PT - JOURNAL ARTICLE AU - Theisen, Daniel AU - Malisoux, Laurent AU - Genin, Joakim AU - Delattre, Nicolas AU - Seil, Romain AU - Urhausen, Axel TI - Influence of midsole hardness of standard cushioned shoes on running-related injury risk AID - 10.1136/bjsports-2013-092613 DP - 2014 Mar 01 TA - British Journal of Sports Medicine PG - 371--376 VI - 48 IP - 5 4099 - http://bjsm.bmj.com/content/48/5/371.short 4100 - http://bjsm.bmj.com/content/48/5/371.full SO - Br J Sports Med2014 Mar 01; 48 AB - Background In this double-blind randomised controlled trial, we tested if leisure-time runners using shoes with less compliant midsoles have a higher running-related injury (RRI) risk. Method We provided 247 runners with standard running shoes having either a soft study shoes (soft-SS) or a hard study shoes (hard-SS) midsole and followed them prospectively for 5 months regarding RRI. All information about sports practice and injuries was uploaded on a dedicated internet platform and checked for consistency and completeness. RRI was defined as any first-time pain sustained during or as a result of running practice and impeding normal running activity for at least 1 day. Cox proportional hazards regressions were used to identify RRI risk factors. Result The type of study shoes used for running was not associated with RRIs (HR=0.92; 95% CI 0.57 to 1.48). The hard-SS had a 15% greater overall stiffness in the heel region. The two study groups were similar regarding personal and sports participation characteristics, except for years of running experience, which was higher (p<0.05) in the hard-SS group. Global RRI incidence was 12.1 RRI/1000 h of running. No between-group differences were found regarding injury location, type, severity or category. Nevertheless, the adjusted regression model revealed positive associations with RRI risk for body mass index (HR=1.126; 95% CI 1.033 to 1.227), previous injury (HR=1.735; 95% CI 1.037 to 2.902) and mean session intensity (HR=1.396; 95% CI 1.040 to 1.874). Protective factors were previous regular running activity (HR=0.422; 95% CI 0.228 to 0.779) and weekly volume of other sports activities (HR=0.702; 95% CI 0.561 to 0.879). Conclusions Midsole hardness of modern cushioned running shoes does not seem to influence RRI risk.