Table 1 EMG activities of the various muscles

Muscles	Mean±iSD (%jMVIC)		t value	p value
	PHE	PHEIS
ES (Rt)	24.08±9.84	10.21±5.25	–7.82	0.03*
ES (Lt)	25.01±13.54	17.34±10.72	–4.52	0.02*
MF (Rt)	27.71±12.27	29.94±15.99	1.25	0.24
MF (Lt)	24.57±10.41	20.74±8.10	–3.69	0.14
GM (Rt)	28.02±11.75	56.33±6.62	16.61	0.01*
BF (Rt)	30.12±25.14	19.31±10.01	–5.20	0.02*

PHE: prone hip extension, PHEIS: prone hip extension after iliopsoas stretching, ES (Rt): erector spinae in Rt. Side, ES (Lt): erector spinae in Lt. side, MF (Rt): multifidus in Rt. Side, MF (Lt): multifidus in Lt. Side, GM (Rt): gluteus maximus in Rt. Side, BF (Rt): biceps femoris in Rt. Side, SD: standard deviation, MVIC: maximal voluntary isometric contraction.