This study measures muscle properties in people with Chronic Obstructive Pulmonary Disease (COPD) and healthy individuals. COPD is a lung disease that makes breathing hard. The MyotonPro device will be used to check the strength and flexibility of muscles used for breathing, called accessory respiratory muscles, and muscles in arms and legs, called peripheral muscles. The study compares these muscle qualities in COPD patients and healthy people.

Eligibility: To join, COPD patients should belong to group C or D as per GOLD staging (a way to classify COPD severity) and use the same medications for four weeks. They should not have other serious illnesses. Healthy participants must be over 18, without chronic diseases, and non-smokers.

• The study involves measuring muscle properties, which is non-invasive.
• Participants should not have recent COPD flare-ups or other lung diseases.
• There should be no thick fatty tissue at measurement sites for accurate results.