TABLE 6.

Results of the co-contraction EMG activation level (%) between the groups.

Movement	Muscle	Experienced	Novice	p-value	ES
Chest lift	RA/EO	15.4 ± 8.63	13.1 ± 3.92	0.29	0.37
	MU/LO	14.6 ± 63.78	4.3 ± 5.88	0.32	0.46
	RA/MU	6.4 ± 5.94	7.1 ± 6.32	0.73	0.11
	RA/LO	4.6 ± 3.74	6.1 ± 5.53	0.32	0.33
Spine stretch	RA/EO	8.5 ± 7.90	19.5 ± 45.76	0.32	0.41
	MU/LO	7.4 ± 5.15	7.8 ± 7.18	0.84	0.07
	RA/MU	5.8 ± 9.13	8.1 ± 10.64	0.48	0.24
	RA/LO	3.9 ± 5.03	7.2 ± 7.53	0.14	0.50
Roll up	RA/EO	13.4 ± 5.87	15.4 ± 8.62	0.40	0.28
	MU/LO	7.8 ± 15.63	6.4 ± 6.42	0.70	0.14
	RA/MU	6.2 ± 4.69	8.9 ± 6.58	0.15	0.48
	RA/LO	3.9 ± 2.37	5.9 ± 5.66	0.15	0.52
Double leg stretch	RA/EO	17.5 ± 7.24	12.6 ± 4.55	0.02	0.83
	MU/LO	2.9 ± 4.47	4.3 ± 6.77	0.48	0.25
	RA/MU	4.4 ± 4.89	4.9 ± 6.11	0.74	0.11
	RA/LO	2.8 ± 2.43	5.3 ± 6.27	0.12	0.57
Teaser	RA/EO	15.6 ± 5.74	15.5 ± 9.96	0.98	0.01
	MU/LO	5.1 ± 5.31	8.0 ± 7.06	0.32	0.46
	RA/MU	4.9 ± 5.80	7.6 ± 7.25	0.22	0.41
	RA/LO	4.0 ± 2.84	6.7 ± 6.32	0.09	0.59
Jackknife	RA/EO	14.6 ± 0.07	11.7 ± 5.90	0.49	0.23
	MU/LO	7.8 ± 5.52	6.8 ± 6.04	0.48	0.24
	RA/MU	6.7 ± 5.49	9.2 ± 7.32	0.28	0.36
	RA/LO	4.3 ± 3.90	7.3 ± 6.80	0.16	0.50

Data are presented as mean ± standard deviation. Abbreviations: RA/EO, co-contraction of rectus abdominis and external oblique; MU/LO, co-contraction of multifidus and longissimus; RA/MU, co-contraction of rectus abdominis and multifidus; RA/MU, co-contraction of rectus abdominis and multifidus; RA/LO, co-contraction of rectus abdominis and longissimus; EO/MU, co-contraction of external oblique and multifidus; EO/LO, co-contraction of external oblique and longissimus. ES (effect size) values are interpreted as follows: small effect (0.2), medium effect (0.5), and large effect (0.8 or above).