Table 2. Test -retest reliability of level walking for Control and ABI.

	Control t test Dependent, equal variance, 2 tailed	Control λ Bias (Random error)	Control ɸ % variability	Control Mean ICC [3, 1]
Walking speed	t (20) = 0.66, NS	-0.02 (0.25)	8.1	0.70
Gross Oxygen Consumption	t (20) = 1.02, NS	-0.30 (2.73)	11.6	0.55
Net Oxygen Consumption	t (20) = 1.53, NS	-0.43 (2.43)	12.7	0.68
Gross oxygen cost	t (20) = 0.32, NS	0.00 (0.05)	14.7	0.42
Net oxygen cost	t (20) = 0.19, NS	0.00 (0.02)	17.3	0.61
	ABI t test Dependent, equal variance, 2 tailed	ABI λ Bias (Random error)	ABI ɸ % variability	ABI Mean ICC [3,1]
Walking speed	t (9) = 0.53, NS	-0.02 (0.28)	13.7	0.89
Gross Oxygen Consumption	t (9) = 0.47, NS	0.18 (2.33)	11.4	0.51
Net Oxygen Consumption	t (9) = 0.65, NS	0.24 (2.02)	10.5	0.64
Gross oxygen cost	t (9)=2.87, *	0.05 (0.10)	17.4	0.97
Net oxygen cost	t (9)=3.02, *	0.04 (0.04)	20.8	0.93

Walking speed (m·s); oxygen consumption (ml·kg·min) and cost (ml·kg ·m). NS = non-significant. p < 0.05.ɸ Percentage variability was calculated by averaging the absolute value of the difference between each measurement of the group, dividing this by the average of the group, and multiplying by 100.λ Bias (mean difference) (± Random error) (1.96 SD difference).