The effect of manual therapy and exercise on age-related lung function: study protocol for a randomised controlled trial

Background: Ageing is associated with a range of anatomical and physiological changes. Establishing whether a change is part of 'normal' ageing or the early signs of disease will affect management strategies. Progressive stiffening of the thoracic spine, decreasing chest wall compliance and declining lung function begin as early as 40 years of age. Administering an intervention such as manual therapy, which has the potential to mitigate age-related changes in the thoracic spine and chest wall, has the potential to improve thoracic compliance and lung function. The aims of this trial are to investigate whether manual therapy can mitigate the effects of age-related changes in lung function and whether there is a difference in effect between different forms of manual therapy. Methods: The study design is a randomised controlled trial of 372 people with no history of respiratory disease between the ages of 50 and 65 years. The cohort will be divided into three equal groups. The first group will receive a simple 10-min treadmill walking program (Ex). The second group will receive joint mobilisation (MB) of the thoracic spine and ribs plus the same walking program (MB + Ex). The third group will receive joint manipulation (MT) of the thoracic spine and ribs plus the same walking program (MT + Ex). All interventions will be administered a total of six times over a 3-week period. The primary outcome measure is lung function: forced expiratory volume in the 1st second and forced vital capacity. The secondary outcome measures include chest wall expansion (tape measurements) and quality of life measurements (36-Item Short Form Health Survey). Outcome measurements will be taken by blinded assessors on four occasions over a 9-week period. Adverse event data will be gathered at the beginning of each intervention session. Discussion: This randomised controlled trial is designed to investigate whether manual therapy can mitigate the effects of age-related changes in lung function and whether there is a difference in effect between different forms of manual therapy. This is the first fully powered trial designed to test this hypothesis on healthy males and females in this age range. Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR), 12616001317482. Registered on 20 September 2016.