1. University of Michigan Medical School, Department of Physical Medicine & Rehabilitation, Ann Arbor, MI, USA
2. University of Michigan, School of Public Health, Ann Arbor, MI, USA
3. Texas A&M University, Department of Life Sciences, Corpus Christi, TX, USA
4. University of Michigan Institute for Social Research, Ann Arbor, MI, USA
5. University of Michigan Medical School, Department of Internal Medicine, Ann Arbor, MI, USA
6. University of Michigan Medical School, Department of Neurology, Ann Arbor, MI, USA