Age and Type of Task-Based Impact of Mental Fatigue on Balance: Systematic Review and Meta-Analysis

Figures & data

TABLE 1. Example of search strategy for Medline database.

Search	Query
A	Medline via Ovid
1	mental fatigue/
2	mental fatigue.ab,kw,ti.
3	cognitive fatigue.ab,kw,ti.
4	1 OR 2 OR 3
5	balance.ab,kw,ti.
6	Postural balance/
7	postural balance.ab,kw,ti.
8	posture/
9	posture.ab,kw,ti.
10	postural stability.ab,kw,ti
11	Postural sway.ab,kw,ti.
12	5 OR 6 OR 7 OR 8 OR 9 OR 10 OR 11
13	4 AND 12

FIGURE 1. Flow diagram showing selection process of articles following PRISMA guidelines.

TABLE 2. Characteristics of the included studies.

Study	Study design	Population (n)	Gender	Age-mean (SD)	Cognitive task	Control task	Task duration	Balance task	Type of balance task
Morris and Christie (2020)	Cross-over	Healthy young women (16)	M = 0	22.4 (0.93)	Psychomotor vigilance task	Nature video with no sound	20 min	Standing on force platform with posterior translation (perturbation)	Reactive balance
	Cross-over	Healthy old women (16)	M = 0	72.6 (1.63)	Psychomotor vigilance task	Nature video with no sound	20 min	Standing on force platform with posterior translation (perturbation)	Reactive balance
Verschueren et al. (2020)	Cross-over	Healthy young adults (14)	M = 10	22 (1)	Stroop color word test	Watching documentary	90 min	Y-balance test (YBT), Neurocognitive YBT	Proactive balance
Varas-Diaz et al. (2020)	Parallel groups design	Healthy older adults (30-exp = 15, cont = 15)	M = 11	67.6 (7.1)	Stop-signal task	Watching documentary	60 min	Sensory organization test (SOT)-single and dual task	Reactive balance
Qu et al. (2020)	Parallel groups design	Healthy young adults (56)	M = 38	21.6 (1.9)	AX-continuous performance test (AX-CPT)	Nil	90 min	Balance recovery after an induced trip while walking	Reactive balance
Boolani et al. (2020)	Cross-over design	Healthy old adults (11)	M = 4	62.82 (4.64)	Serial-3 subtraction, serial-7 subtraction, continuous performance task, Rapid Visual Input Processing Task, Finger tapping task and the Trail-Making Test Part B.	Rest	30 min	Timed-Up-And Go (TUG) test	Steady-state balance
Tassignon et al. (2020)	Cross-over design	Healthy young adults (12)	M = 8	23 (2)	Stroop color word test	Watching documentary	90 min	Y-balance test (YBT), Neurocognitive YBT	Proactive balance
Hachard et al. (2020)	Cross-over design	Healthy young adults (20)	M = 13	21.8 (1.7)	AX-continuous performance test (AX-CPT)	Watching documentary	90 min	1. Standing on stable force platform (Eyes open and closed) 2. standing on wobble board (Unstable surface)	1.Steady-state balance 2. Proactive balance
Deschamps et al. (2013)	Cross-over design	Healthy young adults (10)	M = 10	22.1 (1.7)	Psychomotor vigilance task	Nil	30 min (two-15 min sessions with 1-3 min rest in between)	Standing on firm surface (EO & EC), Standing on foam surface (FEO & FEC)	Steady-state balance
Lew and Qu (2014)	Parallel groups design	Healthy young adults (44)	M = 28	23.5	AX-continuous performance test (AX-CPT)	Nil	90 min	Balance recovery after an induced slip while walking	Reactive balance
Fletcher & Osler, 2021	Cross-over design	Healthy young adults (10) Healthy older adults (10)	Young adults (M = 6) Older adults (M = 4)	Young adults: 21 (1) Older adults: 74 (6)	Stroop color word test	Leisurely reading of magazine	25 min	1. Standing with feet together 2. Timed-Up-And Go (TUG) test	Steady-state balance
Gebel et al. (2022)	Pre-post design	Healthy young adults (15)	M = 9	28.8 (3.4)	Attention network test	Nil	30 min	standing on wobble board	Proactive balance
Nikooharf Salehi et al. (2022)	Parallel groups design	Healthy older adults (40)	M = 20	Mental fatigue group: 66.64 (3.38) Control group: 64.11 (4.59)	Stroop color word test	Watching documentary	30 min	standing on Biodex balance system	Proactive balance

Abbreviations: M: male; EO: Eyes open; EC: Eyes closed; FEO: Foam surface, eyes open; FEC: Foam surface eyes closed.

FIGURE 2. Review authors judgment about each risk of bias item presented as percentage across all included studies.

FIGURE 3. Review authors judgment about each risk of bias item for each included study.

TABLE 3. Quality assessment score for individual studies.

Study	1	2	3	4	5	6	7	10	11	12	14	15	16	18	20	21	23	24	25	27	Total	%	Quality
Hachard et al. (2020)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	0	1	0	0	0	0	14	70	HIGH
Fletcher and Osler (2021)	1	1	1	2	1	1	0	0	0	1	1	1	1	1	0	1	1	0	0	0	14	70	HIGH
Deschamps et al. (2013)	1	1	0	1	1	1	0	0	0	1	1	1	1	1	0	1	0	0	0	0	11	55	LOW
Gebel et al. (2022)	1	1	1	1	1	1	1	0	0	1	1	1	1	1	0	1	0	0	0	0	13	65	LOW
Boolani et al. (2020)	1	1	1	2	1	1	0	0	0	1	1	1	1	1	0	1	0	0	1	0	14	70	HIGH
Nikooharf Salehi et al. (2022)	1	1	1	2	1	1	1	1	1	1	1	1	1	1	1	1	0	0	0	0	17	85	HIGH
Morris and Christie (2020)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	0	1	0	0	0	0	14	70	HIGH
Verschueren et al. (2020)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	1	1	1	0	1	0	17	85	HIGH
Tassignon et al. (2020)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	1	1	1	0	1	0	17	85	HIGH
Qu et al. (2020)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	0	1	0	0	0	0	14	70	HIGH
Lew and Qu (2014)	1	1	1	2	1	1	1	0	0	1	1	1	1	1	0	1	0	0	0	0	14	70	HIGH
Varas-Diaz et al. (2020)	1	1	1	2	1	1	0	0	0	1	1	1	1	1	0	1	0	0	1	0	14	70	HIGH

Note: Low-quality studies were defined as having a quality assessment score of <70%, whereas high-quality studies had a score of ≥70%.

FIGURE 4. Meta-analysis results showing the difference in subjective mental fatigue between the experimental and control conditions in (a) young and (b) older adults.

FIGURE 5. (a–c) Meta-analysis results showing the difference in cognitive performance between the first and last blocks of the cognitive task in young and older adults (objective markers of mental fatigue). (a) Objective mental fatigue (Reaction time)-Young adults. (b) Objective mental fatigue (accuracy)-Young adults. (c) Objective mental fatigue (Reaction time)-Older adults

FIGURE 6. Meta-analysis results showing the effect of mental fatigue on steady-state balance in young adults.

FIGURE 7. (a–e) Meta-analyses results showing the effect of mental fatigue on Proactive (anticipatory) balance control in young adults. (a) YBT-anterior. (b) YBT-Posteromedial. (c) YBT-Posterolateral. (d) Neurocognitive YBT (Reaction time). (e) Neurocognitive YBT (Accuracy). (YBT = Y-balance test).

FIGURE 8. (a, b) Meta-analyses results showing the effect of mental fatigue on reactive balance control in young adults. (a) COM/COP displacement. (b) COM/COP velocity. COM: Center of mass; COP: Center of pressure.

FIGURE 9. Meta-analysis results showing the effect of mental fatigue on steady-state balance in older adults.

FIGURE 10. Meta-analysis results showing the effect of mental fatigue on reactive balance control in older adults.

Morris, A. J., & Christie, A. D. (2020). The effect of a mentally fatiguing task on postural balance control in young and older women. Experimental Gerontology, 132, 110840. https://doi.org/10.1016/j.exger.2020.110840

 PubMed Web of Science ®Google Scholar

Verschueren, J., Tassignon, B., Proost, M., Teugels, A., Van Cutsem, J., Roelands, B., Verhagen, E., & Meeusen, R. (2020). Does mental fatigue negatively affect outcomes of functional performance tests? Medicine and Science in Sports and Exercise, 52(9), 2002–2010. https://doi.org/10.1249/MSS.0000000000002323

 PubMed Web of Science ®Google Scholar

Varas-Diaz, G., Kannan, L., & Bhatt, T. (2020). Effect of mental fatigue on postural sway in healthy older adults and stroke populations. Brain Sciences, 10(6), 388. https://doi.org/10.3390/brainsci10060388

 PubMed Web of Science ®Google Scholar

Qu, X., Xie, Y., Hu, X., & Zhang, H. (2020). Effects of fatigue on balance recovery from unexpected trips. Human Factors, 62(6), 919–927. https://doi.org/10.1177/0018720819858794

 PubMed Web of Science ®Google Scholar

Boolani, A., Ryan, J., Vo, T., Wong, B., Banerjee, N. K., Banerjee, S., Fulk, G., Smith, M. L., & Martin, R. (2020). Do changes in mental energy and fatigue impact functional assessments associated with fall risks? An exploratory study using machine learning. Physical & Occupational Therapy in Geriatrics, 38(3), 283–301. https://doi.org/10.1080/02703181.2020.1748788

 Web of Science ®Google Scholar

Tassignon, B., Verschueren, J., De Pauw, K., Roelands, B., Van Cutsem, J., Verhagen, E., & Meeusen, R. (2020). Mental fatigue impairs clinician‐friendly balance test performance and brain activity. Translational Sports Medicine, 3(6), 616–625. https://doi.org/10.1002/tsm2.177

 Google Scholar

Hachard, B., Noé, F., Ceyte, H., Trajin, B., & Paillard, T. (2020). Balance control is impaired by mental fatigue due to the fulfilment of a continuous cognitive task or by the watching of a documentary. Experimental Brain Research, 238(4), 861–868. https://doi.org/10.1007/s00221-020-05758-2

 PubMed Web of Science ®Google Scholar

Deschamps, T., Magnard, J., & Cornu, C. (2013). Postural control as a function of time-of-day: Influence of a prior strenuous running exercise or demanding sustained-attention task. Journal of Neuroengineering and Rehabilitation, 10(1), 26. https://doi.org/10.1186/1743-0003-10-26

 PubMedGoogle Scholar

Lew, F. L., & Qu, X. (2014). Effects of mental fatigue on biomechanics of slips. Ergonomics, 57(12), 1927–1932. https://doi.org/10.1080/00140139.2014.937771

 PubMed Web of Science ®Google Scholar

Fletcher, L. J., & Osler, C. J. (2021). Effects of mental fatigue on static upright stance and functional balance in older adults. Aging and Health Research, 1(4), 100043. https://doi.org/10.1016/j.ahr.2021.100043

 Google Scholar

Gebel, A., Busch, A., Stelzel, C., Hortobágyi, T., & Granacher, U. (2022). Effects of physical and mental fatigue on postural sway and cortical activity in healthy young adults. Frontiers in Human Neuroscience, 16, 871930. https://doi.org/10.3389/fnhum.2022.871930

 PubMed Web of Science ®Google Scholar

Nikooharf Salehi, E., Jaydari Fard, S., & Jaberzadeh, S. (2022). Mental fatigue impairs postural stability in older adults. Research Quarterly for Exercise and Sport, 94(2), 401–408. https://doi.org/10.1080/02701367.2021.1999892

 PubMed Web of Science ®Google Scholar

Availability of data and materials

All data generated or analyzed during this study is available and can be provided if required.