A study of football footwear bending stiffness

For the past century, football boots have constantly changed, with new designs and materials being developed by sporting goods manufacturers to meet player demands. Investigating the effect of such changes on performance was important to further develop football boots. Bending stiffness has been demonstrated as an important performance parameter in running footwear; a concept with potential to investigate football footwear. As football boots consisted of an upper and an outsole, with the latter being manufactured from a far stiffer material than the upper, it could be speculated that the outsole limits the boot's flexibility. The aim of this paper was to create a testing device to quantify whether the whole shoe needed to be considered when designing football boots. The test device consisted of a simplified foot based on biomechanical factors linked to an Instron machine to quantify the load during bending. The bending stiffness of the uppers and boots were found to be non-linear, highlighting the need to specify the angle at which the stiffness was recorded. The upper was shown to have a significant effect on the bending stiffness of the overall boot construction, whilst different upper constructions were shown to affect the bending stiffness. With regard to the findings in this paper, it was concluded that the upper was an important consideration in boot design. © 2014 Published by Elsevier Ltd.