1. Department of Geriatrics, National Institute of Geriatrics Rheumatology and Rehabilitation, 02-637 Warsaw, Poland
2. Faculty of Electronics, Military University of Technology, 00-908 Warsaw, Poland
3. Gerontology, Public Health and Education Department, National Institute of Geriatrics Rheumatology and Rehabilitation, 02-637 Warsaw, Poland
4. Department of Ultrasound, Institute of Fundamental Technological Research Polish Academy of Sciences, 02-106 Warsaw, Poland