**6. Conclusion**

In conclusion, we and others have shown that use of OEP can demonstrate the following: (i) dynamic hyperinflation of the chest wall may not necessarily be the principal reason for ex‐ ercising limitation and breathlessness in COPD patients; (ii) pulmonary rehabilitation im‐ proves COPD patients' endurance and exercise-related perceptions regardless of changes in chest wall kinematics; (iii) in contrast with what is commonly believed, chest wall dynamic hyperinflation may have a salutary mechanical effect in patients with expiratory flow limita‐ tion and dynamic hyperinflation, who increase functional residual capacity because of ach‐ ieving more tidal expiratory flow; (iv) OEP provides complementary information on operationl volumes to that provided by spirometry.

Finally, there are very few reports on the use of OEP in pulmonary rehabilitation and thora‐ cic surgery in patients with chronic respiratory disease other than COPD. We hope that the results presented here will stimulate new contributions on this topic.
