Table 2. Summary and agreement statistics for spatiotemporal gait parameters using Kinect tracking from the left side (one-sided).

Parameter	Our System	VICON	Pearson’s correlation			Bland-Altman			ICC(A,1)
	Mean ± SD	Mean ± SD	R	P	N	Bias	RPC	CV (%)
Stride length L (cm)	145.95 ±11.08	145.36 ±8.49	0.786	<0.001	267	0.59	13.43	4.71	0.758
Stride length R (cm)	146.27 ±10.22	147.04 ±9.01	0.923	<0.001	187	-0.78	7.77	2.70	0.913
Step length L (cm)	72.85 ±6.18	73.95 ±5.36	0.667	<0.001	267	-1.10	9.34	6.49	0.649
Step length R (cm)	73.40 ±8.36	71.67 ±4.48	0.538	<0.001	281	1.73	13.81	9.72	0.434
Step width L (cm)	10.02 ±4.69	11.51 ±3.15	0.569	<0.001	267	-1.49	7.62	36.13	0.493
Step width R (cm)	14.58 ±7.33	11.91 ±2.97	0.475	<0.001	281	2.68	12.69	48.88	0.297
AV stride length L (cm)	146.30 ±8.70	145.66 ±7.98	0.997	<0.001	10	0.64	1.90	4.71	0.991
AV stride length R (cm)	146.16 ±8.94	146.95 ±8.43	0.994	<0.001	10	-0.79	2.15	2.70	0.989
AV stride length AVG (cm)	146.24 ±8.75	146.20 ±8.17	0.998	<0.001	10	0.04	1.53	0.53	0.996
AV step length L (cm)	72.97 ±4.17	74.10 ±5.13	0.939	<0.001	10	-1.13	3.69	2.56	0.900
AV step length R (cm)	73.36 ±5.12	71.67 ±3.60	0.898	<0.001	10	1.69	4.84	3.40	0.799
AV step length AVG (cm)	73.19 ±4.40	72.82 ±3.96	0.996	<0.001	10	0.36	1.12	0.78	0.988
AV step width L (cm)	10.03 ±2.67	11.55 ±1.85	0.750	0.01	10	-1.52	3.47	16.39	0.591
AV step width R (cm)	14.57 ±2.44	11.91 ±1.74	0.845	0.002	10	2.66	2.63	10.13	0.452
AV step width AVG (cm)	12.39 ±2.15	11.73 ±1.76	0.944	<0.001	10	0.66	1.49	6.30	0.882

Notice, the difference in agreement between the left and right body half for the step width and step length. RPC: reproducibility coefficient (1.96*SD); CV: coefficient of variation (SD in % of the mean value); ICC(A,1): intraclass correlation coefficient for absolute agreement. Subject averages across steps (AV) and sides (AVG) are labeled accordingly. Measures in bold can be compared to previously reported systems [1,2].