Whole Body Vibration in Chronic Obstructive Pulmonary Disease

Inclusion Criteria: * severe COPD defined as a post-bronchodilator forced expiratory volume at one second (FEV1)/ forced vital capacity (FVC) \< 0.7 and FEV1 \< 50% predicted, * stable disease defined as no exacerbation, * hospital admission or change in treatment in the previous 3 months. Exclusion Criteria: * other significant respiratory disease (bronchiectasis, * lung fibrosis, asthma, etc), * active smoking, * severe cardiovascular, * neurological, and/or metabolic pathology that could interfere with the results, * total hip, knee or ankle arthroplasty, * previous vitreous haemorrhage, * severe alcoholism (\> 80 g/day) and * severe malnutrition (BMI \< 19 Kg/m2) to reduce the risk of falling and dropouts.