Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Mar 1;5(2):100259.
doi: 10.1016/j.arrct.2023.100259. eCollection 2023 Jun.

Peak Quadriceps Muscle Torque and Electromyographic Output in Patients With Chronic Respiratory Disorders: Effects of Pulmonary Rehabilitation

Gregory Grandio  1 , Guadalupe Yetter  2 , Spencer Briglio  2 , Kimberly Ong  2 , Joel Froding  2 , Jimmy Kim  2 , Juan Cortez  3 , Ahmet Baydur  1
Affiliations

Peak Quadriceps Muscle Torque and Electromyographic Output in Patients With Chronic Respiratory Disorders: Effects of Pulmonary Rehabilitation

Gregory Grandio et al. Arch Rehabil Res Clin Transl. .

Abstract

Objective: To assess the change in relation of the peak quadriceps electromyographic signal to the peak torque produced during a train of 5 isokinetic knee extensions (from 90 degrees below horizontal at a constant speed of 60 degrees/s) at baseline, and at 4 and 8 weeks of pulmonary rehabilitation.

Design: In this prospective observational study, isokinetic contractions were recorded during the extensions from the knee bent at 90 degrees to the horizontal plane against graded resistance. Peak quadriceps torque signal (Tq) and peak electromyographic signal (Eq) were recorded by dynamometry and surface electrodes placed at designated locations over the muscle group, respectively.

Setting: Physical therapy department in a tertiary care medical center.

Participants: Eighteen patients (9 restrictive lung disease, 6 chronic airflow limitation, 3 non-ILD restrictive; N=18) were compared with 11 healthy control subjects.

Interventions: Patients underwent an 8-week pulmonary rehabilitation program.

Main outcome measures: Comparisons of Tq, Eq, and Tq/Eq ratio among patients and controls were by analysis of variance. Associations between physiological variables were determined by multivariable Pearson's correlation.

Results: Compared with patients, controls exhibited a 22% higher baseline mean peak Eq (P<.05) and 76% higher mean peak Tq (P=.02) during knee extensions. Patients' peak Eq/Tq was twice as high as in the controls (P=.02); at 4 weeks, Eq/Tq in patients decreased by 44% (P<.04) with no further decline at 8 weeks; changes in Eq/Tq of 5 of 6 patients paralleled changes in their respective St George's Respiratory Questionnaire scores. There was no change in Tq or Eq/Tq over time among the control cohort.

Conclusions: Eight weeks of pulmonary rehabilitation result in a decrease in Eq/Tq, indicating improvement in force generation of limb muscles, with the change occurring in the first 4 weeks.

Keywords: Chronic airflow limitation; Dynamometry; Electromyography; Interstitial lung disease; Isokinetic contractions; Limb muscle function; Pulmonary rehabilitation.

PubMed Disclaimer

Figures

Fig 1
Fig 1
Flow chart for patients screened, recruited and tested.
Fig 2
Fig 2
Change in Eq/Tq after 8 weeks of pulmonary rehabilitation with respect to baseline total SGRQ scores (expressed as percent predicted). r2=0.383 (NS).
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Skeletal muscle dysfunction in chronic obstructive pulmonary disease. A statement of the American Thoracic Society and European Respiratory Society. Am J Respir Crit Care Med. 1999;159:S1–40. - PubMed
    1. Gosselink R, Troosters T, Decramer M. Peripheral muscle weakness contributes to exercise limitation in COPD. Am J Respir Crit Care Med. 1996;153:976–980. - PubMed
    1. Coronell C, Orozco-Levi M, Méndez R, et al. Relevance of assessing quadriceps endurance in patients with COPD. Eur Respir J. 2001;24:129–136. - PubMed
    1. Butcher SJ, Meske JM, Sheppard MS. Reductions in functional balance, coordination, and mobility measures among patients with stable chronic obstructive pulmonary disease. J Cardiopulmonary Rehabil. 2004;24:274–280. - PubMed
    1. Iepsen U, Munch G, Rugbjerg M, et al. Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD: a pilot study. Int J Chron Obstruct Pulmon Dis. 2016;11:2659–2669. - PMC - PubMed

LinkOut - more resources