PURPOSE: Little is known about the physiology of walking in chronic obstructive pulmonary disease (COPD). Our objective was to evaluate the cardiac and respiratory responses as well as the electrical activity of lower limb muscles during walking in patients with COPD compared with healthy controls. METHODS: Cardiorespiratory parameters were monitored during a 6-min walking test (6 MWT) in 10 patients with COPD and 11 healthy controls. Surface EMG (sEMG) data were recorded in five muscle groups (soleus, medial gastrocnemius, tibialis anterior, vastus lateralis, and rectus femoris) of the right leg during walking. The integrated signal (iEMG) and the median frequency were obtained from the sEMG signal of each muscle group. RESULTS: Although the walking distance and speed were significantly reduced in patients with COPD compared with those in controls, patients walked at a higher percentage of peak VO2. The overall sEMG patterns were similar between patients with COPD and controls. A fall in the sEMG median frequency during the 6 MWT was observed for the vastus lateralis and the rectus femoris in patients with COPD and in controls suggesting a muscle fatiguing contracting profile. CONCLUSION: The 6 MWT was performed at a relatively higher intensity in patients with COPD compared with healthy controls. The progressive fall in the sEMG median frequency of the vastus lateralis and rectus femoris in both groups suggested the occurrence of a muscle fatiguing profile during walking. The performance of a daily activity such as walking imposes a high physiological demand in patients with COPD.
PURPOSE: Little is known about the physiology of walking in chronic obstructive pulmonary disease (COPD). Our objective was to evaluate the cardiac and respiratory responses as well as the electrical activity of lower limb muscles during walking in patients with COPD compared with healthy controls. METHODS: Cardiorespiratory parameters were monitored during a 6-min walking test (6 MWT) in 10 patients with COPD and 11 healthy controls. Surface EMG (sEMG) data were recorded in five muscle groups (soleus, medial gastrocnemius, tibialis anterior, vastus lateralis, and rectus femoris) of the right leg during walking. The integrated signal (iEMG) and the median frequency were obtained from the sEMG signal of each muscle group. RESULTS: Although the walking distance and speed were significantly reduced in patients with COPD compared with those in controls, patients walked at a higher percentage of peak VO2. The overall sEMG patterns were similar between patients with COPD and controls. A fall in the sEMG median frequency during the 6 MWT was observed for the vastus lateralis and the rectus femoris in patients with COPD and in controls suggesting a muscle fatiguing contracting profile. CONCLUSION: The 6 MWT was performed at a relatively higher intensity in patients with COPD compared with healthy controls. The progressive fall in the sEMG median frequency of the vastus lateralis and rectus femoris in both groups suggested the occurrence of a muscle fatiguing profile during walking. The performance of a daily activity such as walking imposes a high physiological demand in patients with COPD.
Authors: François Maltais; Marc Decramer; Richard Casaburi; Esther Barreiro; Yan Burelle; Richard Debigaré; P N Richard Dekhuijzen; Frits Franssen; Ghislaine Gayan-Ramirez; Joaquim Gea; Harry R Gosker; Rik Gosselink; Maurice Hayot; Sabah N A Hussain; Wim Janssens; Micheal I Polkey; Josep Roca; Didier Saey; Annemie M W J Schols; Martijn A Spruit; Michael Steiner; Tanja Taivassalo; Thierry Troosters; Ioannis Vogiatzis; Peter D Wagner Journal: Am J Respir Crit Care Med Date: 2014-05-01 Impact factor: 21.405
Authors: Janneke Annegarn; Martijn A Spruit; Hans H C M Savelberg; Paul J B Willems; Coby van de Bool; Annemie M W J Schols; Emiel F M Wouters; Kenneth Meijer Journal: PLoS One Date: 2012-05-18 Impact factor: 3.240
Authors: Jennifer M Yentes; Kendra K Schmid; Daniel Blanke; Debra J Romberger; Stephen I Rennard; Nicholas Stergiou Journal: Respir Res Date: 2015-02-28