Table 3.

Effect size (Cohen’s d) referenced by quiet nasal breathing (Q-Bre) in the supine posture.

	Posture	Breathing task
		Q-Bre	Deep-Bre	Forced-Expi	Exertion-Inspi
Inspiratory phase
TrA-IO	Supine	ref	0.02	0.08	0.69†
	Elbow-toe	0.40	0.39	0.17	1.57*
EO	Supine	ref	0.49	1.07*	3.07*
	Elbow-toe	21.84*	21.14*	21.40*	20.12*
IAP	Supine	ref	7.49*	6.04*	3.69*
	Elbow-toe	7.55*	20.01*	15.92*	18.57*
Expiratory phase
TrA-IO	Supine	ref	0.03	2.26*	0.69†
	Elbow-toe	0.31	0.57†	1.34*	1.42*
EO	Supine	ref	0.44	12.82*	2.51*
	Elbow-toe	20.81*	22.34*	26.71*	19.60*
IAP	Supine	ref	10.53*	53.43*	4.94*
	Elbow-toe	10.33*	26.20*	30.60*	21.07*

ref reference value, IAP intra-abdominal pressure, TrA-IO transverse abdominal and internal oblique muscle, EO external oblique muscle, Q-Bre quiet nasal breathing, Deep nasal deep breathing until abdominal wall expansion, 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.

*Large effect (d > 0.8).

^†Moderate effect (d > 0.5).