About the Authors

Steven H. Collins


Affiliation Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands

Arthur D. Kuo

Affiliation Departments of Mechanical and Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America

Competing Interests

S.H.C. is part-owner of Intelligent Prosthetic Systems L.L.C., which was incorporated to perform research and development on the energy-recycling technology reported in this manuscript. None of the data presented here is proprietary, however the design of the artificial foot is partially covered by US Provisional Patent no. 60/705,019. Foot prostheses based on this technology are under development, but none are currently available as marketed products. We will make available all data used to reach the conclusions presented in this study.

Author Contributions

Conceived and designed the experiments: SHC ADK. Performed the experiments: SHC. Analyzed the data: SHC. Wrote the paper: SHC ADK. Designed and built artificial foot: SHC.