Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent airflow limitation, progressive dyspnea, and peripheral muscle dysfunction, significantly impairing functional capacity and quality of life. Although the combined implementation of aerobic and resistance exercises is recommended in pulmonary rehabilitation programs, early-onset ventilatory limitation in individuals with COPD often hinders tolerance to high exercise intensities. This limitation increases the need for alternative exercise approaches targeting peripheral muscle adaptations. Low-load blood flow restriction training (LL-BFRT), which enables improvements in muscle strength with low mechanical loads, has emerged as a potential option for this patient population. However, evidence regarding the effects of LL-BFRT in individuals with COPD-particularly on upper extremity muscles-remains limited.
The aim of this study is to comparatively investigate the effects of LL-BFRT and sham-BFRT, both administered in addition to an aerobic exercise program in individuals diagnosed with stage II and III COPD, on upper extremity muscle strength, upper extremity functional capacity, activities of daily living performance, quality of life, functional exercise capacity, muscle oxygenation, and respiratory parameters. The study is designed as a randomized controlled, single-blind, quasi-experimental interventional trial.
The expected outcomes are that LL-BFRT may enhance upper extremity muscle strength and functional capacity, improve activities of daily living and quality of life, and increase exercise tolerance due to its applicability at low mechanical loads. Furthermore, findings related to muscle oxygenation and respiratory parameters are anticipated to provide clinical evidence regarding the physiological effects of LL-BFRT on peripheral muscle adaptations. These results are expected to guide the integration of LL-BFRT as an alternative and safe approach in upper extremity exercise prescription within pulmonary rehabilitation programs, support clinical decision-making processes, and establish a scientific foundation for future research.
Individuals aged 40-80 years with stage 2 and 3 COPD diagnosed according to GOLD criteria
Clinically stable COPD (no exacerbation in the last 6 weeks)
Stable medical treatment for at least 4 weeks
No orthopedic or neurological problems that would prevent them from performing upper extremity exercises
Uncontrolled hypertension
Severe arrhythmia
Recent MI
Deep vein thrombosis
Parallel
Low-Load Blood Flow Restriction Training (LL-BFRT) + Aerobic Exercise
Other interventionParticipants will undergo an 8-week upper extremity aerobic exercise program combined with low-load blood flow restriction training (LL-BFRT). The aerobic exercise will be performed using an arm cycle ergometer at 60-70% of age-predicted maximum heart rate for 20 minutes, preceded and followed by 5 minutes of unloaded cycling. In addition, LL-BFRT will be applied to the proximal upper extremity with a pneumatic cuff at 30-40% of arterial occlusion pressure. Resistance exercises will be performed at 30% of one-repetition maximum (1RM) using a 4-set protocol (30-15-15-15 repetitions) with 45-second inter-set rest periods while maintaining cuff pressure. Target muscles include the biceps brachii, triceps brachii, and anterior deltoid.
Sham Low-Load Blood Flow Restriction Training (LL-BFRT) + Aerobic Exercise
Other interventionParticipants will undergo the same 8-week upper extremity aerobic exercise program as the intervention group. Aerobic exercise will be performed using an arm cycle ergometer at 60-70% of age-predicted maximum heart rate for 20 minutes, preceded and followed by 5 minutes of unloaded cycling. In addition, sham blood flow restriction training will be applied with a pneumatic cuff placed proximally on the upper extremity. The cuff pressure will be set at a level insufficient to produce therapeutic blood flow restriction. The exercise structure, sets, repetitions, and muscle groups targeted will be identical to the intervention group.
Upper Extremity Functional Capacity
Upper extremity functional capacity and endurance will be assessed using the 6-Minute Pegboard \& Ring Test (6-PBRT). During the test, participants will be seated in front of a pegboard and instructed to use both hands simultaneously to transfer as many rings as possible from two lower pegboards positioned at shoulder level to two upper pegboards located 20 cm above, and then back to the lower boards. The test duration is 6 minutes. Prior to the actual test, participants will be allowed to practice by transferring a few rings to familiarize themselves with the procedure. During the test, the physiotherapist will provide standardized verbal encouragement every minute to motivate the participant. At the end of the 6 minutes, the total number of rings transferred throughout the test will be recorded as the final score (16).
Pulmonary Function Assessment
Pulmonary function will be assessed using spirometric measurements. Spirometry is a standard pulmonary function test that evaluates lung volume and airflow rates. During the test, participants will be instructed to exhale forcefully and completely to achieve maximal lung emptying. Parameters including Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC), and the FEV1/FVC ratio will be recorded. In addition, post-bronchodilator FEV1/FVC \< 0.70 will be used for diagnosis and classification in accordance with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines (18).
Muscle Strength Assestment
Muscle strength of the biceps brachii, triceps brachii, and anterior deltoid muscles will be assessed using a Hand-Held Dynamometer (HHD). Measurements will be performed in standardized seated positions at specific joint angles. Biceps brachii strength will be measured with the elbow flexed at 90° and the forearm in supination (19). Triceps brachii strength will be measured during maximal isometric elbow extension, and anterior deltoid strength during shoulder flexion at 90°. Three measurements will be taken for each muscle group and the highest value will be recorded for analysis.
Activity Of Daily Living Assestment
Activities of daily living will be evaluated using the Londrina Activities of Daily Living (Londrina ADL) Scale. This protocol includes five activities involving upper and lower extremity movements as well as trunk flexion, inclination, and rotation. Participants will sit in front of a table and transfer ten objects of different weights (250 g, 500 g, and 1 kg) from one side of the table to the other using both hands and then return them to the initial position. Participants will also walk three consecutive times over a 6-meter distance as part of the protocol. The total time required to complete all activities will be recorded as the outcome measure.
Quality Of Life Assestment
Quality of life will be assessed using the St. George's Respiratory Questionnaire (SGRQ). The SGRQ is a disease-specific quality of life instrument consisting of 50 items and three domains. The Symptoms domain evaluates the frequency and severity of respiratory symptoms; the Activity domain assesses the impact of respiratory problems on daily activities; and the Impacts domain measures the psychosocial and functional effects of the disease on the individual's life. Response options for the items range between 2 and 5 points, and each item is weighted according to its predefined scoring algorithm during calculation (23).
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