Optimal control simulation predicts effects of midsole materials on energy cost of running

Abstract

Testing sports equipment with athletes is costly, time-consuming, hazardous and sometimes impracticable. We propose a method for virtual testing of running shoes and predict how midsoles made of BOOST^TM affect energy cost of running. We contribute a visco-elastic contact model and identified model parameters based on load-displacement measurements. We propose a virtual study using optimal control simulation of musculoskeletal models. The predicted reduction in energy cost of $\sim 1\%$ for BOOST^TM in comparison to conventional materials is consistent with experimental studies. This indicates that the proposed method is capable of replacing experimental studies in the future.

Keywords:

• Virtual design
• footwear
• running
• musculoskeletal simulation

Acknowledgement

The authors thank Anne Koelewijn, who implemented the model of muscle energy expenditure. This study was supported by a contract from adidas AG with Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany. Eva Dorschky gratefully acknowledges the support of the Bavarian Ministry of Economic Affairs, Regional Development and Energy within the Embedded Systems Initiative (ESI). Bjoern Eskofier gratefully acknowledges the support of the German Research Foundation (DFG) within the framework of the Heisenberg professorship programme (grant number ES 434/8-1).

Disclosure statement

Eva Dorschky, Daniel Krüger, Nicolai Kurfess, Sandro Wartzack and Bjoern M. Eskofier have no conflicts of interest relevant to the content of this article. Heiko Schlarb is an employee of adidas AG. Antonie J. van den Bogert is a paid consultant to adidas AG.

Additional information

Funding

The Bavarian Ministry of Economic Affairs, Regional Development and Energy partially funded the research.