Table 2.

Time domain and time event features (shaded grey) of sEMG signals. Two numbers assigned to a feature correspond to the arithmetic mean and standard deviation of that feature.

	Number	Symbol	Number	Symbol
Time event features	The mean and standard deviation of phase shifts ${\varnothing }_{X,Y}$ between X and Y muscles for total strides		The mean and standard deviation of the signal root-mean-square ${\rho }_X$ of muscle X for total strides
	1,2	${\varnothing }_{\mathrm{RBF},\mathrm{RVM}}$	31, 32	${\mathsf{\rho }}_{\mathrm{RBF}}$
	3,4	${\varnothing }_{\mathrm{RBF},\mathrm{RVL}}$	33, 34	${\mathsf{\rho }}_{\mathrm{RVM}}$
	5,6	${\varnothing }_{\mathrm{RVM},\mathrm{RVL}}$	35, 36	${\mathsf{\rho }}_{\mathrm{RVL}}$
	7,8	${\varnothing }_{\mathrm{LBF},\mathrm{LVM}}$	37, 38	${\mathsf{\rho }}_{\mathrm{LBF}}$
	9,10	${\varnothing }_{\mathrm{LBF},\mathrm{LVL}}$	39, 40	${\mathsf{\rho }}_{\mathrm{LVM}}$
	11,12	${\varnothing }_{\mathrm{LVM},\mathrm{LVL}}$	41, 42	${\mathsf{\rho }}_{\mathrm{LVL}}$
	13,14	${\varnothing }_{\mathrm{RBF},\mathrm{LBF}}$	Asymmetry of ${\varnothing }_{X,Y}$ between the right and left leg.
	15,16	${\varnothing }_{\mathrm{RVM},\mathrm{LVM}}$	43	${\sum }_{({\varnothing }_{\mathrm{BF},\mathrm{VM}})}$
	17,18	${\varnothing }_{\mathrm{RVL},\mathrm{LVL}}$	44	${\sum }_{({\varnothing }_{\mathrm{BF},\mathrm{VL}})}$
	The mean and standard deviation of the active time percentages ${\alpha }_X$ of muscle X for total strides		45	${\sum }_{({\varnothing }_{\mathrm{VM},\mathrm{VL}})}$
	19,20	${\mathsf{\alpha }}_{\mathrm{RBF}}$	Asymmetry of ${\alpha }_X$ between the right and left leg.
	21,22	${\mathsf{\alpha }}_{\mathrm{RVM}}$	46	${\sum }_{{\mathsf{\alpha }}_{\mathrm{BF}}}$
	23, 24	${\mathsf{\alpha }}_{\mathrm{RVL}}$	47	${\sum }_{{\mathsf{\alpha }}_{\mathrm{VM}}}$
	25, 26	${\mathsf{\alpha }}_{\mathrm{LBF}}$	48	${\sum }_{{\mathsf{\alpha }}_{\mathrm{VL}}}$
	27, 28	${\mathsf{\alpha }}_{\mathrm{LVM}}$	Asymmetry of ${\rho }_X$ between the right and left leg.
	29, 30	${\mathsf{\alpha }}_{\mathrm{LVL}}$	49	${\sum }_{{\mathsf{\rho }}_{\mathrm{BF}}}$
Total number of time-domain features = 51 Total number of time event features = 36			50	${\sum }_{{\mathsf{\rho }}_{\mathrm{VM}}}$
			51	${\sum }_{{\mathsf{\rho }}_{\mathrm{VL}}}$