Motor Dual-task Research Articles

Feasibility and potential cognitive impact of a cognitive-motor dual-task training program using a custom exergame in older adults: A pilot study.

Dual-task training may be relevant and efficient in the context of active aging. An issue in training programs lies in enhancing the adherence of participants. This can potentially be improved using games as support. We designed and developed a custom interactive exergame in this way. The objective of this pilot study was to explore the potential use of this exergame and the feasibility of our intervention, including the level of safety and adherence. The result's trends on cognitive and motor capacities, as well as on the level of motivation for physical activity, fear of falling, and quality of life of participants, were also explored. Older adults aged 65 years or older were recruited and realized 30 min of supervised training in groups of 4, 2-3 times a week for 12 weeks. Exercises consisted of incorporated cognitive and motor dual tasks, with an increased difficulty over the weeks. Our program's safety, engagement, attendance, and completion levels were evaluated. Participants' postural control in single-task and dual-task conditions, as well as their performances in mental inhibition, flexibility, working memory, mobility, and postural control, and their levels of motivation for physical activity, fear of falling, and quality of life were also assessed. We realized a per protocol statistical analysis with a p-value set at 0.05. Thirty-nine participants (aged 84.6 ± 8.5 years) were recruited. No adverse events, and 89% adherence, 88% attendance, and 87% completion rates were observed. A potentially significant effect of our exergame on working memory in single-task conditions and on the cognitive aspect of dual-task conditions was also observed. We observed no differences in other parameters. Our exergame seemed feasible and safe and was enjoyed by participants, mainly due to the gamification of our training program. Moreover, our exergame may be efficient for cognitive training in older adults, as well as for the maintenance of motor functions, motivation for physical activity, fear of falling, and quality of life levels. This constitutes the first step for our solution with interesting results that need to be further studied.

Dual-Task Upper Extremity Motor Performance Measured by Video Processing as Cognitive-Motor Markers for Older Adults

Introduction: The use of dual-task model such as dual-task gait has been extensively studied to assess cognitive-motor performance among older adults. However, space restriction and safety factor limit its applications in remote assessment. To address the gap, we propose a video processing-based approach to remotely quantify cognitive-motor performance using a 20-s repetitive elbow flexion-extension test with dual-task condition, called video-based motoric-cognitive meter (MCM). Methods: Eighteen older participants (age: 78.6 ± 6.5 years) who were clinically diagnosed as having either mild cognitive impairment or dementia were included in this study. Participants were asked to perform 20-s repetitive elbow flexion-extension exercise with a memory exercise by counting backward from a two-digit number. During the test, all movements of the forearm were recorded by a video camera. As a comparator, a validated wrist-worn sensor was used, which allowed quantifying upper extremity kinematics. Results: The results showed a good agreement (r ≥ 0.530 and ICC2,1 ≥ 0.681) between the derived dual-task upper extremity motor performance from the proposed video-based MCM and a clinically validated sensor-based MCM. We also observed moderate correlations (r ≥ 0.496) between some measures of video-based MCM (flexion time, extension time, and flexion-extension time) and clinical cognitive scale (Mini-Mental State Examination [MMSE]). Additionally, some measures of dual-task upper extremity motor performance (speed, flexion time, extension time, and flexion-extension time) were associated with dual-task gait speed (r ≥ 0.557), which has been found to be correlated with cognitive impairment. Lastly, the selected dual-task motor performance metric (flexion time) was sensitive to predict MMSE scores in linear regression analyses with statistical significance (adjusted R2 = 0.306, p = 0.025). Conclusion: This study proposes a video processing-based approach to analyze dual-task upper extremity motor performance from a simple and convenient upper extremity function test. The results indicate concurrent validity of the proposed video-based MCM compared with the sensor-based MCM, and associations between dual-task upper extremity motor performance and clinically validated cognitive markers (MMSE scores and dual-task gait). Future studies are warranted to explore sensitivity of this solution to promote remote assessment of cognitive-motor performance among older adults in telehealth applications.

Effects of Motor Task Difficulty on Postural Control Complexity during Dual Tasks in Young Adults: A Nonlinear Approach.

Few studies have evaluated the effect of a secondary motor task on the standing posture based on nonlinear analysis. However, it is helpful to extract information related to the complexity, stability, and adaptability to the environment of the human postural system. This study aimed to analyze the effect of two motor tasks with different difficulty levels in motor performance complexity on the static standing posture in healthy young adults. Thirty-five healthy participants (23.08 ± 3.92 years) performed a postural single task (ST: keep a quiet standing posture) and two motor dual tasks (DT). i.e., mot-DT(A)-perform the ST while performing simultaneously an easy motor task (taking a smartphone out of a bag, bringing it to the ear, and putting it back in the bag)-and mot-DT(T)-perform the ST while performing a concurrent difficult motor task (typing on the smartphone keyboard). The approximate entropy (ApEn), Lyapunov exponent (LyE), correlation dimension (CoDim), and fractal dimension (detrending fluctuation analysis, DFA) for the mediolateral (ML) and anterior-posterior (AP) center-of-pressure (CoP) displacement were measured with a force plate while performing the tasks. A significant difference was found between the two motor dual tasks in ApEn, DFA, and CoDim-AP (p < 0.05). For the ML CoP direction, all nonlinear variables in the study were significantly different (p < 0.05) between ST and mot-DT(T), showing impairment in postural control during mot-DT(T) compared to ST. Differences were found across ST and mot-DT(A) in ApEn-AP and DFA (p < 0.05). The mot-DT(T) was associated with less effectiveness in postural control, a lower number of degrees of freedom, less complexity and adaptability of the dynamic system than the postural single task and the mot-DT(A).

Cognitive and motor performances in dual tasks in older adults with chronic neck pain: A randomized controlled clinical trial

Aim: There is limited information on dual-task performance in older individuals with chronic neck pain. This study aims to investigate cognitive and motor performances during dual tasks in older adults with chronic neck pain. Methods: Thirty-five older adults with chronic neck pain and 35 older adults without neck pain were included in the study. The timed up and go test evaluated individuals’ single-task performance. To assess the dual-task performances of the groups, the individuals were given motor and cognitive (forward and backward digit span) tasks simultaneously with the timed up and go test. During cognitive dual-task, the cognitive performances of individuals were evaluated and the duration of their timed up and go test was recorded. Results: There was no difference between the groups in terms of single-task timed up and go test (p >0.05). There was also no difference between the groups in terms of cognitive-forward and cognitive-backward (p >0.05). However, cognitive performance of the chronic neck pain group during dual-task was worse than that of the control group (p <0.05). Additionally, the motor dual-task of older adults in the chronic neck pain group was worse than the control group (p <0.05). Conclusion: Older adults with chronic neck pain struggle more in motor dual-task situations than asymptomatic older adults. Therefore, gait assessment with a motor dual task should be performed for older adults with chronic neck pain. In addition, during cognitive dual-task conditions, the cognitive performance of older adults should be evaluated in addition to their gait performance. Keywords: Aged; Gait; Neck Pain; Postural Balance; Task Performance and Analysis.

Functional Mobility and postural balance in older adults with Alzheimer's disease: comparative study between mild and moderate stages

Objective: This study aimed to compare the functional mobility and postural balance of older adults among smild and moderate stages of Alzheimer's disease using the Timed Up and Go test (TUGT) and the Clinical Test of Sensory Interaction and Balance (CTSIB). Methodology: Forty elderly people were divided into two groups according to the mild (CDR1; n = 26) and moderate (CDR2; n = 14) stages of the disease. The Clinical Dementia Rating Scale (CDR) was used for staging the disease, which allows classifying the different degrees of dementia, assessing cognition and behavior. The scale allows classification into CDR 0 (normal or no alteration); 0.5 (questionable or mild cognitive impairment); 1 (mild dementia); 2 (moderate dementia) and 3 (severe dementia). In this study, only subjects classified as CDR 1 or CDR 2 were included. For the assessment of functional mobility, the Timed Up and Go Test (TUGT) was used in the conditions of single task, dual cognitive task and dual motor task, and the Clinical Test of Sensory (CTSIB) to assess postural balance. Data were compared between groups. Results: Performance on the TUGT single task, cognitive dual task, and motor dual task was significantly worse in the CDR2 group compared to the CDR1 group (p < 0.05). The CTSIB was not significantly different between the groups in the four conditions. Conclusion: Functional mobility during tasks involving cognition differs between older adults with mild and moderate dementia, and this commitment is more accentuated in dual-task situations. Postural balance did not differ between the stages of the disease.

Structural and functional magnetic resonance imaging correlates of fatigue and dual-task performance in progressive multiple sclerosis.

Frontal cortico-subcortical dysfunction may contribute to fatigue and dual-task impairment of walking and cognition in progressive multiple sclerosis (PMS). To explore the associations among fatigue, dual-task performance and structural and functional abnormalities of frontal cortico-subcortical network in PMS. Brain 3T structural and functional MRI sequences, Modified Fatigue Impact Scale (MFIS), dual-task motor and cognitive performances were obtained from 57 PMS patients and 10 healthy controls (HC). The associations of thalamic, caudate nucleus and dorsolateral prefrontal cortex (DLPFC) atrophy, microstructural abnormalities of their connections and their resting state effective connectivity (RS-EC) with fatigue and dual-task performance were investigated using random forest. Thirty-seven PMS patients were fatigued (F) (MFIS ≥ 38). Compared to HC, non-fatigued (nF) and F-PMS patients had significantly worse dual-task performance (p ≤ 0.002). Predictors of fatigue (out-of-bag [OOB]-accuracy = 0.754) and its severity (OOB-R2 = 0.247) were higher Expanded Disability Status scale (EDSS) score, lower RS-EC from left-caudate nucleus to left-DLPFC, lower fractional anisotropy between left-caudate nucleus and left-thalamus, higher mean diffusivity between right-caudate nucleus and right-thalamus, and longer disease duration. Microstructural abnormalities in connections among thalami, caudate nuclei and DLPFC, mainly left-lateralized in nF-PMS and more bilateral in F-PMS, higher RS-EC from left-DLPFC to right-DLPFC in nF-PMS and lower RS-EC from left-caudate nucleus to left-DLPFC in F-PMS, higher EDSS score, higher WM lesion volume, and lower cortical volume predicted worse dual-task performances (OOB-R2 from 0.426 to 0.530). In PMS, structural and functional frontal cortico-subcortical abnormalities contribute to fatigue and worse dual-task performance, with different patterns according to the presence of fatigue.

POSTURAL CONTROL DURING MOTOR DUAL-TASK IN YOUNG ADULTS WITH DIFFERENT LEVELS OF PHYSICAL ACTIVITY

Introduction: Center of pressure (CoP) is an objective measure to assess postural control. A higher displacement of the CoP position can express a decline in postural control. Previous studies have demonstrated that a sedentary lifestyle affects balance negatively and increases the risk of falling. In addition, most activities of daily living involve performing two or more tasks concurrently. Thus, while performing a dual or multi-tasks, it is essential to maintain an adequate postural control to prevent the risk of falls and injuries. Objective: The main goal of this study was to compare the center of pressure displacement between healthy young adults with different levels of physical activity during motor dual-task performance. Method: After checking eligibility criteria, 35 healthy young adults (23.09 ± 3.97 years, mean ± SD) were recruited to perform a motor dual-task: maintaining quiet upright standing posture while performing a concurrent motor task – answer the smartphone, during 60 s. The total excursion of the center of pressure (TOTEX_CoP), the displacement anterior-posterior (CoP-AP), and medial-lateral (CoP-ML) of the center of pressure were recorded by Bertec® force plate, and the data was assessed with a Matlab routine. To analyze center of pressure excursions in different levels of physical activity, the International Physical Activity Questionnaire (IPAQ) – short version was used to assess physical activity levels. Then, the participants were divided into three groups: sedentary (n=5), minimally active (n=13), and highly active (n=17). Statistical analyses were performed using IBM-SPSS (version 25.0). To compare center of pressure displacement between different levels of physical activity during motor dual-task was used the Kruskal-Wallis test. The significance level was set at p < 0.05, and the data were shown as the median and interquartile range (IQR). Results: A tendency for a higher total displacement of the center of pressure was observed in the sedentary group (TOTEX_CoP: 3110.67 (2466.54-3908.73) mm) compared to the physically active groups (minimally active - TOTEX_CoP: 2600.75 (2500.34-3205.97) mm; highly active - TOTEX_CoP: 2712.99 (2499.01-3275.84) mm), but differences were not statistically significant between the three groups (p > 0.05). The same happened in the anteroposterior and mediolateral center of pressure displacement (p > 0.05). Conclusions: Physically active young adults did not present less postural oscillation than sedentary young adults during motor dual-task performance. The small sample in each physical activity group could have contributed to the lack of statistical significance. Therefore, we suggest more studies that assess the influence of the level of physical activity on postural control.

Cognitive benefits of using non-invasive compared to implantable neural feedback

A non-optimal prosthesis integration into an amputee’s body schema suggests some important functional and health consequences after lower limb amputation. These include low perception of a prosthesis as a part of the body, experiencing it as heavier than the natural limb, and cognitively exhausting use for users. Invasive approaches, exploiting the surgical implantation of electrodes in residual nerves, improved prosthesis integration by restoring natural and somatotopic sensory feedback in transfemoral amputees. A non-invasive alternative that avoids surgery would reduce costs and shorten certification time, significantly increasing the adoption of such systems. To explore this possibility, we compared results from a non-invasive, electro-cutaneous stimulation system to outcomes observed with the use of implants in above the knee amputees. This non-invasive solution was tested in transfemoral amputees through evaluation of their ability to perceive and recognize touch intensity and locations, or movements of a prosthesis, and its cognitive integration (through dual task performance and perceived prosthesis weight). While this managed to evoke the perception of different locations on the artificial foot, and closures of the leg, it was less performant than invasive solutions. Non-invasive stimulation induced similar improvements in dual motor and cognitive tasks compared to neural feedback. On the other hand, results demonstrate that remapped, evoked sensations are less informative and intuitive than the neural evoked somatotopic sensations. The device therefore fails to improve prosthesis embodiment together with its associated weight perception. This preliminary evaluation meaningfully highlights the drawbacks of non-invasive systems, but also demonstrates benefits when performing multiple tasks at once. Importantly, the improved dual task performance is consistent with invasive devices, taking steps towards the expedited development of a certified device for widespread use.

The effects of Baduanjin exercise vs. brisk walking on physical fitness and cognition in middle-aged patients with schizophrenia: A randomized controlled trial.

ObjectivePatients with schizophrenia have deficits in physical and cognitive function that may become salient in their middle ages. These deficits need active intervention to prevent functional decline. Baduanjin and brisk walking show promise as interventions in patients with schizophrenia. This study investigated the effects of Baduanjin exercise vs. brisk walking in middle-aged patients with schizophrenia.MethodsIn this single-blind, 2-arm, parallel, randomized controlled trial, 48 participants aged older than 40 years were enrolled and assigned to the intervention group (Baduanjin) or the control group (brisk walking). The training of both groups took place twice a week, 60 min per session, for 12 weeks. The participants were evaluated with physical, cognitive, and functional outcomes at baseline, postintervention, and 4 weeks after the intervention.ResultsThe results of the study demonstrated significant time effects in walking distance (p = 0.035, η2 = 0.094) and lower extremity strength (p = 0.006, η2 = 0.152). Post-hoc analysis revealed both groups had significant improvement in changes from baseline to the postintervention assessment (ps < 0.05) and follow-up (ps < 0.05). The results demonstrated a significant group-by-time interaction in change scores of global cognition (F = 7.01, p = 0.011, η2 = 0.133). Post-hoc analysis revealed a significant improvement in the Baduanjin group from baseline to postintervention (p = 0.021), but the improvements were not maintained at the follow-up assessment (p = 0.070). The results also demonstrated significant group effects in balance function (p < 0.001, η2 = 0.283), motor dual-task performance (p = 0.026, η2 = 0.103), and cognitive dual-task performance (p < 0.001, η2 = 0.307). Post-hoc analysis revealed that the Baduanjin group improved more than the brisk walking group in the above outcomes (ps < 0.05).ConclusionThis study demonstrated the differential effects of Baduanjin exercise and brisk walking in middle-aged patients with schizophrenia. Baduanjin might be a beneficial regimen for improving physical and cognitive function in this population. Further research with a larger sample is warranted.Clinical trial registration[ClinicalTrials.gov], identifier [202000817B0C602].

Throwing Strategy in a Dual-Motor-Task of Aiming at the Bullseye While Walking in Virtual Reality

Humans perform movement tasks using motor and cognitive skills. The optimum outcome of the task is dependent on how the motor and cognitive skills are combined. When a dual-task is performed, this combination becomes even more important as the user has to devote limited available attention to the competing tasks. In this study, a ball throwing task to a specified location was performed in a virtual environment while the participant walked on a treadmill performing a dual-motor-task. Fifteen healthy participants took part in the study. The task paradigm involved three conditions-warm-up treadmill walking, throwing a ball to the target while standing, and throwing a ball to the target while walking on a treadmill. The throwing strategy was investigated with quantifiable task-space performance and scoring in the game. The correlation between the task-space performance and the cognitive tests was evaluated in the single and the dual-motor-task. Results demonstrate that during the throwing activity in the single and the dual-motor tasks, the choice of orienting the throwing plane in space was pre-determined prior to releasing the ball in a projectile motion and was interconnected with the motor ability. However, in dual-tasking, once the throwing plane was selected, the variation of hit point localization in the target plane was correlated with the cognitive ability. The task was executed with an allocation of motor and cognitive abilities to control specific performance variables while dual-tasking. This strategy potentially helped participants to reduce the load on attentional capacity during dual-tasking. This study showcases an optimized utilization of skill interaction to achieve the overall task objective. The paradigm designed in this work can be utilized to improve specific motor and cognitive skills by performing only one dual-motor-task.

Contributions of open-loop and closed-loop control in a continuous tracking task differ depending on attentional demands during practice.

Improving tracking performance requires numerous adjustments in the motor system, including peripheral muscle functions and central motor commands. These commands can rely on sensory feedback processing during tracking, i.e., closed-loop control. In the case of repeated tracking sequences, these commands can rely on an inner representation of the target trajectory to optimize pre-planning, i.e., open-loop control. Implicit learning in a continuous tracking task with repeated sequences proves the availability of an inner target representation, which emerges by learning task regularities, even without explicit knowledge. We hypothesize that the actual use of open-loop or closed-loop control is influenced by the demand for attention. Specifically, we suggest that closed-loop control and its development during practice need attentional resources, whereas open-loop control can work and evolve in a more automatic way without attentional demands. To test this, we investigated motor-control strategies when extensively practicing a continuous compensatory force-tracking task using isometric leg muscle activation, either as a single-motor task or as a motor-cognitive dual task. After training, we found evidence for predominantly closed-loop control in the single-task training group and for open-loop control in the dual-task training group. In particular, we ascertained dual-task motor costs and a weakly developed implicit knowledge of task regularities in the single-task training group. In contrast, in the dual-task training group dual-task motor costs disappeared, while implicit learning was clearly observed. We conclude that motor-cognitive dual-task training may boost implicit motor learning, without necessarily impeding concurrent improvement in the cognitive task. Data repository: reserved doi: https://doi.org/10.5281/zenodo.6759377.

Dual-task cost of the Enhanced Gait Variability Index in community-dwelling older adults

BackgroundGait variability is associated with brain abnormalities, falls, and disability in older adults. The Enhanced Gait Variability Index (EGVI), a composite measure of gait variability, offers advantages over traditional measures of variability for individual spatiotemporal parameters (STPs). Gait assessment under complex conditions may reveal additional information about performance and provide insight into potential abnormalities. The EGVI has not been investigated in older adults while performing a concurrent motor task. Research questionTo examine dual-task cost of the EGVI and STPs in a sample of community-dwelling older adults. MethodsThirty-eight community-dwelling older adults (mean age = 72.5 years) walked at self-selected speeds on an instrumented walkway under a single-task (ST) and a motor dual-task (DT) condition. Descriptive statistics were calculated for the EGVI, STPs included in the EGVI, and several other common STPs (cadence, stride width, percent double-support). Wilcoxon signed-rank tests assessed differences in each gait variable between conditions. Dual-task cost (DTC) was calculated for each gait variable. ResultsGoing from ST to DT walking, EGVI scores increased significantly (104.5 ± 8.4 to 125.1 ± 10.8, p < .001). Participants also increased double-support (p < .001) and stance time (p < .01), while decreasing stride velocity (p < .001), step length (p < .001), and single-support time (p < .05). Significant changes were not observed for cadence, stride width, or step time. Stride velocity and EGVI showed the greatest DTC. SignificanceWhen confronted with a concurrent motor dual-task, older adults responded by increasing their EGVI and altering several STPs. The EGVI is a single composite measure that may have utility under ST and DT conditions to enhance understanding of gait variability in older adults. Further research should examine if DTC of EGVI scores predict meaningful constructs such as falls, participation, and self-rated health in older adults.

Abnormal neural oscillations during gait and dual-task in Parkinson's disease.

Gait dysfunctions are debilitating motor symptoms of Parkinson’s disease (PD) and may result in frequent falling with health complications. The contribution of the motor-cognitive network to gait disturbance can be studied more thoroughly by challenging motor-cognitive dual-task gait performances. Gait is a complex motor task that requires an appropriate contribution from motor and cognitive networks, reflected in frequency modulations among several cortical and subcortical networks. Electrophysiological recordings by scalp electroencephalography and implanted deep brain stimulation (DBS) electrodes have unveiled modulations of specific oscillatory patterns in the cortical-subcortical circuits in PD. In this review, we summarize oscillatory contributions of the cortical, basal ganglia, mesencephalic locomotor, and cerebellar regions during gait and dual-task activities in PD. We detail the involvement of the cognitive network in dual-task settings and compare how abnormal oscillations in the specific frequency bands in the cortical and subcortical regions correlate with gait deficits in PD, particularly freezing of gait (FOG). We suggest that altered neural oscillations in different frequencies can cause derangements in broader brain networks, so neuromodulation and pharmacological therapies should be considered to normalize those network oscillations to improve challenged gait and dual-task motor functions in PD. Specifically, the theta and beta bands in premotor cortical areas, subthalamic nucleus, as well as alpha band activity in the brainstem prepontine nucleus, modulate under clinically effective levodopa and DBS therapies, improving gait and dual-task performance in PD with FOG, compared to PD without FOG and age-matched healthy control groups.

Effects of cognitive- and motor-dual tasks on postural control regularity following anterior cruciate ligament reconstruction

Effects of cognitive- and motor-dual tasks on postural control regularity following anterior cruciate ligament reconstruction

Comparative Effects of Motor and Cognitive Dual- Task Gait Training on balance and mobility in persons with Intellectual Disabilities

Background: Dual tasks fall into two main groups: motor dual tasks, which require performance of a motor task and a postural control task at the same time; and cognition dual task that require performance of a cognition task and postural control task at the same time. Aim: To focus on comparative effects of motor and cognitive dual-task gait training on balance and mobility in persons with intellectual disabilities Methodology: A randomized clinical trial was conducted on 52 subjects (n=26) in a District Headquarter Hospital, Mirpur AJK. Fifty-two patients were randomly allocated in two groups as Group A received motor dual task and Group B received cognitive dual task training. Total duration of study was three weeks and assessment done before treatment and after every week. Rancho Los Amigos Cognitive Functional Scale (RLACF), Berg Balance Scale (BBS), Walking While Talking Test (WWT) and Stair Climb Test (SCT) for the assessment of the patient’s improvement in skills, balance and mobility. Results: The results of the study concluded that Rancho Los Amigos Cognitive Function Scale, Berg Balance Scale, Walking While Talking Test and Stair Climb Test scores were improved in both groups significantly. But on comparison; Cognitive dual task training significantly produce better results in improving the balance and mobility in the person with intellectual disability as compared to Motor dual task training with p value&lt;0.005. Conclusion: The study concluded that Cognitive dual task training is statistically and clinically more significant in improving the balance and mobility in the intellectual disable persons as compared to Motor dual task training. Key words: Cognitive dual task, Intellectual disabilities, Motor and cognitive dual-task gait training.

The Relationship Between Dual-Task Performance and Functional Independence in Stroke Patients

Purpose: Dual-task performance have a role in independent motor functions such as gait and balance. Although walking and balance parameters are important in functional independence, the level of independence is a complex condition affected by many factors. The aim of this cross-sectional study is to investigate the relationship between dual-task performance and functional independence levels in stroke patients.&#x0D; Material and Methods: 26 hemiplegic patients were included in this research in a tertiary healthcare institution. The participants’ independence levels were evaluated by the functional independence mesasure(FIM). Single task performance, motor dual-task performance, and cognitive dual-task performance were evaluated by calculating walking time in a 10-meter walking test. The relationship between dual-task interference and functional independence level was examined by Spearman correlation analysis.&#x0D; Results: The motor dual-task interference was found as 0.7 (0.0-0.26) and the cognitive dual-task interference was found as 0.19 (0.05-0.38). There was a negative, moderate, and statistically significant correlation between the FIM score and the motor dual-task interference (r = -0.48, p = 0.01). However, no significant correlation was detected between FIM score and cognitive dual-task interference (p = 0.16).&#x0D; Conclusion: The level of functional independence in stroke patients is associated with motor dual-task interference. Rehabilitation programs that improve dual-task performance can increase the functional independence levels of stroke patients.

Standing Posture in Motor and Cognitive Dual-Tasks during Smartphone Use: Linear and Nonlinear Analysis of Postural Control.

Analysis of the center of pressure (CoP) during cognitive or motor dual-tasking is widely used to characterize postural control. Most studies use traditional measures of CoP to quantify postural control, but given its complexity, nonlinear analysis of CoP is of growing interest in the area. This study aims to analyze CoP behavior in healthy young adults during standing posture performance while simultaneously performing motor or cognitive tasks on a smartphone, using linear and nonlinear analysis of CoP. Thirty-six healthy participants (23.08 ± 3.92 years) were found eligible for this study. They performed a single task (ST), cognitive dual-task (cog-DT), and motor dual-task (mot-DT). The total excursion of CoP, displacement of CoP in the anterior-posterior and medial-lateral directions, mean total velocity of CoP, and mean anterior-posterior and medial-lateral velocities of CoP were measured with a force plate. Approximate entropy (ApEn) of the anterior-posterior (ApEn-AP) and medial-lateral (ApEn-ML) displacement of CoP were also calculated. The results showed that dual-task costs for the total excursion, displacement in the anterior-posterior direction, mean total velocity, and mean anterior-posterior velocity of CoP were greater during the cog-DT than the mot-DT (p < 0.05). In the nonlinear analysis of the CoP, there was no difference (p > 0.05) between the cog-DT and mot-DT for ApEn values of the anterior-posterior and medial-lateral time series of the CoP. Both linear and nonlinear analyses showed differences between the cog-DT and ST (p < 0.05), revealing a decline in postural control during the cog-DT compared with the ST. In conclusion, performing a cog-DT causes sway impairments and lower postural control efficacy compared with motor single and dual-tasks. Furthermore, both linear and nonlinear analyses were able to distinguish between conditions.

The effect of the motor dual-task on static and dynamic postural control and classification of the motor task difficulty - Systematic Review

Many daily activities require performing multiple tasks and involve the integration of cognitive and motor skills, on which the outcome depends. Many studies approach the influence of cognitive tasks on gait and postural control, but few studies analyze the effect of another motor task during gait or postural control. This review aims to analyze the motor tasks used in motor dual-tasks studies and classify motor tasks as to their difficulty level. The literature review was conducted according to PRISMA guidelines in the databases: Medline, Web on Science, and Scopus during December 2019, using the key-words: motor dual-task, secondary motor task, gait, and postural control. It included observational studies based on the effects of motor dual-tasking in static and dynamic postural control, published in the last ten years. N = 215 studies were found within the databases, and this review included sixteen studies. One study analyzed gait with secondary motor task of different levels of complexity. Three studies analyzed the primary motor task (gait) at different difficulty levels or conditions. They all found that more complex tasks lead to poorer gait performance.In conclusion, a classification of the motor tasks is suggested according to their complexity level and suggests the need for more studies with motor tasks of different levels of difficulty. The static and dynamic postural control parameters analyzed in this review were negatively affected compared to the simple motor task, regardless of age or clinical condition.

Effects of cognitive- and motor-dual tasks on postural control regularity following anterior cruciate ligament reconstruction

BackgroundHigh injury rates following anterior cruciate ligament reconstruction (ACLR) motivate the need to better understand lingering movement deficiencies following return to sport. Athletic competition involves various types of sensory, motor, and cognitive challenges; however, postural control deficiencies during this spectrum of conditions are not well understood following ACLR. Research questionTo what extent is postural control altered following ACLR in the presence of sensory, motor, and cognitive challenges, and does postural control correlate with patient-reported symptoms? MethodsFourteen individuals following ACLR (4 m/10 f, 21.2 ± 2.4 yr, 76.9 ± 19.1 kg, 1.70 ± 0.14 m) and fourteen matched healthy controls (4 m/10 f, 21.2 ± 1.4 yr, 75.4 ± 15.3 kg, 1.70 ± 0.15 m) participated in the study. Participants completed single-leg balance, ACLR limb or matched side for controls, under four conditions: 1) eyes open, 2) eyes closed, 3) visual-cognitive dual task (i.e., reverse digit span), and 4) motor dual task (i.e., catching a ball). Sample entropy (SEn) was calculated for each balance condition to characterize regularity of center of pressure control. Participants also completed patient-reported outcomes to characterize self-reported knee function, symptoms, and fear. A mixed effects model tested for differences in SEn between balance conditions, and Spearman correlations tested for relationships between SEn and patient-reported outcomes. ResultsA significant Group-by-Condition interaction was detected (P = 0.043). While the motor dual task and eyes closed balance conditions were associated with the lowest SEn for both groups, only the visual-cognitive dual task condition demonstrated a significant difference between groups, with the ACLR group having lower SEn [95% confidence interval for ΔSEn: (0.03, 0.35)]. Lower KOOS-Sport scores were associated with decreased SEn for the ACLR group (ρ = 0.81, P < 0.001). SignificanceThese findings are consistent with ACLR individuals using a less automatic approach to postural control compared to controls, particularly when presented with a visual-cognitive challenge. Altered neuromuscular control persists well after ACLR surgery and can be related to patient-reported outcomes.

Embodiment modifies attention allotment for the benefit of dual task performance

Many everyday tasks, like walking down a street, require us to dual task to also avoid collisions of our swinging arms with other pedestrians. The collision avoidance is possible with ease because humans attend to all our (embodied) limbs. But how does the level of embodiment affect attention distribution, and consequently task performance in dual tasks? Here we examined this question with a dual task that required participants to perform a cued button-press (main task) with their right hand, while reacting to possible collisions by a moving object with a left ‘robot’ hand (secondary task). We observed that participants consistently improve main task performance when they perceived the robot hand to be embodied, compared to when they don’t. The secondary task performance could be maintained in both cases. Our results suggest that embodiment of a limb modifies attention allotment for the benefit of dual motor task performance using limbs.