Heel-shoe interactions and the durability of EVA foam running-shoe midsoles

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

A finite element analysis (FEA) was made of the stress distribution in the heelpad and a running shoe midsole, using heelpad properties deduced from published force-deflection data, and measured foam properties. The heelpad has a lower initial shear modulus than the foam (100 vs. 1050 kPa), but a higher bulk modulus. The heelpad is more non-linear, with a higher Ogden strain energy function exponent than the foam (30 vs. 4). Measurements of plantar pressure distribution in running shoes confirmed the FEA. The peak plantar pressure increased on average by 100% after 500km run. Scanning electron microscopy shows that structural damage (wrinkling of faces and some holes) occurred in the foam after 750 km run. Fatigue of the foam reduces heelstrike cushioning, and is a possible cause of running injuries. (C) 2004 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Pages (from-to)1379-1386
Number of pages8
JournalJournal of Biomechanics
Volume37
Publication statusPublished - 1 Sep 2004