About the Authors

David B. Lipps

Affiliation Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America

Andrzej T. Galecki

Affiliations Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America, Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States of America

James A. Ashton-Miller

jaam@umich.edu

Affiliations Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America, Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States of America, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DBL ATG JAA-M. Performed the experiments: DBL ATG. Analyzed the data: DBL ATG JAA-M. Contributed reagents/materials/analysis tools: ATG. Wrote the paper: DBL ATG JAA-M.