Effect of Respiratory Muscle Stretch Gymnastic on Chest Expansion and Peak Expiratory Flow Rate among People with Chronic Obstructive Pulmonary Diseases: A Systematic Narrative Review

Abstract Background: Chronic obstructive pulmonary disease (COPD) is a respiratory disorder characterized by persistent airflow limitation and chronic airway inflammation. Respiratory muscle stretch gymnastics (RMSG) is a therapeutic intervention designed to improve chest wall mobility by reducing stiffness of the respiratory muscles. Also, according to Laplace’s law, effective ventilation depends on the mechanical properties and dimensions of respiratory structures. This systematic narrative review aimed to evaluate and summarize evidence regarding the effects of RMSG on chest expansion and peak expiratory flow rate (PEFR) in geriatric patients with COPD. Materials and Methods: A systematic literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases, including PubMed, Google Scholar, ScienceDirect, and ResearchGate, were searched for studies published between January 2013 and December 2025. Eligible studies included full-text English-language interventional studies involving geriatric patients with COPD that evaluated the effects of RMSG on chest expansion and/or PEFR.