Table 1. Changes in muscle activity and hemodynamics in the sitting position (mean ± SD, n=25).

			Upright (a1)	10° flexion (a2)	20° flexion (a3)	Maximum flexion (a4)	Re-upright (a5)		Upright (a1)	10° extension (a2)	Maximum extension (a3)	Re-upright (a4)
NIRS	Oxy-Hb	LES	−0.4 ± 1.2	−0.5 ± 2.1	−0.8 ± 4.3	−1.8 ± 5.2	3.0 ± 2.7	LES	−0.2 ± 0.5	1.4 ± 3.0	4.4 ± 5.5	0.4 ± 4.7
		MF	−0.2 ± 0.9	−0.8 ± 2.5	−2.6 ± 4.4	−5.0 ± 6.2	3.2 ± 3.9	MF	0.0 ± 0.5	0.6 ± 2.7	5.1 ± 5.0	−0.2 ± 3.1
	De-Oxy-Hb	LES	−0.0 ± 0.5	2.9 ± 4.5#	7.1 ± 6.9#	9.7 ± 9.2#	1.4 ± 3.8	LES	−0.1 ± 0.5	−0.6 ± 2.9	−0.6 ± 5.6	0.1 ± 3.0
		MF	0.1 ± 0.4	−0.1 ± 3.2#	2.2 ± 4.5#	4.5 ± 7.2#	0.8 ± 3.6	MF	−0.1 ± 0.4	−1.0 ± 2.6	2.5 ± 6.7	−0.7 ± 2.5
	Total-Hb	LES	−0.5 ± 1.4	2.3 ± 5.6#	6.4 ± 9.3#	8.0 ± 11.4#	4.4 ± 4.6	LES	−0.3 ± 0.6	0.8 ± 5.4	3.9 ± 9.7	0.4 ± 5.8
		MF	−0.1 ± 0.7	−0.8 ± 4.6#	−0.4 ± 4.9#	−0.5 ± 8.0#	4.0 ± 5.9	MF	−0.1 ± 0.7	−0.4 ± 4.8	7.6 ± 11.0	−0.9 ± 4.3
%iEMG		LES	7.4 ± 4.7	15.0 ± 6.4	17.0 ± 7.3	3.4 ± 3.5	7.1 ± 4.2	LES	5.5 ± 3.7	4.7 ± 4.2	5.3 ± 3.9	5.7 ± 3.8
		MF	7.3 ± 4.8	17.6 ± 7.8	19.7 ± 9.1	3.2 ± 2.1	7.1 ± 5.0	MF	5.3 ± 4.0	5.0 ± 2.8	6.5 ± 3.6	6.0 ± 4.7
NIRS	Oxy-Hb	LES					a1,2,3,4<a5 *		a1,2<a3 *		a3>a4 *
		MF			a1,2>a3 *	a1,2,3>a4 *	a1,2,3,4<a5 *
	De-Oxy-Hb	LES		a1<a2 *	a1,2<a3 *	a1,2,3<a4 *	a3,4>a5 *		n.s.
		MF	n.s.
	Total-Hb	LES	a1<a3,4,5 *	a2<a3,4 *				LES	n.s.
		MF	a1<a5 *					MF			a1,2<a3 *	a3>a4 *
%iEMG		LES	a1<a2,3 *		a2,3>a5 *	a1,2,3>a4 *	a4<a5 *		n.s.
		MF	a1<a2,3 *		a2,3>a5 *	a1,2,3>a4 *	a4<a5 *

NIRS: change of hemodynamic (au; arbitrarily unit. value/10⁻²), %iEMG: muscle activity (%), *p<0.05 (factor of trunk angle), #p<0.05 (factor of measurement point), n.s.: not significant