Table 1 Characteristics of included studies, participants, interventions, and outcome measures

Studies examining the effects of balance training on spinal excitability in healthy young individuals

Giboin [63]

HY-BT

18(8)

27 ± 8

BT: unipedal stance on floor and tilt board

1 day

Time in balance during unipedal stance on tiltboard, hands akimbo

SOL H-reflex amplitude normalized to Mmax at rest, bipedal stance on floor/board

Freyler [27]

HY-BT 1

HY-BT 2

16(8)

16(7)

24 ± 2

24 ± 2

BT partially unloaded balance exercises

BT 2: mix of balance exercises

35 min, 2/wk, 4wks

CoP displacement in AP and ML direction during uni/bipedal stance on stable and unstable surfaces, hands akimbo

SOL H-reflex amplitude during stable surface uni/bipedal and unipedal unstable surface stance

Keller [65]

HY-BT

HY-CON

12(6)

12(6)

24 ± 1

BT: Slackline standing and walking, increasing difficulty

CON: no intervention

90 min, 2–3/wk, 4wks

Sway path during bipedal EO stabilization of Posturomed following perturbation and slackline standing

SOL H/M-ratios during bipedal quiet stance and unipedal stance on cushion, Posturomed and slackline

Giboin [68]

HY-BT

Y-CON

22(12)

2(8)

25 ± 4

22 ± 2

BT: Slackline standing and walking

CON: no intervention

45 min, 2/wk, 6wks

Number of steps on slackline and time in balance during unipedal stance on tiltboard, hands akimbo

SOL H-reflex amplitude normalized to Mmax assessed stepping onto slackline/ tiltboard

Schubert [31]

HY- BT

HY-ST

HY-CON

14(8)

12(7)

11(7)

26 ± 3

27 ± 6

28 ± 5

BT: Unipedal stance on different devices

ST: Plantar extensions and dorsal flexions ankle joint

CON: no intervention

45–55 min, 4/wk, 4wks

Ground reaction forces directed to compensate backwards perturbation

SOL Hmax/Mmax during dynamic plantar flexion/ perturbation and quiet standing

Gruber [28]

HY-BT

HY-ST

HY-CON

11(7)

9(4)

9(5)

25 ± 3

26 ± 5

26 ± 3

BT: unipedal EO stance on different devices

ST: explosive ankle strength training

CON: no intervention

60 min, 4/wk, 4wks

Sway path during unipedal stance on Posturomed, hands akimbo

SOL Hmax/Mmax during seated rest

Taube [29]

HY-BT

HY-CON

13(8)

10(4)

25 ± 3

27 ± 5

BT: unipedal stance on different devices

CON: no intervention

60 min, 4/wk, 4wks

Ground reaction forces directed to compensate perturbation, sway path on platform

SOL Hmax/Mmax during short and long latency response to backwards perturbation

Beck [30]

HY-BT

HY-ST

HY-CON

9(6)

8(4)

10(7)

28 ± 2

28 ± 2

26 ± 1

BT: unipedal stance on different devices

ST: ballistic ankle strength training

CON: no intervention

60 min, 4/wk, 4wks

Sway path during unipedal EO stance on Posturomed, hands akimbo

SOL and TA Hmax/Mmax during plantarflexion, backward perturbation, and rest

Behrens [64]

HY-BT

HY-CON

13(7)

13(7)

25 ± 3

23 ± 2

BT: uni- and bipedal stance on different devices, increasing difficulty

CON: no intervention

60 min, 2/wk, 8wks

CoP sway in AP and ML direction during bipedal stance EO on rigid and foam surface, hands akimbo

SOL Hmax/Mmax at rest and during MVC

Studies examining the effects of balance training on spinal excitability in healthy older individuals

Alizadehsaravi [16]

HO-BT

22(11)

73 ± 4

BT: Mix of unipedal exercises

1 × 30-min and 10 × 45-min, 3wks

Balance robustness: mean time in balance on a balance platform, CoM velocity in ML direction

H-reflex and paired-pulse depression

Penzer [67]

HO-ST

HO-BT

HO-CON

10(2)

8(2)

8(2)

71 ± 6

71 ± 6

70 ± 6

ST: leg strength exercises

BT: uni- and bipedal EO and EC stance on different devices

CON: no intervention

60 min, 2/wk, 6wks

CoP velocity during bipedal EO/EC standing on unstable surface

SOL Hmax/Mmax and Hslope during rigid EO bipedal standing

Ruffieux [66]

HO-BT

HO-CON

15(7)

13(8)

70 ± 4

71 ± 5

BT: unipedal stance on different devices

CON: no intervention

3/wk, 5wks

CoP sway and # of errors in uni/bipedal stance on stable surface and unstable platform

SOL Hmax/Mmax during quiet stance

Lauber [69]

HO-BT

HO-CON

13(7)

10(5)

67 ± 2

68 ± 4

SKI: alpine skiing

CON: no intervention

28.5 days over 12wks

Postural sway while bipedal EO standing and while standing on a spinning top

SOL Hmax/Mmax during stable and unstable bipedal stance

Chen [70]

HO-BT

HO-CON

20(11)

14(6)

73 ± 4

73 ± 7

BT: Tai Chi@CON: no intervention

60 min, 3/wk, 12wks

CoP displacement during bipedal EO and EC stance on a stable and unstable surface

SOL Hmax/Mmax during bipedal EO and EC stance on a stable and unstable surface

Studies examining the effects of balance training on corticospinal excitability in healthy young individuals

Bakker [39]

HY-BT

HY-CT

HY-CON

12(6)

12(6)

12(6)

21 ± 1

21 ± 2

22 ± 3

BT: bipedal stance wobble board

CT: stationary cycling

CON: no intervention

1 × 20 min

Time in balance on wobble board, ST and DT beam walking on wide and narrow beam, and CoP velocity during bipedal EO/EC stance on rigid and foam surface in wide and narrow stance

TMS: MEP, SICI, LICI, ICF in TA during sitting and standing

Mouthon [73]

HY-BT

HY-CON

13(9)

13(9)

24 ± 3

BT: Bipedal stance on movable platform

CON: no intervention

45 min, 3/wk, 2wks

Time in balance on stable, semi-stable and unstable device, bipedal EO stance

TMS: MEP and SICI in TA and SOL during bipedal EO stance on stable, semi-stable and unstable device

Taube [71]

HY-ST

HY-BT

24(14)

23 ± 2

ST: explosive strength training

BT: unipedal stance on different devices, increasing difficulty

60 min, 3/wk, 4wks

Sway path during unipedal quiet stance and recovery following AP perturbations

TMS: SICI in SOL and TA during plantar/dorsiflexion, balance perturbations or at rest

Lauber [72]

HY-BT-ST

HY-ST-BT

12(5)

12(5)

23 ± 2

ST: leg strength exercises

BT: unipedal EO stance on different devices, increasing difficulty

3/wk, 4wks

Platform sway during unipedal stance on Posturomed when standing still and post perturbation

TMS: MEP and SICI in SOL during dynamic plantarflexions, balance perturbations and rest

Schubert [31]

HY- BT

HY-ST

HY-CON

14(8)

12(7)

11(7)

26 ± 3

27 ± 6

28 ± 5

BT: Unipedal stance on different devices

ST: Plantar extensions and dorsal flexions ankle joint

CON: no intervention

45–55 min, 4/wk, 4wks

Ground reaction forces directed to compensate backwards perturbation

Conditioned SOL H-reflex during dynamic plantar flexion/ backwards perturbation and quiet standing

Taube [29]

HY-BT

HY-CON

13(8)

10(4)

25 ± 3

27 ± 5

BT: unipedal stance on different devices

CON: no intervention

60 min, 4/wk, 4wks

ground reaction forces directed to compensate perturbation, sway path on platform

TMS: MEP and conditioned H-reflex in SOL during short and long latency response to backwards perturbation

Beck [30]

HY-BT

HY-ST

HY-CON

9(6)

8(4)

10(7)

28 ± 2

28 ± 2

26 ± 1

BT: unipedal stance on different devices

ST: ballistic ankle strength training

CON: no intervention

60 min, 4/wk, 4wks

Sway path during unipedal EO stance on Posturomed, hands akimbo

TMS: During plantarflexion, backward perturbation, and rest: MEP, SICI and ICF in SOL and TA

Studies examining the effects of balance training on corticospinal excitability in healthy older individuals

Penzer [67]

HOA-ST

HOA-BT

HO-CON

10(2)

8(2)

8(2)

71 ± 6

71 ± 6

70 ± 6

ST: leg strength exercises

BT: uni- and bipedal EO and EC stance on different devices

CON: no intervention

60 min, 2/wk, 6wks

CoP velocity during bipedal EO/EC standing on unstable surface

TMS: MEP and MEP slope in SOL during rigid EO bipedal standing

Ruffieux [66]

HO-BT

HO-CON

15(7)

13(8)

70 ± 4

71 ± 5

BT: unipedal stance on different devices

CON: no intervention

3/wk, 5wks

CoP sway and # of errors in uni/bipedal stance on stable surface and unstable platform

TMS: SOL conditioned H-reflex during anterior posterior perturbation

Esculier [32]

HO-BT

PD-BT

8(5)

8(5)

62 ± 12

64 ± 12

BT: Wii-fit with balance and squat exercises

40 min, 3/wk, 6wks

Unipedal EO stance time, CoP RMS velocity and dynamic balance tasks

TMS: MEP in QF and SOL during AO, imagery, and imitation

Studies examining the effects of balance training on cortical activity in healthy young individuals

Peterson [75]

HY VR1

HY-VR2

HY-BT

10(5)

10(5)

10(5)

23 ± 5

Heel to toe beam walking, visual conditions:

(1) VR + pert., (2) VR no pert., (3) unaltered view

1 × 30 min

# of beam walking errors

EEG: whole brain theta, alpha, beta and gamma power during beam walking

Zandvoort [74]

HY-BT

15(11)

24.7 ± 3.1

Unipedal stance on unstable boards, increasing difficulty

1 × 30 min

Time to recovery following a platform perturbation, allowed to use arms

EEG: Cortical source localization, cortico synergy connectivity following a perturbation

Ueta [56]

HY-BT-AT

HY-AT-BT

14

14

22 ± 1

BT: slackline training

AT: stationary cycling

1 × 30 min + after 4 weeks 1 × 30 min

Slackline standing and walking, unipedal EC standing on floor and balance disk, star excursion test

fMRI at rest: functional connectivity

Patel [76]

HY-BT

10

27 ± 4

BT: Treadmill-Slip perturbation training

3 days

# of compensatory steps and COM stability following treadmill perturbation

fMRI: activity during motor imagery of slipping and walking tasks

Taubert [33]

HY-BT

HY-CON

28(14)

26 ± 3

BT: bipedal standing on unstable device

45 min, 1/wk, 6wks

Time in balance on unstable device, bipedal EO stance

fMRI at rest: functional connectivity

Giboin [68]

HY-BT

HY-CON

22(12)

22(8)

25 ± 4

22 ± 2

BT: Slackline standing and walking

45 min, 2/wk, 6wks

Number of steps on slackline and time in balance during unipedal stance on tiltboard, hands akimbo

fMRI at rest: functional connectivity

Studies examining the effects of balance training on cortical activity in healthy older individuals

Ruffieux [40]

HO-BT

HO-CON

15(7)

12(7)

70 ± 4

72 ± 5

BT: One leg BT on unstable devices

CON: no training

60 min, 3/wk, 5wks

# of errors in unipedal stance on stable and unstable platform

fMRI: activity during motor imagery and action observation + motor imagery

Magon [35]

HO-BT

HO-CON

14(8)

14(8)

62 ± 5

62 ± 5

BT: slackline standing and walking, increasing difficulty

CON: educational fall prevention sessions

30 min, 3/wk, 6wks

Slackline stance time in unipedal and tandem EO stance

fMRI at rest: functional connectivity

Adcock [59]

HO-BT

19(9)

71 ± 6

Exergame based on Tai Chi and dance

40 min, 3/wk, 7wks

Gait speed in single and dual-task walking, balance score extended SPPB

EEG: Cortical activity during resting state, ROI: parieto-occipital

Eggenberger [36]

HO-BT

HO-DT

14(5)

19(7)

78 ± 7

73 ± 6

BT: uni/bipedal stance on different devices

DT: interactive video game-based dancing

30 min, 3/wk, 8wks

Balance score extended SPPB

fNIRS: cortical activity during walking at preferred and fast speed, ROI: PFC

Kubica [34]

HO-BT1

HO-BT2

HO-CON

28(13)

15(9)

23(14)

66 ± 1

65 ± 1

64 ± 1

BT: mix of balance exercises

BT: Wii Fit Balance board

CON: no intervention

30/60 min, 3/wk, 12wks

POMA

fMRI: during motor imagery and/or action observation

Chen [77]

HO-BT

HO-CON

12

15

68 ± 1

70 ± 1

BT: Tai Chi

CON: health lectures

60 min, 4/w, 16wks

Gait speed (m/s) during negotiating obstacle task with and without an added cognitive task

fNIRS: cortical activity during negotiating obstacle task, ROI: PFC

Studies examining the effects of balance training on structural brain adaptations in healthy young individuals

Ueta [56]

HY-BT-AT

HY-AT-BT

14

14

22 ± 1

BT: slackline training

AT: stationary cycling

1 × 30 min + after 4 weeks 1 × 30 min

Slackline standing and walking, unipedal EC standing on floor and balance disk, star excursion test

MRI: gray matter volume and WM microstructure

Taubert [22]

Exp. 1: HY-BT

HY-CON1

Exp 2: HY-BT

Exp 3: HY-CON2

21(10)

16(8)

11(4)

11(5)

26 ± 4

26 ± 4

26 ± 3

28 ± 3

BT: bipedal standing on unstable device

CON1: seated rest

CON2: motor action control task: repetitive high knees

Exp. 1: 1 × 45 min

Exp 2: BT: 1 day, 3 × 20 min

Exp 3: 1 × 45 min

Time in balance on unstable device, bipedal EO stance

MRI: cortical thickness and gray matter density

Taubert [37]

HYA-BT

HY-CON

28(14)

26 ± 3

BT: bipedal standing on unstable device

45 min, 1/wk, 6wks

Time in balance on unstable device, bipedal EO stance

MRI: gray matter volume and structural connectivity: fractional anisotropy in white matter regions

Im [57]

HA-BT

17(11)

47 ± 13

BT: home based mix of bipedal and uni/bipedal stance on different devices

30 min, 3/wk, 4wks

BBS and Community Balance and Mobilty Scale

MRI: whole brain fractional anisotropy

Rogge [78]

HA-BT

HA-CON

19 (7)

18 (7)

44 ± 15

46 ± 15

BT: uni- and bipedal EO and EC stance on different devices, increasing difficulty

CON: relaxation training

50 min, 2/wk, 12wks

Time in balance during bipedal EO stance on unstable platform, hands akimbo

MRI: cortical thickness and gray matter volume, ROI: hippocampus and basal ganglia

Studies examining the effects of balance training on structural brain adaptations in healthy older individuals

Sehm [17]

PD-BT

HO-BT

20(11)

16(9)

65 ± 2

63 ± 2

BT: bipedal stance unstable platform

 ~ 45 min, 1/wk, 6wks

Time in balance on unstable platform

MRI: whole brain gray matter volume

Burciu [60]

CD-BT

H-BT

19(13)

19(11)

56 ± 12

54 ± 13

BT: move COG to target during bipedal stance on stable and unstable platform, increasing difficulty

30/60 min, 7/wk, 2wks

Gait speed, postural sway, COG displacement velocity during bipedal EO and EC on a stable and unstable platform, BBS and TUG

MRI: whole brain gray matter volume

Magon [35]

HO-BT

HO-CON

14(8)

14(8)

62 ± 5

62 ± 5

BT: slackline standing and walking, increasing difficulty

CON: educational fall prevention sessions

30 min, 3/wk, 6wks

Slackline stance time in unipedal and tandem EO stance

MRI: brain volume

Adcock [58]

HO-BT

HO-CON

15(5)

16(10)

77 ± 6

71 ± 5

BT: Exergame based on Tai Chi and dance

CON: no intervention

30-40 min, 3/wk, 16-18wks

Gait speed in single and dual-task walking

MRI: brain volume, ROI: hippocampus, frontal lobe, and cerebellum

Nagamatsu [61]

HO-AT

HO-BT

54(14)

47(29)

67 ± 6

65 ± 6

AT: walking

BT: balance and toning exercises

40 min, 1/wk, 52wks

TUG

MRI: brain volume, ROI: basal ganglia

Nieman [79]

HO-AT

HO-BT

HO-CON

17(5)

19(6)

13(6)

68 ± 3

70 ± 5

69 ± 3

AT: nordic walking

BT: mix of balance exercises

CON: stretching and relaxing

45–60 min, 3/wk, 52wks

Unipedal stance time EO

MRI: brain volume, ROI: hippocampus

Studies examining the effects of balance training on neurochemical blood markers of neural adaptation in healthy young individuals

N.A

Studies examining the effects of balance training on neurochemical blood markers of neural adaptation in healthy older individuals

Solianik [80]

HO-BT

HO-CON

15(13)

15(13)

60–78

BT: Tai Chi

CON: no intervention

60 min, 2/wk, 10wks

CoP velocity during bipedal stance with EO and EC during ST and DT

BDNF

Cekanauskaite [81]

HO-BT

HO-CON

18(1)

15(2)

67 ± 6

BT: Yoga

CON: no intervention

90 min, 2/wk, 10wks

CoP velocity during bipedal and tandem stance with EO and EC during ST and DT

BDNF

Kubica [34]

HO-BT 1

HO-BT 2

HO-CON

28(13)

15(9)

23(14)

66 ± 1

65 ± 1

64 ± 1

BT: mix of balance exercises

BT: Wii Fit Balance board

CON: no intervention

30/60 min, 3/wk, 12wks

POMA

BDNF

Szymura [62]

HO. BT

PD. BT

HO.CON

PD.CON

16 (11)

13(8)

16(10)

16(10)

66 ± 3

65 ± 7

67 ± 7

66 ± 4

BT: Uni- and bipedal stance on different devices

CON: no intervention

30–60 min, 3/wk, 12wks

POMA

BDNF