Muscle Coactivation during Stability Exercises in Rhythmic Gymnastics: A Two-Case Study

Table 1

Mean values and standard deviation of the EMG amplitude normalized to MVIC (%) of the support leg muscles of gymnasts A and B in balance exercises. Statistically significant differences between means: letters “a–i” in the upper index.

	Muscle	Gymnast A			Gymnast B
		Side split with hand support (SSps)	Ring with hand support (RS)	Back split without hand support (BSp)	Side split with hand support (SSps)	Ring with hand support (RS)	Back split without hand support (BSp)
Ankle joint	Antagonist
	TA	74.96 ± 17.89	53.45 ± 6.23	43.59 ± 2.72	48.52 ± 3.66	19.25 ± 1.89^c	17.68 ± 0.71^c
	Agonist
	GM	135.39 ± 31.32^a	187.16 ± 12.85^a	152.59 ± 24.75	64.45 ± 1.92^c	68.89 ± 2.34^a,c	53.69 ± 0.67^c
	GL	123.46 ± 47.92^a,d	214.18 ± 39.63^a,d	91.91 ± 76.26	47.64 ± 6.11	56.36 ± 2.14^a,c	27.44 ± 2.74
Knee joint	Antagonist
	BF	65.62 ± 16.35	45.69 ± 14.49	17.13 ± 15.93^g,h	10.62 ± 1.43^c	36.34 ± 6.97^i	8.98 ± 1.73^h
	Agonist
	VM	30.73 ± 5.33^b	5.15 ± 1.06^b	9.56 ± 8.02	51.13 ± 11.18^b,c	34.91 ± 3.04^c	21.22 ± 0.19
	VL	27.55 ± 4.14^b	3.37 ± .032^b	8.56 ± 8.88	30.72 ± 8.13^b,f	17.32 ± 1.66^b,c,f	14.74 ± 1.12
	RF	17.28 ± 6.68^b	1.83 ± 0.48^b	4.75 ± 4.68	29.21 ± 13.43^b,e	10.83 ± 2.79^b,e	10.27 ± 0.37

^aStatistically significant difference as compared with TA. ^bStatistically significant difference as compared with BF. ^cStatistically significant between gymnast A and B. ^dStatistically significant between GM and GL. ^eStatistically significant between VM and RF. ^fStatistically significant between VM and VL. ^gStatistically significant between BSp and SSpS. ^hStatistically significant between BSp and RS. ⁱStatistically significant between RS and SSpS.