Dual-task Walking Research Articles

Assessment of gait in patients with fibromyalgia during motor and cognitive dual task walking: a cross-sectional study

BackgroundThe aim of the study was to assess gait pattern of patients diagnosed with fibromyalgia (FM) while performing demanding motor and/or cognitive dual tasks while walking. Further, idea was to explore possible correlations of dual task gait pattern alterations to patients’ functional status and presence or absence of clinical symptoms associated with FM.MethodsTwenty-four female FM patients and 24 healthy female subjects performed a basic walking task, a dual motor, a dual mental (cognitive) and a combined, dual motor and cognitive task simultaneously. Quantitative spatial (stride length) and temporal (cycle time, swing time and double support time) gait parameters were measured using GAITRite walkway system and their variability was assessed. Patients underwent clinical examination including assessment of functional status, pain and fatigue level, psychiatric and cognitive manifestations.ResultsThe motor, cognitive and combined dual tasks affect gait performance in FM patients. Difference in tasks between FM and healthy subjects was found as double support time prolongation. Comparison of tasks showing that cycle time in FM was longer than controls and stride length was shorter in patients for all conditions, while no changes were found in any of the gait parameters variability. Further, mental/cognitive dual tasks had a larger effect than motor tasks. Correlations were also found between depression and functional status of the patients and the gait parameters.ConclusionsGait is affected in FM patients while dual task walking. No changes in stride-to-stride variability point that patients preserve stability in complex walking situations. Analysis of gait may provide additional information for the FM identification based on presence of clinical features and cognitive status. Correlation of dual task gait alterations with occurrence of clinical symptoms and influence of cognitive changes on gait pattern could additionally define FM subgroups.

Mobility Deviations in Adults With Human Immunodeficiency Virus: A Cross-Sectional Assessment Using Gait Analysis, Functional Performance, and Self-Report.

BackgroundLittle is known about how human immunodeficiency virus (HIV) affects walking biomechanics, or about associations between HIV-related gait deviations, functional performance, and self-reported outcomes. This paper reports on (1) gait biomechanics and variability in people with HIV (PWH) and (2) associations with clinical tests, self-reported function, and falls.MethodsA cross-sectional study tested consecutively sampled PWH (n = 50) and HIV-seronegative participants ([SNP] n = 50). Participants underwent 3-dimensional gait analysis, performed clinical tests (short walk and single leg stance tests with and without dual tasking, chair-rise tests, and a physical performance battery), and completed questionnaires about function and falls. Between-group comparisons were done using analysis of covariance. Linear correlations between gait variability, clinical tests, and patient-reported outcomes were established.ResultsPeople with HIV and SNP had comparable median ages (PWH = 36.6, interquartile range [IQR] = 32.0–45.6]; SNP = 31.1, IQR = 23.2–45.1). Compared with SNP, PWH walked slower (adjusted mean difference [MD] = −0.2 meters per second [m/s], 95% confidence interval [CI] = −0.3 to −0.1) with greater variability (adjusted MD = 14.7 variability score points, 95% CI = 9.9–19.5). Moreover, PWH were slower in five-times sit-to-stand (5STS) performance (adjusted MD = 1.9 seconds, 95% CI = 1.00–2.9). Significant deviations in hip kinematics (increased flexion; adjusted MDs = 2.4°–2.8°, P = .012–.016) and knee kinematics (reduced flexion; adjusted MDs = 2.3°–3.7°, P = .007–.027) were found in PWH during dual-task (DT) walking. The PWH’s 5STS moderately correlated with larger gait variability (usual pace r = −0.5; dual task r = −0.6), poorer self-reported mobility (r = 0.4) and self-care function (r = 0.5), and fear of falling (P = .003).ConclusionsPeople with HIV presented with biomechanical deviations suggestive of a slowed and variable gait, especially under cognitive challenges. Five-times STS may be useful to screen for gait deviations in PWH.

EEG beta-modulations reflect age-specific motor resource allocation during dual-task walking

The parallel execution of two motor tasks can lead to performance decrements in either one or both of the tasks. Age-related declines can further magnify the underlying competition for cognitive resources. However, little is known about the neural dynamics underlying motor resource allocation during dual-task walking. To better understand motor resource conflicts, this study investigated sensorimotor brain rhythms in younger and older adults using a dual-task protocol. Time-frequency data from two independent component motor clusters were extracted from electroencephalography data during sitting and walking with an additional task requiring manual responses. Button press-related desynchronization in the alpha and beta frequency range were analyzed for the impact of age (< 35 years, ≥ 70 years) and motor task (sitting, walking). Button press-related desynchronization in the beta band was more pronounced for older participants and both age groups demonstrated less pronounced desynchronizations in both frequency bands during walking compared to sitting. Older participants revealed less power modulations between sitting and walking, and less pronounced changes in beta and alpha suppression were associated with greater slowing in walking speed. Our results indicate age-specific allocations strategies during dual-task walking as well as interdependencies of concurrently performed motor tasks reflected in modulations of sensorimotor rhythms.

An interrater reliability study of gait analysis systems with the dual task paradigm in healthy young and older adults

Background and aimsOne reason for the controversial discussion of whether the dual task (DT) walking paradigm has an added value for diagnosis in clinical conditions might be the use of different gait measurement systems. Therefore, the purpose was 1) to detect DT effects of central gait parameters obtained from five different gait analysis devices in young and old adults, 2) to assess the consistency of the measurement systems, and 3) to determine if the absolut and proportional DT costs (DTC) are greater than the system-measurement error under ST.MethodsTwelve old (72.2 ± 7.9y) and 14 young adults (28.3 ± 6.2y) walked a 14.7-m distance under ST and DT at a self-selected gait velocity. Interrater reliability, precision of the measurement and sensitivity to change were calculated under ST and DT.ResultsAn age effect was observed in almost all gait parameters for the ST condition. For DT only differences for stride length (p < .029, ɳ2p = .239) as well as single and double limb support (p = .036, ɳ2p = .227; p = .034, ɳ2p = .218) remained. The measurement systems showed a lower absolute agreement compared to consistency across all systems.ConclusionsWhen reporting DT effects, the real changes in performance and random measurement errors should always be accounted for. These findings have strong implications for interpreting DT effects.

Quantification of Gait During a Standardized IADL Task

Abstract Date Presented 04/200/21 Current methods to assess functional performance often rely on subjective reporting and are commonly not generalizable. A cross-sectional comparison of standard straight-line gait under a cognitive load and a functional task that included cognitive and visual components was performed using instrumented gait mats. Preliminary results suggest traditional linear dual-task walking may not accurately depict functional gait, highlighting the need for ecologically valid assessments of function. Primary Author and Speaker: Maxwell Toepfer Additional Authors and Speakers: Natalie Robek, Megan Dougherty, and Anna Murray Contributing Authors: Lindy Weaver, Amy Darragh

A template for physical resilience research in older adults: Methods of the PRIME-KNEE study.

Older adults with similar health conditions often experience widely divergent outcomes following health stressors. Variable recovery after a health stressor may be due in part to differences in biological mechanisms at the molecular, cellular, or system level, that are elicited in response to stressors. We describe the PRIME-KNEE study as an example of ongoing research to validate provocative clinical tests and biomarkers that predict resilience to specific health stressors. PRIME-KNEE is an ongoing, prospective cohort study that will enroll 250 adults ≥60 years undergoing total knee arthroplasty. Data are collected at baseline (pre-surgery), during surgery, daily for 7 days after surgery, and at 1, 2, 4, and 6months post-surgery. Provocative tests include a cognition-motor dual-task walking test, cerebrovascular reactivity assessed by functional near-infrared spectroscopy, peripheral blood mononuclear cell reactivity ex vivo to lipopolysaccharide toxin and influenza vaccine, and heart rate variability during surgery. Cognitive, psychological, and physical performance batteries are collected at baseline to estimate prestressor reserve. Demographics, medications, comorbidities, and stressor characteristics are abstracted from the electronic medical record and via participant interview. Blood-based biomarkers are collected at baseline and postoperative day 1. Repeated measures after surgery include items from a delirium assessment tool and pain scales administered daily by telephone for 7 days and cognitive change index (participant and informant), lower extremity activities of daily living, pain scales, and step counts assessed by Garmin actigraphy at 1, 2, 4, and 6months after surgery. Statistical models use these measures to characterize resilience phenotypes and evaluate prestressor clinical indicators associated with poststressor resilience. If PRIME-KNEE validates feasible clinical tests and biomarkers that predict recovery trajectories in older surgical patients, these tools may inform surgical decision-making, guide pre-habilitation efforts, and elucidate mechanisms underlying resilience. This study design could motivate future geriatric research on resilience.

Effects of cognitive workload on heart and locomotor rhythms coupling

Different physiological signals could be coupled under specific conditions, in some cases related to pathologies or reductions in system complexity. Cardiac-locomotor synchronization (CLS) has been one of the most investigating coupling. The influence of a cognitive task on walking was investigated in dual-task experiments, but how different cognitive tasks may influence CLS has poorly been investigated. Twenty healthy subjects performed a dual-task walking (coupled with verbal fluency vs calculation) on a treadmill at three different speeds (comfortable speed CS; fast-speed: CS + 2 km/h; slow-speed: CS-2 km/h) while cardiac and walking rhythms were recorded using surface electrodes and a triaxial accelerometer, respectively.According to previous studies, we found a cognitive-motor interference for which cognitive performance was affected by motor exercise, but not vice-versa. We found a CLS at the baseline condition, at fast speed in both cognitive tasks, while at comfortable speed only for the verbal fluency task.In conclusion, the cardiac and locomotor rhythms were not coupled at slow speed and at comfortable speed during subtraction task. Cognitive performances generally increased at faster speed, when cardiac locomotor coupling was stronger.

Effects of Attentional Control on Gait and Inter-Joint Coordination During Dual-Task Walking.

In the process of walking, attentional resources are flexibly allocated to deal with varying environmental constraints correlated with attentional control (AC). A dual-task paradigm was used to investigate the effects of AC on gait and inter-joint coordination. Fifty students volunteered to participate in this study. Based on the reaction time (RT) in the Stroop task, the top 15 participants were assigned to the High Attentional Control (HAC) group, while the last 15 participants were assigned to the Low Attentional Control (LAC) group. The participants in the two groups were randomly asked to perform three tasks: (i) single 2-back working memory task (ST 2-back); (ii) single walking task (ST walking); and (iii) dual task (DT). Cognitive outcomes and gait spatiotemporal parameters were measured. Continuous relative phase (CRP), derived from phase angles of two adjacent joints, was used to assess inter-joint coordination. The LAC group exhibited significant task effects regarding RT, correct rate (CR), step width, gait cycle, step time, forefoot contact times, heel-forefoot times, hip-knee mean absolute relative phase (MARP), and deviation phase (DP) in the stance and swing phases (p < 0.05). In the HAC group, significant task effects were only detected in RT and foot progression angle of the left foot (p < 0.05). Under the three task conditions, the LAC group exhibited a higher CR in ST, longer heel contact times, and longer heel-forefoot times when compared with the LAC group (p < 0.05). Compared with the LAC group, the HAC group exhibited significantly smaller (closer to zero) MARP and weaker hip-knee DP values in the swing phase across all gait conditions (p < 0.05). In the stance phase, the HAC group had smaller MARP (closer to zero) values when compared with the LAC group (p < 0.05). In conclusion, the ability to maintain gait control and modulate inter-joint coordination patterns in young adults is affected by the level of attentional control in accommodating gait disturbances. AC is correlated with the performance of motor control, which theoretically supports the competitive selection of athletes and fall prevention strategies for a specific population.

Feasibility and effectiveness of interactive stepping exercise on community-dwelling older adults: A pilot randomized controlled trial

Recently, the interactive stepping exercise (ISE) was developed on the basis of square stepping exercise. The aim of this study was to examine the feasibility and effectiveness of ISE on executive function and gait variability among community-dwelling older adults. Fourteen participants were recruited and randomly assigned to the experimental group (n=7) or control group (n=7) and received ISE or home exercise program, respectively, three times a week for 12 weeks. The outcomes included retention rate, attendance rate, Trail Making Test, and dual-task walking. The results showed that participants had high retention and attendance rate for the ISE intervention. Moreover, significant improvement in the part A of Trail Making Test and stride length variability during cognitive dual-task walking after 12-week ISE intervention. The current results suggested that ISE is a feasible and effective intervention on executive function and gait variability in community-dwelling older adults.

Gait Variability and Complexity during Single and Dual-Task Walking on Different Surfaces in Outdoor Environment.

Nowadays, gait assessment in the real life environment is gaining more attention. Therefore, it is desirable to know how some factors, such as surfaces (natural, artificial) or dual-tasking, influence real life gait pattern. The aim of this study was to assess gait variability and gait complexity during single and dual-task walking on different surfaces in an outdoor environment. Twenty-nine healthy young adults aged 23.31 ± 2.26 years (18 females, 11 males) walked at their preferred walking speed on three different surfaces (asphalt, cobbles, grass) in single-task and in two dual-task conditions (manual task—carrying a cup filled with water, cognitive task—subtracting the number 7). A triaxial inertial sensor attached to the lower trunk was used to record trunk acceleration during gait. From 15 strides, sample entropy (SampEn) as an indicator of gait complexity and root mean square (RMS) as an indicator of gait variability were computed. The findings demonstrate that in an outdoor environment, the surfaces significantly impacted only gait variability, not complexity, and that the tasks affected both gait variability and complexity in young healthy adults.

SY2.5. Balance and gait assessment

Postural instability and walking difficulties are the most disabling symptoms in Parkinson disease (PD), leading to falls, physical injuries, functional decline and early institutionalization. Medical, surgical and rehabilitation are the mainstay of management for balance and gait disorders. Evaluation of balance and gait disorders is crucial to determine the problems of the patients so that targeted treatment can be given. Postural instability manifests as reductions in limits of stability, postural adjustment, and postural responses. Gait disorders comprise reduced gait speed, short stride length, freezing of gait, and dual-task deficits. Postural instability and gait disorders can be evaluated using reliable and validated clinical tests, measurement scales, questionnaires and technological equipment. Objective clinical tests and measurement scales require simple equipment and needs a short time to complete the tests. Questionnaires are useful to reflect patients’ perceived balance and gait ability. Technological equipment can be costly but they can increase the measurement sensitivity. The clinical tests used to evaluate postural instability include retropulsion tests, Functional reach test, and one-leg-stance test, whilst those for gait disorders include single or dual-task walk test, timed-up-and-go-test, and 6-minute walk test. Measurement scales including Berg’s balance scale, mini-Balance evaluation system test and Tinetti mobility test, are used to assess overall balance and gait limitations. Most of the measurement scales have cut-off scores for predicting fall risk. Validated questionnaires such as Activities-specific balance confidence scale and Fall efficacy scale evaluate one’s perceived level of balance confidence. Freezing-of-gait questionnaire subjectively assess the severity of freezing of gait. Most of the technological equipment are bulky, laboratory-based and may require a long time to complete the test and/or to analysis the data. Nowadays, body worn sensors is getting more popular because they allow measurement to be taken anywhere including patients’ home and in the community. Algorithm has been built in some systems to shorten the data analyzing time. There are many choices of outcome measures and clinicians/researchers can choose the evaluation methods that is best for their measurement purposes.

CHANGES IN DUAL-TASK GAIT VELOCITY COST FOLLOWING CONCUSSION

Background:Changes in gait velocity have been identified in the literature between concussed and non-concussed individuals. Concussed patients demonstrate slower gait speed; the gait velocity cost has not been evaluated as extensively.Hypothesis:Hypothesis 1: Dual-task gait velocity cost will decrease at time of clearance compared to initial testing.Hypothesis 2: Subjects with a SRC will demonstrate greater decreases in gait velocity costs than those with non-SRC.Hypothesis 3: Symptom severity will be positively correlated to dual-task gait costs within the first 5 days after concussion.Methods:Patients evaluated for concussion in primary care sports medicine clinic within five days of injury were recruited between October 2017 and May 2019. The mechanism of injury was documented and used to classify sport-related (SRC) versus non sport-related (non-SRC) concussion. A standard concussion evaluation was performed at each visit to assess history, symptoms, neurocognitive, neuromuscular and vestibular dysfunction. Dual-task walking trials were incorporated with a cognitive task such as reciting the months of the year in reverse order or spelling words backwards. During the walking trials, gait velocity was measured using an Xsens MVN BIOMCH system (Xsens Technologies BV, Enschede, The Netherlands). A two-way mixed ANOVA with one within-subjects factor (time) and one between-groups factor (mechanism of injury) was used to determine if dual-task gait velocity costs differed over time and between those with a SRC versus those with a non-SRC. A Pearson’s product-moment correlation was used to assess the relationship between symptom severity scores and dual-task gait costs at initial visit.Results:There was no statistically significant interaction between the mechanism of injury and time on gait velocity cost, F(1, 79) = .033, p = .86. The main effect of time showed a statistically significant difference in mean gait velocity cost from initial to clearance, F(1, 79) = 6.19, p = 0.015, generalized η2 = .0.013. There was no main effect of mechanism of injury in mean gait velocity costs, F(1, 79) = 0.800, p = 0.374, generalized η2 = 0.008.There was a statistically significant, small positive correlation between symptom severity and dual-task gait velocity costs, r = .30, p < .007, with symptom severity explaining 9 % of the variation in dual-task gait velocity costs.Conclusion:The gait velocity cost demonstrates a statistically significant change from the time of injury to clearance in concussion patients. A small but significant relationship also exists between symptom severity and gait velocity cost.

Prefrontal cortex activation during dual-task walking in older adults is moderated by thickness of several cortical regions.

Dual tasking, a defined facet of executive control processes, is subserved, in part, by the prefrontal cortex (PFC). Previous functional near-infrared spectroscopy (fNIRS) studies revealed elevated PFC oxygenated hemoglobin (HbO2) under Dual-Task-Walk (DTW) compared to Single-Task Walk (STW) conditions. Based on the concept of neural inefficiency (i.e., greater activation coupled with similar or worse performance), we hypothesized that decreased cortical thickness across multiple brain regions would be associated with greater HbO2 increases from STW to DTW. Participants were 55 healthy community-dwelling older adults, whose cortical thickness was measured via MRI. HbO2 levels in the PFC, measured via fNIRS, were assessed during active walking under STW and DTW conditions. Statistical analyses were adjusted for demographics and behavioral performance. Linear mixed-effects models revealed that the increase in HbO2 from STW to DTW was moderated by cortical thickness in several regions. Specifically, thinner cortex in specific regions of the frontal, parietal, temporal, and occipital lobes, cingulate cortex, and insula was associated with greater increases in HbO2 levels from single to dual-task walking. In conclusion, participants with thinner cortex in regions implicated in higher order control of walking employed greater neural resources, as measured by increased HbO2, in the PFC during DTW, without demonstrating benefits to behavioral performance. To our knowledge, this is the first study to examine cortical thickness as a marker of neural inefficiency during active walking.

Cognitive Reserve Moderates Associations Between Walking Performance Under Single- and Dual-Task Conditions and Incident Mobility Impairment in Older Adults.

Among older adults, walking performance is a reliable indicator of adverse health outcomes including incident mobility impairment. Whereas, attention and executive functions have been implicated in cognitive control of locomotion, much less is known about the role of cognitive reserve (CR) in predicting mobility impairments among older adults. Specifically, whether CR moderates the relationship between gait performance and incident mobility impairment has not been reported. To address this gap in the literature, we examined whether gait performance under single-task walk (STW) and dual-task walk (DTW) conditions predicted incident mobility impairment and whether CR moderated this relationship. Participants were 176 (mean age = 75.57; % female = 53) older adults with baseline Short Physical Performance Battery (SPPB) scores of 10-12. Participants completed neuropsychological testing, the SPPB, and a DTW protocol. CR was evaluated using the Wide Range Achievement Test, third edition. Participants were followed for 3 years; individuals whose SPPB scores declined below 10 were defined as incident cases of mobility impairment (n = 42). Moderation analyses revealed significant interaction effects of CR with walking velocity under STW (b = 0.09, 95% CI [0.01, 0.17], z = 2.30, p = .02) and DTW (b = 0.10, 95% CI [0.02, 0.17], z = 2.55, p = .01) conditions, wherein slower gait predicted increased risk of incident mobility impairment among individuals with lower CR. These findings extend knowledge about the interrelation of cognitive and mobility functions, revealing the critical role of CR in identifying older adults at risk of developing incident mobility impairment.

Golf as a physical activity to improve walking speed and cognition in older adults: A non-randomized, pre-post, pilot study

The aims of this non-randomized, pre-post, pilot investigation (ClinicalTrials.gov NCT03916887) were to assess: 1) feasibility, safety, and adherence of a 10-week golf program for non-golfer older adults, 2) estimated effects of the program on single- (ST) and dual-task (DT) walking, and cognition, and 3) whether findings support development of a randomized controlled trial (RCT).Eligible participants included healthy male and female non-golfers, 60–80 years, who could walk independently, swing a golf club, and received medical clearance. The program, conducted at a golf course, focused on improving physical and cognitive function, as opposed to golf performance. ST and DT walking speeds were assessed on a ProtoKinetics Walkway, and cognitive changes using the California Verbal Learning Test II, and NIH Cognitive Toolbox. Of fifteen screened and enrolled participants, fourteen (7F and 7M, 69.5 ± 6.05 yrs) completed the study. One participant sustained a work-related injury and did not complete the study. Average attendance was 94.3%; there were no golf-related adverse events. Estimated increase in physical activity was 25.5% with small Hedges g effect size (ES). Estimated increases in CVLT II composite score (11.2%) and immediate recall (12.6%), and ST (7.2%) and DT (9.1%) walking speeds occurred with medium-large ES. Increases in NIH card sorting (9.3%) and composite (7.3%) scores had small ES's. In an exit survey, participants reported improved physical function, mental and social well-being, and all planned to continue playing golf. ES estimates suggest 50 participants per group will be required to adequately power (β = 0.8; p < 0.05) a future RCT. The study was funded by the Royal & Ancient Golf Association.

193-OR: Memory Advancement with Intranasal Insulin in Type 2 Diabetes: Randomized Control Trial

Type 2 diabetes mellitus (T2DM) increases the risk of dementia. Intranasal insulin (INI) has emerged as treatment for T2DM-related cognitive impairment. This randomized, doubled blind trial consisted of 24-week treatment with 40 IU of intranasal insulin (Novolin® R) or placebo (sterile saline) once daily and 24-week follow-up period. T2DM and control participants &amp;gt; 50 years old and able to walk for 6 minutes, were enrolled. The primary outcomes were INI effect on cognition and normal and dual task walking. A total of 244 participants (122 women; 65.8 ± 9.1 years old) were randomized in the four groups (57 DM-INI, 58 DM-Placebo, 65 Control-INI, 64 Control-Placebo). Of 223 at baseline, 174 completed treatment (84 DM [70% of planned enrollment] and 90 controls [100%]), and 156 (69 DM) completed the follow-up. In T2DM, INI did not improve cognitive outcomes or depression as compared to placebo. In controls, INI improved verbal learning during on-treatment (p=0.03) and post-treatment (p=0.03) periods (Mixed Models). DM-INI group had faster normal walking at baseline and on-treatment (p&amp;lt;0.05), and dual task walking at baseline, on-treatment and post-treatment (p&amp;lt;0.05), as compared to DM-placebo. In T2DM, INI treatment increased perfusion in medio-prefrontal cortex (n=8) (p&amp;lt;0.001) measured using pseudo-continuous arterial spin labeling on 3T MRI. There were no clinically significant adverse events related to treatment. This was the Phase 2 Trial, thus the research design was not sufficiently powered to determine efficacy. On-INI improvement of normal and dual-task walking of ~ 5cm/s in T2DM participants and improvement of cognitive function in INI-treated controls are clinically significant and warrant further investigation (NCT02415556). Disclosure V. Novak: Advisory Panel; Spouse/Partner; Endonovo Therapeutics, Inc., Consultant; Spouse/Partner; Dysimmune Foundtation, Other Relationship; Spouse/Partner; Oxford University Press. L. Aponte becerra: None. L. H. Ngo: Consultant; Self; Five Islands Consulting, Other Relationship; Self; Radiological Society of America. C. Mantzoros: Advisory Panel; Self; Amgen Inc., GENFIT, Intercept Pharmaceuticals, Inc., Novo Nordisk, Regeneron Pharmaceuticals Inc. P. Novak: Other Relationship; Self; Dysimmune Foundation, Endonovo Therapeutics, Oxford Press. R. Mcglinchey: None. W. Dai: None. V. Lioutas: Consultant; Self; QMetis. S. Buss: Consultant; Self; Kinto Care. C. B. Fortier: None. F. Khan: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK103902); U.S. Food and Drug Administration (IND107690); Novo Nordisk (ISS-001063), Medtronic (NERP15-0310); World Health Organization (UTN-U111-1175-1588)

Dual-task walking and automaticity after Stroke: Insights from a secondary analysis and imaging sub-study of a randomised controlled trial

Objective: To test the extent to which initial walking speed influences dual-task performance after walking intervention, hypothesising that slow walking speed affects automatic gait control, limiting executive resource availability. Design: A secondary analysis of a trial of dual-task (DT) and single-task (ST) walking interventions comparing those with good (walking speed ⩾0.8 m s−1, n = 21) and limited (walking speed <0.79 m s−1, n = 24) capacity at baseline. Setting: Community. Subjects: Adults six-months post stroke with walking impairment. Interventions: Twenty sessions of 30 minutes treadmill walking over 10 weeks with (DT) or without (ST) cognitive distraction. Good and limited groups were formed regardless of intervention received. Main measures: A two-minute walk with (DT) and without (ST) a cognitive distraction assessed walking. fNIRS measured prefrontal cortex activation during treadmill walking with (DT) and without (ST) Stroop and planning tasks and an fMRI sub-study used ankle-dorsiflexion to simulate walking. Results: ST walking improved in both groups (∆baseline: Good = 8.9 ± 13.4 m, limited = 5.3±8.9 m, Group × time = P < 0.151) but only the good walkers improved DT walking (∆baseline: Good = 10.4 ± 13.9 m, limited = 1.3 ± 7.7 m, Group × time = P < 0.025). fNIRS indicated increased ispilesional prefrontal cortex activation during DT walking following intervention (P = 0.021). fMRI revealed greater DT cost activation for limited walkers, and increased resting state connectivity of contralesional M1 with cortical areas associated with conscious gait control at baseline. After the intervention, resting state connectivity between ipsilesional M1 and bilateral superior parietal lobe, involved in integrating sensory and motor signals, increased in the good walkers compared with limited walkers. Conclusion: In individual who walk slowly it may be difficult to improve dual-task walking ability. Registration: ISRCTN50586966

Digital Biomarkers of Cognitive Frailty: The Value of Detailed Gait Assessment Beyond Gait Speed

Background: Cognitive frailty (CF), defined as the simultaneous presence of cognitive impairment and physical frailty, is a clinical symptom in early-stage dementia with promise in assessing the risk of dementia. The purpose of this study was to use wearables to determine the most sensitive digital gait biomarkers to identify CF. Methods: Of 121 older adults (age = 78.9 ± 8.2 years, body mass index = 26.6 ± 5.5 kg/m2) who were evaluated with a comprehensive neurological exam and the Fried frailty criteria, 41 participants (34%) were identified with CF and 80 participants (66%) were identified without CF. Gait performance of participants was assessed under single task (walking without cognitive distraction) and dual task (walking while counting backward from a random number) using a validated wearable platform. Participants walked at habitual speed over a distance of 10 m. A validated algorithm was used to determine steady-state walking. Gait parameters of interest include steady-state gait speed, stride length, gait cycle time, double support, and gait unsteadiness. In addition, speed and stride length were normalized by height. Results: Our results suggest that compared to the group without CF, the CF group had deteriorated gait performances in both single-task and dual-task walking (Cohen’s effect size d = 0.42–0.97, p < 0.050). The largest effect size was observed in normalized dual-task gait speed (d = 0.97, p < 0.001). The use of dual-task gait speed improved the area under the curve (AUC) to distinguish CF cases to 0.76 from 0.73 observed for the single-task gait speed. Adding both single-task and dual-task gait speeds did not noticeably change AUC. However, when additional gait parameters such as gait unsteadiness, stride length, and double support were included in the model, AUC was improved to 0.87. Conclusions: This study suggests that gait performances measured by wearable sensors are potential digital biomarkers of CF among older adults. Dual-task gait and other detailed gait metrics provide value for identifying CF above gait speed alone. Future studies need to examine the potential benefits of gait performances for early diagnosis of CF and/or tracking its severity over time.

The influence of cognitive load on balance control during steady-state walking

For an individual to successfully walk, they must maintain control of their dynamic balance. However, situations that require increased cognitive attention may impair an individual’s ability to actively control their balance. While dual-task studies have analyzed walking-while-talking conditions, few studies have focused specifically on the influence of cognitive load on balance control. The purpose of this study was to assess how individuals prioritize their cognitive resources and control dynamic balance during dual-task conditions of varying difficulty. Young healthy adults (n = 15) performed two single-task conditions (spelling-while-standing and treadmill walking with no cognitive load) and three dual-task conditions (treadmill walking with increasing cognitive load: attentive listening and spelling short and long words backwards). Cognitive performance did not change between the single- and dual-task as measured by spelling percent error and response rate (p = 0.300). Balance control, assessed using the range of whole-body angular momentum, did not change between the no load and listening conditions, but decreased during the short and long spelling conditions (p < 0.001). These results highlight that in young adults balance control decreases during dual-task treadmill walking with increased cognitive loads, but their cognitive performance does not change. The decrease in balance control suggests that participants prioritized cognitive performance over balance control during these dual-task walking conditions. This work offers additional insight into the automaticity of walking and task-prioritization in healthy young individuals and provides the basis for future studies to determine differences in neurologically impaired populations.

The performance of balance exercises during daily tooth brushing is not sufficient to improve balance and muscle strength in healthy older adults

BackgroundHigh prevalence rates have been reported for physical inactivity, mobility limitations, and falls in older adults. Home-based exercise might be an adequate means to increase physical activity by improving health- (i.e., muscle strength) and skill-related components of physical fitness (i.e., balance), particularly in times of restricted physical activity due to pandemics.ObjectiveThe objective of this study was to examine the effects of home-based balance exercises conducted during daily tooth brushing on measures of balance and muscle strength in healthy older adults.MethodsFifty-one older adults were randomly assigned to a balance exercise group (n = 27; age: 65.1 ± 1.1 years) or a passive control group (n = 24; age: 66.2 ± 3.3 years). The intervention group conducted balance exercises over a period of eight weeks twice daily for three minutes each during their daily tooth brushing routine. Pre- and post-intervention, tests were included for the assessment of static steady-state balance (i.e., Romberg test), dynamic steady-state balance (i.e., 10-m single and dual-task walk test using a cognitive and motor interference task), proactive balance (i.e., Timed-Up-and-Go Test [TUG], Functional-Reach-Test [FRT]), and muscle strength (i.e., Chair-Rise-Test [CRT]).ResultsIrrespective of group, the statistical analysis revealed significant main effects for time (pre vs. post) for dual-task gait speed (p < .001, 1.12 ≤ d ≤ 2.65), TUG (p < .001, d = 1.17), FRT (p = .002, d = 0.92), and CRT (p = .002, d = 0.94) but not for single-task gait speed and for the Romberg-Test. No significant group × time interactions were found for any of the investigated variables.ConclusionsThe applied lifestyle balance training program conducted twice daily during tooth brushing routines appears not to be sufficient in terms of exercise dosage and difficulty level to enhance balance and muscle strength in healthy adults aged 60–72 years. Consequently, structured balance training programs using higher exercise dosages and/or more difficult balance tasks are recommended for older adults to improve balance and muscle strength.