Effects of Scalene Muscle Stretching on Slow Vital Capacity and Chest Expansion in Patients After Coronary Artery Bypass Grafting: An Interventional Study

Abstract

Background: Coronary artery bypass grafting (CABG) is a coronary revascularization technique associated with diminished pulmonary function. During the first week after CABG, slow vital capacity (SVC) decreases by 30%–60%. Scalene muscles affect pulmonary function because they attach to the 1st and 2nd ribs. Shorter scalene muscles can decrease inhalation volume and chest expansion. Very few studies have assessed the effects of scalene stretching on SVC and chest expansion in patients post-CABG. Therefore, this study was aimed at determining the effects of scalene muscle stretching on SVC and chest expansion in such patients. Methods: A total of 74 patients post-CABG (phase 2) meeting the inclusion criteria were randomly allocated to two groups: an intervention group (n = 30) performing scalene muscle stretching and a control group (n = 30) performing active neck exercise. Pre & Post SVC and chest expansion were measured in all patients. A total of 14 patients were excluded. Statistical analysis was conducted in SPSS software (version 20.0). Results: SVC showed significant increase (P < 0.05) in the intervention group compared with the control group. Chest expansion was statistically non-significant between groups (P > 0.05). Conclusion and clinical implications: Scalene muscle stretching improves SVC in patients post-CABG (phase 2). Hence, scalene stretching should be included in programs for improving respiratory function.