AUTHOR=Hart David A. , Zernicke Ronald F. TITLE=Editorial: Optimal Mobility and Function Across the Lifespan JOURNAL=Frontiers in Physiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.652640 DOI=10.3389/fphys.2021.652640 ISSN=1664-042X