Barefoot influence on arch height
“Our aims were to establish the prevalence of flat foot in a population of schoolchildren in rural India and to determine whether this prevalence varied between shod and unshod children”
First, it is hard to translate this research over to an American population. Just because it is the prevalence in India, doesn’t mean that it will be the prevalence in other countries. Until I have other research though…this is all I have to work with.
Unshod means not wearing shoes. Therefore, shod means wearing shoes.
“…2300 children between the ages of four and 13…static footprints of both feet were obtained from all 2300 children”
This encompasses a large age span from the time prior to arch formation to post arch formation. I remember learning in school that the arch starts to take shape around the age of 8, but this may just be a tradition that has carried through the ages of PT students. Anyway, this is a large sample size to look at.
“The footprints were classified as normal, high-arched or flat. Some form of footwear was worn by 1555 children and 745 never used shoes.”
It’s still hard to believe that there were this many children that hadn’t used shoes. The children in the study were between the ages of 4 and 13. We sometimes take for granted all of the “needs” that we have here in the states. Anyway, here is a link to give an idea of what the arches would look like on a static footprint. One way to think of it is to get your foot wet and go walk on a wood floor or deck. You would have an imprint of your foot as follows: picture of arch height.
“…1551 were considered to have normal arches in both feet, 595 had a high arch in one or both feet and 154 had unilateral or bilateral flat foot. The prevalence of flat foot progressively decreased with increasing age.”
This last statement is what is taught in PT school. There are so many facts that are taught in PT school, but we don’t learn the research behind the facts. A majority of children go on to develop normal arch height. There needs to be a further breakdown of the children that go on to develop an “abnormal arch height”.
“There was a significantly higher prevalence in children who wore shoes (8.6%) than among the unshod (2.8%)”
There is a large difference between the two populations of children, but we also have to consider the small sample size of 154 children. I would love to see this study take it one step further and search for all children in a larger radius with flat feet and see if the same types of prevalence rates are present. If this is the case, then we can start to make some assumptions regarding footwear affecting arch height. There are so many other variables that are not accounted for that could also play a role in arch formation, so this study has to be taken with a grain of salt. It does though make a statement that kids wearing shoes may not develop a normal arch compared to those not wearing shoes. It literally states: “…shoe-wearing predisposes to flat foot”.
“It seems that closed-toe shoes inhibit the development of the arch of the foot more than do slippers or sandals. This may because intrinsic muscle activity is necessary to keep slippers from falling off.”
This is a good theory, but would have to be proven. As a PT, we tend to recommend against sandal or flip flops because of the same reason: we have to work differently to keep the shoes from falling off. There is something called the windlass mechanism that can be altered when wearing shoes that can easily fall off. Again, more research is needed in order to figure out which party is right.
Excerpts taken from:
Rao UD, Joseph B. The Influence of Footwear On the Prevalence Of Flat Foot. J Bone Joint Surg [Br]. 1992;74-B:525-527.