Influence of midsole hardness of standard cushioned shoes on running-related injury risk
- Daniel Theisen1,
- Laurent Malisoux1,
- Joakim Genin1,
- Nicolas Delattre2,
- Romain Seil1,3,
- Axel Urhausen1,3
- 1Sports Medicine Research Laboratory, Public Research Centre for Health, Luxembourg, Grand-Duchy of Luxembourg
- 2Essensole, Oxylane Research, Villeneuve d'Ascq, France
- 3Sports Clinique, Centre Hospitalier de Luxembourg, Luxembourg, Grand-Duchy of Luxembourg
- Correspondence to Dr Daniel Theisen, CRP-Santé, 76 rue d'Eich, L-1460 Luxembourg, Grand-Duchy of Luxembourg;
- Accepted 23 August 2013
- Published Online First 16 September 2013
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.