Table 3. Comparison of muscle activity ratio between serratus anterior and pectoralis major depending on the posture during shoulder-strengthening exercise

Muscle	Positions			F value	p value
	Side-lying	Standing	Supine
SA/PM	1.17	0.87	0.90	13.05	0.00*

SA, serratus anterior; PM, pectoralis major.
p<0.05.