Creative Commons Attribution 4.0 International LicenseGirard, OlivierMorin, Jean-BenoitRyu, Joong HyunVan Alsenoy, Ken K.2020-07-152020-07-152020-06-302020-02-23Girard, O., Morin, J. B., Ryu, J. H. & Van Alsenoy, K. (2020) Custom foot orthoses improve performance, but do not modify the biomechanical manifestation of fatigue, during repeated treadmill sprints. European Journal of Applied Physiology, 120, pp. 2037–2045.1439-6327https://eresearch.qmu.ac.uk/handle/20.500.12289/10645https://doi.org/10.1007/s00421-020-04427-0From PubMed via Jisc Publications RouterWe determined the effect of custom foot orthotics manufactured from ethyl-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) materials, both compared to a control condition (CON; shoes only) during repeated sprints on running mechanical alterations. Eighteen males performed eight, 5-s sprints with 25-s recovery on an instrumented sprint treadmill in three footwear conditions (EVA, TPU and CON). Mechanical data consisted of continuous (step-by-step) measurement of running kinetics and kinematics, which were averaged for each sprint for further analysis. Distance ran in 5 s decreased from first to last sprint (P < 0.001), yet with higher sprints 1-8 values for both EVA (P = 0.004) and TPU (P = 0.018) versus CON. Regardless of footwear condition, mean horizontal forces, step frequency, vertical and leg stiffness decreased from sprint 1 to sprint 8 (all P < 0.001). Duration of the propulsive phase was globally shorter for both EVA (P = 0.002) and TPU (P = 0.021) versus CON, while braking phase duration was similar (P = 0.919). In the horizontal direction, peak propulsive (P < 0.001), but not braking (P = 0.172), forces also decreased from sprint 1 to sprint 8, independently of conditions. Compared to shoe only, wearing EVA or TPU custom foot orthotics improved repeated treadmill sprint ability, yet provided similar fatigue-induced changes in mechanical outcomes.2037–2045http://creativecommons.org/licenses/by/4.0/InsolesInstrumented TreadmillLeg-spring BehaviourRunning Kinematicsarticle2020-07-15