J Electrodiagn Neuromuscul Dis.  2023 Aug;25(2):51-58. 10.18214/jend.2023.00024.

Relationship between Chronic Obstructive Pulmonary Disease Severity and Surface Electromyography Parameters during Fatigue Caused by Knee Extensor Contractions

• Shin HJ
• Lee JW
• Kim SH
• Shin MJ
• Jang MH

• KMID: 2545472
• DOI: http://doi.org/10.18214/jend.2023.00024

Abstract

Objective
Skeletal muscle dysfunction, which is characterized by decreased muscle strength and endurance, contributes to dyspnea during exercise in patients with chronic obstructive pulmonary disease (COPD), regardless of pulmonary function. This study analyzed skeletal muscle function in patients with COPD through surface electromyography (sEMG) evaluations and signal processing and attempted to determine whether sEMG parameters for muscle fatigue reflect the course of the disease.
Methods
In 24 patients with COPD, maximal voluntary isometric contraction and ramp contraction were performed during isometric knee extension, and the sEMG activity of the rectus femoris muscle was measured. The patients were divided into three groups according to their modified Medical Research Council (mMRC) grade and Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. Patients with mMRC grades 0 and 1 were classified into group A, grade 2 into group B, and grades 3 and 4 into group C. Patients with GOLD stage 1 were classified into group I, stage 2 into group II, and stages 3 and 4 into group III. sEMG parameters were compared between groups using one-way analysis of variance.
Results
There were significant differences in the minimum median frequency and fatigue index between the mMRC groups. However, the sEMG parameters did not differ significantly among the GOLD groups.
Conclusion
Muscle fatigue differs according to the severity of subjective dyspnea in COPD. sEMG evaluations and signal processing can play supplementary roles in evaluating muscle endurance and predicting functional capacity in COPD.

Keyword

Pulmonary disease, chronic obstructive; Dyspnea; Muscle fatigue; Physical endurance; Electromyography