Carlos Cruz-Montecinos,1–3 Diego Godoy-Olave,4 Felipe A Contreras-Briceño,5 Paulina Gutiérrez,4 Rodrigo Torres-Castro,2 Leandro Miret-Venegas,3 Roger M Engel6 1Laboratory of Biomechanics and Kinesiology, San José Hospital, Santiago, Chile; 2Department of Physical Therapy, Faculty of Medicine, University of Chile, Santiago, Chile; 3Unit of Kinesiology and Physical Therapy, San José Hospital, Santiago, Chile; 4Departamento de Kinesiología, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile; 5Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile; 6Department of Chiropractic, Macquarie University, Sydney, Australia Background and objective: In chronic obstructive pulmonary disease (COPD), accessory respiratory muscles are recruited as a compensatory adaptation to changes in respiratory mechanics. This results in shortening and overactivation of these and other muscles. Manual therapy is increasingly being investigated as a way to alleviate these changes. The aim of this study was to measure the immediate effect on lung function of a soft tissue manual therapy protocol (STMTP) designed to address changes in the accessory respiratory muscles and their associated structures in patients with severe COPD.Methods: Twelve medically stable patients (n=12) with an existing diagnosis of severe COPD (ten: GOLD Stage III and two: GOLD Stage IV) were included. Residual volume, inspiratory capacity and oxygen saturation (SpO2) were recorded immediately before and after administration of the STMTP. A Student’s t-test was used to determine the effect of the manual therapy intervention (P<0.05).Results: The mean age of the patients was 62.4 years (range 46–77). Nine were male. Residual volume decreased from 4.5 to 3.9 L (P=0.002), inspiratory capacity increased from 2.0 to 2.1 L (P=0.039) and SpO2 increased from 93% to 96% (P=0.001).Conclusion: A single application of an STMTP appears to have the potential to produce immediate clinically meaningful improvements in lung function in patients with severe and very severe COPD. Keywords: expiratory reserve volume, plethysmography, residual volume, inspiratory capacity