Table 1

Analysis of variance table for the significant effects (and interactions) on balance control of varying height, surface firmness, and visual reference

		RMS AP sway*		RMS ML† sway		Sway area		Sway velocity
Sourse	df	F value	p Value	F value	p Value	F value	p Value	F value	p Value
*RMS AP sway = root mean square anterior-posterior sway.
†RMS ML sway = root mean square medial-lateral sway.
Main effects
Height	2	58.24	<0.0001	39.51	<0.0001	65.77	<0.0001	30.54	<0.0001
Surface firmness	1	139.13	<0.0001	159.64	<0.0001	162.11	<0.0001	127.79	<0.0001
Visual reference	1	198.74	<0.0001	33.73	<0.0001	64.29	<0.0001	124.49	<0.0001
Interactions
Height × surface firmness	2	14.81	<0.0001	20.14	<0.0001	43.16	<0.0001	59.24	<0.0001
Height × visual reference	2	73.14	<0.0001	3.08	ns	71.58	<0.0001	32.93	<0.0001
Surface firmness × visual reference	1	79.45	<0.0001	34.36	<0.0001	114.66	<0.0001	92.84	<0.0001
Height × surface firmness × visual reference	2	21.53	<0.0001	17.63	<0.0001	60.90	<0.0001	13.29	<0.0001