Table 2.

Comparison of APA and foot lift parameters between the pre- and post-treatment condition in the WBV and sham group (young adults and elderly).

	APA and Foot lift phase	WBV group		Sham group		Group X treatment interaction
	Variables	Pre-treatment	Post-treatment	Pre-treatment	Post-treatment	P-values
Young adults	AP COP shift (cm)	4.94 ± 1.51	5.29 ± 1.23	5.44 ± 1.37	5.52 ± 1.41	NS
	ML COP shift(cm)	4.61 ± 2.17	5.35 ± 2.09***	4.99 ± 1.27	5.12 ± 1.43	<0.001
	AP APA duration (s)	0.05 ± 0.11	0.47 ± 0.01	0.51 ± 0.10	0.50 ± 0.09	NS
	ML APA duration (s)	0.45 ± 0.08	0.47 ± 0.09	0.49 ± 0.01	0.45 ± 0.07	NS
	Foot lift duration (s)	0.12 ± 0.02	0.12 ± 0.03	0.14 ± 0.04	0.13 ± 0.04	NS
	AP COM velocity at HO (m/s)	0.21 ± 0.04	0.22 ± 0.05	0.23 ± 0.04	0.22 ± 0.04	NS
	ML COM velocity at HO (m/s)	0.14 ± 0.04	0.15 ± 0.04**	0.15 ± 0.02	0.15 ± 0.03	0.04
Elderly	AP COP shift (cm)	4.53 ± 1.23	5.03 ± 1.32	4.69 ± 0.64	4.95 ± 1.27	NS
	ML COP shift(cm)	4.21 ± 1.55	4.48 ± 1.63	4.85 ± 1.53	5.05 ± 1.88	NS
	AP APA duration (s)	0.40 ± 0.09	0.36 ± 0.06	0.38 ± 0.06	0.36 ± 0.05	NS
	ML APA duration (s)	0.39 ± 0.09	0.37 ± 0.05	0.36 ± 0.05	0.37 ± 0.05	NS
	Foot lift duration (s)	0.14 ± 0.02	0.14 ± 0.02	0.14 ± 0.02	0.14 ± 0.04	NS
	AP COM velocity at HO (m/s)	0.15 ± 0.05	0.16 ± 0.05	0.14 ± 0.03	0.15 ± 0.05	NS
	ML COM velocity at HO (m/s)	0.11 ± 0.04	0.11 ± 0.03	0.12 ± 0.04	0.12 ± 0.04	NS

Reported values are means ± standard deviation. APA, anticipatory postural adjustments; COM, center of mass; COP, center of pressure; AP, anteroposterior; ML, mediolateral; HO, heel off; NS, non-significant interaction.

^{*, **, ***}Significant difference between the pre and post-treatment condition as revealed with the Tukey post-hoc test, with P < 0.05, P < 0.01, and P <0.001, respectively.