Table 1.

Means and standard errors of force-matching and postural variables for the concurrent force-matching and postural tasks in the level-surface and stabilometer conditions.

Mean ± SE	Level-surface	Stabilometer	Statistics
NFE (%)	9.89 ± 0.78	10.01 ± 0.79	t(13) = −0.328, p = 0.748
RT (ms)	304.8 ± 9.6	310.7 ± 9.8	t(13) = −1.720, p = 0.109
AMF_RMS (degree)	0.012 ± 0.001	0.151 ± 0.023†††	t(13) = −6.138, p < 0.001
AMF_SampEn	0.514 ± 0.013	0.382 ± 0.006†††	t(13) = 8.049, p < 0.001

NFE, normalized force-matching error; RT, reaction time for force-matching; AMF_RMS, root mean square value of ankle movement fluctuations; AMF_SampEn, sample entropy of ankle movement fluctuations;

^†††, stabilometer > level-surface, p < 0.001.