Current Pedorthics | January-February 2019 | Vol.51, Issue 1 | Page 36

Lateral wedges - a crossover study "Since recent research has identified a link between foot symptoms and development of knee OA, and the fact that shoe-worn insoles evoke change directly at the feet, measurement of foot and ankle symptoms with foot-based treatment for knee OA is necessary." statistical differences when comparing group mean comfort ratings, any effect of perceived comfort would have occurred on an individual basis. Jones et al also reported slightly more perceived foot comfort with a combined insole compared to a lateral wedge alone, though the differences were also not statistically significant [21]. Given that 19/26 individuals reported at least some foot pain (values >25% on the FFI-R pain subscale) at the initial baseline assessment, assessment of changes in foot symptoms was important. Within-condition assessment of change in these symptoms from the current study would indicate that the lateral wedges plus arch support were able to improve foot symptoms. Finally, while not statistically tested, more self-reported adverse events were recorded during lateral wedges use (n=11) than during the combined insoles (n=5). While these reports were relatively minor and short-term, this finding provides further justification for the need to comprehensively assess the feet when providing any insoles treatment to people with knee OA to primarily target knee symptoms. Our study is novel, and an important contribution to the literature for a number of reasons. First, this is the first study evaluating shoe-worn insoles in people with knee OA that has considered foot type as an inclusion or exclusion criterion. As noted above, given that pronated foot posture is common in people with knee OA [6], and is associated with a 34 Pedorthic Footcare Association | www.pedorthics.org higher risk of developing knee pain and medial tibiofemoral cartilage damage [11], this subgroup in particular represents an important target for the study of shoe-worn insoles for the treatment of knee OA. More research with a homogeneous sample of pronated foot posture is warranted. This is also the first study, to our knowledge, to assess the impact of insoles on foot symptoms in people with knee OA. Since recent research has identified a link between foot symptoms and development of knee OA [9], and the fact that shoe-worn insoles evoke change directly at the feet, measurement of foot and ankle symptoms with foot-based treatment for knee OA is necessary. Indeed, given that more self- reported adverse events (especially lower leg, ankle, and foot issues) were reported in the present study with the lateral wedges alone, this finding provides important information necessary to inform clinical decision making in this particular subgroup. However, given the potential cost difference between the two types of insoles (potentially in excess of $300 per pair depending on the provider), a cost-effectiveness analysis of any symptomatic benefits of the combined insole must be conducted to assist in the justification of prescribing this addition to a standard lateral wedge. There are some limitations to this study. First, although within-condition changes were observed, our relatively small sample size for this exploratory study likely impacted our