Table 2.

Study characteristics.

Author, year	Design	Demographics (individuals poststroke)	Demographics (healthy controls)	Muscle sets for EMG observation	Factorization technique
Allen et al. 2013 [25]∗	Cross-sectional	n = 11 Sex: 7 males, 4 females; age: 62.2 ± 11.7; time since stroke: 3.5 ± 2.7 years	n = 14 Sex: 2 males, 12 females; age: 63.1 ± 9.1	TA, SO, MG, VM, RF, MH, LH, GM	NNMF
Barroso et al. 2017 [34]	Cross-sectional	n = 9 Sex: 6 males, 3 females; age: 53 ± 11.05; time since stroke: 75.6 ± 65.9 months	None	TA, SO, MG, VL, RF, BF, GM, GMax, TFL, ADL, ES	NNMF
Bowden et al. 2010 [26]∗	Cross-sectional	n = 55 Sex: 35 males, 20 females; age: 59.5 ± 11.7; time since stroke: NR	n = 20 Sex: 4 males, 16 females; age: 65.5 ± 9.8	TA, SO, MG, VM, RF, MH, LH, GM	NNMF
Clark et al. 2010 [14]∗	Cross-sectional	n = 55 Sex: 35 males, 20 females; age: 59.5 ± 11.7; time since stroke: 57.8 ± 64.8 months	n = 20 Sex: 4 males, 16 females; age: 65.5 ± 9.8	TA, SO, MG, VM, RF, MH, LH, GM	NNMF
Coscia et al. 2015 [27]	Cross-sectional	n = 12 Sex: 9 males, 3 females; age: 58.53 ± 16.37; time since stroke: 54.6 ± 56.2 months	n = 10 Sex: 9 males, 3 females; age: 63.3 ± 3.1	PERL, TA, SOL, LG, RF, VM, BF, ST, ADL, TFL, GM, GMax	Factor analysis
Ferrante et al. 2016 [28]	Prepost experimental	n = 2 Sex: 2 males, 0 female; age: 67, 64; time since stroke: 11 years, 9 months	n = 13 Sex: 7 males, 6 females; age: 24.8 ± 1.3	TA, MG, MH, LH, VM, RF, GMax	NNMF
Gizzi et al. 2011 [29]	Cross-sectional	n = 10 Sex: 8 males, 2 females; age: 45.9 ± 16.5; time since stroke: 12 ± 5 weeks	n = 10 Sex: 7 males, 3 females; age: 42.4 ± 14.5	TA, MG, SOL, VL, RF, BF, GMax, RA, ES, LD, BB, TB, AD, UT, ST, SPL	NNMF
Hashiguchi et al. 2016 [30]	Prepost experimental	n = 13 Sex: 10 males, 3 females; age: 58.8 ± 13.2; time since stroke: 66.8 ± 24.2 days	None	TA, LG, SO, RF, VM, BF, ST, GM	NNMF
Kautz et al. 2011 [31]∗	Cross-sectional	n = 56 Sex: 36 males, 20 females; age: 61.0 ± 12.3; time since stroke: 5.1 ± 5.6 years	n = 17 Sex: 2 males, 15 females; age: 65.1 ± 10.4	TA, SO, MG, VM, RF, MH, LH, GM	NNMF
Routson et al. 2013 [32]∗	Prepost experimental	n = 22 Sex: 15 males, 7 females; age: 57.3 ± 13.2; time since stroke: 19 ± 13 months	None	TA, SO, MG, VM, RF, MH, LH, GM	NNMF
Routson et al. 2014 [33]∗	Prepost experimental	n = 27 Sex: 18 males, 9 females; age: 60.15 ± 12.08; time since stroke: >6 months	n = 17 Sex: 9 males, 8 females; age: 54.18 ± 8.33	TA, SO, MG, VM, RF, MH, LH, GM	NNMF

TA: tibialis anterior; PERL: peroneus longus; SO: soleus; MG: medial gastrocnemius; LG: lateral gastrocnemius; VM: vastus medialis; VL: vastus lateralis; RF: rectus femoris; TFL: tensor fasciae latae; BFlh: biceps femoris long head; BFsh: biceps femoris short head; ST: semitendinosus; ADL: adductor longus; MH: medial hamstrings; LH: lateral hamstrings; GM: gluteus medius; GMax: gluteus maximus; RA: rectus abdominis; ES: erector spinae; LD: latissimus dorsi; BB: biceps brachii; TB: triceps brachii; AD: anterior deltoid; UT: upper trapezius; ST: sternocleidomastoid; SPL: splenius capitis; NR: not reported; NNMF: nonnegative matrix factorization; PCA: principal components analysis. ∗ indicates the publication came from the same research group and used a subset of the same sample.