Fit to be sized: A too-small shoe could hurt your child's feet.

RODALE NEWS, EMMAUS PA—Adults sometimes trade comfort for fashion. But if you can’t buy your own shoes—or even tie them—doesn’t it seem unfair you should suffer because of your footwear? And yet, according to a new study, kids often do: Swiss scientists found that 53 percent of the schoolchildren they surveyed were wearing shoes that didn’t fit, exposing their feet to potential injury.

THE DETAILS: Researchers from the University of Zurich in Switzerland evaluated 248 schoolchildren, measuring the length of their shoes, the length of their feet, and the degree to which their big toes angled sideways toward the second toe (a condition called hallux valgus, which occurs when shoes are too tight and can lead to the formation of bunions). Most of the children tested were wearing the wrong size shoe. In the study, just 34 percent of “outdoor shoes” (as opposed to slippers) fit properly; 53 percent were too small, and 13 percent were too big. Just over 3 percent of the children had an abnormal hallux valgus angle.

WHAT IT MEANS: Size, as stated by a shoe manufacturer, means nothing. “There is no such thing as universal sizing or a universal last (the form over which a shoe is made, that determines its size and fit),” says Carol Frey, MD, assistant clinical professor of orthopedic surgery at the University of California, Los Angeles. She notes that this is just as true in the U.S. as it is in Europe. “Each shoe company develops its own last, and therefore the size and fit of its shoes are unique to that company. Which means that a 6 Medium, for instance, might be narrower in a Nike than in a Reebok shoe.” It also means that you absolutely have to try before you buy. “The marked size of the shoe will give you a ballpark,” says Dr. Frey, “but for your child’s sake, you need to become an informed consumer so you know when your child’s shoes fit and when they don’t.”

Here’s how you can make sure your child’s shoes fit:

• Shoe shop at the end of the day. That’s when feet are at their largest.

• Try them right. Make sure your child is standing when trying on shoes, since feet expand when you stand on them. Furthermore, make sure your child is extending his or her toes, not curling them (younger children tend to do this, says Dr. Frey). And be sure to try shoes on both feet. “Sixty-six percent of people, including children, have one foot that's bigger than the other,” she says.

• Make sure they’re loose in front, tight in back. The toe box should feel roomy: “The child should be able to fully extend all his or her toes and wiggle them,” says Dr. Frey. And the heel should feel snug: “The heel should fit well and not slide up and down, which can cause accidents as well as blisters,” she says.

• When in doubt, select sneaks. According to the American Academy of Orthopedic Surgeons (AAOS), a soft, pliable shoe with plenty of room, such as a sneaker, is the ideal shoe for children of all ages. The toe box should provide enough space for growth, and should be wide enough to allow the toes to wiggle. (A finger’s breadth of extra length will usually allow for about 3 to 6 months’ worth of growth, although this can vary depending on your child’s age and rate of growth.)

• Watch for signs of smushing. Never try to force your child’s feet into a pair of shoes. If your child frequently removes his or her shoes, those shoes may be uncomfortable. Routinely check your child’s feet for signs of too-tight shoes, such as redness, calluses, or blisters, says the AAOS.

• Get them measured by an expert. Have your child’s feet measured periodically at the shoe store to determine whether his or her feet have grown enough to warrant a larger pair of shoes. But use size only as a guide, stresses Dr. Frey; fit is what matters.