Psychometric properties of dual-task balance and walking assessments for individuals with neurological conditions: A systematic review

Implicit learning provides advantage over explicit learning for gait-cognitive dual-task interference

Dual-task performance holds significant relevance in real-world scenarios. Implicit learning is a possible approach for improving dual-task performance. Analogy learning, utilizing a single metaphor to convey essential information about motor skills, has emerged as a practical method for fostering implicit learning. However, evidence supporting the effect of implicit learning on gait-cognitive dual-task performance is insufficient. This exploratory study aimed to examine the effects of implicit and explicit learning on dual-task performance in both gait and cognitive tasks. Tandem gait was employed on a treadmill to assess motor function, whereas serial seven subtraction tasks were used to gauge cognitive performance. Thirty healthy community-dwelling older individuals were randomly assigned to implicit or explicit learning groups. Each group learned the tandem gait task according to their individual learning styles. The implicit learning group showed a significant improvement in gait performance under the dual-task condition compared with the explicit learning group. Furthermore, the implicit learning group exhibited improved dual-task interference for both tasks. Our findings suggest that implicit learning may offer greater advantages than explicit learning in acquiring autonomous motor skills. Future research is needed to uncover the mechanisms underlying implicit learning and to harness its potential for gait-cognitive dual-task performance in clinical settings.

Relationship Between Executive Function Subdomains and Postural Balance in Community-Dwelling Older Adults

BACKGROUND

Executive function (EF) deficits are a significant risk factor for falls among older adults (OAs). However, relationship between EF subdomains (shifting, updating, and inhibition), postural balance (PB), and fall risk in healthy OAs, remains poorly understood.

OBJECTIVE

This study aimed to investigate the relationship between EF subdomains (shifting, updating, and inhibition) and PB, and to assess their impact on risk of falls in community-dwelling OAs.

METHODS

A cross-sectional study involving 50 OAs aged over 60 years (average age of 72 years) was conducted. Participants underwent assessments of EF subdomains and PB using validated tests. A correlation analysis was employed to examine the relationships between EF and PB.

RESULTS

The study revealed significant correlations between subdomains and PB. Mental set shifting (r = -.539; p < .001) and inhibition (r = -.395; p = .050) exhibited inverse relationships with PB. Stepwise multiple linear regression showed that Trail Making Test Part B was associated with the PB (R2 = .42, p < .001).

CONCLUSION

These findings highlight the importance of assessing EF subdomains, particularly shifting and inhibition, to identify risk of falls. Trail Making Test Part B largely explains the variability of the PB. Integrating PB assessments and EF training, such as the Mini-BESTest, into routine care can be vital for fall prevention strategies. Significance/Implications: This knowledge underscores the need for cognitive training interventions focusing on shifting and inhibition to enhance PB and potentially reduce falls. Additionally, incorporation of EF assessment tools as Trail Making Test Part B and the Mini-BESTest into routine clinical practice for community-dwelling OAs is recommended to address fall prevention strategies.

Comparing the effects of dual-task training and single-task training on walking, balance and cognitive functions in individuals with Parkinson's disease: A systematic review

BACKGROUND

This systematic review aimed to examine whether dual-task (DT) training was superior to single-task (ST) training in improving DT walking, balance and cognitive functions for individuals with Parkinson's disease (PD).

METHODS

Literature search was performed in the following electronic databases: PubMed, the Cochrane Library, Web of Science, and Metstr covering inception to May 10, 2023. And in order to facilitate comparison across trials, we calculated the effect size (Hedges' g) of gait, balance, cognitive, and other parameters under both ST and DT conditions, using the mean change score and standard deviation (SD) of change score of the experimental and control groups. Randomized controlled trials that examined the effects of DT motor and cognitive training in individuals with Parkinson's disease were included for this systematic review.

RESULTS

A total of 214 participants recruited from six articles (actually five trials) were involved in this review. In terms of walking ability, only double support time and stride time variability showed significant between-group difference (Hedges' g = 0.34, 0.18, respectively). Compared to ST training group, DT training group had a more improvement effect in laboratory balance measurement (Hedges' g = 0.18, 1.25), but no significant improvement in clinical balance measurement. No significant between-group differences were observed, thus its training effect on cognitive function was inconclusive.

CONCLUSIONS

The DT training failed to achieve promising results better than ST training in improving DT walking and balance functions for individuals with PD. Any firm conclusion cannot be drawn at present, due to the limited number of eligible publications. Larger sample size and high-quality studies are needed to investigate the effectiveness of DT training in individuals with PD.

Dual-Task Assessments for Predicting Future Falls in Neurologic Conditions: A Systematic Review

ABSTRACT

This review investigated the ability of dual-task tests to predict falls in people with neurological disorders. Databases were searched to identify prospective cohort studies that analyzed dual-task testing and falls in people with neurological disorders. Reviewers screened studies for eligibility and extracted key information like participant characteristics, intervention details, outcome measures, and significant outcomes. Reviewers assessed methodological quality of eligible studies using the Standard Quality Assessment Criteria. Eighteen studies of strong methodological qualified with 1750 participants were included in the review. Dual-task performances were predictive of future falls in people with Huntington's disease, spinal cord injury, and moderate cognitive impairment, although only one independent study was included for each disability type. In people with stroke, 37% of eligible studies showed dual-task assessments to be predictive of future falls. No dual-task tests predicted prospective falling in people with Alzheimer's or Parkinson's disease. Complex dual tasks seemed to be more predictive of fall risk than simpler dual tasks. Results suggest that disability type, severity of disability, and task complexity play a role in the predictive ability of dual-task assessments and future falling in neurological disorders. Future studies may benefit from using this review to guide the design of effective dual-task assessments and fall interventions.

Post-Stroke Functional Changes: In-Depth Analysis of Clinical Tests and Motor-Cognitive Dual-Tasking Using Wearable Sensors

Clinical tests like Timed Up and Go (TUG) facilitate the assessment of post-stroke mobility, but they lack detailed measures. In this study, 21 stroke survivors and 20 control participants underwent TUG, sit-to-stand (STS), and the 10 Meter Walk Test (10MWT). Tests incorporated single tasks (STs) and motor-cognitive dual-task (DTs) involving reverse counting from 200 in decrements of 10. Eight wearable motion sensors were placed on feet, shanks, thighs, sacrum, and sternum to record kinematic data. These data were analyzed to investigate the effects of stroke and DT conditions on the extracted features across segmented portions of the tests. The findings showed that stroke survivors (SS) took 23% longer for total TUG (p < 0.001), with 31% longer turn time (p = 0.035). TUG time increased by 20% (p < 0.001) from STs to DTs. In DTs, turning time increased by 31% (p = 0.005). Specifically, SS showed 20% lower trunk angular velocity in sit-to-stand (p = 0.003), 21% longer 10-Meter Walk time (p = 0.010), and 18% slower gait speed (p = 0.012). As expected, turning was especially challenging and worsened with divided attention. The outcomes of our study demonstrate the benefits of instrumented clinical tests and DTs in effectively identifying motor deficits post-stroke across sitting, standing, walking, and turning activities, thereby indicating that quantitative motion analysis can optimize rehabilitation procedures.

Cognitive Task Domain Influences Cognitive-Motor Interference during Large-Magnitude Treadmill Stance Perturbations

Reactive balance is postulated to be attentionally demanding, although it has been underexamined in dual-tasking (DT) conditions. Further, DT studies have mainly included only one cognitive task, leaving it unknown how different cognitive domains contribute to reactive balance. This study examined how DT affected reactive responses to large-magnitude perturbations and compared cognitive-motor interference (CMI) between cognitive tasks. A total of 20 young adults aged 18-35 (40% female; 25.6 ± 3.8 y) were exposed to treadmill support surface perturbations alone (single-task (ST)) and while completing four cognitive tasks: Target, Track, Auditory Clock Test (ACT), Letter Number Sequencing (LNS). Three perturbations were delivered over 30 s in each trial. Cognitive tasks were also performed while seated and standing (ST). Compared to ST, post-perturbation MOS was lower when performing Track, and cognitive performance was reduced on the Target task during DT (p < 0.05). There was a larger decline in overall (cognitive + motor) performance from ST for both of the visuomotor tasks compared to the ACT and LNS (p < 0.05). The highest CMI was observed for visuomotor tasks; real-life visuomotor tasks could increase fall risk during daily living, especially for individuals with difficulty attending to more than one task.

Cognitive-motor dual-task interference in Alzheimer's disease, Parkinson's disease, and prodromal neurodegeneration: A scoping review

BACKGROUND

Cognitive-motor interference (CMI) is a common deficit in Alzheimer's (AD) disease and Parkinson's disease (PD) and may have utility in identification of prodromal neurodegeneration. There is lack of consensus regarding measurement of CMI resulting from dual task paradigms.

RESEARCH QUESTION

How are individuals with AD, PD, and prodromal neurodegeneration impacted by CMI as measured by dual-task (DT) performance?

METHODS

A systematic literature search was performed in six datasets using the PRISMA guidelines. Studies were included if they had samples of participants with AD, PD, or prodromal neurodegeneration and reported at least one measure of cognitive-motor DT performance.

RESULTS

4741 articles were screened and 95 included as part of this scoping review. Articles were divided into three non-mutually exclusive groups based on diagnoses, with 26 articles in AD, 56 articles in PD, and 29 articles in prodromal neurodegeneration, and results presented accordingly.

SIGNIFICANCE

Individuals with AD and PD are both impacted by CMI, though the impact is likely different for each disease. We found a robust body of evidence regarding the utility of measures of DT performance in the detection of subtle deficits in prodromal AD and some signals of utility in prodromal PD. There are several key methodological challenges related to DT paradigms for the measurement of CMI in neurodegeneration. Overall, DT paradigms show good potential as a clinical method to probe specific brain regions, networks, and function; however, task selection and effect measurement should be carefully considered.

Profiling cognitive-motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study

BACKGROUND

Performing cognitive-motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown.

OBJECTIVE

To profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level.

METHODS

Secondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (≤ 4, 4.5-5.5, ≥ 6). Spearman correlations were conducted between the DTCmotor with clinical measures. Adjusted significance level was 0.01.

RESULTS

Overall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both p < 0.001), with a DTCmotor of 15.8% and DTCcognitive of 2.7%. All three subgroups walked slower during the DT versus ST, with DTCmotor different from zero (p's < 0.001). Only the EDSS ≥ 6 group had fewer correct answers on the DT versus ST (p < 0.001), but the DTCcognitive did not differ from zero for any of the groups (p ≥ 0.039).

CONCLUSION

Dual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups.

How Reliable and Valid are Dual-Task Cost Metrics? A Meta-analysis of Locomotor-Cognitive Dual-Task Paradigms

OBJECTIVE

To assess the retest reliability, predictive validity, and concurrent validity of locomotor and cognitive dual-task cost (DTC) metrics derived from locomotor-cognitive dual-task paradigms.

DATA SOURCES

A literature search of electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, and Scopus) was conducted on May 29th, 2021, without time restriction.

STUDY SELECTION

For 1559 search results, titles and abstracts were screened by a single reviewer and full text of potentially eligible papers was considered by 2 independent reviewers. 25 studies that evaluated retest reliability, predictive validity, and concurrent validity of locomotor-cognitive DTC in healthy and clinical groups met inclusion criteria.

DATA EXTRACTION

Study quality was assessed using the Consensus-Based Standards for the Selection of Health Measurement Instrument checklist. Data relating to the retest reliability, predictive validity, and concurrent validity of DTC were extracted.

DATA SYNTHESIS

Meta-analysis showed that locomotor DTC metrics (intraclass correlation coefficient [ICC]=0.61, 95% confidence interval [CI; 0.53.0.70]) had better retest reliability than cognitive DTC metrics (ICC=0.27, 95% CI [0.17.0.36]). Larger retest reliability estimates were found for temporal gait outcomes (ICC=0.67-0.72) compared with spatial (ICC=0.34-0.53). Motor DTC metrics showed weak predictive validity for the incidence of future falls (r=0.14, 95% CI [-0.03.0.31]). Motor DTC metrics had weak concurrent validity with other clinical and performance assessments (r=0.11, 95% CI [0.07.0.16]), as did cognitive DTC metrics (r=0.19, 95% CI [0.08.0.30]).

CONCLUSIONS

Gait-related temporal DTC metrics achieve adequate retest reliability, while predictive and concurrent validity of DTC needs to be improved before being used widely in clinical practice and other applied settings. Future research should ensure the reliability and validity of DTC outcomes before being used to assess dual-task interference.

Patient-Reported Outcome Measures for Assessing Dual-Task Performance in Daily Life: A Review of Current Instruments, Use, and Measurement Properties

The patient perspective of dual-task (DT) impairment in real life is unclear. This review aimed (i) to identify patient-reported outcome measures (PROMs) on DT and evaluate their measurement properties and (ii) to investigate the usage of PROMs for the evaluation of DT difficulties. A systematic literature search was conducted using PubMed and Web of Science from inception to March 2022. Methodological quality was evaluated using the COSMIN checklist. Six studies examined the measurement properties of DT PROMs. Nine studies used DT PROMs as the outcome measure. Five PROMs were identified, including the Divided Attention Questionnaire (DAQ), Dual-Task-Impact on Daily-life Activities Questionnaire (DIDA-Q), a Questionnaire by Cock et al. (QOC), Dual-Tasking Questionnaire (DTQ), and Dual-Task Screening-List (DTSL). Fourteen measurement properties were documented: five (35.7%) rated quality as "sufficient", six (42.8%) "insufficient", and three (21.4%) "indeterminate". The quality of evidence for each measurement property ranged from very low to high. While DT performance is investigated in many populations, the use of PROMs is still limited, although five instruments are available. Currently, due to insufficient data, it is not possible to recommend a specific DT PROM in a specific population. An exception is DIDA-Q, which has the highest quality of measurement properties in people with multiple sclerosis.

Comparing the effects of cognitive dual tasking on balance and gait motor performance in people with mild multiple sclerosis and healthy individuals

Background/Aims

People with multiple sclerosis show both cognitive and postural impairment, and various static and dynamic postural activities may be affected under conditions of cognitive distraction. The aim of this study was to determine the effects of cognitive dual tasking on the balance and gait motor performance of people with mild multiple sclerosis (Expanded Disability Status Scale score of 2.0 ± 1.3) and healthy people and to compare these two groups in terms of performing single and dual tasks.

Methods

People with mild multiple sclerosis (n=39) and healthy individuals (n=33) performed static balance tests (Romberg's Test, tandem stance test, single-legged stance test) and dynamic balance tests (Functional Reach Test, Four Square Step Test, Timed Up and Go Test, 10-Metre Walk Test), with and without a word list generation test (single and dual tasks). Independent t-tests were used to evaluate differences between the two groups, and paired t-tests were used for single or dual tasks for all static and dynamic tests. The magnitude of differences in tasks between measures was expressed as Cohen's d.

Results

Dual task effects were more evident during dynamic balance tests in participants with multiple sclerosis and healthy participants (specifically the Timed Up and Go Test and 10-Metre Walk Test) (P<0.001). There was a significant difference between both groups only in terms of static balance (P<0.001).

Conclusions

Dynamic balance and gait were shown to be more affected when performing the dual cognitive task than static balance in people with multiple sclerosis. Dual tasks should be included in diagnoses.

The reliability of gait parameters captured via instrumented walkways: a systematic review and meta-analysis

INTRODUCTION

Electronic pressure-sensitive walkways are commonly available solutions to quantitatively assess gait parameters for clinical and research purposes. Many studies have evaluated their measurement properties in different conditions with variable findings. In order to be informed about the current evidence of their reliability for optimal clinical and scientific decision making, this systematic review provided a quantitative synthesis of the test-retest reliability and minimal detectable change of the captured gait parameters across different test conditions (single and cognitive dual-task conditions) and population groups.

EVIDENCE ACQUISITION

A literature search was conducted in PubMed, Embase, and Scopus until November 2021 to identify articles that examined the test-retest reliability properties of the gait parameters captured by pressure-sensitive walkways (gait speed, cadence, stride length and time, double support time, base of support) in adult healthy individuals or patients. The methodological quality was rated using the Consensus-Based Standards for the Selection of Health Measurement Instruments Checklist. Data were meta-analyzed on intraclass correlation coefficient to examine the test-retest relative reliability. Quantitative synthesis was performed for absolute reliability, examined by the weighted average of minimal detectable change values.

EVIDENCE SYNTHESIS

A total of 44 studies were included in this systematic review. The methodological quality was adequate in half of the included studies. The main finding was that pressure-sensitive walkways are reliable tools for objective assessment of spatial and temporal gait parameters both in single-and cognitive dual-task conditions. Despite few exceptions, the review identified intraclass correlation coefficient higher than 0.75 and minimal detectable change lower than 30%, demonstrating satisfactory relative and absolute reliability in all examined populations (healthy adults, elderly, patients with cognitive impairment, spinocerebellar ataxia type 14, Huntington's disease, multiple sclerosis, Parkinson's disease, rheumatoid arthritis, spinal cord injury, stroke or vestibular dysfunction).

CONCLUSIONS

Current evidence suggested that, despite different populations and testing protocols used in the included studies, the test-retest reliability of the examined gait parameters was acceptable under single and cognitive dual-task conditions. Further high-quality studies with powered sample sizes are needed to examine the reliability findings of the currently understudied and unexplored pathologies and test conditions.

A Novel Way of Measuring Dual-Task Interference: The Reliability and Construct Validity of the Dual-Task Effect Battery in Neurodegenerative Disease

BACKGROUND

Decreased automaticity is common among individuals with neurodegenerative disease and is often assessed using dual-task (DT) paradigms. However, the best methods for assessing performance changes related to DT demands remain inconclusive.

OBJECTIVE

To investigate the reliability and validity of a novel battery of DT measures (DT Effect-Battery (DTE-B)) encompassing three domains: task-specific interference, task prioritization, and automaticity.

METHODS

Data for this retrospective cross-sectional study included 125 participants with Parkinson's disease (PD), 127 participants with Alzheimer's disease (AD), and 84 healthy older adults. Reliability analyses were conducted using a subset of each population. DTE-B measures were calculated from single and DT performance on the Timed Up and Go test and a serial subtraction task. Construct validity was evaluated via associations within the DTE-B and with theoretically supported measures as well as known-groups validity analyses.

RESULTS

Good to excellent reliability was found for DTE-B measures of task interference (motor and cognitive DT effects) (ICCs≥.658) and automaticity (combined DT effect (cDTE)) (ICCs≥.938). Evidence for convergent validity was found with associations within the hypothesized constructs. Known-groups validity analyses revealed differences in the DTE-B among the healthy group and PD and AD groups (ps≤.001), excepting task prioritization (ps≥.061).

CONCLUSIONS

This study provides evidence to support the DTE-B as a reliable measure of multiple constructs pertinent to DT performance. The cDTE demonstrated evidence to support its validity as a measure of automaticity. Further investigation of the utility of the DTE-B in both PD and AD, as well as other populations, is warranted.

Task matters: an investigation on the effect of different secondary tasks on dual-task gait in older adults

Background

Dual-task gait performance declines as humans age, leading to increased fall risk among older adults. It is unclear whether different secondary cognitive tasks mediate age-related decline in dual-task gait. This study aimed to examine how type and difficulty level of the secondary cognitive tasks differentially affect dual-task gait in older adults.

Methods

Twenty young and twenty older adults participated in this single-session study. We employed four different types of secondary tasks and each consisted of two difficulty levels, yielding eight different dual-task conditions. The dual-task conditions included walking and 1) counting backward by 3 s or by 7 s; 2) remembering a 5-item or 7-item lists; 3) responding to a simple or choice reaction time tasks; 4) generating words from single or alternated categories. Gait speed and cognitive task performance under single- and dual-task conditions were used to compute dual-task cost (DTC, %) with a greater DTC indicating a worse performance.

Results

A significant three-way interaction was found for the gait speed DTC (p = .04). Increased difficulty in the reaction time task significantly increased gait speed DTC for older adults (p = .01) but not for young adults (p = .90). In contrast, increased difficulty level in the counting backward task significantly increased gait speed DTC for young adults (p = .03) but not for older adults (p = .85). Both groups responded similarly to the increased task difficulty in the other two tasks.

Conclusions

Older adults demonstrated a different response to dual-task challenges than young adults. Aging might have different impacts on various cognitive domains and result in distinctive dual-task gait interference patterns.

Dual task gait deteriorates gait performance in cervical dystonia patients: a pilot study

Day-to-day walking-related activities frequently involve the simultaneous performance of two or more tasks (i.e., dual task). Dual task ability is influenced by higher order cognitive and cortical control mechanisms. Recently, it has been shown that the concomitant execution of an attention-demanding task affected postural control in subject with cervical dystonia (CD). However, no study has investigated whether dual tasking might deteriorate gait performance in CD patients. To investigate whether adding a concomitant motor and cognitive tasks could affect walking performance in CD subjects.17 CD patients and 19 healthy subjects (HS) participated in this pilot case–control study. Gait performance was evaluated during four walking tasks: usual, fast, cognitive dual task and obstacle negotiation. Spatiotemporal parameters, dual-task cost and coefficients of variability (CV%) were measured by GaitRite^® and were used to detect differences between groups. Balance performance was also assessed with Mini-BEST and Four Step Square tests. In CD participants, correlation analysis was computed between gait parameters and clinical data. Significant differences in complex gait and balance performance were found between groups. CD patients showed lower speed, longer stance time and higher CV% and dual-task cost compared to HS. In CD, altered gait parameters correlated with balance performance and were not associated with clinical features of CD. Our findings suggest that complex walking performance is impaired in patients with CD and that balance and gait deficits might be related

Cognitive-motor dual-task gait training within 3 years after stroke: A randomized controlled trial

Background: Dual-task gait training may improve dual-task gait speed after stroke, but the effects on the relative amount of dual-task interference are unclear.Objective: To compare the efficacy of dual-task gait training (DTGT) and single-task gait training (STGT) on cognitive-motor dual-task interference after stroke.Methods: 36 adults within 3 years of stroke were randomized 1:1 to STGT or DTGT, 3 times a week for 4 weeks. The primary outcomes were the relative dual-task effect on gait speed (DTEg, %) and cognitive task performance (DTEc, %) during walking at preferred and fast speed in two different dual-task conditions (auditory Stroop, auditory clock task).Results: There were no treatment effects on DTEg or DTEc in either group for either dual-task at either walking speed. Across all participants, there were significant improvements in both single and dual-task gait speed in all conditions, without any relative change in the dual-task effect. Subgroup analysis suggested that those with greater interference at baseline may benefit more from DTGT.Conclusions: DTGT and STGT improved single and dual-task gait speed but did not change the amount of relative interference. The findings may be confounded by an unexpectedly small amount of gait-related dual-task interference at baseline.

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.

Foot-Worn Inertial Sensors Are Reliable to Assess Spatiotemporal Gait Parameters in Axial Spondyloarthritis under Single and Dual Task Walking in Axial Spondyloarthritis

The aim of this study was (1) to evaluate the relative and absolute reliability of gait parameters during walking in single- and dual-task conditions in patients with axial spondyloarthritis (axSpA), (2) to evaluate the absolute and relative reliability of dual task effects (DTE) parameters, and (3) to determine the number of trials required to ensure reliable gait assessment, in patients with axSpA. Twenty patients with axSpa performed a 10-m walk test in single- and dual-task conditions, three times for each condition. Spatiotemporal, symmetry, and DTE gait parameters were calculated from foot-worn inertial sensors. The relative reliability (intraclass correlation coefficients-ICC) and absolute reliability (standard error of measurement-SEM and minimum detectable change-MDC) were calculated for these parameters in each condition. Spatiotemporal gait parameters showed good to excellent reliability in both conditions (0.59 < ICC < 0.90). The reliability of symmetry and DTE parameters was low. ICC, SEM, and MDC were better when using the mean of the second and the third trials. Spatiotemporal gait parameters obtained from foot-worn inertial sensors assessed in patients with axSpA in single- and dual-task conditions are reliable. However, symmetry and DTE parameters seem less reliable and need to be interpreted with caution. Finally, better reliability of gait parameters was found when using the mean of the 2nd and the 3rd trials.

Using wearable sensors to characterize gait after spinal cord injury: evaluation of test-retest reliability and construct validity

STUDY DESIGN

Quantitative cross-sectional study.

OBJECTIVES

Evaluate the test-retest reliability and the construct validity of inertial measurement units (IMU) to characterize spatiotemporal gait parameters in individuals with SCI.

SETTING

Two SCI rehabilitation centers in Canada.

METHODS

Eighteen individuals with SCI participated in two evaluation sessions spaced 2 weeks apart. Fifteen able-bodied individuals were also recruited. Participants walked 20 m overground under five conditions that challenged balance to varying degrees. Five IMU were attached to the lower-extremities and the sacrum to collect the mean and the coefficient of variation of five gait parameters (gait cycle time, double-support percentage, cadence, stride length, stride velocity). Intra-class correlation coefficients (ICC) were used to evaluate the test-retest reliability. Linear mixed-effects models were used to compare the five walking conditions to evaluate known-group validity while Spearman's correlation coefficients were used to characterize the level of association between gait parameters and the Mini BESTest (MBT).

RESULTS

Cadence was reliable across all walking conditions. Reliability was higher for the mean (ICC = 0.55-0.98) of the parameters compared to their coefficient of variation (ICC = 0.16-0.97). Cadence collected with IMU had construct validity as their values differed across walking conditions and groups of participants. The coefficient of variation was generally better than the mean to show differences across the five walking conditions. The MBT was moderately to strongly associated with mean cadence (ρ ≥ 0.498) and its coefficient of variation (ρ ≤ -0.49) during most walking conditions.

CONCLUSIONS

IMU provide reliable and valid measurements of gait parameters in ambulatory individuals with SCI.

Minimal Detectable Change in Dual-Task Cost for Older Adults With and Without Cognitive Impairment

BACKGROUND AND PURPOSE

Dual-task (DT) training has become a common intervention for older adults with balance and mobility limitations. Minimal detectable change (MDC) of an outcome measure is used to distinguish true change from measurement error. Few studies reporting on reliability of DT outcomes have reported MDCs. In addition, there has been limited methodological DT research on persons with cognitive impairment (CI), who have relatively more difficulty with DTs than persons without CI. The purpose of this study was to describe test-retest reliability and MDC for dual-task cost (DTC) in older adults with and without CI and for DTs of varying difficulty.

METHODS

Fifty participants 65 years and older attended 2 test sessions within 7 to 19 days. Participants were in a high cognitive group (n = 27) with a Montreal Cognitive Assessment (MoCA) score of 26 or more, or a low cognitive group (n = 23) with a MoCA score of less than 26. During both sessions, we used a pressure-sensing walkway to collect gait data from participants. We calculated motor DTC (the percent decline in motor performance under DT relative to single-task conditions) for 4 DTs: the Timed Up and Go (TUG) while counting forward by ones (TUG1) and counting backward by threes (TUG3); and self-selected walking speed (SSWS) with the same secondary tasks (SSWS1 and SSWS3). Intraclass correlation coefficients (ICCs) and MDCs were calculated for DTC for the time to complete the TUG and spatiotemporal gait variables during SSWS. A 3-way analysis of variance was used to compare differences in mean DTC between groups, tasks, and sessions.

RESULTS AND DISCUSSION

ICCs varied across groups and tasks, ranging from 0.02 to 0.76. MDCs were larger for individuals with low cognition and for DTs involving counting backward by threes. For example, the largest MDC was 503.1% for stride width during SSWS3 for individuals with low cognition, and the smallest MDC was 5.6% for cadence during SSWS1 for individuals with high cognition. Individuals with low cognition demonstrated greater DTC than individuals with high cognition. SSWS3 and TUG3 resulted in greater DTC than SSWS1 and TUG1. There were no differences in DTC between sessions for any variable.

CONCLUSIONS

Our study provides MDCs for DTC that physical therapists may use to assess change in older adults who engage in DT training. Persons with low cognition who are receiving DT training must exhibit greater change in DTC before one can be confident the change is real. Also, greater change must be observed for more challenging DTs. Thus, cognitive level and task difficulty should be considered when measuring change with DT training.

Brain volumes and dual-task performance correlates among individuals with cognitive impairment: a retrospective analysis

Cognitive impairment (CI) is a prevalent condition characterized by loss of brain volume and changes in cognition, motor function, and dual-tasking ability. To examine associations between brain volumes, dual-task performance, and gait and balance in those with CI to elucidate the mechanisms underlying loss of function. We performed a retrospective analysis of medical records of patients with CI and compared brain volumes, dual-task performance, and measures of gait and balance. Greater cognitive and combined dual-task effects (DTE) are associated with smaller brain volumes. In contrast, motor DTE is not associated with distinct pattern of brain volumes. As brain volumes decrease, dual-task performance becomes more motor prioritized. Cognitive DTE is more strongly associated with decreased performance on measures of gait and balance than motor DTE. Decreased gait and balance performance are also associated with increased motor task prioritization. Cognitive DTE appears to be more strongly associated with decreased automaticity and gait and balance ability than motor DTE and should be utilized as a clinical and research outcome measure in this population. The increased motor task prioritization associated with decreased brain volume and function indicates a potential for accommodative strategies to maximize function in those with CI. Counterintuitive correlations between motor brain volumes and motor DTE in our study suggest a complicated interaction between brain pathology and function.

Test-Retest Reliability of Cognitive-Motor Interference Assessments in Walking With Various Task Complexities in Persons With Multiple Sclerosis

Background. Simultaneous execution of motor and cognitive tasks can result in worsened performance on one or both tasks, indicating cognitive-motor interference (CMI). A growing amount of research on CMI in persons with multiple sclerosis (pwMS) is observed. However, psychometric properties of dual-task outcomes have been scarcely reported. Objective. To investigate the between-day test-retest reliability of the motor and cognitive dual-task costs (DTCs) during multiple CMI test conditions with various task complexities in pwMS and matched healthy controls (HCs). Methods. A total of 34 pwMS (Expanded Disability Status Scale score 3.0 ± 0.8) and 31 HCs were tested and retested on 3 single cognitive, 4 single motor, and 12 cognitive-motor dual tasks. Cognitive tasks included serial subtraction by 7, titrated digit span backward, and auditory vigilance. Motor tasks were walking at self-selected speed, over obstacles, crisscross, and while carrying a water-filled cup. Outcome measures were cognitive and motor DTC, calculated as percentage change of dual-task performance compared with single-task performance. Intraclass correlations (ICCs) and Spearman correlation coefficients were calculated as appropriate. Results. For DTCmotor of gait speed, ICCs ranged from 0.45 to 0.81 and Spearman correlations from 0.74 to 0.82. For DTCcognitive, ICCs ranged from −0.18 to 0.49 and Spearman correlations from −0.28 to 0.26. Reliability depended on the type of motor and cognitive task. Conclusion. Reliability of the DTCmotor was, overall, good, whereas that of the DTCcognitive was poor. The “walking” and “cup” dual-task conditions were the most reliable regardless of the integrated cognitive task.

Virtual reality gait training versus non-virtual reality gait training for improving participation in subacute stroke survivors: study protocol of the ViRTAS randomized controlled trial

Background

A stroke often results in gait impairments, activity limitations and restricted participation in daily life. Virtual reality (VR) has shown to be beneficial for improving gait ability after stroke. Previous studies regarding VR focused mainly on improvements in functional outcomes. As participation in daily life is an important goal for rehabilitation after stroke, it is of importance to investigate if VR gait training improves participation. The primary aim of this study is to examine the effect of VR gait training on participation in community-living people after stroke.

Methods/design

The ViRTAS study comprises a single-blinded, randomized controlled trial with two parallel groups. Fifty people between 2 weeks and 6 months after stroke, who experience constraints with walking in daily life, are randomly assigned to the virtual reality gait training (VRT) group or the non-virtual reality gait training (non-VRT) group. Both training interventions consist of 12 30-min sessions in an outpatient rehabilitation clinic during 6 weeks. Assessments are performed at baseline, post intervention and 3 months post intervention. The primary outcome is participation measured with the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P). Secondary outcomes are subjective physical functioning, functional mobility, walking ability, walking activity, fatigue, anxiety and depression, falls efficacy and quality of life.

Discussion

The results of the study provide insight into the effect of VR gait training on participation after stroke.

Trial registration

Netherlands National Trial Register, Identifier NTR6215. Registered on 3 February 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3165-7) contains supplementary material, which is available to authorized users.

Psychometric properties of outcome measures evaluating decline in gait in cerebellar ataxia: A systematic review

Cerebellar ataxia often results in impairment in ambulation secondary to gait pattern dysfunction and compensatory gait adjustments. Pharmaceutical and therapy-based interventions with potential benefit for gait in ataxia are starting to emerge, however evaluation of such interventions is hampered by the lack of outcome measures that are responsive, valid and reliable for measurement of gait decline in cerebellar ataxia. This systematic review aimed for the first time to evaluate the psychometric properties of gait and walking outcomes applicable to individuals with cerebellar ataxia. Only studies evaluating straight walking were included. A comprehensive search of three databases (MEDLINE, CINAHL and EMBASE) identified 53 studies meeting inclusion criteria. Forty-nine were rated as 'poor' as assessed by the COnsensus-based Standards for the selection of health Measurement INstruments checklist. The primary objective of most studies was to explore changes in gait related to ataxia, rather than to examine psychometric properties of outcomes. This resulted in methodologies not specific for psychometric assessment. Thirty-nine studies examined validity, 11 examined responsiveness and 12 measured reliability. Review of the data identified double and single support and swing percentage of the gait cycle, velocity, step length and the Scale for Assessment and Rating of Ataxia (SARA) gait item as the most valid and responsive measures of gait in cerebellar ataxia. However, further evaluation to establish their reliability and applicability for use in clinical trials is clearly warranted. We recommend that inter-session reliability of gait outcomes should be evaluated to ensure changes are reflective of intervention effectiveness in cerebellar ataxia.

Dual-task training effects on motor and cognitive functional abilities in individuals with stroke: a systematic review

Objective:

This systematic review aimed to examine the effects of dual-task balance and mobility training in people with stroke.

Methods:

An extensive electronic databases literature search was conducted using MEDLINE, PubMed, EBSCO, The Cochrane Library, Web of Science, SCOPUS, and Wiley Online Library. Randomized controlled studies that assessed the effects of dual-task training in stroke patients were included for the review (last search in December 2017). The methodological quality was evaluated using the Cochrane Collaboration recommendation, and level of evidence was determined according to the criteria described by the Oxford Center for Evidence-Based Medicine.

Results:

About 13 articles involving 457 participants were included in this systematic review. All had substantial risk of bias and thus provided level IIb evidence only. Dual-task mobility training was found to induce more improvement in single-task walking function (standardized effect size = 0.14–2.24), when compared with single-task mobility training. Its effect on dual-task walking function was not consistent. Cognitive-motor balance training was effective in improving single-task balance function (standardized effect size = 0.27–1.82), but its effect on dual-task balance ability was not studied. The beneficial effect of dual-task training on cognitive function was provided by one study only and thus inconclusive.

Conclusion:

There is some evidence that dual-task training can improve single-task walking and balance function in individuals with stroke. However, any firm recommendation cannot be made due to the weak methodology of the studies reviewed.

Effects of cognitive versus motor dual-task on spatiotemporal gait parameters in healthy controls and multiple sclerosis patients with and without fall history

BACKGROUND

The purpose of the current study was to compare the effects of cognitive or motor tasks on gait performance between healthy controls and multiple sclerosis (MS) patients with and without fall history.

METHODS

The investigation included MS patients with fall history (n = 25) and without fall history (n = 25) and matched healthy controls (n = 25). Participants walked at their preferred speed on a motorized treadmill under three walking conditions in a randomized order: walking only, walking while performing a concurrent cognitive task (counting backward aloud by 3s), and walking while performing a concurrent motor task (carrying a tray with glasses).

RESULTS

The findings showed that in patients with MS, regardless of fall history, spatiotemporal gait parameters were different compared to healthy controls. In contrast to average gait parameters, variability in stride length and stride time could discriminate between MS fallers and non-fallers. Simultaneous performance of cognitive task and walking resulted in higher dual-task costs (DTC) in gait performance compared to the motor dual-task. However, the pattern of change was not different among the three groups. All participants responded to the cognitive task challenges by increasing stride length and decreasing cadence and stride length variability while maintaining cognitive task performance.

CONCLUSIONS

The findings may reflect successful adaptation of locomotor system to preserve cognitive task performance under cognitive dual-task condition. Future studies should examine more complex concurrent cognitive and motor tasks to better understand the dual-task-related gait changes and their contribution to falls in patients with MS.