The Influence of a Cognitive Dual Task on the Gait Parameters of Healthy Older Adults: A Systematic Review and Meta-Analysis

Cognitive-motor dual task to reveal gait impairments in multiple sclerosis patients at an early stage: A systematic review

BACKGROUND

Multiple sclerosis can cause locomotor and cognitive impairments even at lower levels of disability, which can impact daily life. The cognitive-motor dual task is commonly used to assess everyday locomotion. Thus, this study aimed to examine the effect of cognitive-motor dual tasks on gait parameters among patients with multiple sclerosis in the early disease stages and to determine whether dual tasks could be used as a clinical test to detect locomotion impairments.

METHODS

A systematic search of five databases was conducted in May 2024. The population of interest was patients with multiple sclerosis with an Expanded Disability Status Scale score of 4 or less. The following outcome measures were examined: spatiotemporal and kinematic parameters. The Newcastle-Ottawa Scale was used to assess the quality of the studies.

FINDINGS

Eleven studies including 270 patients with multiple sclerosis and 221 healthy controls. Three spatiotemporal parameters were modified both in patients with multiple sclerosis and healthy controls during dual-task performance: gait speed, stride length and the double support phase. No spatiotemporal parameter was affected during dual-task performance in patients with multiple sclerosis alone.

INTERPRETATION

Dual-task performance could be useful for assessing gait impairments in patients with multiple sclerosis provided that assessments and protocols are standardized. Nevertheless, the spatiotemporal parameters did not allow discrimination between patients with multiple sclerosis at an early stage and healthy controls. Three-dimensional gait analysis during dual-task performance could be a useful approach for detecting early gait impairments in patients with multiple sclerosis, assessing their progression and adjusting rehabilitation programs.

Effects of a dual-task activity on gait parameters of people with and without intellectual disabilities

BACKGROUND

The main objective of this study was to evaluate gait parameters in people with intellectual disability (ID) and without intellectual disability (WID) in two different walking conditions [single task vs. dual task (DT)]. A secondary aim was to evaluate the dual-task cost (DTC) that the DT causes in each group.

METHODS

A total of 119 participants joined in this study: 56 ID (30 men) and 63 WID (30 men). The OptoGait system was used to assess gait. In addition, Witty photocells were added to assess gait under the DT condition.

RESULTS

Single support time was lower for participants with ID (P < 0.01), while double support time was higher (P < 0.05). All coefficients of variation for gait parameters were higher in participants with ID. Additionally, changes in gait were observed in both groups during the DT condition compared with the single-task condition. These changes were larger for participants with ID in step length, double support time and gait speed (P < 0.001), resulting in a higher DTC in these variables in the ID group (P < 0.01).

CONCLUSIONS

Both groups reduced gait performance in the DT condition. However, greater gait variability occurred in the ID group. In addition, DTC was higher for the ID group in all variables analysed. Therefore, people with ID show worse gait performance during a DT than people WID.

Associations Between Object Control Skills and Cognitive Functions in Boys, Younger and Older Men: Across-Sectional Study

Purpose: This study aimed to explore the association of cognitive function and process- as well product-oriented outcomes of object control skills (OCS) in boys, younger and older men. Methods: A total of 77 male participants took part in this study, including 35 primary school children (9.04 ± 0.53 years), 22 younger adults (23.5 ± 2.34 years), and 20 older adults (69.5 ± 4.43 years). We assessed the process-oriented performance of throwing, kicking, and catching performance using the component approach. For the product-oriented performance, throwing and kicking velocity was recorded with a STALKER SOLO 2.0 radar gun. For catching, the number of caught balls was assessed. Cognitive function was evaluated using the Trail-Making-Test (TMT) one day later. Results: Younger adults performed better in both domains than the other two groups. The results of the children and older adults were comparable in the motor and cognitive domains. However, the older adults yielded significantly better results for the process-oriented catching and product-oriented throwing performances. Moderate to strong correlations exist between OCS- and TMT performance, with significant correlations predominantly between product-oriented OCS results and TMT in children. Conclusion: The results of both domains support a hypothetical lifespan developmental trajectory with a progression from childhood to younger adult age and a degression in older adults. Furthermore, our results suggest that the suspected relationship between motor and cognitive function depends on age, the analyzed cognitive and motor skills, and the applied methodological approach (process-oriented vs. product-oriented).

Brain control of dual-task walking can be improved in aging and neurological disease

The peak prevalence of multiple sclerosis has shifted into older age groups, but co-occurring and possibly synergistic motoric and cognitive declines in this patient population are poorly understood. Dual-task-walking performance, subserved by the prefrontal cortex, and compromised in multiple sclerosis and aging, predicts health outcomes. Whether acute practice can improve dual-task walking performance and prefrontal cortex hemodynamic response efficiency in multiple sclerosis has not been reported. To address this gap in the literature, the current study examined task- and practice-related effects on dual-task-walking and associated brain activation in older adults with multiple sclerosis and controls. Multiple sclerosis (n = 94, mean age = 64.76 ± 4.19 years) and control (n = 104, mean age = 68.18 ± 7.01 years) participants were tested under three experimental conditions (dual-task-walk, single-task-walk, and single-task-alpha) administered over three repeated counterbalanced trials. Functional near-infrared-spectroscopy was used to evaluate task- and practice-related changes in prefrontal cortex oxygenated hemoglobin. Gait and cognitive performances declined, and prefrontal cortex oxygenated hemoglobin was higher in dual compared to both single task conditions in both groups. Gait and cognitive performances improved over trials in both groups. There were greater declines over trials in oxygenated hemoglobin in dual-task-walk compared to single-task-walk in both groups. Among controls, but not multiple sclerosis participants, declines over trials in oxygenated hemoglobin were greater in dual-task-walk compared to single-task-alpha. Dual-task walking and associated prefrontal cortex activation efficiency improved during a single session, but improvement in neural resource utilization, although significant, was attenuated in multiple sclerosis participants. These findings suggest encouraging brain adaptability in aging and neurological disease.

Perturbation-based dual task assessment in older adults with mild cognitive impairment

Background

Dual tasking (i.e., concurrent performance of motor and cognitive task) is significantly impaired in older adults with mild cognitive impairment (OAwMCI) compared to cognitively intact older adults (CIOA) and has been associated with increased fall risk. Dual task studies have primarily examined volitionally driven events, and the effects of mild cognitive impairment on reactive balance control (i.e., the ability to recover from unexpected balance threats) are unexplored. We examined the effect of cognitive tasks on reactive balance control in OAwMCI compared to CIOA.

Methods

Adults >55 years were included and completed the Montreal Cognitive Assessment (MoCA) to categorize them as OAwMCI (MoCA: 18-24, n = 15) or CIOA (MoCA: ≥25, n = 15). Both OAwMCI [MoCA: 22.4 (2.2), 65.4 (6.1) years, 3 females] and CIOA [MoCA: 28.4 (1.3), 68.2 (5.5) years, 10 females] responded to large magnitude stance slip-like perturbations alone (single task) and while performing perceptual cognitive tasks targeting the visuomotor domain (target and tracking game). In these tasks, participants rotated their head horizontally to control a motion mouse and catch a falling target (target game) or track a moving object (track). Margin of stability (MOS) and fall outcome (harness load cell >30% body weight) were used to quantify reactive balance control. Cognitive performance was determined using performance error (target) and sum of errors (tracking). A 3 × 2 repeated measures ANOVA examined the effect of group and task on MOS, and generalized estimating equations (GEE) model was used to determine changes in fall outcome between groups and tasks. 2 × 2 repeated measures ANOVAs examined the effect of group and task on cognitive performance.

Results

Compared to CIOA, OAwMCI exhibited significantly deteriorated MOS and greater number of falls during both single task and dual task (p < 0.05), and lower dual task tracking performance (p < 0.01). Compared to single task, both OAwMCI and CIOA exhibited significantly deteriorated perceptual cognitive performance during dual task (p < 0.05); however, no change in MOS or fall outcome between single task and dual task was observed.

Conclusion

Cognitive impairment may diminish the ability to compensate and provide attentional resources demanded by sensory systems to integrate perturbation specific information, resulting in deteriorated ability to recover balance control among OAwMCI.

Cognitive-motor interference during walking with modified leg mechanics: a dual-task walking study

Background

The use of mobile exoskeletons as assistive walking devices has the potential to affect the biomechanics of the musculoskeletal system due to their weight and restricted range of motion. This may result in physical and cognitive load for the user. Understanding how lower extremity loading affects cognitive-motor interference is crucial for the design of wearable devices, including powered exoskeletons, and the development of effective training interventions.

Objective

This study aims to examine the effects of modified leg mechanics on cognitive-motor interference in dual-task walking. Gait variability, as an indicator of motor control, was analyzed to investigate its relation to cognitive task difficulty and to determine whether lower extremity loading modifies this relationship. Additionally, the impact on the gait pattern, as represented by the mean values of spatio-temporal gait parameters were investigated.

Method

Fifteen healthy young adults walked on a treadmill with and without weight cuffs bilaterally attached to their thighs and shanks while performing a visual-verbal Stroop test (simple task) and a serial subtraction task (difficult task). Dependent variables include mean values and variability (coefficients of variation) of step length, step width, stride time and double support time. Additionally, secondary task performance as correct response rates and perceived workload were assessed.

Results

Double support time variability decreased during dual-task walking, but not during walking with modified leg mechanics while performing the difficult secondary task. Walking with modified leg mechanics resulted in increased gait variability compared to normal walking, regardless of cognitive load. During walking with modified leg mechanics, step length, step width, and stride time increased, while double support time decreased. The secondary tasks did not affect the gait pattern.

Conclusion

The interplay between an external focus of attention and competition for attentional resources may influence the variability of double support time. The findings suggest that walking with modified leg mechanics could increase cognitive-motor interference for healthy young adults in demanding dual-task situations. Therefore, it is important to analyze the underlying mechanisms of cognitive-motor interference in the context of human-exoskeleton interaction.

Gait patterns during overground and virtual omnidirectional treadmill walking

BACKGROUND

Omnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults.

METHODS

Fifteen young adults completed forward walk, 180° turn, and 360° turn tasks under three conditions: (1) overground, (2) on the Infinadeck ODT in a virtual environment without a handrail, and (3) on the ODT with a handrail. Kinematic data for all walking trials were gathered using 3D optical motion capture.

RESULTS

Overall, gait speed was slower during ODT walking than overground. When controlling for gait speed, ODT walking resulted in shorter steps and greater variability in step length. There were no significant differences in other spatiotemporal metrics between ODT and overground walking. Turning on the ODT required more steps and slower rotational speeds than overground turns. The addition of the stability handrail to the ODT resulted in decreased gait variability relative to the ODT gait without the handrail.

CONCLUSION

Walking on an ODT resembles natural gait patterns apart from slower gait speed and shorter step length. Slower walking and shorter step length are likely due to the novelty of physically navigating a virtual environment which may result in a more conservative approach to gait. Future work will evaluate how older adults and those with neurological disease respond to ODT walking.

Cortical thickness moderates intraindividual variability in prefrontal cortex activation patterns of older adults during walking

OBJECTIVE

Increased intraindividual variability (IIV) in behavioral and cognitive performance is a risk factor for adverse outcomes but research concerning hemodynamic signal IIV is limited. Cortical thinning occurs during aging and is associated with cognitive decline. Dual-task walking (DTW) performance in older adults has been related to cognition and neural integrity. We examined the hypothesis that reduced cortical thickness would be associated with greater increases in IIV in prefrontal cortex oxygenated hemoglobin (HbO2) from single tasks to DTW in healthy older adults while adjusting for behavioral performance.

METHOD

Participants were 55 healthy community-dwelling older adults (mean age = 74.84, standard deviation (SD) = 4.97). Structural MRI was used to quantify cortical thickness. Functional near-infrared spectroscopy (fNIRS) was used to assess changes in prefrontal cortex HbO2 during walking. HbO2 IIV was operationalized as the SD of HbO2 observations assessed during the first 30 seconds of each task. Linear mixed models were used to examine the moderation effect of cortical thickness throughout the cortex on HbO2 IIV across task conditions.

RESULTS

Analyses revealed that thinner cortex in several regions was associated with greater increases in HbO2 IIV from the single tasks to DTW (ps < .02).

CONCLUSIONS

Consistent with neural inefficiency, reduced cortical thickness in the PFC and throughout the cerebral cortex was associated with increases in HbO2 IIV from the single tasks to DTW without behavioral benefit. Reduced cortical thickness and greater IIV of prefrontal cortex HbO2 during DTW may be further investigated as risk factors for developing mobility impairments in aging.

Gait Characteristics during Dual-Task Walking in Elderly Subjects of Different Ages

BACKGROUND

In older age, walking ability gradually decreases due to factors including impaired balance, reduced muscle strength, and impaired vision and proprioception. Further, cognitive functions play a key role during walking and gradually decline with age. There is greater variability in gait parameters when the demands during walking increase, in dual- and multiple-task situations. The aim of this study was to analyze gait parameters while performing a demanding cognitive and motor dual task in three different age-related healthy elderly subject groups.

METHOD

A total of 132 healthy individuals (54 males, 78 females) were divided into three groups-55 to 65, 66 to 75, and 76 to 85 years. The subjects performed a basic walking task, dual motor task, dual mental task, and combined motor and mental task while walking. The gait parameters cycle time, stride length, swing time, and double support time were noted, as well as the variability of those parameters.

RESULTS

Cycle time was longer and stride length was shorter in the >76-year-old group than in the 51-65-year-old group in all test conditions. A comparison of all three groups did not show a significant difference in swing time, while double support time was increased in the same group.

CONCLUSIONS

Changes are observed when gait is performed simultaneously with an additional motor or cognitive task. Early detection of gait disorders can help identify elderly people at increased risk of falls. Employing a dual-task paradigm during gait assessment in healthy elderly subjects may help identify cognitive impairment early in the course of the disturbance.

Evaluation of mild-to-moderate COVID-19 through dual-task paradigm: a longitudinal case-controlled study

INTRODUCTION

Coronavirus disease (COVID-19) was associated with cognitive alterations affecting everyday life activities. These need input integration of both motor and cognitive systems. The study aim is to evaluate cognitive-motor interference phenomenon in previously independent patients with mild-to-moderate COVID-19 (PwMCOVID-19) compared with healthy controls (HC), through dual-task (DT) paradigm.

METHODS

PwMCOVID-19 were included if being independent at home, had no previous referred cognitive impairment, mechanical ventilation or oxygen need. They were assessed at admission and after 6 months with a motor-cognitive DT test (counting backward by twos while walking 2 min). HC were enrolled as control group. Differences between single-task (ST) and DT performance, DT effect (DTE) and task prioritization amongst groups and during time points were analyzed.

RESULTS

One-hundred PwMCOVID-19 [mean age=67.32(12.08) years; 53 M/47 F] and 39 HC [mean age=63.11(9.90) years; 20 M/19 F] were recruited. Upon T0, PwMCOVID-19 showed lower cognitive and motor DT performances than ST and HC. Mutual interference pattern was predominant in PwMCOVID-19. At T1, 41 PwMCOVID-19 were examined [mean age=64.85(10.75); 22 M/19 F]. They had a worse DT performance compared to ST, although DT improved at T1. A stronger cognitive ST-DT difference was present at T0, compared to ST-DT difference at T1, while motor ST-DT difference was unchanged over time in PwCOVID-19.

CONCLUSION

In PwMCOVID-19, there is an impairment of DT counting while walking at baseline and after 6 months from hospitalization, with a more pronounced DT mutual interference pattern at T0. After 6 months, the motor and cognitive ST and DT performances ameliorated, not reaching the HC level.

An Exploratory Study of Walking, Listening, and Remembering in Younger and Middle-Aged Adults

PURPOSE

The purpose of this study was to assess how needing to listen and remember information while walking affects speech perception, memory task performance, and gait in younger and middle-aged adults.

METHOD

Four gait parameters (stride duration, step variability, whole-body center of mass acceleration, and mediolateral head acceleration) were measured when younger and middle-aged participants stood or walked on a treadmill while they simultaneously completed a speech-on-speech perception task and a preload memory task, singly and in combination.

RESULTS

Speech perception was significantly poorer for middle-aged than for younger participants. Performance on the speech perception measure did not differ significantly between walking and standing for either group of participants, but the additional cognitive load of the memory task reduced performance on the speech perception task. Memory task performance was significantly poorer when combined with the speech perception task than when measured in isolation for both participant groups, but no further declines were noted when participants were also walking. Mediolateral head acceleration, which has been linked to loss of balance, was significantly greater during multitask trials, as compared to when participants were only walking without being required to listen or remember. Post hoc analysis showed that dual- and multitask influences on mediolateral head acceleration were more prominent for middle-aged than for younger participants. Stride duration was longer in the multitask condition than when participants were only walking.

CONCLUSIONS

Results of this exploratory study indicate that gait may be impacted when individuals (both younger and middle-aged) are listening and remembering while walking. Data also substantiate prior findings of early age-related declines in the perception of speech in the presence of understandable speech maskers.

Uneven surface and cognitive dual-task independently affect gait quality in older adults

BACKGROUND

Real-world mobility involves walking in challenging conditions. Assessing gait during simultaneous physical and cognitive challenges provides insights on cognitive health.

RESEARCH QUESTION

How does uneven surface, cognitive task, and their combination affect gait quality and does this gait performance relate to cognitive functioning?

METHODS

Community-dwelling older adults (N = 104, age=75 ± 6 years, 60 % females) performed dual-task walking paradigms (even and uneven surface; with and without alphabeting cognitive task (ABC)) to mimic real-world demands. Gait quality measures [speed(m/s), rhythmicity(steps/minute), stride time variability (%), adaptability (m/s2), similarity, smoothness, power (Hz) and regularity] were calculated from an accelerometer worn on the lower back. Linear-mixed modelling and Tukey analysis were used to analyze independent effects of surface and cognitive task and their interaction on gait quality. Partial Spearman correlations compared gait quality with global cognition and executive function.

RESULTS

No interaction effects between surface and cognitive task were found. Uneven surface reduced gait speed(m/s) (β = -0.07). Adjusted for speed, uneven surface reduced gait smoothness (β = -0.27) and increased regularity (β = 0.09), Tukey p < .05, for even vs uneven and even-ABC vs uneven-ABC. Cognitive task reduced gait speed(m/s) (β = -0.12). Adjusted for speed, cognitive task increased variability (β = 7.60), reduced rhythmicity (β = -6.68) and increased regularity (β = 0.05), Tukey p < .05, for even vs even-ABC and uneven vs uneven-ABC. With demographics as covariates, gait speed was not associated with cognition. Gait quality [lower variability during even-ABC (ρp =-.31) and uneven-ABC (ρp =-.28); greater rhythmicity (ρp between.22 and.29) and greater signal-adaptability AP (ρp between.22 and.26) during all walking tasks] was associated with better global cognition. Gait adaptability during even (ρp =-0.21, p = 0.03) and uneven(ρp =-0.19, p = 0.04) walking was associated with executive function.

SIGNIFICANCE

Surface and cognitive walking tasks independently affected gait quality. Our study with high-functioning older adults suggests that task-related changes in gait quality are related to subtle changes in cognitive functioning.

Walking performance of persons with chronic stroke changed when looking down but not in dimly lit environment

Background and purpose

It is common to walk under different conditions, such as looking straight head, looking down at the feet or in dimly lit environment. The purpose of this study was to determine the impact of these different conditions on walking performance in persons with and without stroke.

Methods

This was a case-control study. Persons with chronic unilateral stroke and age-matched control (n = 29 each) underwent visual acuity test, Mini Mental Status Examination (MMSE) and joint position sense test of the knee and ankle. The participants walked at their preferred speed under three walking conditions, looking ahead (AHD), looking down (DWN), and in dimly lit environment (DIM). A motion analysis system was used for the recording of the limb matching test and walking tasks.

Results

Stroke participants differed from the control group in MMSE, but not in age, visual acuity or joint position sense. For the control group, the differences between the three walking conditions were nonsignificant. For the stroke group, DWN had significantly slower walking speed, greater step width and shorter single leg support phase, but not different symmetry index or COM location, compared to AHD. The differences between AHD and DIM were nonsignificant.

Conclusion

Healthy adults did not change their gait patterns under the different walking conditions. Persons with chronic stroke walked more cautiously but not more symmetrically when looking down at the feet, but not in dimly lit environment. Ambulatory persons with stroke may need to be advised that looking down at the feet while walking could be more challenging.

Cognitive and visual task effects on gaze behaviour and gait of younger and older adults

Cognitive dual tasks alter gait of younger and older adults and recent research has demonstrated that they also influence gaze behaviour and standing postural control. These findings suggest that age-related changes in cognitive and gaze function might increase fall risk in older adults. The purpose of this study was to determine the effect cognitive and visual dual tasks on the gait and gaze behaviour of younger and older adults. Ten older and ten younger adults walked for 3 min on a treadmill at preferred walking speed under three conditions, single task, cognitive and visual dual task conditions. Gait dynamics were measured using accelerometry and gaze behaviour was measured using wearable eye-trackers. Stride time variability and centre of mass (COM) motion complexity increased in dual-task conditions in older adults but had no difference for younger adults. Dual tasks had limited effect on gaze behaviour; however, visual input duration was greater, and visual input frequency and saccade frequency were lower in older than younger adults. The gaze adaptations in older adults may be the result of slower visual processing or represent a compensatory strategy to suppress postural movement. The increase in gait COM motion complexity in older adults suggests the dual tasks led to more automatic gait control resulting from both cognitive and visual tasks.

Placebo effect on gait: a way to reduce the dual-task cost in older adults

The ability to perform two tasks simultaneously is essential for daily activities. In older adults, this ability is markedly reduced, as evidenced by the dual-task cost on gait. Preliminary evidences indicate that the dual-task cost can be influenced by different types of manipulations. Here, we explored the effectiveness of a new approach to reduce the dual-task cost, based on the placebo effect, a psychobiological phenomenon whereby a positive outcome follows the administration of an inert device thought to be effective. Thirty-five healthy older adults were asked to walk on a sensorized carpet (single-task condition) and to walk while counting backward (dual-task condition) in two sessions (pre-test and post-test). A placebo group, randomly selected, underwent sham transcranial direct current stimulation over the supraorbital areas between sessions, along with information about its positive effects on concentration and attention. A control group did not receive any intervention between sessions. The dual-task cost was significantly reduced in the placebo group at the post-test session compared to the pre-test for several gait parameters (Cohen's d > 1.43). At the post-test session, the dual-task cost was also lower in the placebo group than in the control group (d > 0.73). Cognitive (number of subtractions and number of errors) and subjective (perceived mental fatigability) variables remained stable across sessions. The reduced dual-task cost in the placebo group could indicate the ability to re-establish the allocation of attentional resources between tasks. These findings could contribute to the development of cognitive strategies that leverage positive expectations to boost motor control in older adults.

Dual-task gait and white matter hyperintensities in Lewy body diseases: An exploratory analysis

Background

Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) are part of a spectrum of Lewy body disorders, who exhibit a range of cognitive and gait impairments. Cognitive-motor interactions can be examined by performing a cognitive task while walking and quantified by a dual task cost (DTC). White matter hyperintensities (WMH) on magnetic resonance imaging have also been associated with both gait and cognition. Our goal was to examine the relationship between DTC and WMH in the Lewy body spectrum, hypothesizing DTC would be associated with increased WMH volume.

Methods

Seventy-eight participants with PD, PD with mild cognitive impairment (PD-MCI), PD with dementia or DLB (PDD/DLB), and 20 cognitively unimpaired participants were examined in a multi-site study. Gait was measured on an electronic walkway during usual gait, counting backward, animal fluency, and subtracting sevens. WMH were quantified from magnetic resonance imaging using an automated pipeline and visual rating. A median split based on DTC was performed. Models included age as well as measures of global cognition and cardiovascular risk.

Results

Compared to cognitively unimpaired participants, usual gait speed was lower and DTC was higher in PD-MCI and PDD/DLB. Low DTC participants had higher usual gait speed. WMH burden was greater in high counting DTC participants. Frontal WMH burden remained significant after adjusting for age, cardiovascular risk and global cognition.

Conclusion

Increased DTC was associated with higher frontal WMH burden in Lewy body disorders after adjusting for age, cardiovascular risk, and global cognition. Higher DTC was associated with age.

Systematic review of candidate prognostic factors for falling in older adults identified from motion analysis of challenging walking tasks

The objective of this systematic review is to identify motion analysis parameters measured during challenging walking tasks which can predict fall risk in the older population. Numerous studies have attempted to predict fall risk from the motion analysis of standing balance or steady walking. However, most falls do not occur during steady gait but occur due to challenging centre of mass displacements or environmental hazards resulting in slipping, tripping or falls on stairs. We conducted a systematic review of motion analysis parameters during stair climbing, perturbed walking and obstacle crossing, predictive of fall risk in healthy older adults. We searched the databases of Pubmed, Scopus and IEEEexplore.A total of 78 articles were included, of which 62 simply compared a group of younger to a group of older adults. Importantly, the differences found between younger and older adults did not match those found between older adults at higher and lower risk of falls. Two prospective and six retrospective fall history studies were included. The other eight studies compared two groups of older adults with higher or lower risk based on mental or physical performance, functional decline, unsteadiness complaints or task performance. A wide range of parameters were reported, including outcomes related to success, timing, foot and step, centre of mass, force plates, dynamic stability, joints and segments. Due to the large variety in parameter assessment methods, a meta-analysis was not possible. Despite the range of parameters assessed, only a few candidate prognostic factors could be identified: older adults with a retrospective fall history demonstrated a significant larger step length variability, larger step time variability, and prolonged anticipatory postural adjustments in obstacle crossing compared to older adults without a fall history. Older adults who fell during a tripping perturbation had a larger angular momentum than those who did not fall. Lastly, in an obstacle course, reduced gait flexibility (i.e., change in stepping pattern relative to unobstructed walking) was a prognostic factor for falling in daily life. We provided recommendations for future fall risk assessment in terms of study design.In conclusion, studies comparing older to younger adults cannot be used to explore relationships between fall risk and motion analysis parameters. Even when comparing two older adult populations, it is necessary to measure fall history to identify fall risk prognostic factors.

Does texting while walking affect spatiotemporal gait parameters in healthy adults, older people, and persons with motor or cognitive disorders? A systematic review and meta-analysis

BACKGROUND

Smartphone use during postural-locomotor tasks is an everyday activity for individuals of all ages in diverse environmental situations and with various health conditions. Nevertheless, the use of smartphones during walking is responsible for many accidents.

RESEARCH QUESTION

This systematic review and meta-analysis examined spatiotemporal gait parameters during the dual-task situation "texting + gait" versus isolated gait task (single task) in adult persons (>18 years).

METHODS

Electronic database searches were performed in PubMed, Embase, CINHAL, and LISSA. Two examiners assessed the eligibility and quality of appraisal with the Downs and Black checklist. The standardized mean difference (SMD) with 95 % confidence intervals was calculated to compare single- and dual-task situations. The pooled estimates of the overall effect were computed using a random or fixed effects method, and forest plots were generated.

RESULTS AND SIGNIFICANCE

A total of 25 studies were included. All studies included healthy adults, with four studies including older persons and three including people with pathological conditions. The walking task was with (N = 4) and without (N = 21) obstacles and in laboratory (N = 21) or ecological conditions (N = 7). The quality scores were 6-8/16 for eight studies, 9-12/16 for seven studies, and more than 12/16 for three studies. During the "texting + gait" tasks, the meta-analysis highlighted a significant impairment of gait speed, step and stride length, cadence, and double and single support (p < 0.05). The spatiotemporal parameters of gait were systematically altered during the texting task regardless of the population and test conditions. However, the quality of the studies is moderate, and few studies have been conducted for people with motor deficiencies. The impact of texting on walking should be better considered to develop prevention actions.

Effects of two different dual-task training protocols on gait, balance, and cognitive function in community-dwelling older adults: a 24-week randomized controlled trial

Background

Although alternating dual-task (ADT) training is functionally easier for older adults, a large part of the motor and cognitive tasks is simultaneously performed, especially during activities of daily living that require maintaining body balance.

Objective

To evaluate the effects of mixed dual-task training on mobility, cognitive function, and balance in community-dwelling older adults.

Methods

Sixty participants were randomly allocated at a 1:1 ratio into the experimental group-single motor task (SMT) and simultaneous dual task (SDT) interchangeably in stage 1 (for 12 weeks) and after strictly with SDT in stage 2 (the last 12 weeks)-or into the control group-only SMT and SDT interchangeably in stages 1 and 2. Gait parameters were acquired by two inertial sensors. Physical and cognitive performance were acquired by specific questionnaires. Generalized linear mixed models were used for analyzing interaction and main effects.

Results

No between-group difference was observed for gait performance. Both protocols improved mobility (mean change ((MC) = 0.74)), dual-task effect (MC = -13.50), lower limb function (MC = 4.44), static (MC = -0.61), and dynamic balance (MC = -0.23), body sway (MC = 4.80), and cognitive function (MC = 41.69).

Conclusion

Both dual-task training protocols improved these outcomes.

Impacts of Adiposity on the Attentional Cost of Sensory-Motor Performance Associated with Mobility in a Dual-Task Paradigm

(1) Background: Obesity is one of the most prevalent health problems worldwide. Studies have evidenced that the increase in body weight affects the normal neuromusculoskeletal function, which leads to abnormal gait patterns and impaired balance. (2) Objective: The aim of this study was to examine the influence of dual-task activity (cognitive-motor task) on gait parameters and balance among obese students. (3) Material and methods: A cross-sectional study was conducted among students (18-28 years old), including 120 obese and 120 age-matched normal-weight control subjects, selected at random using simple random sampling, from the Majmaah, Riyadh, Dammam, and Jizan regions of Saudi Arabia. The gait speed was measured in seconds while the controls and the obese subjects performed a dual-task activity of walking down a level, well-lit, narrow lane at their own speed, counting backwards from 100 by 4 s. (4) Results: The results of our study suggest a significant difference in the effect of the dual-task paradigm on the gait speed (t = 21.05, p = 000) of obese participants when compared to their age-matched counterparts. A significant correlation was found between BMI and gait speed and balance, irrespective of the gender of the obese student. A high degree of positive correlation (r = 0.705, p < 0.001) was found between BMI and gait speed, and a high degree of inverse correlation (r = -0.648, p < 0.001) was found between BMI and balance among obese students A multiple regression model explained 60% of the variance in gait speed and was statistically significant (R² = 0.60, F (4, 235) = 90.65, p = 0.000) with BMI (β = 0.018, p = 0.000) and balance (β = 0.015, p = 0.000) significantly predicting gait speed. (5) Conclusion: The results of the current study provide evidence that obesity significantly influences gait speed and balance due to the inclusion of a contemporaneous cognitive task. The results also suggest that the dual-task paradigm affects both genders equally.

Gait in Cerebral Amyloid Angiopathy

Background Gait is a complex task requiring coordinated efforts of multiple brain networks. To date, there is little evidence on whether gait is altered in cerebral amyloid angiopathy (CAA). We aimed to identify impairments in gait performance and associations between gait impairment and neuroimaging markers of CAA, cognition, and falls. Methods and Results Gait was assessed using the Zeno Walkway during preferred pace and dual task walks, and grouped into gait domains (Rhythm, Pace, Postural Control, and Variability). Participants underwent neuropsychological testing and neuroimaging. Falls and fear of falling were assessed through self-report questionnaires. Gait domain scores were standardized and analyzed using linear regression adjusting for age, sex, height, and other covariates. Participants were patients with CAA (n=29), Alzheimer disease with mild dementia (n=16), mild cognitive impairment (n=24), and normal elderly controls (n=47). CAA and Alzheimer disease had similarly impaired Rhythm, Pace, and Variability, and higher dual task cost than normal controls or mild cognitive impairment. Higher Pace score was associated with better global cognition, processing speed, and memory. Gait measures were not correlated with microbleed count or white matter hyperintensity volume. Number of falls was not associated with gait domain scores, but participants with low fear of falling had higher Pace (odds ratio [OR], 2.61 [95% CI, 1.59-4.29]) and lower Variability (OR, 1.64 [95% CI, 1.10-2.44]). Conclusions CAA is associated with slower walking, abnormal rhythm, and greater gait variability than in healthy controls. Future research is needed to identify the mechanisms underlying gait impairments in CAA, and whether they predict future falls.

Cognitive dual-task cost depends on the complexity of the cognitive task, but not on age and disease

Introduction

Dual-tasking (DT) while walking is common in daily life and can affect both gait and cognitive performance depending on age, attention prioritization, task complexity and medical condition. The aim of the present study was to investigate the effects of DT on cognitive DT cost (DTC) (i) in a dataset including participants of different age groups, with different neurological disorders and chronic low-back pain (cLBP) (ii) at different levels of cognitive task complexity, and (iii) in the context of a setting relevant to daily life, such as combined straight walking and turning.

Materials and methods

Ninety-one participants including healthy younger and older participants and patients with Parkinson's disease, Multiple Sclerosis, Stroke and cLBP performed a simple reaction time (SRT) task and three numerical Stroop tasks under the conditions congruent (StC), neutral (StN) and incongruent (StI). The tasks were performed both standing (single task, ST) and walking (DT), and DTC was calculated. Mixed ANOVAs were used to determine the effect of group and task complexity on cognitive DTC.

Results

A longer response time in DT than in ST was observed during SRT. However, the response time was shorter in DT during StI. DTC decreased with increasing complexity of the cognitive task. There was no significant effect of age and group on cognitive DTC.

Conclusion

Our results suggest that regardless of age and disease group, simple cognitive tasks show the largest and most stable cognitive effects during DT. This may be relevant to the design of future observational studies, clinical trials and for clinical routine.

Effects of gender on dual-tasking and prioritization in older adults

BACKGROUND

The ability to produce effective posture and balance while distracted (dual-tasking; DT), is critical for mobility. In particular, individuals implicit prioritization across posture and secondary, distracting stimuli may impact fall risk. However, the impact of gender on DT and prioritization during gait is poorly understood.

RESEARCH QUESTION

Does gender impact DT effects or prioritization while DT walking?

METHODS

One hundred older adults participated. The timed up and go (TUG) was completed with and without a secondary cognitive task (counting backwards by 3's). Gait (time to complete the TUG), and cognitive (rate of correct numbers listed) performance was recorded during both single tasks and while dual-tasking. DT effects were calculated for cognitive and gait performance. Prioritization was calculated as the difference between cognitive and gait DT effects. The effect of gender on DT and prioritization was assessed, controlling for age and cognitive ability.

RESULTS

Gender by condition (single vs. dual-task) interaction effects were observed (Gait: F_1,96 =8.7; p = 0.004; Cognition: F_1,96 =5.2; p = 0.024) such that, compared to male participants, females exhibited smaller cognitive DT effects, and larger gait DT effects. Further, females exhibited significantly larger prioritization scores (F_1,95 =10.0, p = 0.002), indicating a cognitive prioritization compared to males.

SIGNIFICANCE

Given the link between posture-second strategies and falls, the current findings may provide some insight into previous results suggesting an increased fall-risk in older-adult women. However, this study did not investigate falls. Therefore, additional work is necessary to confirm current findings and further investigate the relationship between gender, prioritization, and falls; and its possible clinical relevance.

Cognitive reserve and risk of mobility impairment in older adults

BACKGROUND

Cognitive reserve (CR) protects against cognitive decline and dementia but its relation to mobility impairment has not been established. To address this important gap in the literature, we conducted a longitudinal investigation to test the hypothesis that higher baseline CR was associated with a lower risk of developing mobility impairment in older adults.

METHODS

Participants were dementia-free older adults who received brain magnetic resonance imaging and had gait speed assessments during follow-up. Using the residuals approach, CR was computed as the variance in the Modified Mini-Mental Status Examination total score, that was left after accounting for structural brain integrity, education, and race. Mobility impairment was defined using a validated cutoff score in gait speed of 0.8 m/s. Logistic regression models using general estimating equations were utilized to examine longitudinal associations between baseline CR and the risk of developing mobility impairment across repeated assessments.

RESULTS

Of the participants (n = 237; mean age = 82 years; %female = 56%) who were free of mobility impairment at baseline, 103 developed mobility impairment during follow-up (mean = 3.1 years). Higher CR at baseline was associated with a lower risk of developing incident mobility impairment-odds ratio (OR) = 0.819, 0.67-0.98, p = 0.038 (unadjusted); OR = 0.815, 0.67-0.99, p = 0.04 (adjusted for socio-demographic variables and depression); OR = 0.819, 0.68-0.88, p = 0.035 (adjusted for illness history); OR = 0.824, 0.68-0.99, p = 0.045 (adjusted for white matter hyperintensities); OR = 0.795, 0.65-0.95, p = 0.016 (adjusted for falls history).

CONCLUSION

Higher CR at baseline was protective against developing incident mobility impairment during follow-up among community-residing older adults.

Turning when using a smartphone in persons with and without neurologic conditions: an observational study (Preprint)

BACKGROUND

Turning during walking is a relevant and common everyday movement and it depends on a correct top-down intersegmental coordination. This could be reduced in several conditions (en bloc turning), and an altered turning kinematics has been linked to increased risk of falls. Smartphone use has been associated with poorer balance and gait; however, its effect on turning-while-walking has not been investigated yet. This study explores turning intersegmental coordination during smartphone use in different age groups and neurologic conditions.

OBJECTIVE

This study aims to evaluate the effect of smartphone use on turning behavior in healthy individuals of different ages and those with various neurological diseases.

METHODS

Younger (aged 18-60 years) and older (aged >60 years) healthy individuals and those with Parkinson disease, multiple sclerosis, subacute stroke (<4 weeks), or lower-back pain performed turning-while-walking alone (single task [ST]) and while performing 2 different cognitive tasks of increasing complexity (dual task [DT]). The mobility task consisted of walking up and down a 5-m walkway at self-selected speed, thus including 180° turns. Cognitive tasks consisted of a simple reaction time test (simple DT [SDT]) and a numerical Stroop test (complex DT [CDT]). General (turn duration and the number of steps while turning), segmental (peak angular velocity), and intersegmental turning parameters (intersegmental turning onset latency and maximum intersegmental angle) were extracted for head, sternum, and pelvis using a motion capture system and a turning detection algorithm.

RESULTS

In total, 121 participants were enrolled. All participants, irrespective of age and neurologic disease, showed a reduced intersegmental turning onset latency and a reduced maximum intersegmental angle of both pelvis and sternum relative to head, thus indicating an en bloc turning behavior when using a smartphone. With regard to change from the ST to turning when using a smartphone, participants with Parkinson disease reduced their peak angular velocity the most, which was significantly different from lower-back pain relative to the head (P<.01). Participants with stroke showed en bloc turning already without smartphone use.

CONCLUSIONS

Smartphone use during turning-while-walking may lead to en bloc turning and thus increase fall risk across age and neurologic disease groups. This behavior is probably particularly dangerous for those groups with the most pronounced changes in turning parameters during smartphone use and the highest fall risk, such as individuals with Parkinson disease. Moreover, the experimental paradigm presented here might be useful in differentiating individuals with lower-back pain without and those with early or prodromal Parkinson disease. In individuals with subacute stroke, en bloc turning could represent a compensative strategy to overcome the newly occurring mobility deficit. Considering the ubiquitous smartphone use in daily life, this study should stimulate future studies in the area of fall risk and neurological and orthopedic diseases.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00022998; https://drks.de/search/en/trial/DRKS00022998.

Association of Affect and Performance in Dual-Task Walking in Non-demented Older Adults

Objective: We examined whether individual differences in positive and negative affective states predicted dual-task costs using an established Dual-Task Walking protocol in non-demented older adults. We hypothesized that positive and negative affect would be associated with smaller and larger dual-task costs, respectively. Methods: Participants (N = 403; mean age = 76.22 ± 6.55; females = 56%) completed the Positive and Negative Affect Schedule and the walking protocol involving three conditions: Single-Task-Alpha, Single-Task-Walk (STW), and Dual-Task-Walk (DTW). Gait velocity was assessed via an instrumented walkway. Results: Negative affect was associated with greater decline in gait velocity from STW to DTW (95% confidence interval [-0.73 to -0.03]) but not the decline of the rate of correct letter generation. There was no significant relationship between positive affect and DTW performance. Discussion: Findings suggest negative affect is adversely associated with allocation of attentional resources, leading to worse mobility outcomes in older adults.

Beam width and arm position but not cognitive task affect walking balance in older adults

Detection of changes in dynamic balance could help identify older adults at fall risk. Walking on a narrow beam with its width, cognitive load, and arm position manipulated could be an alternative to current tests. Therefore, we examined additive and interactive effects of beam width, cognitive task (CT), and arm position on dynamic balance during beam walking in older adults. Twenty older adults (69 ± 4y) walked on 6, 8, and 10-cm wide beams (2-cm high, 4-m-long), with and without CT, with three arm positions (free, crossed, akimbo). We determined cognitive errors, distance walked, step speed, root mean square (RMS) of center of mass (COM) displacement and trunk acceleration in the frontal plane. Beam width decrease progressively reduced distance walked and increased trunk acceleration RMS. Step speed decreased on the narrowest beam and with CT. Arm crossing decreased distance walked and step speed. COM displacement RMS and cognitive errors were not affected by any manipulation. In conclusion, distance walked indicated that beam width and arm position, but less so CT, affected dynamic balance, implying that beam walking has the potential to become a test of fall risk. Stability measurements suggested effective trunk adjustments to control COM position and keep dynamic balance during the task.

AI-enabled photonic smart garment for movement analysis

Smart textiles are novel solutions for remote healthcare monitoring which involve non-invasive sensors-integrated clothing. Polymer optical fiber (POF) sensors have attractive features for smart textile technology, and combined with Artificial Intelligence (AI) algorithms increase the potential of intelligent decision-making. This paper presents the development of a fully portable photonic smart garment with 30 multiplexed POF sensors combined with AI algorithms to evaluate the system ability on the activity classification of multiple subjects. Six daily activities are evaluated: standing, sitting, squatting, up-and-down arms, walking and running. A k-nearest neighbors classifier is employed and results from 10 trials of all volunteers presented an accuracy of 94.00 (0.14)%. To achieve an optimal amount of sensors, the principal component analysis is used for one volunteer and results showed an accuracy of 98.14 (0.31)% using 10 sensors, 1.82% lower than using 30 sensors. Cadence and breathing rate were estimated and compared to the data from an inertial measurement unit located on the garment back and the highest error was 2.22%. Shoulder flexion/extension was also evaluated. The proposed approach presented feasibility for activity recognition and movement-related parameters extraction, leading to a system fully optimized, including the number of sensors and wireless communication, for Healthcare 4.0.

The 180° Turn Phase of the Timed Up and Go Test Better Predicts History of Falls in the Oldest-Old When Compared With the Full Test: A Case-Control Study

The 180° turn phase of the test may better differentiate the oldest-old regarding their history of falls. This is a case-control study designed to detect the ability of the 180° turn timed up and go (TUG) phase to detect a history of falls in the oldest-old. Sixty people aged 85 years and older were assessed in their homes. The single-task and dual-task TUG tests were performed using an inertial sensor (G-Walk). Sociodemographic data, physical activity levels, mental status, depressive symptoms, concern for falls occurrence, number of medicines in use, self-perception of balance, and the functional reach test were also assessed. The logistic regressions revealed the 180° turn phase of both the single-task and dual-task TUG was almost three times better than the full TUG test to detect a history of falls, thus providing insights that can be used to better assess functional mobility in the oldest-old.

Degree and pattern of dual-task interference during walking vary with component tasks in people after stroke: a systematic review

QUESTIONS

What are the degree and pattern of dual-task interference during walking in people after stroke? How do these vary with disease chronicity and different component tasks in people after stroke? How does dual-task interference differ between people after stroke and people without stroke?

DESIGN

Systematic review with meta-analysis of studies reporting gait-related dual-task interference.

PARTICIPANTS

People after stroke and people without stroke.

OUTCOME MEASURES

Measures of walking and secondary (cognitive or manual) task performance under dual-task conditions relative to those under single-task conditions.

RESULTS

Seventy-six studies (2,425 people after stroke and 492 people without stroke) were included. Manual and mental tracking tasks imposed the greatest dual-task interference on gait speed, although there was substantial uncertainty in these estimates. Among mental tracking tasks, the apparently least-complex task (serial 1 subtractions) induced the greatest dual-task interference (-0.17 m/s, 95% CI -0.24 to -0.10) on gait speed, although there was substantial uncertainty in these estimates. Mutual interference (decrement in both walking and secondary component task performances during dual-tasking) was the most common dual-task interference pattern. The results of the sensitivity analyses for studies involving people with chronic stroke were similar to the results of the primary analyses. The amount of dual-task interference from a mental tracking or manual task during walking was similar between people with or without stroke.

CONCLUSIONS

The degree and pattern of dual-task interference vary with the choice of component tasks. When evaluating limitations to functional mobility during dual-tasking conditions and in planning interventions accordingly, clinicians should select dual-task assessments that correspond to the daily habits and physical demands of people after stroke.

REGISTRATION

CRD42017059004.

Dual-Task Gait as a Predictive Tool for Cognitive Impairment in Older Adults: A Systematic Review

The use of the dual-task model as a cognitive-motor interface has been extensively investigated in cross-sectional studies as a training task in cognitive impairment. However, few existing longitudinal studies prove the usefulness of this tool as a clinical marker of cognitive impairment in older people. What is the evidence in prospective studies about dual-task gait as a predictor of cognitive impairment in older adults? This study aims to review and discuss the current state of knowledge in prospective studies on the use of dual-task gait as a predictive tool for cognitive impairment in older adults. The methodology used was a systematic review, according to the PRISMA criteria for the search, summarize and report. A search in 3 databases (Pubmed, Web of Science, and Scopus) was carried out until April 2021. The search terms used were: "(gait OR walking) AND (cognitive decline) AND (dual-task) AND (follow-up OR longitudinal OR long-term OR prospective OR cohort OR predict)." We included prospective research articles with older people with cognitive evaluation at the beginning and the end of the follow-up and dual-task gait paradigm as initial evaluation associated with the presentation of cognitive impairment prediction using any dual-task gait parameters. After exclusion criteria, 12 studies were reviewed. The results indicate that eight studies consider dual-task gait parameters a useful cognitive-motor tool, finding that some of the evaluated parameters of dual-task gait significantly correlate with cognitive impairment over time. The most promising DT parameters associated with cognitive impairment prediction seem to be gait speed, speed cost, DT time, numbers of words during DT, among others. In sum, this study reviews the variety of dual-task gait parameters and their relevance as a simple tool for early cognitive impairment screening, opening a diagnostic window for the screening of cognitive impairment in older people.

Younger and Late Middle-Aged Adults Exhibit Different Patterns of Cognitive-Motor Interference During Locomotor Adaptation, With No Disruption of Savings

It has been proposed that motor adaptation and subsequent savings (or faster relearning) of an adapted movement pattern are mediated by cognitive processes. Here, we evaluated the pattern of cognitive-motor interference that emerges when young and late middle-aged adults perform an executive working memory task during locomotor adaptation. We also asked if this interferes with savings of a newly learned walking pattern, as has been suggested by a study of reaching adaptation. We studied split-belt treadmill adaptation and savings in young (21 ± 2 y/o) and late middle-aged (56 ± 6 y/o) adults with or without a secondary 2-back task during adaptation. We found that young adults showed similar performance on the 2-back task during baseline and adaptation, suggesting no effect of the dual-task on cognitive performance; however, dual-tasking interfered with adaptation over the first few steps. Conversely, dual-tasking caused a decrement in cognitive performance in late middle-aged adults with no effect on adaptation. To determine if this effect was specific to adaptation, we also evaluated dual-task interference in late middle-aged adults that dual-tasked while walking in a complex environment that did not induce motor adaptation. This group exhibited less cognitive-motor interference than late middle-aged adults who dual-tasked during adaptation. Savings was unaffected by dual-tasking in both young and late middle-aged adults, which may indicate different underlying mechanisms for savings of reaching and walking. Collectively, our findings reveal an age-dependent effect of cognitive-motor interference during dual-task locomotor adaptation and no effect of dual-tasking on savings, regardless of age. Young adults maintain cognitive performance and show a mild decrement in locomotor adaptation, while late middle-aged adults adapt locomotion at the expense of cognitive performance.

Cognitive Reserve Moderates the Efficiency of Prefrontal Cortex Activation Patterns of Gait in Older Adults

BACKGROUND

Cognitive Reserve (CR) protects against cognitive decline, but whether CR influences the efficiency of cortical control of gait has not been reported. The current study addressed this important gap in the literature. Specifically, we determined the role of CR in moderating the efficiency of functional Near-Infrared-Spectroscopy (fNIRS)-derived HbO2 in the prefrontal cortex (PFC) assessed during active walking. We hypothesized that higher CR would be associated with more efficient brain activation patterns.

METHODS

Participants were 55 (mean age=74.84; %female=49.1) older adults who underwent the combined walking/fNIRS protocol and had MRI data. We used an established dual-task walking paradigm that consisted of three task conditions: Single-Task-Walk (STW), Single-Task-Alpha (STA, cognitive task) and Dual-Task-Walk (DTW). Using the residuals approach, CR was derived from a word-reading test score by removing variance accounted for by socio-demographic variables, tests of current cognitive functions and a measure of structural brain integrity.

RESULTS

CR moderated the change in fNIRS-derived HbO2 in the PFC across tasks. Higher CR was associated with smaller increases in fNIRS-derived HbO2 from the single tasks to dual task walking (CR x DTW compared to STW: estimate = .183; p < .001; CR x DTW compared to STA: estimate =.257; p < .001). The moderation effect of CR remained significant when adjusting for multiple covariates and concurrent moderation effects of measures of gait performance, current cognitive functions and structural integrity of the brain.

CONCLUSION

The current study provided first evidence that higher CR was associated with better neural efficiency of walking in older adults.

The effects of a secondary task on gait in axial spondyloarthritis

Studies on the effects of dual tasking in patients with chronic inflammatory rheumatic diseases are limited. The aim of this study was to assess dual tasking while walking in patients with axial spondyloarthritis (axSpA) in comparison to healthy controls. Thirty patients with axSpA and thirty healthy controls underwent a 10-m walk test at a self-selected comfortable walking speed in single- and dual-task conditions. Foot-worn inertial sensors were used to compute spatiotemporal gait parameters. Analysis of spatiotemporal gait parameters showed that the secondary manual task negatively affected walking performance in terms of significantly decreased mean speed (p < 0.001), stride length (p < 0.001) and swing time (p = 0.008) and increased double support (p = 0.002) and stance time (p = 0.008). No significant interaction of group and condition was observed. Both groups showed lower gait performance in dual task condition by reducing speed, swing time and stride length, and increasing double support and stance time. Patients with axSpA were not more affected by the dual task than matched healthy controls, suggesting that the secondary manual task did not require greater attention in patients with axSpA. Increasing the complexity of the walking and/or secondary task may increase the sensitivity of the dual-task design to axial spondyloarthritis.

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.

Effects of Exergame-Based Dual-Task Training on Executive Function and Dual-Task Performance in Community-Dwelling Older People: A Randomized-Controlled Trial

Objective: Aging is associated with decline in executive function that may lead to reduced dual-task performance. Regular exercise has been recommended for promoting or maintaining mental and physical health in older adults, yet only a fraction of older adults exercise regularly. Exergame training may have the potential to enhance exercise adherence. Therefore, the aim of this study was to examine the effects of exergame-based dual-task training on executive function and dual-task performance in community-dwelling older adults. Materials and Methods: This was a single-blinded, randomized-controlled trial. Twenty community-dwelling older adults were recruited and randomly assigned to one of two groups. All participants completed 36 trainings, including three 60-minute sessions/week over 12 weeks. Participants in the experimental group received exergame-based dual-task training, while those in the control group received home-based multicomponent exercise training. Measures of executive function, dual-task performance, and community walking ability were assessed before and after the intervention. Results: Significant group × time interactions (P = 0.000-0.027) with large effects were found in all selected outcome measures. Compared with the control group, the experimental group improved significantly in measures of general executive function (P = 0.014), inhibitory control (P = 0.037), cognitive dual-task performance (P < 0.001), and community walking ability (P = 0.002). Enhanced general executive function was highly correlated with either improved motor dual-task performance (r = 0.674) or improved cognitive dual-task performance (r = -0.701). Conclusion: These results suggested that exergame-based dual-task training improved both executive function and dual-task performance in older people. These positive effects could be transferred to enhance community walking ability. Clinical Trial Registration number: ACTRN 12617000095369.

Proposed Mobility Assessments with Simultaneous Full-Body Inertial Measurement Units and Optical Motion Capture in Healthy Adults and Neurological Patients for Future Validation Studies: Study Protocol

Healthy adults and neurological patients show unique mobility patterns over the course of their lifespan and disease. Quantifying these mobility patterns could support diagnosing, tracking disease progression and measuring response to treatment. This quantification can be done with wearable technology, such as inertial measurement units (IMUs). Before IMUs can be used to quantify mobility, algorithms need to be developed and validated with age and disease-specific datasets. This study proposes a protocol for a dataset that can be used to develop and validate IMU-based mobility algorithms for healthy adults (18–60 years), healthy older adults (>60 years), and patients with Parkinson’s disease, multiple sclerosis, a symptomatic stroke and chronic low back pain. All participants will be measured simultaneously with IMUs and a 3D optical motion capture system while performing standardized mobility tasks and non-standardized activities of daily living. Specific clinical scales and questionnaires will be collected. This study aims at building the largest dataset for the development and validation of IMU-based mobility algorithms for healthy adults and neurological patients. It is anticipated to provide this dataset for further research use and collaboration, with the ultimate goal to bring IMU-based mobility algorithms as quickly as possible into clinical trials and clinical routine.

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

Background and aims

One 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.

Methods

Twelve 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.

Results

An age effect was observed in almost all gait parameters for the ST condition. For DT only differences for stride length (p < .029, ɳ²_p = .239) as well as single and double limb support (p = .036, ɳ²_p = .227; p = .034, ɳ²_p = .218) remained. The measurement systems showed a lower absolute agreement compared to consistency across all systems.

Conclusions

When 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.

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

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.

Associations of Social Network Characteristics With Gait Speed in Older Women From Physical Activity Community Groups

The identification of social network factors associated with gait speed may offer different perspectives for improving community and clinical interventions for older adults. The objective of this study was to explore the associations of the social network of friends with gait speed. This was a cross-sectional study conducted in a sample of 128 older adult women recruited in community groups of physical activity. Clinical screening, social network questions, body composition evaluation, and gait speed test were applied to the participants. Logistic regression models were used to analyze associations between characteristics of the social network of friends and high gait speed. Findings indicated that social isolation was not associated with high gait speed and that popularity and proportion of friends with high gait speed were significantly associated with high gait speed. Findings suggested that there was a relationship between social network factors and the ability to perform high gait speed.

Spatio-temporal gait parameters obtained from foot-worn inertial sensors are reliable in healthy adults in single- and dual-task conditions

Inertial measurement units (IMUs) are increasingly popular and may be usable in clinical routine to assess gait. However, assessing their intra-session reliability is crucial and has not been tested with foot-worn sensors in healthy participants. The aim of this study was to assess the intra-session reliability of foot-worn IMUs for measuring gait parameters in healthy adults. Twenty healthy participants were enrolled in the study and performed the 10-m walk test in single- and dual-task ('carrying a full cup of water') conditions, three trials per condition. IMUs were used to assess spatiotemporal gait parameters, gait symmetry parameters (symmetry index (SI) and symmetry ratio (SR)), and dual task effects parameters. The relative and the absolute reliability were calculated for each gait parameter. Results showed that spatiotemporal gait parameters measured with foot-worn inertial sensors were reliable; symmetry gait parameters relative reliability was low, and SR showed better absolute reliability than SI; dual task effects were poorly reliable, and taking the mean of the second and the third trials was the most reliable. Foot-worn IMUs are reliable to assess spatiotemporal and symmetry ratio gait parameters but symmetry index and DTE gait parameters reliabilities were low and need to be interpreted with cautious by clinicians and researchers.

Virtual reality-based assessment of cognitive-locomotor interference in healthy young adults

BACKGROUND

A recent literature review emphasized the importance of assessing dual-task (DT) abilities with tasks that are representative of community ambulation. Assessing DT ability in real-life activities using standardized protocols remains difficult. Virtual reality (VR) may represent an interesting alternative enabling the exposure to different scenarios simulating community walking. To better understand dual-task abilities in everyday life activities, the aims of this study were (1) to assess locomotor and cognitive dual-task cost (DTC) during representative daily living activities, using VR, in healthy adults; and 2) to explore the influence of the nature and complexity of locomotor and cognitive tasks on DTC.

METHODS

Fifteen healthy young adults (24.9 ± 2.7 years old, 8 women) were recruited to walk in a virtual 100 m shopping mall corridor, while remembering a 5-item list (DT condition), using an omnidirectional platform and a VR headset. Two levels of difficulty were proposed for the locomotor task (with vs. without virtual agent avoidance) and for the cognitive task (with vs. without items modification). These tasks were also performed in single task (ST) condition. Locomotor and cognitive DTC were measured by comparing performances in ST and DT conditions. Locomotor performance was characterized using walking speed, walking fluidity, and minimal distance between the participant and the virtual agent during avoidance. Cognitive performance was assessed with the number of items correctly recalled. Presence of DTC were determined with one-sample Wilcoxon signed-rank tests. To explore the influence of the tasks' complexity and nature on DTC, a nonparametric two-way repeated measure ANOVA was performed.

RESULTS

No locomotor interference was measured for any of the outcomes. A cognitive DTC of 6.67% was measured (p = .017) while participants performed simultaneously both complex locomotor and cognitive tasks. A significant interaction between locomotor task complexity and cognitive task nature (p = .002) was identified on cognitive DTC.

CONCLUSIONS

In challenging locomotor and cognitive conditions, healthy young adults present DTC in cognitive accuracy, which was influenced by the locomotor task complexity task and the cognitive task nature. A similar VR-based protocol might be used to investigate DT abilities in older adults and individuals with a stroke.

The effect of text-based math task on dynamic stability control during stair descent

Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent.

Effects of individual progressive single- and dual-task training on gait and cognition among older healthy adults: a randomized-controlled comparison study

PURPOSE

Dual-task training has beneficial effects on older individuals for gait and cognition. This study was aimed to make a comparison between the effects of individual progressive single- and dual-task training on gait and cognition among healthy older individuals.

METHODS

A total of 32 participants were divided randomly into two groups as the single-task group (n = 16, 64.6 ± 3.3 years, 7 males and 9 females) and dual-task group (n = 16, 65.6 ± 2.6 years, 8 males and 8 females). The 10-m walk test with the LEGSys device was used to assess spatio-temporal gait parameters. The cognitive parameters were evaluated using the Standardized Mini-Mental State Exam and Stroop Test. An individual progressive 60 min single- and dual-task training programs were applied twice per week for a period of 6 weeks.

RESULTS

There were significant differences for both gait and cognition variables in the dual-task training group (p < 0.05), according to the comparison of pre- and post-treatment results. In the single-task training group, there were significant differences only in gait parameters with single-task conditions (p < 0.05). The comparisons of the delta values between the groups indicated that the dual-task training group was better compared to the single-task training group in gait speed, cadence, and many cognitive variables (p < 0.05).

CONCLUSION

Individual progressive dual-task training is an effective and useful method that improves gait performance and cognitive skills among older individuals.

TRIAL REGISTRATION NUMBER AND DATE

NCT03777111, 12/13/2018.

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.

Intraindividual variability in neural activity in the prefrontal cortex during active walking in older adults

Intraindividual variability in gait and cognitive performance is distinct from central-tendency measures and associated with clinical outcomes in aging. Knowledge concerning intraindividual variability in neural activity, however, has been relatively scarce, and no research to date has reported on such variability during active walking. The current study addressed this major gap in knowledge. Participants were community-residing older adults (n = 394; mean age = 76.29 ± 6.65 years; %female = 55). Functional near-infrared spectroscopy (fNIRS) was used to measure oxygenated hemoglobin (HbO2) in the prefrontal cortex under three experimental conditions: single-task-walk, single-task-alpha (cognitive task), and dual-task-walk, which required the participants to perform the two single tasks simultaneously. Intraindividual variability in neural activity was operationalized using the standard deviation of fNIRS-derived HbO2 observations assessed during a 30-s interval in each experimental condition. The increase in intraindividual variability in neural activity in the dual-task-walk condition compared to both single-task conditions was associated with the presence of cognitive impairments and being a male. Furthermore, measures of intraindividual variability in neural activity and gait performance were positively correlated only under the dual-task-walk condition. Intraindividual variability in the neural activity of gait may be a novel marker for age-related impairments in mobility and cognitive function. (PsycInfo Database Record (c) 2020 APA, all rights reserved).