Table 5.

Statistical results for the effects of head shaking (phase effect) on the relative variance rVAR of PP_k for the four testing conditions based on rANOVA. For rANOVA results, partial eta-square (η²) are reported as a measure of the effect size, and 1−β for the observed power. Asterisks (*) indicate significant head-shaking effects on the relative variance of the movement component.

PPk	Trial		Overall rVARk
			F	DoF	p-Value	η 2	1 − β
PP1	Nodding head	eyes open	1.320	2, 30	0.282	0.081	0.263
		eyes closed	1.719	2, 30	0.196	0.103	0.332
	Tilting head	eyes open	0.625	2, 30	0.542	0.040	0.145
		eyes closed	0.274	2, 30	0.763	0.018	0.089
PP2	Nodding head	eyes open	1.228	1.480, 22.201	0.300	0.076	0.213
		eyes closed	6.387	2, 30	0.005 *	0.299	0.870
	Tilting head	eyes open	2.023	2, 30	0.150	0.119	0.384
		eyes closed	0.473	2, 30	0.628	0.031	0.120
PP3	Nodding head	eyes open	2.691	2, 30	0.084	0.152	0.492
		eyes closed	0.977	2, 30	0.388	0.061	0.204
	Tilting head	eyes open	1.418	2, 30	0.258	0.086	0.280
		eyes closed	0.093	2, 30	0.912	0.006	0.063
PP4	Nodding head	eyes open	0.601	2, 30	0.555	0.039	0.141
		eyes closed	0.294	2, 30	0.748	0.019	0.092
	Tilting head	eyes open	0.175	2, 30	0.840	0.012	0.075
		eyes closed	0.737	2, 30	0.487	0.047	0.163
PP5	Nodding head	eyes open	0.726	1.415, 21.218	0.450	0.046	0.141
		eyes closed	0.574	2, 30	0.569	0.037	0.136
	Tilting head	eyes open	0.583	2, 30	0.564	0.037	0.138
		eyes closed	0.476	2, 30	0.626	0.031	0.121