Table 2.

Performance of the participants in the instrumented tests of postural control and gait

Postural control	Healthy subjects		Individuals with Parkinson’s Disease
			All		H&Y I-I.5		H&Y II		H&Y II.5
Modified clinical test of sensory interaction on balance
Speed (cm/s)	0.54 ± 0.1		0.59 ± 0.1a‡		0.50 ± 0.1		0.60 ± 0.1a		0.66 ± 0.1a*b‡
Limits of stability
Maximum displacement (cm)	8.65 ± 1.34		8.37 ± 1.6		9.47 ± 1.5a‡		8.24 ± 1.4b‡		7.14 ± 2.3b
Reaction time (s)	1.09 ± 0.5		1.17 ± 0.5		1.25 ± 0.4		1.05 ± 0.5		1.75 ± 0.6a*c*

Gait
	Single task	Dual task	Single task	Dual task	Single task	Dual task	Single task	Dual task	Single task	Dual task
Gait speed (m/s)	1.1 ± 0.1	1.0 ± 0.2	1.1 ± 0.2	0.9 ± 0.2	1.2 ± 0.1	1.1 ± 0.2a	1.1 ± 0.2	0.9 ± 0.2b	0.9 ± 0.3a‡b*c	0.8 ± 0.3a*b*
Cadence (steps/min)	114.8 ± 11.1	103.9 ± 16.4	112.4 ± 13.1	101.1 ± 14.9	121.4 ± 12.2a‡	108.4 ± 12.2	112.0 ± 10.7b‡	101.3 ± 14.8	98.8 ± 17.4a*b*c	88.1 ± 13.0ab
Stride length (m)	1.2 ± 0.1	1.1 ± 0.1	1.1 ± 0.1	1.1 ± 0.2	1.2 ± 0.1	1.2 ± 0.2	1.1 ± 0.2	1.1 ± 0.2	1.1 ± 0.2a	1.0 ± 0.2a‡b‡
Stride time (s)	1.0 ± 0.1	1.2 ± 0.2	1.1 ± 0.1	1.2 ± 0.2	1.0 ± 0.1	1.1 ± 0.2	1.1 ± 0.1	1.2 ± 0.2	1.2 ± 0.2a‡b*c	1.4 ± 0.2a*bc‡
Stride width (m)	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0	0.1 ± 0.0
Double support time (s)	0.3 ± 0.1	0.3 ± 0.1	0.3 ± 0.1a‡	0.4 ± 0.2	0.2 ± 0.1a‡	0.3 ± 0.1	0.3 ± 0.1a‡	0.4 ± 0.1	0.4 ± 0.2b	0.5 ± 0.2a

Scores of all the participants in the instrumented measures of postural control and gait. Data are presented as mean ± SD. Significant differences after Bonferroni correction are denoted with: only superscript letters for at least 95% confidence; letters plus asterisks * for at least 99% confidence; and letters plus crosses ^‡ for strong trends (at least 90% confidence)

^aDifferent from healthy subjects

^bDifferent from the H&Y I-I.5 group

^cDifferent from the H&Y II group