AAOS Now

Published 3/1/2003

Don’t rely on stated shoe size

Children at risk for foot deformity due to wrong size shoes

Many young children are wearing shoes that are too small, according to the results of a study presented at the 2009 AAOS Annual Meeting. As a result, these children may be at high risk for having serious foot deformities.

“Improper footwear is well recognized to be an extrinsic factor regarding the development of forefoot deformities. Small forefoot boxes in children’s footwear could impair toe function and proper development and promote early establishment of forefoot deformity,” said lead author Norman Espinosa, MD, of the University of Zürich.

Measuring feet and shoes
The study, which took place in Switzerland, included 128 boys and 120 girls from age 5 to age 10. Researchers measured the children’s feet as well as their indoor and outdoor footwear to determine whether the children were wearing properly sized shoes. They also compared their footwear measurements to the sizes given on the manufacturers’ labels to see if the shoes were marked properly. Finally, they measured the angles of the children’s toes to learn whether any of the subjects were developing hallux valgus.

The study found that most of the children tested were wearing the wrong size shoes. “We defined fitting as perfect when the inner shoe length surmounted the foot length by at least 10 mm (optimal 12 mm),” explained Dr. Espinosa.

More than half (52.8 percent) of the children had outdoor shoes that were too small; 13.3 percent of children were wearing outdoor shoes that were too large for them. A similar pattern was seen with children’s indoor shoes or slippers. Six in 10 children (61.6 percent) were wearing indoor shoes that were too small; 1 in 10 (10.2 per­cent) were wearing shoes that were too large.

In part, the problem may arise because parents buy shoes based on the size marked by the manufacturer, perhaps without even having the child present to try on the shoe. When researchers compared the size marked on the shoe to the actual size of the shoe, they found that more than 90 percent of both indoor and outdoor shoes were smaller than the manufacturer’s marked size. Indoor shoes were almost always (97.6 percent) smaller than the manufacturer’s marked size.

“It was a truly striking finding,” says Dr. Espinosa. “The shoe sizes given by the manufacturers almost never matched with the true sizes measured by our group.”

Additionally, Dr. Espinosa notes, the prevalence of hallux valgus among the children in the study was higher than previously reported in the literature. The angle was measured in 153 children and was considered normal when equal to or less than 15 degrees. The results showed that 3.3 percent of the children’s feet had an angle of more than 15 degrees, while more than one in four children (26.1 percent) had an angle of 10 degrees to 15 degrees.

Recommendations
To prevent these problems, Dr. Espinosa makes the following recommendations for parents:

  • Measure the child’s feet every time new footwear is purchased.
  • Consider the actual size of the shoe rather than just the number marked on the inside of the shoe or the box.
  • Check for shoe fit every month or so, especially during times of a growth spurt. Many children will outgrow shoes long before the shoes wear out.

“We truly did not expect such a large percentage of incorrectly declared shoe sizes,” he says. “We now know that we should focus on parental education to help prevent early onset of juvenile foot deformity.”

Dr. Espinosa’s coauthors for the poster presentation “Children’s feet and their footwear: Results of survey in school children” include Patrick Paulet, MD; Linas Jankauskas, MD; and Thomas Boeni, MD, all of Zurich, Switzerland; and Wieland Keinz, MD, of Salzburg, Austria. The authors report no conflicts of interest.