1. Agaplesion Bethanien Hospital, Geriatric Centre of Heidelberg University, Heidelberg, Germany.
2. Network Aging Research (NAR), Heidelberg University, Heidelberg, Germany.
3. Center of Geriatric Medicine, Heidelberg University, Heidelberg, Germany.
4. Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zurich, Switzerland.
5. Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.