Introduction. - This study aimed at assessing the influence of a damaged shoe cushioning system on the rate of blood inflammatory protein after a run. Synthesis of the facts. - The subjects ran using two kind of shoe: a brand new shoe and a shoe which had a mechanically damaged cushioning system. After running, blood was collected and analyzed to define inflammatory protein rates. Conclusion. - The growth of stiffness by mechanical ageing produced an increased of inflammatory protein rates. This study provided an objective point of view on how a damaged shoe cushioning system may harm the body. (C) 2009 Elsevier Masson SAS. All rights reserved.