models with different degrees of flexibility, Ultraflex being the most flexible.

What they found: children walked faster when barefoot and in the Ultraflex shoe, suggesting they were more comfortable. Stance time was shortest when they were barefoot, which correlates with the faster walking speed. However, even though they walked faster when barefoot, the children had a significantly shorter step length, resulting in an increased cadence.

Figure 2. 14-month old walking across a sensor plate to determine plantar pressures. (Provided by the Hospital for Special Surgery.)

Peak plantar pressures were highest relative to the other shoe designs and most similar to the barefoot condition when the early walkers wore the UltraFlex shoe, which may provide a child with increased proprioception and stability. The researchers noted that as children grow and develop through ages two to five and are able to perform increasingly complex functional tasks, their shoe needs can be anticipated to evolve, but that good prioprioceptive feedback may remain useful.

Early study findings were first presented at the 2010 Combined Sections Meeting of the American Physical Therapy Association (see “Stride-Rite taps torsional flexibility,”); their work has been submitted to Clinical Biomechanics.

Stride Rite began reconsidering its shoe designs as the study data rolled out, and in 2009 launched a new brand of baby shoes with what they call Sensory Response Technology (SRT). They say the ultra-flexible shoe improves the way a child learns to walk by allowing for more freedom of movement and a construction that reduces the number of stumbles and falls.

How? Greater feel for terrain. Company officials say that sensory pods in the forefoot of the outsole move independently of each other, offering multiple reaction points and increasing a baby’s feel of the ground beneath him, improving gait stability and response to environmental stimuli. An “hourglass” construction in the midfoot mirrors a baby’s foot structure to help supporting bones and muscles that are not yet fully developed. A smooth, rounded transition from outsole to upper prevents the catching of an edge, thus reducing the risk of stumbles and falls. The ultra-flexible design, they say, allows the foot to move in many directions to help baby learn how to adapt to uneven surfaces.

Logical, right? Ask some some veteran pedorthists and you may hear different.

The author's son, Harry, in his early-walker days.

Shane Hayes, CPed, a nationally recognized leader in pedorthics (he was the first pedorthist published in Journal of the American Medical Association) and a past president of the PFA, practices in Seattle at Shane’s Foot Comfort Center, where he started more than 35 years ago.

From his earliest days fitting children’s shoes, Hayes said they did indeed start with a soft sole and progress to a firmer footing when the child began to walk more.

“In those days we weren’t aware of such things as science and proprioception when making a decision on a child’s footwear,” Hayes said. “We were thinking more of a stable platform for the child to balance to be able to ambulate. That’s where I think things still stand. So it’s truly a leap of faith for a shoe company to base future sales on such a small cohort of study subjects without further study. It doesn’t mean they’re right or wrong at the moment, but I would caution against making any sweeping statements.”

The siren song of style

Science or trend, one thing is for certain, people buy shoes for looks more than comfort, be they adults or children.

Try convincing a woman to shelve her excruciatingly high Christian Louboutin stilettos because they might damage her tendons. The uber-sexy showgirl shoes whip off the shelves with a frenzy because women feel spiritually elevated in his styles.

It is no shock then to see the likes of star-progeny Suri Cruise, known for her toddler-couture wardrobe, splashed across the pages of tabloid magazines in kitten heels. While her mother has been quoted saying they are supportive shoes, made for ballroom dancing, many parents and pedorthists have been underwhelmed by the choice.

Suri Cruise is known for her fashionable -- and perhaps questionable -- footwear. (Photo by Bauer-Griffin.)

“Trendy footwear doesn’t just appeal to adults,” said Kristi Hayes. “High heels on kids is [something] we’re seeing more and more of. While it may indeed be adorable, it puts undue pressure on the ball of the foot, causing any number of problems from metatarsalgia to heavy callusing, cramping and pain in the arch area, hammer toes, bunions, and corns. I don’t think the parents of these children are thinking about their six-year-olds having these problems, but when they get the bill from the foot doctor, they might start.”

Think back to Ancient China, Hayes says, when young women’s feet were bound to keep them from growing, causing deformities.

“This should spur the mind to think about the ramifications of what we are doing to our children’s feet in current society,” Hayes said. “While it may not be as gruesome or cruel, it’s certainly not helping.”

Donna Boland, CPed, who is with Brown’s Enterprises in Washington, MI, said it’s all about how long a child is in the heel. An hour or so, probably no damage.

“I’d never let my child walk around in heels for an extended basis,” Boland said. “But you can’t tell other people what to do.”

Heels are hardly the only point of contention. Slip-on footwear, practitioners warn, requires gripping of the toes to keep the shoes on. That strengthens the muscles that will pull back the toes and result, potentially, in hammer toes, calluses, and corns – even on the littlest feet.

Then there are the shoes that come with little wheels and lights.

“They were all the rage when they first hit the marketplace, until everyone started reporting problems with their kid’s bodies up through adolescence,” Kristi Hayes said. Injuries range from twisted ankles, plantar fasciitis, muscle fatigue, knee, hip and back pain, she said.

There was a time, not that long ago really, when fitting shoes was considerably easier, and considerably more dangerous.

During the early 20th century, children wearing new shoes would step onto a shoe-fitting fluoroscope, an x-ray machine that allowed both the child and the fitter to see how the toes appeared inside the shoe. Easy. But those fluoroscopes were exposing children, during their lifetimes, to the equivalent of 12 or 14 chest x-rays. And shoe salesmen like Scherer’s father, Bernard Scherer, who worked for Kitty Kelly Shoes in Newark, was getting irradiated daylong.  He died at the age of 41 from facial radiation exposure. Seven years later, in 1957, the machines were removed from stores.

But technology, Paul Scherer said, and its application to children’s footwear, has given everyone new perspective and avenues for further study.

“This is the first time,” Scherer said. “Before, if you went to 10 different pediatricians, orthopedic surgeons and podiatrists and gave them 10 shoes, you’d have 10 different opinions. This is the first time we have data to show that one is better than the other.”

At least when it comes to early walkers. Scherer said the next step is to conduct a longitudinal study involving more ambulatory children. Practitioners like Scherer believe that children – age three to six – may require a more rigid shoe and greater protection as they become more active and older.

“We’ve been guessing for 50 years,” Scherer said. “Enough.”

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One Response to THINKING SMALL: Making strides in children’s footwear

  1. Jay A Shank, MS., PTA says:

    The proprioception issue is key in the child’s development of a functional gait pattern. The more cutaneous receptors that can be stimulated across the plantar aspect of the child’s foot, the better he/she will be able to maintain a balanced posture and walk with the least amount stress through the foot, ankles and legs. Full contact insoles do not have to be rigid to provide this. It has been studied that the more afferent information the brain receives from the plantar foot and its interface with the ground, the more efficiently the brain can fire muscles to make walking as least stressful on bones, soft tissue and joints as possible. If the pressure mat readings that are provided in this article are typical for this child, it is obvious that she is demonstrating a medial center of pressure progression line and there are large areas on the soles of her feet that aren’t being contacted. This is a pronatory-dominant gait pattern that may or may not correct enough by itself to spare the child future problems.

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