Figure 2.

Representative data of air flow, IAP, and electromyography during the active breathing task (a–d), with the inspiratory (↓) and expiratory phase (↑). The vertical dotted line indicates the elbow-toe posture interval. I inspiratory phase (↓), E expiratory phase (↑), IAP intra-abdominal pressure, TrA-IO transverse abdominal and internal oblique muscle, EO external oblique muscle, Q-Bre quiet nasal breathing, Forced-Expi completely forced expiration with pursed-lips until the abdominal wall hollowed, Exertion-Inspi exertional nasal inhalation with abdominal muscle isometric contraction to prevent abdominal wall expansion.