Characteristic activation of respiratory muscles in Liuzijue practice: a preliminary study based on surface electromyography in healthy individuals.

Purpose: Liuzijue, a traditional Chinese Qigong, is effective for respiratory rehabilitation, yet its underlying mechanisms remain largely theoretical due to complex movement patterns. This study aimed to record respiratory muscle surface electromyography (EMG) during Liuzijue practice, analyze muscle activation characteristics, and provide a scientific basis for its clinical application.

Methods: Thirty-two proficient Liuzijue practitioners underwent calm breathing, deep breathing, and Liuzijue training with surface EMG recordings. Contraction strength, duration, recruitment sequence of respiratory muscles, and physiological parameters (heart rate, perceived exertion, oxygen saturation) were analyzed across the three phases.

Results: Compared to calm breathing, Liuzijue significantly increased activation of external intercostal muscles, diaphragm, rectus abdominis, and transversus abdominis. During Liuzijue, internal oblique and multifidus activation was higher than during deep breathing. The activation state of the tested respiratory muscles was also influenced by the different movements within Liuzijue. Liuzijue also extended the contraction time of certain muscles and adjusted the activation sequence of transversus abdominis and external oblique muscles. Heart rate during Liuzijue was consistent with low-intensity exercise, with no significant differences in perceived respiratory fatigue or oxygen saturation compared to the other phases.

Conclusion: As a low-intensity exercise, Liuzijue enhances respiratory muscle activation, extends contraction duration, and adjusts activation sequence, supporting its clinical application in respiratory rehabilitation.

Trial Registration: The study was registered with the China Clinical Trial Registry on July 26, 2024 (No. ChiCTR2400087442).