In men, <2% of our population reported wearing poor shoe types. This could make seeing any possible relationship between foot pain and shoewear very difficult due to sparse statistical power to detect a possible difference. We also observed several protective, nonsignificant associations in men between shoewear and foot pain. Despite the large number of men in our study, very few reported wearing good or poor shoes. It may well be that other studies with larger numbers of men reporting good or poor shoe types (57% and 92% of men in our study reported average shoes for current shoewear and past shoewear, respectively) could have sufficient power to examine these possible protective effects in more detail.
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In addition, participants were given a list of 11, nonspecific categories from which to choose the 1 shoe type that was worn most often currently and at past age groupings. Since these categories were broad and inadequately specified, there is most probably misclassification that has occurred in the categorization of footwear. Due to the time constraints of the study, we were forced to limit the choices of categories and were not able to measure this as accurately or specifically as would have been ideal. This probable misclassification would lead to results that are biased towards the null. Sandals, in particular, are likely to be misclassified given the fact that some sandals may actually provide excellent support for the foot. Due to the time constraints in this study, only 1 category for sandals was used. Despite this limitation, it is important to realize that regular sandal use in the Northeastern US is not particularly common (4% in this study), and therefore may not be a major factor. There was also opportunity for recall bias when participants were asked to remember what type of shoe they were wearing as long ago as 60 years.
