1. Department of Nursing and Physiotherapy, Universidad de León, Ponferrada Campus, 24001 Ponferrada, Spain
2. Department of Preventive Medicine and Public Health, University of Valladolid, 47005 Valladolid, Spain
3. SALBIS Research Group, Department of Electrical, Systems and Automatics Engineering, Universidad de León, Campus de Vegazana, 24071 León, Spain
4. SALBIS Research Group, Department of Nursing and Physiotherapy, Universidad de León, Campus de Vegazana, 24071 León, Spain