The effect of manual therapy on diaphragm function in adults with asthma: Protocol for a randomized controlled trial [version 2; peer review: 2 approved]

Background Diaphragm dysfunction is prevalent among individuals with asthma due to lung hyperinflation and hyperventilation in asthma paroxysm. This study was designed to evaluate the effect of the manual diaphragm release technique (MDRT) on diaphragm function in individuals with asthma. Methods Adults with diagnosed stable asthma (n = 24), will be recruited from the General Hospital of Kifissia “Agioi Anargyroi” in Athens, Greece. The volunteers who meet the inclusion criteria will be randomly allocated to two groups: (a) the experimental group (n = 12) that will receive 12 sessions of MDRT in conjunction with breathing retraining exercises (BRE), and (b) the control group (n = 12) that will receive 12 sessions of BRE. Measurements will occur at three time points: before the initiation of treatment sessions (week 0), followed by 12 treatment sessions (week 6), and three months from the beginning of the trial (week 12). The main outcomes will be the diaphragm excursion (ultrasonography) and chest expansion (inch tape), with secondary outcomes the maximal respiratory pressures (digital pressure manometer), dysfunctional breathing (Nijmegen questionnaire), asthma control (ACT), dyspnea (Borg scale) and quality of life (SF-12v2). Discussion The proposed protocol is the first to examine the effectiveness of MRDT on diaphragm’s function in individuals with asthma. Manual Therapy (MT) is a low-cost alternative and supplementary therapy to standard treatment procedures that might improve the biomechanics of respiration in pulmonary rehabilitation. Trial Registration Registered on Clinical Trials.gov (ID: NCT05709054) Protocol version 29/09/2023