1. Oregon Research Institute, Eugene, OR 97403, USA
2. Shanghai University of Sport, Shanghai, China
3. Willamette University, Department of Exercise and Health Science, Salem, OR 97301, USA
4. Division of General Internal Medicine & Geriatrics, Oregon Health & Science University, Portland, OR 97239, USA
5. McKenzie Willamette Medical Center, Springfield, OR 97477, USA
6. Voit Better Balance, Seattle, WA 98104, USA
7. Iowa State University, Department of Kinesiology, Ames, IA 50011, USA