Reducing Overpronation Studies Reviewed: 1. Cheung RTH, Chung RCK & Ng GYF. Efficacies of different external controls for excessive foot pronation: A meta-analysis. British Journal of Sports Medicine 2011; 45: 743-751. 2. Mills K, Blanch P & Chapman AR. Foot orthoses and gait: A system -atic review and meta-analysis of literature pertaining to potential mechanisms. British Journal of Sports Medicine 2010 ; 44: 1035-1046. BACKGROUND INFORMATION Although no consensus exists on the definition of “overpronation,” its consequences are well known, biomechanically logical and supported by the literature. In conjunction with internal rotation of the tibia, valgus collapse at the knee and an increased adduction moment at the hip, overpronation can contribute to a myriad of biomechanical concerns and conditions such as stress fractures, Achilles tendinopathy, patellofemoral pain syn-drome, plantar fasciitis and medial tibial stress syndrome. A variety of interventions are commonly employed to address overpronation, including prefabricated and custom foot orthotics, motion control footwear, and taping. The two pa-pers included in this review sought to synthesize the literature on the efficacy of these inter-ventions on addressing overpronation 1 and summarize the effects of foot orthotics on gait. 2 SUMMARY Efficacy of Foot Orthoses, Motion Control Shoes and Taping for Controlling Overpronation: • Twenty-nine studies were included in this review. • Overall, all three interventions can potentially improve overpronation. Foot or-thotics were the least effective means and therapeutic taping was most effective. However, the difference among the three interventions was only about 0.5° – questionable in that it could result from measurement error and inconsistencies amongst the studies included. Mechanisms of Action for Gait Alterations with Foot Orthotics: • Twenty-two studies were included in this review. • Overall, this review concluded that there is wide variability in how individu-als respond to orthotics. Posted orthotics that aren’t customized seem to affect rearfoot kinematics and tibial internal rotation, whereas moulded (customized) orthotics may attenuate loading rate and vertical impact force. • Readers should keep in mind that most studies included subjects with no history of injury. CONCLUSIONS AND PRACTICAL APPLICATIONS In general, it appears that orthotics, motion control footwear and taping are all poten-tially effective for reducing overpronation. Practically speaking, orthotics or footwear seem more reasonable despite the fact that taping was most effective when data were pooled. This difference was minimal, and taping is not a reasonable, long-term solution in most cases. The literature also suggests that non-customized, posted orthotics may control rear-foot eversion and tibial motion more than a control intervention, whereas customized orthotics may have more of an effect on loading and force attenuation than if they are just posted (When was the last time an orthotic company rep gave you this information?). Given that patient response to orthotics seems to be variable (this is something the literature demonstrated quite clearly), clinicians should continue to customize their pre-scription after careful assessment and evaluation of each patient. • To read this review in full, including study methods, complete summaries and detailed results, please visit www.canadianchiropractor.ca. www.canadianchiropractor.ca Shawn Thistle, BKin (Hons), DC, CSCS Dr. Shawn Thistle is the founder and president of Research Review Service Inc., an online, subscription-based service designed to help busy practitioners to integrate current, relevant scientific evidence into their practice. Shawn graduated from CMCC and holds an Hon-ours Degree in Kinesiology from McMaster University. He also holds a certificate in Contemporary Medi-cal Acupuncture from McMaster University, and is a Certified Active Release Techniques (ART®) Pro-vider. For more information about the Research Review Service, visit www.researchreviewservice.com. 46 • CANADIAN CHIROPRACTOR | FEBRUARY 2012
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