1. Research, Health, and Podiatry Group, Department of Health Sciences, Faculty of Nursing and Podiatry, Industrial Campus of Ferrol, Universidade da Coruña, 15403 Ferrol, Spain
2. Departament de Podologia, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
3. Facultad de Enfermería, Fisioterapia y Podología, Universidad Complutense de Madrid, 28040 Madrid, Spain
4. Faculty of Health Sciences, Universidad Rey Juan Carlos, 28922 Alcorcon, Spain
5. Frailty Research Organizaded Group (FROG), Department of Nursing, Faculty of Nursing and Podiatry, University of Valencia, 46010 Valencia, Spain
6. Escola Superior de Saúde da Cruz Vermelha Portuguesa, 1300-125 Lisbon, Portugal
7. Department of Sociology, Social Work and Public Health, Faculty of Labour Sciences, University of Huelva, 21004 Huelva, Spain
8. Health and Safety Postgraduate Programme, Universidad Espíritu Santo, Guayaquil 092301, Ecuador