Table 1 Sample characteristics, study design, and outcome measures used in the included NIBS studies

[22] Tolmacheva et al. 2017

Finland

Parallel

Randomized

Double-blind

Sham-controlled

n = 5

ASIA Scale (A/B/C/D): B1C3D1

Level of injury (C/T/L): C5

Gender (male): 4

Etiology: –

Age (years): 47.8 (12.85)

Duration (months): 51.8 (25.88)

Spasticity = UMAS, LMAS

Timing; 0, 4 week

1 month

[25] Benito et al. 2012

Spain

Crossover Randomized

Double-blind

Sham-controlled

Washout period: 3-weeks

n = 17

ASIA Scale (A/B/C/D): D17

Level of injury(C/T/L): C7T10

Gender (male): 13

Aetiology: Traumatic 9; non-traumatic 8

Age (years): 38.10 (13.49)

Duration (months): 7.88 (3.12)

Extremity strength = LEMS

Extremity function = JTHFT

Mobility function = 10MWT

Spasticity = LMAS

Balance = TUG

Timing;0, 3 week

2 weeks

[26] Gharooni et al. 2018

UK

Crossover

Randomized

Single-blind

Sham-controlled

Washout period:2-weeks

n = 10

ASIA Scale (A/B/C/D): B1C4D5

Level of injury(C/T/L): C10

Gender(male): 8

Aetiology: Traumatic 8; non-traumatic 2

Age(years):46.8 (12.5)

Duration(months):11.4(14.96)

Extremity strength = UEMS, LEMS

Spasticity = UMAS

Timing;0, 4 week

–

[27] Gomes-Osman et al. 2015

USA

Crossover

Double-blind Randomized

Sham-controlled

n = 11

ASIA Scale (A/B/C/D): C5D6

Level of injury(C/T/L): C11

Gender(male): 1

Etiology: Traumatic 11

Age (years): 46.7(12)

Duration (years):6.6 (8.2)

Extremity function = JTHFT

Timing; before and after the intervention

–

[10] Krogh et al. 2022

Denmark

Double-blinded, Randomized

Sham-controlled

n = 19(10/9)

ASIA Scale (A/B/C/D);

Exp = A1C3D6; Con = C2D7;

Level of injury(C/T/L):

Exp = C5T4L1; Con = C6T1L2;

Gender(male): Exp = :8; Con = 7

Aetiology:

Exp = traumatic 3; non-traumatic 7

Con = traumatic 3; non-traumatic 6

Age (years):

Exp = 57.1 (8.3); Con = 51.8 (12.1)

Duration (days):

Exp = 91.3(40.8); Con = 87.3(69.5)

Extremity strength = LEMS

Mobility function = 6MWT,10MWT

Balance = TUG

Timing; 0, 4 week

[23] Kumru et al. 2016

Spain

Double-blind

Randomized

Sham-controlled

n = 31 (15/16)

ASIA Scale (A/B/C/D):

Exp = C12D3; Con = C14D2

Level of injury(C/T/L):

Exp = C8T7; Con = C6T10

Gender (male): Exp = 10; Con = 14

Aetiology:

Exp = traumatic 6; non-traumatic 9

Con = traumatic 8; non-traumatic 8

Age (years):

Exp = 46.4(15.5); Con = 48.7 (16.5)

Duration (months):

Exp = 3.5(1.6); Con = 2.5(1.5)

Extremity strength = UEMS, LEMS

Spasticity = LMAS

Timing; 0,4 week

4 weeks

[28] Nardone et al. 2014

Austria

Crossover

Double-blind

Randomized

Sham-controlled

Washout period: 4-weeks

n = 9

ASIA Scale (A/B/C/D):C4D5

Level of injury(C/T/L):C5T4

Gender (male): 8

Aetiology: traumatic 7; non-traumatic 2

Age (years): 45.67(11.73)

Duration (years):10.44(4.19)

Spasticity = LMAS, H/M amplitude ratio

Timing;0, 1 week

1 week

[29] Nardone et al. 2017

Austria

Crossover,

Randomized

Double-blind

Sham-controlled

Washout period: > 2 months

n = 10

ASIA Scale (A/B/C/D): C4D6

Level of injury (C/T/L): C6T4

Gender (male): 7

Aetiology: traumatic 9; non-traumatic 1

Age (years): 42.8 (12.52)

Duration (years):8.3 (4.79)

Spasticity = LMAS, H/M amplitude ratio

Timing; 0, 2 week

1 week, 4 weeks

[30] Kumru et al. 2010

Spain

Crossover

Randomized

Double-blind Sham-controlled

Washout period: 2-weeks

n = 15

ASIA Scale (A/B/C/D): C10D5

Level of injury(C/T/L): C4T11;

Gender(male):13

Aetiology: traumatic 10; non-traumatic 5

Age (years): 36.2 (15.8);

Duration (months):7.3 (3.9)

Spasticity = LMAS, H/M amplitude ratio

Timing; 0, 4 week

2 weeks

[12] Kumru et al. 2016

Spain

Randomized

Double-blind

Sham-controlled

n = 24(12/12)

ASIA Scale (A/B/C/D):

Exp = C11D1; Con = C9D3

Level of injury(C/T/L):

Exp = C7T5; Con = C8T4

Gender(male): Exp = :8; Con = 8

Aetiology:

Exp = traumatic 8; non-traumatic 4

Con = traumatic 5; non-traumatic 7

Age (years):

Exp = 49.67 (15.05);

Con = 52.83 (13.91)

Duration (months):

Exp = 3.42(1.56); Con = 4.92 (2.13)

Extremity strength = LEMS

Timing;0, 4 week

1 month

[24] Raithatha et al. 2016

USA

Randomized,

Double-blind

Sham-controlled

n = 15 (9/6)

ASIA Scale (A/B/C/D):

Exp = C7D1B1; Con = C4D2

Level of injury (C/T/L):

Exp = C4T4L1; Con = C5L1

Gender (male): Exp = 5; Con = 5

Aetiology: traumatic 15

Age (years):

Exp = 40.56 (12.24);

Con = 58.0 (5.36)

Duration (years):

Exp = 8 (8.43); Con = 7.67 (15.36)

Mobility function = 10MWT, 6MWT

Balance = TUG, BBT

Timing; 0, 12 week

4 weeks

[15] Simis et al. 2021

USA

Parallel

Randomized

Double-blind

n = 43(21/22)

ASIA Scale (A/B/C/D):

Exp = C10D11; Con = C10D12

Level of injury(C/T/L):

Exp = C4T17; Con = C11T11

Gender(male): Exp = 17; Con = 15

Aetiology:

Exp = traumatic 19; non-traumatic 2

Con = traumatic18; non-traumatic 4

Age (years):

Exp = 31(14.82);

Con = 41 (15.56)

Duration (months):

Exp = 16 (13.33); Con = 15.5 (11.85)

Mobility function = 10MWT, 6MWT

Spasticity = LMAS

Balance = TUG, BBT

Timing; 0, 4 week

3 months

[11] Yozbatiran et al. 2016

USA

Randomized

Double-blind

Sham-controlled

n = 8(4/4)

ASIA Scale (A/B/C/D):

Exp = C1D3; Con = C2D2

Level of injury(C/T/L):

Exp = C4; Con = C4

Gender (male): Exp = 4; Con = 3

Aetiology: –

Age (years):

Exp = 49.7(5.40); Con = 55.7(2.90)

Duration (months):

Exp = 25.2(10.4); Con = 141.2(48.2)

Extremity function = JTHFT

Timing;0, 2 week

2 months

[13] Potter-Baker et al. 2017

USA

Longitudinal

Randomized, Double-blinded

Sham-controlled

n = 8 (4/4)

ASIA Scale (A/B/C/D): B2D6

Level of injury(C/T/L): C8

Gender (male): 8

Etiology: traumatic 8

Age (years): 53.3 (4.1)

Duration (months):

Exp = 54.4(30.8); Con = 164(153.6)

Extremity strength = UEMS

Timing; 0, 2 week

3 months