Physical Therapy Korea

Table 2

Comparison of muscle activity of each muscle by exercises and forearm positions

Variable		SIER	STER	PRER	SLER	F
Posterior deltoid	Neutral	2.65 ± 1.35	15.69 ± 5.51^a	52.38 ± 13.21^a,b	17.12 ± 6.98^a,c	152.400**
	Supinated	2.35 ± 1.11	15.77 ± 6.62^a	47.95 ± 10.81^a,b	15.51 ± 6.90^a,c	171.749**
	Difference	0.30 ± 0.52	–0.08 ± 2.88	4.43 ± 7.61^a,b	1.61 ± 2.47^a	5.994**
	t	3.164**	–0.150	3.184**	3.580**
Infraspinatus	Neutral	26.77 ± 9.01	45.01 ± 13.74^a	80.39 ± 18.67^a,b	54.66 ± 11.51^a,b,c	180.628**
	Supinated	23.09 ± 8.87	43.99 ± 13.42^a	77.08 ± 16.54^a,b	52.95 ± 11.13^a,b,c	215.421**
	Difference	3.68 ± 3.90	1.02 ± 4.70	3.31 ± 9.37	1.71 ± 5.67	1.633
	t	5.168**	1.188	1.938	1.651
Biceps brachii	Neutral	9.23 ± 4.50	13.49 ± 9.51^a	9.73 ± 11.01^b	3.30 ± 2.51^a,b,c	43.155**
	Supinated	8.03 ± 4.22	16.69 ± 9.85^a	11.78 ± 14.10^b	4.28 ± 3.08^a,b,c	29.706**
	Difference	1.20 ± 3.34	–3.20 ± 3.38^a	–2.05 ± 5.22^a	–0.98 ± 1.70^a,b	9.574**
	t	1.967	–5.185**	–2.153*	–3.162**

Values are presented as mean ± standard deviation. SIER, sitting external rotation at 0° abduction; STER, standing external rotation at 90° abduction; PRER, prone external rotation at 90° of abduction; SLER, side-lying external rotation at 0° abduction. ^aThere is a significant difference from SIER (p < 0.05), ^bThere is a significant difference from STER (p < 0.05), ^cThere is a significant difference from PRER (p < 0.05). *p < 0.05, **p < 0.01.

Phys. Ther. Korea 2022;29:106~116 https://doi.org/10.12674/ptk.2022.29.2.106