An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Mock CN, Abantanga F, Cummings P, Koepsell TD.Mock CN, et al. Among authors: koepsell td.Bull World Health Organ. 1999;77(12):955-64.Bull World Health Organ. 1999.PMID: 10680242Free PMC article.
Shumway-Cook A, Silver IF, LeMier M, York S, Cummings P, Koepsell TD.Shumway-Cook A, et al. Among authors: koepsell td.J Gerontol A Biol Sci Med Sci. 2007 Dec;62(12):1420-7. doi: 10.1093/gerona/62.12.1420.J Gerontol A Biol Sci Med Sci. 2007.PMID: 18166695Clinical Trial.