Validation of quantitative gait analysis systems for Parkinson’s disease for use in supervised and unsupervised environments

Table 4 Absolute normal difference distribution (mean ± standard deviation) from PD patients versus healthy controls (PDvsControl) and Parkinson’s disease patients between ON and OFF states (ONvsOFF) for each gait parameter [39,40,41,42]. Bias (mean ± standard deviation) values for each gait parameter for the inertial-based 3D full-body kinematics (IMU Bias) and the smartphone-based kinematics (Mob Bias). P-value is determined by Welch’s t-test when comparing PDvsControl / IMU Bias, PDvsControl / Mob Bias, ONvsOFF / IMU Bias and ONvsOFF / Mob Bias

	PDvsControl mean ± SD	ONvsOFF mean ± SD	IMU Bias mean ± SD	Mob Bias mean ± SD	PDvsControl / IMU Bias p value	PDvsControl / Mob Bias p value	ONvsOFF / IMU Bias p value	ONvsOFF / Mob Bias p value
Stride duration (s)	0.040 ± 0.126	0.03 ± 0,156	0.003 ± 0,015	−0.001 ± 0,027	0,0013	0,0014	0,0203	0,0166
Stance duration (s)	0.044 ± 0,093	0.032 ± 0,094 ^a	−0.005 ± 0.021	−0.014 ± 0,033	< 0.0001	< 0.0001	0.0002	0.0002
Swing duration (s)	0.009 ± 0,273	0.007 ± 0,053	0.008 ± 0,022	0.011 ± 0,034	0,9754	0,9518	0,8876	0,6776
Double support time (s)	0.253 ± 0.035 ^a	0.164 ± 0,026 ^a	−0.007 ± 0,021	–	< 0,0001	–	< 0,0001	–
Cadence (strides/min)	4.000 ± 16.101	3.500 ± 13.086	−0.175 ± 0,819	0.058 ± 1.405	0,0331	0,0458	0,0077	0,0141
Stride speed (m/s)	0.160 ± 0,325 ^a	0.060 ± 0,030	−0.004 ± 0,021	−0.004 ± 0,047	< 0,0001	< 0,0001	0,0040	0,0092
Stride length (m)	0.210 ± 0,292 ^a	0.140 ± 0,292 ^a	−0.001 ± 0,023	−0.007 ± 0,037	< 0,0001	< 0,0001	< 0,0001	< 0,0001
Step width (m)	0.008 ± 0,031	0.001 ± 0,038	0.008 ± 0,021	–	> 0,9999	–	0,2520	–

a – indicates that statistical significant differences were reached in the original study from which the normal difference distribution was pooled. Significant results are displayed in bold

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