1. Division of Physical Therapy, Department of Rehabilitation, Faculty of Health Sciences, University of Tokyo Health Sciences: 4-11 Ochiai, Tama City, Tokyo 206-0033, Japan
2. Dysphagia Rehabilitation, Department of Gerontology and Gerodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
3. Social Welfare Service Corporation Sawarabi-kai Special Nursing Home for the Elderly, Syugetsu, Japan