Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

Are Static and Dynamic Postural Balance Assessments Two Sides of the Same Coin? A Cross-Sectional Study in the Older Adults

The aim of this study was to investigate if the combination of static and dynamic postural balance assessments gives more accurate indications on balance performance among healthy older adults. We also aimed at studying the effect of a dual-task condition on static and dynamic postural balance control. Fifty-seven healthy older adults (age = 73.2 ± 5.0 year, height = 1.66 ± 0.08 m, and body mass = 72.8 ± 13.8 kg) completed the study. Static and dynamic balance were assessed both in single-task and dual-task conditions through a force plate and an oscillating platform. The dominant handgrip strength was also measured with a dynamometer. Pearson’s correlation revealed non-statistically significant correlations between static and dynamic balance performance. The dual-task worsened the balance performance more in the dynamic (+147.8%) than in the static (+25.10%, +43.45%, and +72.93% for ellipse area, sway path, and AP oscillations, respectively) condition (p < 0.001). A weak correlation was found between dynamic balance performance and handgrip strength both in the single (p < 0.05; r = −0.264) and dual (p < 0.05; r = −0.302) task condition. The absence of correlations between static and dynamic balance performance suggests including both static and dynamic balance tests in the assessment of postural balance alterations among older adults. Since cognitive-interference tasks exacerbated the degradation of the postural control performance, dual-task condition should also be considered in the postural balance assessment.

Implementing an Online Virtual Falls Prevention Intervention During a Public Health Pandemic for Older Adults with Mild Cognitive Impairment: A Feasibility Trial

PURPOSE

This study evaluates the feasibility of delivering a virtual (online) falls prevention intervention for older adults with mild cognitive impairment (MCI).

METHODS

Community-dwelling older adults with MCI (mean age = 76.2 years, 72% women) were randomized to either a Tai Ji Quan (n = 15) or stretching group (n = 15) and participated in 60-minute virtual exercise sessions, via Zoom, twice weekly for 24 weeks. The primary outcome was the incidence of falls. Secondary outcomes were the number of fallers and changes from baseline in the 4-Stage Balance Test, 30-second chair stands, and Timed Up and Go Test under both single- and dual-task conditions.

RESULTS

The intervention was implemented with good fidelity, an overall attendance rate of 79%, and 13% attrition. Compared with stretching, Tai Ji Quan did not reduce falls (incidence rate ratio = 0.58; 95% confidence interval [CI], 0.32 to 1.03) or the number of fallers (relative risk ratio = 0.75; 95% CI, 0.46 to 1.22) at week 24. The Tai Ji Quan group, however, performed consistently better than the stretching group in balance (between-group difference in change from baseline, 0.68 points; 95% CI, 0.12 to 1.24), 30-second chair stands (1.87 stands; 95% CI, 1.15 to 2.58), and Timed Up and Go under single-task (-1.15 seconds; 95% CI, -1.85 to -0.44) and dual-task (-2.35; 95% CI, -3.06 to -1.64) conditions. No serious intervention-related adverse events were observed.

CONCLUSION

Findings from this study suggest the feasibility, with respect to intervention fidelity, compliance, and potential efficacy, of implementing an at-home, virtual, interactive Tai Ji Quan program, delivered in real-time, as a potential balance training and falls prevention intervention for older adults with MCI. The study provides preliminary data to inform future trials.

Effects of acute exercise at different intensities on fine motor-cognitive dual-task performance while walking: A functional near-infrared spectroscopy study

Studies on the effects of acute exercises on cognitive functions vary greatly and depend on the duration and intensity of exercise and the type of cognitive tasks. This study aimed to investigate the neural correlates that underpin the acute effects of high-intensity interval (HIIE) versus moderate-intensity continuous exercise (MCE) on fine motor-cognitive performance while walking (dual-task, DT) in healthy young adults. Twenty-nine healthy right-handers (mean age: 25.1 years ± 4.04; 7 female) performed the digital trail-making-test (dTMT) while walking (5 km/h) before and after acute exercise. During task performance, the hemodynamic activation of the frontopolar area (FPA), dorsolateral prefrontal (DLPFC), and motor cortex (M1) was recorded using functional near-infrared spectroscopy (fNIRS). Both HIIE and MCE resulted in improved dTMT performance, as reflected by an increase in the number of completed circles and a reduction in the time within and between circuits (reflecting improvements in working memory, inhibition, and decision making). Notably, HIIE evoked higher cortical activity on all brain areas measured in the present study than the MCE group. To our knowledge, these results provide the first empirical evidence using a mobile neuroimaging approach that both HIIE and MCE improve executive function during walking, likely mediated by increased activation of the task-related area of the prefrontal cortex and the ability to effectively use, among other things, high fitness levels as neural enrichment resources.

Effect of dual-task training on balance in patients with multiple sclerosis: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effects of dual-task training on static and dynamic balance in patients with multiple sclerosis.

DATA SOURCES

PubMed/MEDLINE, EMBASE, Scopus, and PEDro databases were searched from inception to March 1, 2021.

METHODS

This study was conducted in agreement with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two reviewers assessed studies for inclusion and extracted data. We used the Physiotherapy Evidence Database scale to evaluate the methodological quality and the risk-of-bias. Randomized clinical trial data were pooled for the meta-analysis. The effect sizes and 95% confidence interval (CI) were calculated by random-effect models. Egger regression and Begg-Mazumdar rank correlation test were used for publication bias.

RESULTS

A total of 13 studies involving 584 patients (42.3 ± 9 years mean ± SD; 377 females) met the inclusion criteria for the systematic review, while nine were included in the meta-analysis. People who received dual-task training interventions showed significant improvements in the Timed Up & Go test 0.44 [(95% CI = 0.22; 0.65), P-value<0.001], and in the Berg Balance scale 0.46 [(95% CI = 0.07; 0.85), P-value = 0.02]. Low and moderate heterogeneity between the studies was found for the Timed Up & Go test and the Berg Balance scale, respectively.

CONCLUSION

The findings from the current meta-analysis support dual-task training as a beneficial therapy for improving dynamic balance and functional mobility in patients with multiple sclerosis. The limited number of studies that investigated static balance performance after dual-task training do not currently allow us to draw a conclusion about any possible improvements in this ability.

Α Virtual Reality App for Physical and Cognitive Training of Older People With Mild Cognitive Impairment: Mixed Methods Feasibility Study

Background

Therapeutic virtual reality (VR) has emerged as an effective treatment modality for cognitive and physical training in people with mild cognitive impairment (MCI). However, to replace existing nonpharmaceutical treatment training protocols, VR platforms need significant improvement if they are to appeal to older people with symptoms of cognitive decline and meet their specific needs.

Objective

This study aims to design and test the acceptability, usability, and tolerability of an immersive VR platform that allows older people with MCI symptoms to simultaneously practice physical and cognitive skills on a dual task.

Methods

On the basis of interviews with 20 older people with MCI symptoms (15 females; mean age 76.25, SD 5.03 years) and inputs from their health care providers (formative study VR1), an interdisciplinary group of experts developed a VR system called VRADA (VR Exercise App for Dementia and Alzheimer’s Patients). Using an identical training protocol, the VRADA system was first tested with a group of 30 university students (16 females; mean age 20.86, SD 1.17 years) and then with 27 older people (19 females; mean age 73.22, SD 9.26 years) who had been diagnosed with MCI (feasibility studies VR2a and VR2b). Those in the latter group attended two Hellenic Association Day Care Centers for Alzheimer’s Disease and Related Disorders. Participants in both groups were asked to perform a dual task training protocol that combined physical and cognitive exercises in two different training conditions. In condition A, participants performed a cycling task in a lab environment while being asked by the researcher to perform oral math calculations (single-digit additions and subtractions). In condition B, participants performed a cycling task in the virtual environment while performing calculations that appeared within the VR app. Participants in both groups were assessed in the same way; this included questionnaires and semistructured interviews immediately after the experiment to capture perceptions of acceptability, usability, and tolerability, and to determine which of the two training conditions each participant preferred.

Results

Participants in both groups showed a significant preference for the VR condition (students: mean 0.66, SD 0.41, t₂₉=8.74, P<.001; patients with MCI: mean 0.72, SD 0.51, t₂₆=7.36, P<.001), as well as high acceptance scores for intended future use, attitude toward VR training, and enjoyment. System usability scale scores (82.66 for the students and 77.96 for the older group) were well above the acceptability threshold (75/100). The perceived adverse effects were minimal, indicating a satisfactory tolerability.

Conclusions

The findings suggest that VRADA is an acceptable, usable, and tolerable system for physical and cognitive training of older people with MCI and university students. Randomized controlled trial studies are needed to assess the efficacy of VRADA as a tool to promote physical and cognitive health in patients with MCI.

Effects of Nonelastic Taping and Dual Task on Kinematics and Kinetics of the Ankle Joint

Objectives

The purpose of this experimental study was to investigate the effects of nonelastic taping and dual task on ankle kinematics and kinetics in gait analysis of healthy adults.

Methods

A total of 21 healthy adults completed trials of gait analysis using a Vicon system combining ground walking with different cognitive task conditions (none, modified Stroop color/character naming, and serial-7 subtraction), with or without nonelastic taping. Ankle kinematics and kinetics including speed, ankle plantarflexion and inversion angle, ground reaction force (GRF), and stride time variability (STV) under all conditions of taping (YES or NO) and cognitive task (none, naming, and subtraction) were characterized and analyzed with repeated-measures ANOVA.

Results

As regards cognitive performance, the serial-7 subtraction performance under walking conditions with and without taping was significantly poorer than simple sitting condition (P < 0.001). For kinematics and kinetics, STV showed statistically significant decrease (P=0.02) when subjects underwent taping application. Vertical GRF was significantly greater under taping than barefoot (P=0.001). Ankle plantarflexion at initial contact (IC) under the dual-task walking was significantly more than under simple walking (P=0.008).

Conclusions

Applications of nonelastic taping and dual task may lead to the STV, vertical GRF, ankle plantarflexion, and speed alterations because of restricted joint range of motion and changed sensorimotor neural circuit. When healthy adults performed dual-task walking, central neural resources allocation was disturbed, leading to weakened performance in both motor and cognitive tasks.

The effects of dual-task training on balance and gross motor function in children with spastic diplegia

The purpose of this study was to investigate changes in dynamic balance and gross motion function when dual-task training was performed on an unstable support surface by children with spastic diplegia. The subjects of this study were 14 children (experimental group n=7, control group n=7) who were medical diagnosed with spastic diplegia. Both groups were administered treatment for 30 min, 2 times a week for 8 weeks, with the experimental group performing dual-task exercise in which cognitive tasks related to daily living were performed while maintaining balance on an unstable surface, and the control group being administered neurodevelopmental treatment. Balance and gross motor function Assessments were conducted before intervention and after 8 weeks of intervention. Wilcoxon signed-rank test was performed to analyze changes in balance, gross motor function in the group, and the Mann–Whitney test was conducted to compare the differences between the two groups before and after intervention. The results showed that there was a statistically significant difference in both groups when balance in a sitting position and gross motor function (P<0.05). There was a statistically significant difference between the two groups in balance and gross motor function assessment (P<0.05). Based on the results of this study, it was confirmed that dual-task training improves balance, gross motor function in children with spastic diplegia. Therefore, dual-task training may be considered as an effective method of intervention method in the functional aspect of children with spastic diplegia.

The Influence of Cognitive Dual Tasks on Concussion Balance Test Performance

OBJECTIVE

To determine the influence of a cognitive dual task on postural sway and balance errors during the Concussion Balance Test (COBALT).

METHODS

Twenty healthy adults (12 females, eight males; aged 21.95 ± 3.77 years; height = 169.95 ± 9.95 cm; weight = 69.58 ± 15.03 kg) partook in this study and completed single- and dual-task versions of a reduced COBALT.

RESULTS

Sway velocity decreased during dual-task head rotations on foam condition (p = .021, ES = -0.57). A greater number of movement errors occurred during dual-task head rotations on firm surface (p = .005, ES = 0.71), visual field flow on firm surface (p = .008, ES = 0.68), and head rotations on foam surface (p < .001, ES = 1.61) compared with single-task conditions. Cognitive performance was preserved throughout different sensory conditions of the COBALT (p = .985).

DISCUSSION

Cognitive dual tasks influenced postural control and destabilized movements during conditions requiring advanced sensory integration and reweighting demands. Dual-task versions of the COBALT should be explored as a clinical tool to identify residual deficits past the acute stages of concussion recovery.

Dual task training effects on gait and balance outcomes in multiple sclerosis: A systematic review

BACKGROUND

People with Multiple Sclerosis (PwMS) exhibit deteriorated balance and gait performance during dual task (DT) conditions. Impaired dual tasking is related to increased fall risk and lower quality of life in PwMS. While dual task interventions have proven effective in various patient populations, evidence is lacking to support the use of DT interventions to improve clinical measures of balance and gait in PwMS. Therefore, the purpose of this systematic review was to synthesize the effectiveness of DT intervention at improving balance and gait in PwMS.

METHODS

A systematic search was completed using CINHAL, PubMed and MEDLINE. Methodological quality, level of evidence and recommendations for included studies was assessed by two reviewers. Effect sizes with 95% confidence intervals comparing single and DT outcomes were calculated for all balance and gait variables.

RESULTS

Five randomized control trials (RCTs) were included for review. Of the 23 effect sizes calculated, three had 95% confidence intervals which did not pass zero and were therefore interpreted as strong. Due to inconsistent level one evidence of DT interventions being superior to single task balance and gait interventions a grade B recommendation was given.

CONCLUSION

There is inconsistent evidence supporting the use of DT interventions to improve clinical balance measures in PwMS. There is supportive evidence for the use of DT interventions to improve both single and DT gait speed. However, there was heterogeneity between interventions and dosage among RCTs. Despite multiple promising findings, DT interventions appear to have minimal impact on clinical balance and gait measures in PwMS.

Association between the level of attention and dual-task costs on postural sway and cognitive yield in children, adolescents, and young adults

BACKGROUND

Postural stability requires attentional resources. Dual-task paradigms are used to investigate the attentional demand of the studied tasks. However, no studies have been conducted on the subjects' level of attention, analyzing its association with dual-task costs (DTC).

RESEARCH QUESTION

To evaluate the attentional level and DTC on postural sway and cognitive yield in children, adolescents, and young adults, investigating age-related differences, and to analyze if the participants' attention level is associated with DTC.

METHODS

Postural sway and cognitive-yield of 30 children, 24 adolescents, and 32 young adults were assessed in a dual-task paradigm. We calculated DTC on postural sway and cognitive yield. Attention level was tested using Psychological Battery for Attention Assessment. We tested the association between DTC and attention level.

RESULTS

Young adults showed higher DTC on area and velocity of postural sway than children and adolescents. No differences in DTC on cognitive yield were found between the groups. Children showed lower attention levels than adolescents and young adults. Attention level was negatively associated with DTC on cognitive yield in young adults. Focused Attention is responsible for 24.4% of the variance in DTC on cognitive yield.

CONCLUSION

Age impacts DTC on postural stability, but not on cognitive performance. The smaller changes in sway found in children/adolescents when dual-tasking, potentially reflect less developed attentional levels and postural control, which make them performing postural tasks closed to their stability boundaries, and, therefore, make them prioritize stability protection more than adults. Similar DTC on cognition between groups may reflect an equalization of the chosen cognitive task at everyone's difficulty level. The lower attention levels of children may reflect an attentional system in development, with prioritization o postural tasks when dual-tasking to maintain stability. Although attention level increases throughout age, attention only predicted DTC on cognition. Better Focused Attention's levels predicted lower DTC on cognitive yield for young adults.

Effects of 6-Month Multimodal Physical Exercise Program on Bone Mineral Density, Fall Risk, Balance, and Gait in Patients with Alzheimer's Disease: A Controlled Clinical Trial

We aimed to determine the short- and medium-term effects of a multimodal physical exercise program (MPEP) on bone health status, fall risk, balance, and gait in patients with Alzheimer’s disease. A single-blinded, controlled clinical trial was performed where 72 subjects were allocated in a 3:1 ratio to an intervention group (IG; n = 53) and control group (CG; n = 19), where the IG’s subjects were admitted to live in a State Reference Center of Alzheimer’s disease, which offers the targeted exercise program, while the CG’s subjects resided in independent living. A multidisciplinary health team assessed all patients before allocation, and dependent outcomes were again assessed at one, three, and six months. During the study, falls were recorded, and in all evaluations, bone mineral density was measured using a calcaneal quantitative ultrasound densitometer; balance and gait were measured using the performance-oriented mobility assessment (POMA), the timed up and go test (TUG), the one-leg balance test (OLB), and the functional reach test (FR). There were no differences between groups at baseline for all outcome measures. The prevalence of falls was significantly lower in the IG (15.09%) than in the CG (42.11%) (χ² = 5.904; p = 0.015). We also found that there was a significant time*group interaction, with a post hoc Šidák test finding significant differences of improved physical function, especially in gait, for the IG, as assessed by POMA-Total, POMA-Gait, and TUG with a large effect size (ƞ²p = 0.185–0.201). In balance, we found significant differences between groups, regardless of time, and a medium effect size as assessed by POMA-Balance and the OLB (ƞ²p = 0.091–0.104). Clinically relevant effects were observed, although without significant differences in bone health, with a slowing of bone loss. These results show that a multimodal physical exercise program reduces fall risk and produces an improvement in gait, balance, and bone mineral density in the short and medium term in institutionalized patients with Alzheimer’s disease.

Sensory assessment of balance regulation of physically active women, 60-79 years old

OBJECTIVE: To evaluate the performance of sensory regulation of static and dynamic balance in older women, and to verify the sensitivity and specificity levels of the Body Balance Test (Teste de Equilíbrio Corporal, TEC) in relation to its reference standard, determining the best cutoff point for identifying risk of falling. METHODS: 74 women (age 67.59 ± 5.26 years) participated in the study, divided into fallers (n = 18) and non-fallers (n = 56). RESULTS: Comparatively, non-fallers had higher performance scores on static balance exteroceptive regulation (SBER), dynamic balance exteroceptive regulation (DBER), and dynamic balance interoceptive regulation (DBIR). Statistically significant differences were found in DBER (p = ≤0.001) and DBIR (p = 0.031). The area under the ROC curve was 0.73 (95%CI 0.58 – 0.88; p = 0.003), with a sensitivity level of 42.30% and specificity of 84.80%. CONCLUSIONS: The greatest chance of falling was found for dynamic balance in situations of exteroceptive and interoceptive regulation for older women with and without a history of falls. Deficits in sensory regulation of body balance are common in older women, both fallers and non-fallers.

Normative Data for a Tablet-Based Dual-Task Assessment in Healthy Older Adults

OBJECTIVE

The objective of this study is to provide normative data for a tablet-based dual-task assessment in older adults without cognitive deficits.

METHOD

In total, 264 participants aged between 60 and 90 years, French and English-speaking, were asked to perform two discrimination tasks, alone and concurrently. The participants had to answer as fast as possible to one or two images appearing in the center of the tablet by pressing to the corresponding buttons. Normative data are provided for reaction time (RT), coefficient of variation, and accuracy. Analyses of variance were performed by trial types (single-pure, single-mixed, dual-mixed), and linear regressions assessed the relationship between performance and sociodemographic characteristics.

RESULTS

The participants were highly educated and a large proportion of them were women (73.9%). The accuracy on the task was very high across all blocks. RT data revealed both a task-set cost and a dual-task cost between the blocks. Age was associated with slower RT and with higher coefficient of variability. Men were significantly slower on dual-mixed trials, but their coefficient of variability was lower on single-pure trials. Education was not associated with performance.

CONCLUSIONS

This study provides normative data for a tablet-based dual-task assessment in older adults without cognitive impairment, which was lacking. All participants completed the task with good accuracy in less than 15 minutes and thus, the task is transferable to clinical and research settings.

The effect of dual-task conditions on gait and balance performance in children with cerebral palsy: A systematic review and meta-analysis of observational studies

Dual-task conditions are commonly experienced in daily routines. The aim of the present systematic review is to investigate the effect of dual-task conditions on gait and balance performance in children with cerebral palsy (CP) and to perform meta-analyses where applicable. Five databases, "ProQuest", "PubMed", "OTSeeker", "Scopus", and "PEDro" from the incipient date of databases up to Aug 24, 2020 were searched for studies focusing on the effects of dual-task conditions on gait and balance performance in children with CP. After removing irrelevant articles and applying inclusion and exclusion criteria, nine articles were included in the present systematic review and meta-analysis. The results of the meta-analysis showed that walking speed was slower during dual-task conditions compared to single-task conditions in children with CP (WMD = -0.29 m/s, 95% CI = -0.34, -0.24, P ≤ 0.001) and walking speed decreased in children with CP during dual-task conditions in comparison with the typical development (TD) control group (WMD = -0.19 m/s, 95% CI = -0.23 to -0.15, P ≤ 0.001). The results of subgroup analysis based on the type of task indicated that adding concurrent tasks to walking degrades walking speed under varied dual-task conditions. Additionally, theoretical synthesis of the literature demonstrated that other gait and balance variables are changed by performing cognitive and motor secondary tasks differently. Although these changes may be compensatory strategies to retain their stability, there was not sufficient evidence to reach a firm conclusion. Research gaps and recommendations for future studies are discussed.

Feasibility and acceptability study on the use of a smartphone application to facilitate balance training in the ageing population

OBJECTIVES

This study aims to investigate the feasibility and acceptability of using an app-based technology to train balance in the older population.

DESIGN

Prospective feasibility study.

SETTING

The study was conducted in a university setting and participants' homes.

PARTICIPANTS

Thirty-five volunteers ≥55 years old were recruited.

INTERVENTION

Participants were asked to follow a balance exercise programme 7 days a week for 3 weeks using a phone application. Seventeen participants trained for a further 3 weeks.

OUTCOME MEASURES

Postural sway measures during quiet standing with feet at shoulder width apart and feet together, one leg standing and tandem stance were measured at baseline, and at the end of the 3 and 6 training weeks; the International Physical Activity Questionnaire (IPAQ) assessed participants' physical activity level before training; and app acceptability was recorded using a user experience questionnaire.

RESULTS

Participants on the 3 and 6-week programme on average completed 20 (±5) and 38 (±11) days of training, respectively, and all scored moderate to high on the IPAQ. Between baseline and the 3-week assessments, statistically significant improvements were observed for anteroposterior sway, mediolateral sway, sway area during tandem stance, for anteroposterior sway during one leg standing and for sway area during feet together stance. Improvements were observed at 6 week compared with baseline but those between 3 and 6 weeks were not significant. Based on the questionnaire, participants reported that the app is an appropriate tool for balance training (77%), they reported benefits from the training (50%) and found it easy to fit it into daily routine (88%).

CONCLUSION

The high level of adherence and improvements observed in the analysed measures demonstrate the feasibility of using an app to train balance in moderately to highly physically active older participants. This demonstrates that given appropriate tools the older population is positive towards and receptive of digital interventions aimed to improve balance.

Additional Functional Performance Gains After 24-Week Unstable Strength Training With Cognitive Training in Community-Dwelling Healthy Older Adults: A Randomized Trial

The authors investigated the effects of unstable strength training (UST) without or with cognitive training (C+UST) on functional performance in community-dwelling older adults. A total of 50 participants were randomly assigned (1:1) to either 24 weeks of thrice-weekly UST (n = 25) or C+UST (n = 25). All participants performed moderate-intensity strength exercises using unstable surfaces, and C+UST participants simultaneously received cognitive training in addition to UST. Primary outcomes included measures of functional performance: single- and dual-task timed up and go tests. Secondary outcomes included dynamic balance, mobility, handgrip strength, flexibility, quality of life, and concern about falling. The authors observed similar improvements on functional performance through the interventions. The C+UST group experienced additional gains at completion (single-task timed up and go: -0.90 s, 95% confidence interval [-2.38, -0.03]; dual-task timed up and go: -4.80 s, 95% confidence interval [-8.65, -0.95]) compared with the UST group. Moreover, significant differences were observed in mobility (sitting-rising test: -1.34, 95% confidence interval [-2.00, -0.20]) at 24 weeks. Both exercise modes improved single-task functional performance, while adding cognitive-training-optimized dual-task functional performance gains.

The influence of cognitive load on static balance in chronic obstructive pulmonary disease patients

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) may demonstrate cognitive function and balance deterioration. These two phenomena are often realized simultaneously during daily living activities, where the risk of falling may be increased due to possible postural disturbance when focusing on a cognitive task during motion. Despite the high rate of falls in COPD, there is currently a lack of affordable clinical instruments to quantify the interaction between cognitive tasks and static balance in these patients. Therefore, this study aims to assess the balance perturbation induced by cognitive tasks using a new cost-effective protocol which can easily be implemented in clinical settings.

METHOD

A total of 21 COPD patients (Age: 64 ± 8 yrs, Forced Expiratory Volume in one second = 41 ± 17%, Women: 7) and 21 matched healthy controls participated in the study. They performed two cognitive tasks (counting backward by 3s and naming animals) with eyes open and with eyes closed. Each trial lasted 60 s, with balance-related parameters recorded and quantified using a Wii Balance Board. A three-way ANOVA (cognitive task, eyes action, and health status) for balance-related parameters derived from the center of pressure displacement was performed.

RESULTS

COPD, vision, and cognitive tasks altered the balance; no interaction between conditions was observed. There was no correlation between cognitive ability, respiratory function, and the balance-related parameters.

CONCLUSION

Compared to healthy controls, the COPD patients had impaired balance. Cognitive tasks altered postural control in both COPD and controls, where this alteration was more pronounced with eyes closed.

Effects of exergames and cognitive-motor dual-task training on cognitive, physical and dual-task functions in cognitively healthy older adults: An overview

This overview aims to summarize the effectiveness of cognitive-motor dual-task and exergame interventions on cognitive, physical and dual-task functions in healthy older adults, as well as the feasibility, safety, adherence, transfer and retention of benefits of these interventions. We searched for systematic reviews or meta-analyses assessing the effects of cognitive-motor dual-task and exergame interventions on cognitive, physical and dual-task functions in cognitively healthy older adults through eight databases (CDSR (Cochrane), MEDLINE (PubMed), Scopus, EMBASE, CINAHL, PsycINFO, ProQuest and SportDiscus). Two reviewers performed the selection, data extraction and risk of bias evaluation independently (PROSPERO ID: CRD42019143185). Eighteen reviews were included in this overview. Overall, positive effects of cognitive-motor dual-task interventions on cognitive, physical and dual-task functions, as well as exergames on cognitive functions only, were observed in cognitively healthy older adults. In contrast, the effects of exergames on physical functions are more controversial, and their effects on dual-task functions have not been studied. The feasibility, safety, adherence, transfer and retention of benefits for both intervention types are still unclear. Future studies should follow more rigorous methodological standards in order to improve the quality of evidence and provide guidelines for the use of cognitive-motor dual-task and exergame interventions in older adults.

Cognitive Loading Produces Similar Change in Postural Stability in Patients With Chronic Ankle Instability and Controls

Purpose

While postural stability is compromised in individuals with chronic ankle instability (CAI), few studies have attempted to examine how performing simultaneous cognitive and balancing tasks may alter the complexity of the center of pressure. The purpose of this study was to compare postural stability in patients with CAI to controls during a dual-task condition via sample entropy.

Methods

Thirty participants (15 CAI, 15 healthy control) performed 3-trials of single-leg stance for 60-seconds each under two different conditions: single-task and dual-task (serial subtraction). Sample entropy (SampEn), a measure of pattern regularity, was calculated from the center of pressure excursion in the anterio-posterior (AP) and medio-lateral (ML) directions. 2x2 mixed-model ANOVAs determined any differences by task or group (p≤0.05).

Results

SampEn-AP decreased in the dual-task condition compared to single-task, single-leg balance across groups (F1,28=8.23, p=0.008, d=0.53). A significant interaction for group by task was found for SampEn-ML (F1,28=4.18, p=0.05), but post hoc testing failed to reveal significant differences. Serial subtraction was completed with significantly fewer errors during dual-task compared to single-task (F1,27=12.75, p=0.001, d=0.66).

Conclusions

Patients with CAI do not display differences in regularity of postural stability, even when attention is divided. However, the addition of serial subtraction increased the regularity of AP center-of-pressure motion. Increased regularity may suggest a change in motor control strategy, reducing natural fluctuations and flexibility within movement patterns during more challenging tasks. Clinicians could utilize dual-task situations during rehabilitation of patients with CAI, in order to adequately restore stability and function when attention is divided.

Effects of adiposity on postural control and cognition in older adults

BACKGROUND

Understanding the impacts of increased adiposity on postural control and cognitive deficits in adults is critical for health practitioners in recommending or prescribing effective weight loss regimens. Despite prior work in this area, the knowledge of increased adiposity impacts on postural control and cognitive deficits in older adults (OAs) is still limited.

RESEARCH QUESTION

The purposes of the current study were: (a) to assess the relationship between postural measures and adiposity measures by using regression model analyses and, (b) to examine the impacts of increased adiposity and age on cognitive performance.

METHODS

A total of thirty (30) individuals aged 60+ years participated in the study. Participants were classified into three groups based upon their BMI scores at the onset of the study. The normal weight (NW) (BMI: 18.5-24.9 kg/m²), the overweight (OW) (BMI: 25-29.9 kg/m²), and the obese (OB) groups (BMI: 30-40 kg/m²) each had five females and five males. Participants were required to perform two test sessions: (1) anthropometry assessment and body composition scanning; and (2) evaluation of plantar tactile function, postural control, and cognitive function.

RESULTS

Overall, our findings indicate that increased adiposity in OAs is associated with declines in both cognitive function and postural control.

SIGNIFICANCE

Our data also indicate that measures such as BMI and abdominal fat mass amounts/ratios offer the best insight to the impact of adiposity on cognitive function and postural control measures. However, further work is still needed to clarify the mechanistic links between adiposity and cognitive-postural deficits.

Dual-tasking effects on static and dynamic postural balance performance: a comparison between endurance and team sport athletes

In sports, postural balance control has been demonstrated to be one of the limiting factors of performance and a necessary component to achieve any sport technique. Team players (TP) must process and react to multiple external stimuli while executing at the same time the skills of the game. By contrast, endurance athletes (END) must perform the same gesture repetitively without a concurrent coordination of continuous stimuli-related actions. However, END are used to facilitate their physical performance by adopting cognitive strategies while performing their sport gesture. Therefore, we aimed to investigate static and dynamic balance performance in these two types of athletes, both in single and dual-task conditions. Nineteen END and sixteen TP underwent a static and a dynamic balance assessment on a dynamometric platform and an instrumented oscillating board, respectively. Among TP static but not dynamic postural balance performance was negatively affected by dual-tasking considering the area of the confidence ellipse (p < 0.001; d = 0.52) and the sway path mean speed (p < 0.001; d = 0.93). Conversely, END unaltered static balance performance but showed an overall improvement in the dynamic one when dual-tasking occurred. The limited human processing capacity accounted the worsening of the cognitive performance in both TP (p < 0.05; d = 0.22) and END (p < 0.001; d = 0.37). Although TP are more used coping dual tasking, the better performance of END could be accounted for by the employment of the external attentive focus (i.e. counting backward aloud) that called into play a strategy close to those adopted during training and competitions. These surprising results should be considered when driving and developing new trainings for team players in dual-tasking conditions.

Diagnostic Balance Tests for Assessing Risk of Falls and Distinguishing Older Adult Fallers and Non-Fallers: A Systematic Review with Meta-Analysis

Falls are a major cause of injury and morbidity in older adults. To reduce the incidence of falls, a systematic assessment of the risk of falling is of paramount importance. The purpose of this systematic review was to provide a comprehensive comparison of the diagnostic balance tests used to predict falls and for distinguishing older adults with and without a history of falls. We conducted a systematic review of the studies in which instrumented (force plate body sway assessment) or other non-instrumented balance tests were used. We analyzed the data from 19 prospective and 48 retrospective/case-control studies. Among the non-instrumented tests, the single-leg stance test appears to be the most promising for discrimination between fallers and non-fallers. In terms of body sway measures, the center-of-pressure area was most consistently associated with falls. No evidence was found for increased benefit of the body sway test when cognitive tasks were added, or the vision was eliminated. While our analyses are limited due to the unbalanced representation of different test and outcome measures across studies, we can recommend the single-leg test for the assessment of the risk of falling, and the measurements of body sway for a more comprehensive assessment.

Trunk balance control during beam walking improves with the haptic anchors without the interference of an auditory-cognitive task in older adults

BACKGROUND

Prior studies have shown that older adults reduced trunk acceleration when walking on a balance beam with haptic inputs provided by anchors; however, it is unknown whether these benefits would remain in the presence of a concurrent cognitive task.

RESEARCH QUESTION

This study aimed to evaluate the effect of a cognitive task on balance control when using the anchors while walking on a balance beam in older adults.

METHODS

Thirty older adults participated in this study. They walked on a balance beam under four conditions combining haptic inputs (with and without anchors) and a cognitive task (present and absent). The anchors consisted of a flexible cable with a small load (125 g) attached at the end contacting the ground. Participants held one anchor in each hand and dragged the loads over the ground while walking. In the cognitive task, participants silently counted the number of times they heard a target number within a series of random numbers and provided their response at the end of each trial. Trunk acceleration and normalized step speed were assessed.

RESULTS

The anchors reduced the normalized step speed and the trunk acceleration amplitude in the frontal plane when walking on the beam. The cognitive task also diminished the normalized step speed in the beam walking. The use of the anchors did not influence the cognitive task performance.

SIGNIFICANCE

Even on a balance beam in the presence of a cognitive task, haptic anchors were able to reduce trunk acceleration in older adults to improve balance control. The cognitive task did not affect the use of haptic anchors.

Standing Balance Strategies and Dual-Task Interference Are Differentially Modulated Across Various Sensory Contexts and Cognitive Tests in Individuals With Chronic Stroke

BACKGROUND AND PURPOSE

Mental tracking and verbal fluency tests have been linked to poor mobility and falls; however, no studies have examined the influence of imposing these tests on standing balance post-stroke. The purpose of this study was to investigate standing balance and cognitive performance across sensory conditions and cognitive tests post-stroke.

METHODS

Ninety-two participants with chronic stroke stood on dual-force platforms while performing various sensory conditions (eyes open/fixed surface, eyes closed/fixed surface, eyes open/sway-referenced surface, and eyes closed/sway-referenced surface) and cognitive tests (no cognitive test, serial subtractions, and verbal fluency). Equilibrium scores were computed based on the anterior-posterior sway angle. The number of correct verbal responses was recorded.

RESULTS

Performing serial subtractions during eyes closed/sway-referenced surface revealed the highest equilibrium score (64.0 ± 13.5), followed by the same sensory condition with added verbal fluency test (59.6 ± 15.1), followed by the single-task condition with no cognitive test (52.6 ± 20.9). The number of correct serial subtractions between seated (7.7 ± 3.7) and standing (7.2 ± 3.5) conditions was similar. A trend for more correct verbal fluency responses emerged when seated (8.1 ± 2.9) than the eyes open/sway-referenced surface condition (7.5 ± 2.8). Greater correct verbal fluency responses emerged when seated (8.6 ± 3.1) than the eyes closed/sway-referenced surface condition (7.8 ± 2.7).

DISCUSSION AND CONCLUSIONS

Standing balance enhancement (higher equilibrium score/better balance) depends on the neuropsychological process targeted and the sensory input available post-stroke. Cognitive dual-task interference emerged for the verbal fluency test during the most attention demanding sensory condition. Cognitive tests that enhance standing balance should be considered in assessments and interventions to evaluate and improve dual-tasking post-stroke.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A321).

The execution of the Grooved Pegboard test in a Dual-Task situation: A pilot study

Background

Manual dexterity is an important aspect in everyday life, which is widely studied through the Grooved Pegboard Test (GPT). Since Dual-Tasks (DT) activities are widely investigated and important to simulate everyday life situations, the objectives of the present pilot study were the evaluation of the effect of a cognitive task and a motor task during the performance of the GPT and the feasibility of the GPT in a DT contest. A secondary objective was to evaluate the training effect of the GPT.

Methods

A total of 31 young adults (20 man and 11 woman, age (SD): 27.7 (2.5)) performed the GPT eight times to understand the presence of a training effect before performing the GPT in DT. The additional tasks were a secondary cognitive task and a secondary motor task.

Results

All participants were able to complete the required conditions. The GPT performed in motor DT were significantly slower than those performed singularly (p < 0.01). The GPT performed with the cognitive task was slower than the secondary motor task (p < 0.05). A training effect was present up to the 4^th consecutive trial.

Conclusions

The GPT can be executed with a cognitive or motor task to increase the difficulty of the trial to better evaluate manual dexterity and cognitive capacities.

Dual-Task Conditions on Static Postural Control in Older Adults: A Systematic Review and Meta-Analysis

Dual-task (DT) consists of the performance of two tasks simultaneously. An index of DT difficulty has been linked to decreased postural control. Because a wide range of DT is employed, this study aimed to evaluate its effects in static balance in older adults. PubMed, Web of Science, and Scopus were screened, and the secondary tasks were grouped as manual, reaction time, discrimination and decision making, mental tracking, verbal fluency, working memory, or "other" tasks. A total of 66 studies have been included. The meta-analysis was conducted on 28 effects and showed a significant mean effect size of d = 0.24 (p = .02, SE = 0.10; confidence interval [0.04, 0.44]), indicating a worsening in stability during DT. In conclusion, postural control was worsened by the Stroop test and the arithmetic tasks improved it. The results do not underpin any conclusive statement on the impact of DT, and a standard operating procedure was created.

Adaptation of balancing behaviour during continuous perturbations of stance. Supra-postural visual tasks and platform translation frequency modulate adaptation rate

When humans are administered continuous and predictable perturbations of stance, an adaptation period precedes the steady state of balancing behaviour. Little information is available on the modulation of adaptation by vision and perturbation frequency. Moreover, performance of supra-postural tasks may modulate adaptation in as yet unidentified ways. Our purpose was to identify differences in adaptation associated to distinct visual tasks and perturbation frequencies. Twenty non-disabled adult volunteers stood on a platform translating 10 cm in antero-posterior (AP) direction at low (LF, 0.18 Hz) and high frequency (HF, 0.56 Hz) with eyes open (EO) and closed (EC). Additional conditions were reading a text fixed to platform (EO-TP) and reading a text stationary on ground (EO-TG). Peak-to-peak (PP) displacement amplitude and AP position of head and pelvis markers were computed for each of 27 continuous perturbation cycles. The time constant and extent of head and pelvis adaptation and the cross-correlation coefficients between head and pelvis were compared across visual conditions and frequencies. Head and pelvis mean positions in space varied little across conditions and perturbation cycles but the mean head PP displacements changed over time. On average, at LF, the PP displacement of the head and pelvis increased progressively. Adaptation was rapid or ineffective with EO, but slower with EO-TG, EO-TP, EC. At HF, the head PP displacement amplitude decreased progressively with fast adaptation rates, while the pelvis adaptation was not apparent. The results show that visual tasks can modulate the adaptation rate, highlight the effect of the perturbation frequency on adaptation and provide evidence of priority assigned to pelvis stabilization over visual tasks at HF. The effects of perturbation frequency and optic flow and their interaction with other sensory inputs and cognitive tasks on the adaptation strategies should be investigated in impaired individuals and considered in the design of rehabilitation protocols.

Effects of spatial working memory in balance during dual tasking in traumatic brain injury and healthy controls

OBJECTIVES

The aim of this research was to assess cognitive-motor interactions though dual tasks of working memory in patients with traumatic brain injury (TBI) and control subjects. Methods: Twenty patients with chronic TBI with good functional level and 19 matched healthy controls performed dual working memory tasks (1-back numeric and 1-back spatial (S)) while sitting, standing, and walking. The center of pressure (COP) displacement amplitude, cadence, and error percentage (PER) were recorded as dependent variables. Results: The results revealed main effects of Group (TBI, controls) (p = .011) and Task factors (Single, Dual Standing 1-back, Dual Standing 1-back (S); p = .0001) for the COP. Patients showed greater displacement than controls (p = .011), and an analysis of the Task factor showed a minor displacement for the dual 1-back (S) task compared with the 1-back and single task (p = .002 and p = .001, respectively). Conclusions: Postural control during both standing and walking improved during performance of the spatial working memory task. In the dual task, both patients and controls showed a postural prioritization as an adaptive response to the increase in cognitive demand.

The Effects of a Cognitive Dual Task on Jump-landing Movement Quality

Investigations on movement quality deficits associated with jump landing are numerous, however, these studies are often performed in laboratories with little distraction to the participant. This is contrary to how injury typically occurs secondary to sport-specific distraction where the athlete is cognitively loaded during motor performance. Thus, the purpose of this study was to determine the effect of a cognitive load on jump-landing movement quality. A dual-task design was used to determine the effects of a dual-task on tuck jump movement quality in 20 participants. There were three cognitive conditions (no cognitive task, easy-cognitive task, and difficult-cognitive task). The dual task elicited statistically significant changes in overall tuck jump score (movement quality) across the conditions with tuck jump score increasing from 3.52±1.64 baseline to 4.37±1.25 with the easy-cognitive task to 4.67±1.24 with the difficult-cognitive task. The findings of this study may be useful to screen for individuals at risk of lower extremity injury utilizing the tuck jump when paired with a cognitive task. The screening would then identify individuals who may have poor neuromuscular control when cognitively loaded.

Dual-task training on gait, motor symptoms, and balance in patients with Parkinson’s disease: a systematic review and meta-analysis

Objective:

The aim of the present study was to systematically evaluate and quantify the effectiveness of dual-task training on gait parameters, motor symptoms and balance in individuals diagnosed with Parkinson’s disease.

Data resources:

A systematic review of published literature was conducted until May 2020, using PubMed, EMBASE, Cochrane Library, Web of Science, EBSCO and CNKI databases.

Methods:

We included randomized controlled trials (RCTs) and non-RCTs to evaluate the effects of dual-task training compared with those of non-intervention or other forms of training. The measurements included gait parameters, motor symptoms and balance parameters. Methodological quality was assessed using the PEDro scale. Outcomes were pooled by calculating between-group mean differences using fixed- or random-effects models based on study heterogeneity.

Results:

A total of 11 RCTs comprising 322 subjects were included in the present meta-analysis. Results showed that dual-task training significantly improved gait speed (standardized mean difference [SMD], −0.23; 95% confidence interval [CI], −0.38 to −0.08; P = 0.002), cadence (SMD, −0.25; 95% CI, −0.48 to −0.02; P = 0.03), motor symptoms (SMD, 0.56; 95% CI, 0.18 to 0.94; P = 0.004) and balance (SMD, −0.44; 95% CI, −0.84 to −0.05; P = 0.03). However, no significant changes were detected in step length or stride length.

Conclusion:

Dual-task training was effective in improving gait performance, motor symptoms and balance in patients with Parkinson’s disease relative to other forms of training or non-intervention.

Virtual reality training enhances gait poststroke: a systematic review and meta-analysis

Virtual reality (VR)-based interventions are gaining widespread attention for managing neurological disorders such as stroke. A metastatistical consensus regarding the intervention is strongly warranted. In this study, we attempt to address this gap in the literature and provide the current state of evidence for the effects of VR on gait performance. We conducted both between- and within-group meta-analyses to provide a state of evidence for VR. Moreover, we conducted a search adhering to PRISMA guidelines on nine databases. Out of 1866 records, 32 studies involving a total of 809 individuals were included in this review. Considering all included studies, significant enhancements in gait parameters were observed with VR-based interventions compared with conventional therapy. A between-group meta-analysis reported beneficial significant medium effects of VR training on cadence (Hedge's g = 0.55), stride length ((STrL; Hedge's g = 0.46), and gait speed (Hedge's g = 0.30). Similarly, a within-group meta-analysis further revealed positive medium effects of VR on cadence (Hedge's g = 0.76), STrL (Hedge's g = 0.61), and gait speed (Hedge's g = 0.69). Additional subgroup analyses revealed beneficial effects of joint application of VR and robot-assisted gait training on gait speed (Hedge's g = 0.50). Collectively, findings from this review provide evidence for the effectiveness of VR-based gait training for stroke survivors.

Prevalence of Falls, Physical Performance, and Dual-Task Cost While Walking in Older Adults at High Risk of Falling with and Without Cognitive Impairment

PURPOSE

To compare the prevalence of falls, physical performance, and dual-task cost during walking between cognitively healthy and impaired older adults at high risk of falling.

METHODS

A cross-sectional analysis of 670 community-dwelling older adults who were considered at high risk of falling, operationalized as 1) having fallen at least once in the preceding 12 months and having a health-care practitioner's referral indicating that the participant was at risk of falls or 2) having impaired mobility as evidenced by a Timed Up and Go (TUG) result ≥13.5 s. Participants (mean age = 77.7 years, SD = 5.6) were divided into cognitively healthy (n = 461) or cognitively impaired (n = 209) groups using a cutoff score of <23 on the Montreal Cognitive Assessment test. Assessment included self-reported number of falls over the previous 12 months, functional reach, TUG, Short Physical Performance Battery (SPPB), and single- and dual-task walk performance. Data were analyzed using Poisson regression to estimate the prevalence ratios of falls and analysis of variance to examine between-group differences on physical performance and dual-task cost during walking performance.

RESULTS

In the analysis, 82.3% of older adults with cognitive impairment and 69.4% of unimpaired older adults reported 1 or more falls in the previous 12 months. Compared with cognitively healthy participants, those with cognitive impairment were 2.57 (95% confidence interval [CI] = 2.17 to 3.05) times more likely to have any fall and 2.33 (95% CI = 1.95 to 2.78) times more likely to have multiple falls. Older adults with cognitive impairment performed worse on functional reach (mean difference [MD] = -2.33 cm, 95% CI = -3.21 to -1.46), TUG (MD = 3.05 s, 95% CI = 2.22 to 3.88), and SPPB (MD = -1.24 points, 95% CI = -1.55 to -0.92) and showed increase in dual-task costs (MD = 6.59%, 95% CI = 4.19 to 9.03) compared to those without cognitive impairment.

CONCLUSION

Older adults at high risk for falls and who have cognitive impairment are associated with a greater risk for falls and decrements in physical and dual-task performance.

Novel methodology for assessing total recovery time in response to unexpected perturbations while walking

Walking stability is achieved by adjusting the medio-lateral and anterior-posterior dimensions of the base of support (step length and step width, respectively) to contain an extrapolated center of mass. We aimed to calculate total recovery time after different types of perturbations during walking, and use it to compare young and older adults following different types of perturbations. Walking trials were performed in 12 young (age 26.92 ± 3.40 years) and 12 older (age 66.83 ± 1.60 years) adults. Perturbations were introduced at different phases of the gait cycle, on both legs and in anterior-posterior or medio-lateral directions, in random order. A novel algorithm was developed to determine total recovery time values for regaining stable step length and step width parameters following the different perturbations, and compared between the two participant groups under low and high cognitive load conditions, using principal component analysis (PCA). We analyzed 829 perturbations each for step length and step width. The algorithm successfully estimated total recovery time in 91.07% of the runs. PCA and statistical comparisons showed significant differences in step length and step width recovery times between anterior-posterior and medio-lateral perturbations, but no age-related differences. Initial analyses demonstrated the feasibility of comparisons based on total recovery time calculated using our algorithm.

Perturbation-based gait training to improve daily life gait stability in older adults at risk of falling: protocol for the REACT randomized controlled trial

Background

The European population is rapidly ageing. There is an urgent need for innovative solutions to reduce fall risk in older adults. Perturbation-based gait training is a promising new method to improve reactive balance responses. Whereas positive effects on task-specific dynamic balance recovery during gait have been shown in clinical or laboratory settings, translation of these effects to daily life gait function and fall risk is limited. We aim to evaluate the effect of a 4-week perturbation-based treadmill training on daily-life dynamic gait stability, assessed with inertial sensor data. Secondary outcomes are balance recovery performance, clinical balance and gait assessment scores, the amount of physical activity in daily life and falls incidence during 6 months follow-up.

Methods

The study is a monocenter assessor-blinded randomized controlled trial. The target study sample consists of 70 older adults of 65 years and older, living in the community and with an elevated risk of falling. A block-randomization to avoid seasonal effects will be used to allocate the participants into two groups. The experimental group receives a 4-week, two times per week perturbation-based gait training programme on a treadmill, with simulated slips and trips, in combination with cognitive dual tasks. The control group receives a 4-week, two times per week treadmill training programme under cognitive dual-task conditions without perturbations. Participants will be assessed at baseline and after the 4-weeks intervention period on their daily-life gait stability by wearing an inertial sensor on the lower back for seven consecutive days. In addition, clinical balance and gait assessments as well as questionnaires on falls- and gait-efficacy will be taken. Daily life falls will be followed up over 6 months by a fall calendar.

Discussion

Whereas perturbation-based training has shown positive effects in improving balance recovery strategies and in reducing laboratory falls, this study will contribute to investigate the translation of perturbation-based treadmill training effects in a clinical setting towards improving daily life gait stability and reducing fall risk and falls.

Trial registration

NTR7703 / NL66322.028.18, Registered: January 8, 2019; Enrolment of the first participant April 8, 2019.

The Effects of Cognitive Loading on Motor Behavior in Injured Individuals: A Systematic Review

BACKGROUND

Research suggests that individuals with musculoskeletal injury may have difficulty negotiating physical tasks when they are combined with cognitive loads.

OBJECTIVE

Our objective was to conduct a systematic review to understand the effects of increased cognitive demand on movement patterns among individuals with musculoskeletal injuries.

METHODS

A comprehensive search of PubMed, MEDLINE, the Cumulative Index for Nursing and Allied Health Literature (CINAHL), and SPORTDiscus was conducted to find research reports that included a population that had previously experienced an ankle, knee, or low back injury, included an uninjured control group, and assessed a dual-task paradigm.

RESULTS

Forty-five full-text research reports were assessed, of which 28 studies (six ankle injury, nine knee injury, and 13 low back pain studies) were included in the review. Included studies were assessed for methodological quality and the study design extracted for analysis including the participants, cognitive and physical tasks performed, as well as outcome measures (e.g., three-dimensional kinematics, center of pressure, etc.). All studies included were cross-sectional or case-control with methodological quality scores of 17.8 ± 2.2 out of a possible 22. Twenty-five of the 28 studies found changes in motor performance with dual-task conditions compared with single tasks. Furthermore, 54% of studies reported a significant group by task interaction effect, reporting at least one alteration in injured groups' motor performance under dual-task conditions when compared with an uninjured group.

CONCLUSION

The results of this systematic review indicate that motor performance is further impaired by placing a cognitive load on individuals in populations with musculoskeletal injury. More demanding tasks such as gait appear to be more affected in injured individuals than simple balance tasks. Future investigators may want to consider the difficulty of the tasks included as well as the impact of dual-task paradigms on rehabilitation programs.

Individual and combined effects of a cognitive task, light finger touch, and vision on standing balance in older adults with mild cognitive impairment

BACKGROUND

Postural instability and balance dysfunction have been identified in older adults with mild cognitive impairment (MCI). Performing a secondary task while standing can additionally jeopardize their balance.

AIMS

The purpose of the exploratory study was to investigate the individual and combined effects of a cognitive task, light finger touch and vision on postural sway in older adults with MCI as compared to healthy older adults.

METHODS

Five individuals with MCI and ten age-matched control subjects stood on the force platform with and without the performance of a cognitive task (counting backward from a randomly chosen three-digit number), with and without light finger touch contact applied to an external stable structure, and with eyes open or closed. The center of pressure (COP) excursion, range, velocity in antero-posterior and medial-lateral directions and sway area were calculated.

RESULTS

Participants demonstrated significantly larger postural sway when vision was not available (p < 0.05), smaller postural sway when using a finger touch contact (p < 0.05) and increased postural sway during the performance of the cognitive task (p < 0.05). When finger touch and a cognitive task were performed simultaneously, body sway decreased as compared to just standing in healthy older adults but not in individuals with MCI (p < 0.05).

CONCLUSIONS

The results help to better understand the individual and combined effects of vision, light touch and a cognitive task in postural control of individuals with MCI. The study outcome also provides a basis for future studies of balance control in patients with cognitive impairments.

Effect of Light Finger Touch, a Cognitive Task, and Vision on Standing Balance in Stroke

The aim of the exploratory study was to investigate the individual and combined effects of light finger touch, a cognitive task, and vision on postural sway in individuals with stroke. Nine older adults with stroke stood on the force platform with eyes open and eyes closed, with and without a light finger touch contact with the stationary frame, and when counting backward from a randomly chosen three-digit number or without it. The center of pressure (COP) excursion, velocity, range and sway area was calculated. Participants demonstrated significantly larger postural sway when vision was not available (p < 0.05), smaller postural sway when using a finger touch contact (p < 0.05), and increased postural sway while performing the cognitive task (p < 0.05). When finger touch and a cognitive task was performed simultaneously, body sway decreased as compared to standing and performing a cognitive task in eyes open (p < 0.05) and eyes closed conditions. Results indicate that light touch in individuals with stroke mitigates the impact of cognitive load. The findings contribute to the understanding of the role of sensory integration in balance control of individuals with neurological impairments and older adults.

Dual-task training with progression from variable- to fixed-priority instructions versus dual-task training with variable-priority on gait speed in community-dwelling older adults: A protocol for a randomized controlled trial : Variable- and fixed-priority dual-task for older adults

BACKGROUND

Functional independence and safe mobility, especially in older people, mostly rely on the ability to perform dual tasks, particularly during activities with variable- and fixed-priority attention. The aim of this study is to compare the dual-task training with progression from variable- to fixed-priority instructions versus dual-task training with variable-priority on gait speed in community-dwelling older adults.

METHODS

This is an assessor- and participant-blinded, two-arm, randomized controlled trial with 60 community-dwelling male and female older adults between the ages of 60 and 80 years old. Participants will be randomly allocated into either the intervention group or the control group using a computer-generated permuted block randomization schedule. The intervention group will undertake a progressive dual-task training in which the participants will be progressively submitted to dual-task walking and postural balance exercises with variable- to fixed-priority instructions. The control group will be submitted to dual-task training with variable-priority attention exercises. Both groups will receive 48 sessions lasting for 60 min each over 24 weeks. The primary outcome will be the gait speed under single- and dual-task conditions. Secondary outcomes will include spatiotemporal gait parameters, functional balance, executive function, falls, quality of life, and depression symptoms. All the analyses will be based on the intention-to-treat principle.

DISCUSSION

This is the first assessor- and participant-blinded, two-arm, randomized controlled trial with 6 months of intervention and an additional 6-month post-training follow up aiming to evaluate the effectiveness of training with progression from variable- to fixed-priority instructions on gait biomechanics, postural balance, falls episodes, executive functioning, and quality of life in community-dwelling older adults. If our hypotheses are confirmed, this training protocol can be implemented widely to improve gait speed and other functional activities and quality of life in community-dwelling older adults. This study protocol can be used to improve these functional aspects of community-dwelling older adults. This study may also contribute to future guidelines for the improvement of these clinical and biomechanical aspects in older people.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier - NCT03886805, Registered 22 March 2019.

A Novel Square-Stepping Exercise Program for Older Adults (StepIt): Rationale and Implications for Falls Prevention

The ability to effectively execute compensatory steps is critical for preventing accidental falls, and consequently stepping training is an essential ingredient of fall prevention programs. In this paper, we propose a concept for stepping training that aims to maximize training effects by taking into account recent research evidence and a precise dosing of training ingredients. The concept addresses motor as well as cognitive falls-related aspects, it is suitable for individual as well as group based training, and it does not require costly equipment. Theory and evidence behind all of the training principles is reviewed, and an example of an exercise protocol is described in detail. Participants are presented with stepping patterns which they have to memorize and implement on a mat. In order to enable investigation of dose-response effects, the difficulty level systematically and gradually increases session by session based on four principles: execution speed, pattern complexity, pattern length and execution in dual-/multi-tasking conditions. The presented concept can be used as a framework for the development of further prevention and/or rehabilitation stepping exercise programs. Further studies using this exercise regimen or modified versions of it are encouraged.

Effects of tai chi on postural control during dual-task stair negotiation in knee osteoarthritis: a randomised controlled trial protocol

INTRODUCTION

Stair ascent and descent require complex integration between sensory and motor systems; individuals with knee osteoarthritis (KOA) have an elevated risk for falls and fall injuries, which may be in part due to poor dynamic postural control during locomotion. Tai chi exercise has been shown to reduce fall risks in the ageing population and is recommended as one of the non-pharmocological therapies for people with KOA. However, neuromuscular mechanisms underlying the benefits of tai chi for persons with KOA are not clearly understood. Postural control deficits in performing a primary motor task may be more pronounced when required to simultaneously attend to a cognitive task. This single-blind, parallel design randomised controlled trial (RCT) aims to evaluate the effects of a 12-week tai chi programme versus balance and postural control training on neuromechanical characteristics during dual-task stair negotiation.

METHODS AND ANALYSIS

Sixty-six participants with KOA will be randomised into either tai chi or balance and postural control training, each at 60 min per session, twice weekly for 12 weeks. Assessed at baseline and 12 weeks (ie, postintervention), the primary outcomes are attention cost and dynamic postural stability during dual-task stair negotiation. Secondary outcomes include balance and proprioception, foot clearances, self-reported symptoms and function. A telephone follow-up to assess symptoms and function will be conducted at 20 weeks. The findings will help determine whether tai chi is beneficial on dynamic stability and in reducing fall risks in older adults with KOA patients in community.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (#2018KY-006-1). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR1800018028.

Structured Cognitive-Motor Dual Task Training Compared to Single Mobility Training in Persons with Multiple Sclerosis, a Multicenter RCT

The aim was to compare the effectiveness of dual-task training (DTT) compared to single mobility training (SMT) on dual-task walking, mobility and cognition, in persons with Multiple Sclerosis (pwMS). Forty pwMS were randomly assigned to the DTT or SMT groups. The DTT-group performed dual-task exercises using an interactive tablet-based application, while the SMT-group received conventional walking and balance exercises. Both interventions were supervised and identical in weeks (8) and sessions (20). Nine cognitive-motor dual-task conditions were assessed at baseline, after intervention and at 4-weeks follow-up (FU). The dual-task cost (DTC), percentage change of dual-task performance compared to single-task performance, was the primary outcome. Mobility and cognition were secondarily assessed. Mixed model analyses were done with group, time and the interaction between group and time as fixed factors and participants as random factors. Significant time by group interactions were found for the digit-span walk and subtraction walk dual-task conditions, with a reduction in DTC (gait speed) for the DTT maintained at FU. Further, absolute dual-task gait speed during walking over obstacles only improved after the DTT. Significant improvements were found for both groups in various motor and cognitive measures. However, the DTT led to better dual-task walking compared to the SMT.

Human Balance in Response to Continuous, Predictable Translations of the Support Base: Integration of Sensory Information, Adaptation to Perturbations, and the Effect of Age, Neuropathy and Parkinson’s Disease

This short narrative review article moves from early papers that described the behaviour of healthy subjects balancing on a motorized platform continuously translating in the antero-posterior direction. Research from the laboratories of two of the authors and related investigations on dynamic balancing behaviour are briefly summarized. More recent findings challenging time-honoured views are considered, such as the statement that vision plays a head-in-space stabilizing role. The time interval to integrate vision or its withdrawal in the balancing pattern is mentioned as well. Similarities and differences between ageing subjects and patients with peripheral or central disorders are concisely reported. The muscle activities recorded during the translation cycles suggest that vision and amplitude changes of the anticipatory postural activities play a predominant role in controlling dynamic balance during prolonged administration of the predictable perturbation. The potential of this paradigm for rehabilitation of balance problems is discussed.

Development of a lifestyle-integrated physical exercise training and home modification intervention for older people living in a community with a risk of falling (Part 1): the FIT-at-Home fall prevention program

PURPOSE

In this paper, we report on the development and refinement of a progressive physical exercise training and home modification intervention for older people with a risk of falling located in Germany by using the United Kingdom's Medical Research Council framework.

METHODS

The process was iterative and six phases of development emerged: (1) establishing an intervention development group, (2) identifying the evidence on interventions, (3) identifying a theory to underpin the intervention, (4) designing the intervention components, (5) drafting the intervention manual and training course, and (6) piloting and refining of intervention components.

RESULTS

The result was an evidence-based, theory-informed, and user-endorsed intervention: FIT-at-Home. This intervention comprised nine individual sessions over 12 weeks and two follow-up booster sessions delivered by trained occupational therapists. A feasibility study demonstrated the acceptance and feasibility of intervention delivery. Users responses were generally favorable and included recommendations about the intervention manual, mode of delivery of the home hazard assessment, and producing a manual for older people.

CONCLUSIONS

We developed a feasible home-based lifestyle-integrated physical exercise training and home modification intervention for older people with a risk of falling by using a systematic approach. Implications include how this intervention could enrich occupational therapy fall prevention strategy in older people living at home.IMPLICATIONS FOR REHABILITATIONFalls in older people represent a major public health concern and occupational therapists in rehabilitation practice are encouraged to apply evidence-based interventions that reduce the risk of falls in older people living in a community.Many physical and environmental fall risks are modifiable by lifestyle changes such as physical exercise training, home safety assessment, and home modification. We developed a home-based balance and strength exercise training and home modification intervention that aims to improve strength, balance, and home safety.This study indicates that older people, at risk of falling, with functional limitations, and limited mobility, who participated in the FIT-at-Home intervention, felt that exercising at home suited them best.

Effects of different attention tasks on concurrent speech in adults who stutter and fluent controls

PURPOSE

Motor theories indicate that focusing attention on well-practiced movements interferes with skilled performance; however, specific forms of attention (alerting vs. orienting vs. executive control) associated with this effect are not well understood. The present study explored this question in relation to stuttering, and examined whether dual task conditions that engaged sustained attention or working memory (WM) affected speech fluency in different ways. We also considered whether fluency changes were associated with changes in speech rate and language.

METHODS

Nineteen adults who stutter (AWS) and 20 controls produced spontaneous speech under a baseline condition and two dual task conditions: one involving a sustained attention task, the other involving WM demands.

RESULTS

Both groups produced fewer stutter-like disfluencies under dual task relative to baseline conditions and this reduction did not differ between the two dual tasks (attention vs. WM). Speech rate and language variables, which were potentially influenced by attention conditions, were not affected by dual tasks in the same way as disfluencies, and appeared to be unassociated with fluency results.

CONCLUSIONS

Findings indicate that atypical disfluencies decrease when attention is divided, even when secondary task demands are minimal, as they were in the sustained attention task. For simple secondary tasks, fluency changes do not appear to be a byproduct of slowed rate and are not accompanied by observable changes in language. These results demonstrate that simple manipulations of attention can induce measurable effects on aspects of speech production, and may be a useful tool for facilitating fluency in clinical intervention.

The evaluation of dual-task conditions on static postural control in the older adults: a systematic review and meta-analysis protocol

BACKGROUND

In postural stability evaluation, the dual-task concept is often adopted in order to create a more challenging situation. The dual-task consists of performing simultaneously two tasks, a primary static or dynamic motor task and an additional secondary cognitive task. Usually, a multitask condition leads to a reduction in the postural control performance, especially in older adults. Considering the wide spectrum of secondary task conditions existing in scientific literature, the present manuscript aims to write a peer-reviewed protocol that will be used in a systematic review and meta-analysis performed to identify the effects of different secondary tasks conditions in a population of older adults during static postural stability.

METHODS

The study will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and for this manuscript, the PRISMA Protocol. PICOS criteria (population, intervention, comparison, outcomes, study design) will be also followed. The population examined will be healthy older adults over 60 years of age and all quantitative, qualitative, and mixed methods study design will be included. Original articles will be also included if written in English, while no restriction criteria will be applied to the country of origin. Instead, reviews, meta-analysis, abstracts, citations, scientific conferences, opinion pieces, books, books reviews, statements, letters, editorials, non-peer reviewed journals articles, and commentaries will be excluded. The research of literature will be performed using PubMed, Web of Science, and Scopus with words related to the topic. From each included study, information previously agreed will be extracted and inserted into a spreadsheet and a narrative synthesis containing summary tables and graphs will describe the articles taken in examination. Furthermore, a meta-analysis will be performed to establish which DT condition has a greater effect following the Hedges and Olkin approach, extension of Glass' method and Cohen's d will be calculated.

DISCUSSION

The present manuscript wants to provide the protocol that will be used in the systematic review and meta-analysis with the intent to inform the researchers and professionals about the dual-task condition effects. Such will lead future investigations in using the most appropriate dual-task condition.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018116597.

Effects of 24-week exergame intervention on physical function under single- and dual-task conditions in fibromyalgia: A randomized controlled trial

OBJECTIVE

To evaluate the effects of 24-week exergame intervention in the physical fitness of women with fibromyalgia in both single- and dual-task conditions.

DESIGN

Single-blinded, randomized controlled trial.

SETTING

University facilities.

PARTICIPANTS

Fifty-five women with fibromyalgia, recruited from the local fibromyalgia association, were randomly assigned to one of the two groups: exercise group and control group.

INTERVENTION

The exercise group completed 24 weeks of supervised and group-based exergame protocol, divided into two sessions of 60 minutes. The intervention was focused on mobility, postural control, upper and lower limbs coordination, aerobic fitness, and strength.

MAIN OUTCOME MEASURES

The strength of the upper limbs was measured using the arm curl test. The mobility skill was assessed through the timed-up and go test, and the flexibility of both upper and lower limbs was measured using the back scratch and the sit and reach tests, respectively.

RESULTS

Fifty participants completed the study. In the single-task condition, exergame intervention led to significantly higher effects in the arm curl test (P = 0.008), sit and reach test (P = 0.033), and timed-up and go test (P = 0.021). Moreover, under dual-task condition, exergames led to significant effects in all the physical fitness tests (arm curl test, timed-up and go test, back scratch test, and sit and reach test) compared to the control group.

CONCLUSIONS

Exergame is an effective tool to improve the physical fitness in women with fibromyalgia under single or dual-task conditions.

Dual-task effects on postural sway during sit-to-stand movement in children with Down syndrome

BACKGROUND

Cognitive and postural tasks require common cognitive mechanisms, resulting in conflicts when both tasks are simultaneously performed. The presence of neuromotor dysfunctions, such as Down syndrome, may impair coordination processes required to perform dual-tasks. The objective of this study was to investigate the dual-task effects on postural sway during sit-to-stand movements in typical children and children with Down syndrome in a cross-sectional study.

METHODS

Twenty six typical children (10.2 ± 2.4 years) and 21 with Down syndrome (10.3 ± 2.3 years) performed sit-to-stand in the following conditions: (1) simple task; (2) dual-task bimanual activity (DT-Bim): sit-to-stand while carrying a tray using both hands; (3) dual-task unimanual dominant activity (DT-Uni-Dom): sit-to-stand while holding a plastic cup simulating water using the dominant hand; (4) dual-task unimanual non-dominant activity (DT-Uni-Nondom): sit-to-stand movement while holding a plastic cup simulating water. For data analysis, sit-to-stand was divided into three phases: preparation (phase 1), rising (phase 2), and stabilisation (phase 3). The following variables were calculated for each phase: anterior-posterior and medial-lateral amplitude of centre-of-pressure displacement, anterior-posterior and medial-lateral velocity of centre-of-pressure sway and area of centre-of-pressure sway.

RESULTS

Children with Down syndrome showed greater sway than typical children in all sit-to-stand phases. Typical children showed greater anterior-posterior amplitude in phase 2 of sit-to-stand during DT-Uni Nondom compared with DT-Uni Dom. Children with Down syndrome during simple task condition showed greater and faster values sway in phases 2 and 3 of sit-to-stand movement than in DT-Bim activity, DT-Uni Dom activity and DT-Uni Nondom activity. During the condition of DT-Bim activity, these children showed lower anterior-posterior velocity of sway in phase 2 than during DT-Uni Dom activity.

CONCLUSIONS

Children with Down syndrome showed greater postural sway during sit-to-stand than typical children. The addition of a concurrent motor task to sit-to-stand impacted postural sway in different intensities and in different ways across groups. Dual-tasks increased body sway in typical children in the DT-Uni Nondom condition compared with dominant one. In children with Down syndrome, dual-tasks decreased body sway, apparently resulting in a postural strategy of stiffness.

A Simple Target Interception Task as Test for Activities of Daily Life Performance in Older Adults

Previous research showed that a simple target interception task reveals differences between younger adults (YA) and older adults (OA) on a large screen under laboratory conditions. Participants intercept downward moving objects while a horizontally moving background creates an illusion of the object moving in the opposite direction of the background. OA are more influenced by this illusory motion than YA. OA seem to be less able to ignore irrelevant sensory information than YA. Since sensory integration relates to the ability to perform Activities of Daily Living (ADL), this interception task can potentially signal ADL issues. Here we investigated whether the results of the target interception task could be replicated using a more portable setup, i.e., a tablet instead of a large touch screen. For YA from the same, homogeneous population, the main effects were replicated although the task was more difficult in the tablet set-up. After establishing the tablet's validity, we analyzed the response patterns of OA that were less fit than the OA in previous research. We identified three different illusion patterns: a (large) illusion effect (indicating over integration), a reverse illusion effect, and no illusion effect. These different patterns are much more nuanced than previously reported for fit OA who only show over integration. We propose that the patterns are caused by differences in the samples of OA (OA in the current sample were older and had lower ADL scores), possibly modulated by increased task difficulty in the tablet setup. We discuss the effects of illusory background motion as a function of ADL scores using a transitional model. The first pattern commences when sensory integration capability starts to decrease, leading to a pattern of over-integration (illusion effect). The second pattern commences when compensatory mechanisms are not sufficient to counteract the effect of the background motion, leading to direction errors in the same direction as the background motion (reverse illusion). The third pattern commences when the task requirements are too high, leading OA to implement a probabilistic strategy by tapping toward the center of the screen.