Gender differences in dual task gait performance in older adults

Factors influencing gait performance in older adults in a dual-task paradigm

The aim of this study was to determine the effect of cognitive interference through a dual-task (DT) paradigm on gait parameters by sex or other predictive variables, such as physical fitness, health status, and cognition. A total of 125 older adults joined in this study (age, 72.42 ± 5.56 years old; 28 men and 97 women). The DT paradigm was evaluated through Comfortable Linear Gait (CLG) and Complex Gait Test (CGT). The gait parameters between single task (ST) vs. DT condition in men showed a significant reduction in speed (p < 0.001), cadence (p < 0.001), and step length (p = 0.049) and increased time to execute the CGT (p < 0.001), while women showed a decreased speed (p = 0.014), cadence (p < 0.001), and double support coefficient variation (CV) (p = 0.024) and increased single support time (p < 0.001) and CV step length (p < 0.05). In addition, women increased CGT time (p < 0.001). Furthermore, correlations between DT cost (DTC) cadence vs. Physical Activity for Elderly questionnaire (PASE) (r =  - 0.399; p = 0.008), DTC single support vs. 30 s Sit to Stand Test (r = - 0.356; 0.016), DTC single support vs. Rey Auditory Verbal Learning Test-Learning curve (r =  - 0.335; p = 0.023), DTC double support vs. 30 s Sit to Stand Test (r =  - 0.590; p < 0.001), DTC CV step length vs. 30 s Sit to Stand (r =  - 0.545; p = 0.003), and DTC CGT vs. 30 s Sit to Stand Test (r =  - 0.377; p = 0.048) were found. The results of our study indicate that the gait parameters within the DT condition decreased speed and cadence, while increasing CV step length and CGT time, causing slower gait with shortened steps in men and women.

The impact of music making on neural efficiency & dual-task walking performance in healthy older adults

Music making is linked to improved cognition and related neuroanatomical changes in children and adults; however, this has been relatively under-studied in aging. The purpose of this study was to assess neural, cognitive, and physical correlates of music making in aging using a dual-task walking (DTW) paradigm. Study participants (N = 415) were healthy adults aged 65 years or older, including musicians (n = 70) who were identified by current weekly engagement in musical activity. A DTW paradigm consisting of single- and dual-task conditions, as well as portable neuroimaging (functional near-infrared spectroscopy), was administered. Outcome measures included neural activation in the prefrontal cortex assessed across task conditions by recording changes in oxygenated hemoglobin, cognitive performance, and gait velocity. Linear mixed effects models examined the impact of music making on outcome measures in addition to moderating their change between task conditions. Across participants (53.3% women; 76 ± 6.55 years), neural activation increased from single- to dual-task conditions (p < 0.001); however, musicians demonstrated attenuated activation between a single cognitive interference task and dual-task walking (p = 0.014). Musicians also displayed significantly smaller decline in behavioral performance (p < 0.001) from single- to dual-task conditions and faster gait overall (p = 0.014). Given evidence of lower prefrontal cortex activation in the context of similar or improved behavioral performance, results indicate the presence of enhanced neural efficiency in older adult musicians. Furthermore, improved dual-task performance in older adult musicians was observed. Results have important clinical implications for healthy aging, as executive functioning plays an essential role in maintaining functional ability in older adulthood.

Influence of Sex on Cognitive and Motor Dual-Task Performance Among Young Adults: A Cross-Sectional Study

OBJECTIVE

To investigate the sex-related differences in single-task performance through motor torque, cognitive tasks and walking speed, and the combined dual-task costs (DTCs) considering both motor and cognitive performance in young adults.

METHODS

Sixty-seven non-athletic subjects 37 females and 30 males were enrolled. The study measured their knee extension muscle torque using an isokinetic strength dynamometer and their walking speed using the one step app. these assessments were performed both with and without a cognitive task, and the DTCs were calculated.

RESULTS

The females exhibited significantly larger motor performance dual task effect through (torque-DTC, speed-DTC) compared with males while exhibiting smaller cognitive dual task effect with muscle torque and speed.

CONCLUSION

Deterioration in motor performance during muscle force production and speed during dual tasks was large in females compared to males, whereas males experience a decline in cognitive ability when performing dual tasks compared with females.

Age-related changes in mobility assessments correlate with repetitive goal-directed arm-movement performance

BACKGROUND

There is ample evidence that mobility abilities between healthy young and elderly people differ. However, we do not know whether these differences are based on different lower leg motor capacity or instead reveal a general motor condition that could be detected by monitoring upper-limb motor behavior. We therefore captured body movements during a standard mobility task, namely the Timed Up and Go test (TUG) with subjects following different instructions while performing a rapid, repetitive goal-directed arm-movement test (arm-movement test). We hypothesized that we would be able to predict gait-related parameters from arm motor behavior, even regardless of age.

METHODS

Sixty healthy individuals were assigned to three groups (young: mean 26 ± 3 years, middle-aged 48 ± 9, old 68 ± 7). They performed the arm-movement and TUG test under three conditions: preferred (at preferred movement speed), dual-task (while counting backwards), and fast (at fast movement speed). We recorded the number of contacts within 20 s and the TUG duration. We also extracted TUG walking sequences to analyze spatiotemporal gait parameters and evaluated the correlation between arm-movement and TUG results.

RESULTS

The TUG condition at preferred speed revealed differences in gait speed and step length only between young and old, while dual-task and fast execution increased performance differences significantly among all 3 groups. Our old group's gait speed decreased the most doing the dual-task, while the young group's gait speed increased the most during the fast condition. As in our TUG results, arm-movements were significant faster in young than in middle-aged and old. We observed significant correlations between arm movements and the fast TUG condition, and that the number of contacts closely predicts TUG timefast and gait speedfast. This prediction is more accurate when including age.

CONCLUSION

We found that the age-related decline in mobility performance that TUG reveals strongly depends on the test instruction: the dual-task and fast condition clearly strengthened group contrasts. Interestingly, a fast TUG performance was predictable by the performance in a fast repetitive goal-directed arm-movements test, even beyond the age effect. We assume that arm movements and the fast TUG condition reflect similarly reduced motor function.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS) number: DRKS00016999, prospectively registered on March, 26, 2019.

Comparison of spatio-temporal gait parameters between the GAITRite® platinum plus classic and the GAITRite® CIRFACE among older adults: a retrospective observational study

BACKGROUND

The GAITRite® system is one of the gold standards for gait electronic analysis, especially for older adults. Previous GAITRite® systems were composed of an electronic roll-up walkway. Recently, a new GAITRite® electronic walkway, named CIRFACE, was commercialized. It is composed of a changeable association of stiff plates, unlike previous models. Are the gait parameters measured similar between these two walkways among older adults and according to the cognitive status, the history of falls, and the use of walking aids?

METHODS

In this retrospective observational study, 95 older ambulatory participants (mean, 82.6 ± 5.8 years) were included. Ten spatio-temporal gait parameters were measured simultaneously with the two GAITRite® systems in older adults while walking at comfortable self-selected pace. The GAITRite® Platinum Plus Classic (26') was superimposed on the GAITRite® CIRFACE (VI). Comparisons between the parameters of the two walkways were performed using Bravais-Pearson correlation, between-method differences (corresponding to bias), percentage errors and Intraclass Correlation Coefficients (ICC_2,1). Subgroup analyses were performed according to the cognitive status, the history of falls in the last 12 months and the use of walking aids.

RESULTS

The whole walk parameters recorded by the two walkways were extremely correlated with a Bravais-Pearson correlation coefficient ranging from 0.968 to 0.999, P < .001, indicating a very high correlation. According to the ICC_2,1 calculated for absolute agreement, all gait parameters had excellent reliability (ranging from 0.938 to 0.999). Mean bias for 9 parameters out of 10 were ranged from - 0.27 to 0.54, with clinically acceptable percentage errors (1.2-10.1%). Step length showed a substantially higher bias (1.4 ± 1.2 cm), nevertheless the percentage errors remained clinically acceptable (5%).

CONCLUSION

When walking at comfortable self-selected pace, the standard spatio-temporal walk parameters provided by both the GAITRite® PPC and the GAITRite® CIRFACE seem similar and very highly correlated in older adults with various cognitive or motor status. The data of studies using these systems can be compared and mixed with a very low risk of bias in a meta-analytic process. Also, the geriatric care units can choose the most ergonomic system according to their infrastructure without affecting their gait data.

TRIAL REGISTRATION

NCT04557592 (21/09/2020).

Effects of age, sex, frailty and falls on cognitive and motor performance during dual-task walking in older adults

BACKGROUND

Dual-task (DT) walking is of great interest in clinical evaluation to evaluate the risk of falling or cognitive declines in older adults. However, it appears necessary to investigate deeply the confounding factors to better understand their impact on dual-task performance.

OBJECTIVE

To evaluate the effect of age, sex, falls and frailty on cognitive and motor parameters in dual-task walking.

SUBJECTS

66 older participants (mean age = 75.5 ± 6.3; mean height = 165.8 ± 8.4 cm; mean weight = 68.4 ± 14 kgs) were split into groups based on their age, sex, fall and frailty status.

METHODS

Participants performed single-task walking, single-task cognitive (serial subtraction of 3), and dual-task walking (subtraction + walking) for 1 min at their fast pace. Gait speed, step length, step length variability, stance and swing phase time, single and double support, cadence, step time variability and gait speed variability were recorded in single- and dual-task walking and used to calculate the dual-task effect (DTE) as ((DT - ST) / ST) ∗ 100). The cognitive score (DTEcog) was calculated as the number of correct responses minus errors. Generalized linear mixed models (GLMM) were used to compare the effects of falls, frailty, age and sex on gait and cognitive variables.

RESULTS

The interaction frailty*sex and frailty*age were the major effect on the DTEs. Specifically, the DTE was higher in women than men and in the frail group compared to non-frail.

CONCLUSIONS

The present findings provide a better understanding on the confounding factors explaining the behavior in DT that could be used to develop more effective dual-task clinical programs for community-living older adults.

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.

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.

Differential Relationships Between Brain Structure and Dual Task Walking in Young and Older Adults

Almost 25% of all older adults experience difficulty walking. Mobility difficulties for older adults are more pronounced when they perform a simultaneous cognitive task while walking (i.e., dual task walking). Although it is known that aging results in widespread brain atrophy, few studies have integrated across more than one neuroimaging modality to comprehensively examine the structural neural correlates that may underlie dual task walking in older age. We collected spatiotemporal gait data during single and dual task walking for 37 young (18–34 years) and 23 older adults (66–86 years). We also collected T₁-weighted and diffusion-weighted MRI scans to determine how brain structure differs in older age and relates to dual task walking. We addressed two aims: (1) to characterize age differences in brain structure across a range of metrics including volumetric, surface, and white matter microstructure; and (2) to test for age group differences in the relationship between brain structure and the dual task cost (DTcost) of gait speed and variability. Key findings included widespread brain atrophy for the older adults, with the most pronounced age differences in brain regions related to sensorimotor processing. We also found multiple associations between regional brain atrophy and greater DTcost of gait speed and variability for the older adults. The older adults showed a relationship of both thinner temporal cortex and shallower sulcal depth in the frontal, sensorimotor, and parietal cortices with greater DTcost of gait. Additionally, the older adults showed a relationship of ventricular volume and superior longitudinal fasciculus free-water corrected axial and radial diffusivity with greater DTcost of gait. These relationships were not present for the young adults. Stepwise multiple regression found sulcal depth in the left precentral gyrus, axial diffusivity in the superior longitudinal fasciculus, and sex to best predict DTcost of gait speed, and cortical thickness in the superior temporal gyrus to best predict DTcost of gait variability for older adults. These results contribute to scientific understanding of how individual variations in brain structure are associated with mobility function in aging. This has implications for uncovering mechanisms of brain aging and for identifying target regions for mobility interventions for aging populations.

Predictors of Future Walking Speed: A 12-Month Monitoring Program

The purpose of the current study was to identify significant predictors of walking speed (WS) among community-dwelling older adults, as it is one of the most representative measures of functioning in their daily lives. Seventy-seven (24 adult men, 26 adult women, and 27 older-adult women) community-dwelling older adults (73.7 ± 4.9 years) performed two assessments, over a 12-month period. Several physical, cognitive, and psychological tests were performed, as well as assessing the preferred WS. Multiple linear regression, stratified by gender, was used to identify significant predictors of future WS. For the adult men, walking and functional performances at the first assessment predicted 71.9%; for adult women, reaction time, walking, and balance performance predicted 64.4%; and, for the older-adult women, fast walking and reaction time predicted 48.2% of the variance of future WS. Clinicians should consider including different exercises for each group of older adults to evaluate and preserve functional abilities.

Role of age and sex on dual tasking using a treadmill desk while performing cognitive tests

BACKGROUND

Treadmill desks have been used extensively to increase physical activity and decrease sedentary time in the work environment. However, dual tasking, such as simultaneously walking and performing a cognitive task, may result in diminished performance in one or both tasks.

RESEARCH QUESTION

Do age and sex impact ability to dual task while using a treadmill desk at a preferred walking speed?.

METHODS

A total of n = 24 younger (range of 18-24 years, mean age = 21.1 ± 1.6 years) and n = 25 older (range of 45-65 years, mean age = 53.0 ± 5.1 years) adults self-selected a comfortable walking speed ranging from 0.5 to 2.0 mph and performed the Stroop Color & Word test (measuring Inhibition) and the Sternberg Test of Working Memory (measuring Working Memory) while walking at their chosen speed on a treadmill desk and while seated. Testing was performed in two separate sessions with the order counterbalanced. Step length, stride length, gait cycle time, and coefficient of variation (CV) for each were measured using OptoGait software, and both reaction time and accuracy for the two cognitive tests were assessed. Dual Task Cost (DTC) was calculated by using the formula (Single task score - Dual task score)/Single task score)*100.

RESULTS

Younger adults had faster reaction time compared to older adults for both Working Memory and Inhibition tests (p < 0.05), and both males and females had slower reaction time for the Working Memory test when seated compared to walking (p < 0.05). For DTC, older adults had greater stride length CV during the Working Memory task (32.0 % vs 19.6 %), and regardless of age or sex, DTC for gait was greater than for cognition.

SIGNIFICANCE

These data provide evidence that while aging does decrease reaction time while dual tasking, few age differences and no sex differences were found in dual task cost. However, dual tasking results in diminished gait DTC compared to cognition DTC regardless of age or sex.

Beyond the Mini-Mental State Examination: The Use of Physical and Spatial Navigation Tests to Help to Screen for Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

Spatial navigation and dual-task (DT) performance may represent a low-cost approach to the identification of the cognitive decline in older adults and may support the clinical diagnosis of mild cognitive impairment (MCI) and Alzheimer's disease (AD).

OBJECTIVE

To assess the accuracy of different types of motor tasks in differentiating older persons with MCI and AD from healthy peers.

METHODS

Older adults aged 60 years or over (n = 105; healthy = 39; MCI = 23; AD = 43) were evaluated by the floor maze test (FMT), the senior fitness test, and DT performance. Receiver operating characteristic curve (ROC) analysis was used to evaluate the accuracy of the tests. We also performed principal component analysis (PCA) and logistic regression analysis to explore the variance and possible associations of the variables within the sample.

RESULTS

FMT (AUC = 0.84, sensitivity = 75.7%, specificity = 76.1%, p < 0.001) and DT (AUC = 0.87, sensitivity = 80.4%, specificity = 86.9%, p < 0.001) showed the highest performance for distinguishing MCI from AD individuals. Moreover, FMT presented better sensitivity in distinguishing AD patients from their healthy peers (AUC = 0.93, sensitivity = 94%, specificity = 85.6%, p < 0.001) when compared to the Mini-Mental State Examination. PCA revealed that the motor test performance explains a total of 73.9% of the variance of the sample. Additionally, the results of the motor tests were not influenced by age and education.

CONCLUSION

Spatial navigation tests showed better accuracy than usual cognitive screening tests in distinguishing patients with neurocognitive disorders.

Physiological and Cognitive Determinants of Dual-Task Costs for Gait Parameters: The Yishun Study

BACKGROUND

Studies indicate that physiological and cognitive aging are causally related and functionally interdependent. However, the relative contribution of physiological factors and cognition to dual-task costs (DTC) of gait parameters has not been well studied. In this cross-sectional study, we examined the trajectory of DTC of gait parameters across the adult age spectrum for both sexes and identified the contributions of physical and cognitive performance to DTC of gait.

METHODS

A total of 492 community-dwelling adults, aged 21-90 years, were randomly recruited into the study. Participants were divided into 7 age groups, with 10-year age range for each group. Demographic data, height, body mass, education level, and information on comorbidities were recorded. Cognition was measured using the Repeatable Battery for the Assessment of Neuropsychological Status. Physical performance included visual contrast sensitivity, postural sway, hand reaction time, handgrip strength, knee extensor strength, and single-task and dual-task gait assessments. Stepwise multivariable regression was used to examine the association between physical and cognitive performance with DTC of gait parameters.

RESULTS

Women were found to have significantly higher DTC of gait speed (p = 0.01), cadence (p < 0.01), and double support time (p < 0.01) than men. However, significant aging effect on DTC of gait speed (p = 0.01), step length (p = 0.01), and double support time (p = 0.01) was observed in men but not in women. Immediate memory was the primary determinant for the DTC of gait speed (β = -0.25, p < 0.01), step length (β = -0.22, p < 0.01), and cadence (β = -0.15, p = 0.03) in men. Besides immediate memory, postural sway (β = -0.13, p = 0.03) and hand reaction (β = 0.14, p = 0.02) were also significantly associated with DTC of step length and cadence, respectively, in women.

CONCLUSION

There were sex differences in the amplitude and trajectories of DTC of gait parameters. The DTC increased with age in men but not in women. Immediate memory was the primary determinant of DTC of gait parameters in men while immediate memory, postural sway, and reaction time were associated with DTC of gait in women. Future studies should investigate the clinical implications of the sex differences in the DTC with fall risks.

Dual-Task Gait Assessment in a Clinical Sample: Implications for Improved Detection of Mild Cognitive Impairment

OBJECTIVES

Research has longitudinally linked dual-task gait dysfunction to mild cognitive impairment (MCI) and dementia risk. Our group previously demonstrated that dual-task gait speed assessment distinguished between subjective cognitive complaints (SCC) and MCI in a memory clinic setting, and also found that differences in dual-task gait speed were largely attributable to executive attention processes. This study aimed to reproduce these findings in a larger diverse sample and to extend them by examining whether there were group differences in single- versus dual-task cognitive performance (number of letters correctly sequenced backward).

METHOD

Two-hundred fifty-two patients (M age = 66.01 years, SD = 10.46; 119 MCI, 133 SCC) presenting with cognitive complaints in an academic medical setting underwent comprehensive neuropsychological and gait assessment (single- and dual-task conditions).

RESULTS

Patients with MCI walked slower and showed greater decrement in cognitive performance than those with SCC during dual-task conditions. Neuropsychological measures of executive attention accounted for significant variance in dual-task gait performance across diagnostic groups beyond demographic and health risk factors.

DISCUSSION

Reproduction of our results within a sample over four times the previous size provides support for the use of dual-task gait assessment as a marker of MCI risk in clinical settings.

Reduction of falls in a rat model of PD falls by the M1 PAM TAK-071

RATIONALE

In addition to the disease-defining motor symptoms, patients with Parkinson's disease (PD) exhibit gait dysfunction, postural instability, and a propensity for falls. These dopamine (DA) replacement-resistant symptoms in part have been attributed to loss of basal forebrain (BF) cholinergic neurons and, in interaction with striatal dopamine (DA) loss, to the resulting disruption of the attentional control of balance and complex movements. Rats with dual cholinergic-DA losses ("DL rats") were previously demonstrated to model PD falls and associated impairments of gait and balance.

OBJECTIVES

We previously found that the muscarinic M1-positive allosteric modulator (PAM) TAK-071 improved the attentional performance of rats with BF cholinergic losses. Here, we tested the hypotheses that TAK-071 reduces fall rates in DL rats.

RESULTS

Prior to DL surgery, female rats were trained to traverse a rotating straight rod as well as a rod with two zigzag segments. DL rats were refamiliarized with such traversals post-surgery and tested over 7 days on increasingly demanding testing conditions. TAK-071 (0.1, 0.3 mg/kg, p.o.) was administered prior to daily test sessions over this 7-day period. As before, DL rats fell more frequently than sham-operated control rats. Treatment of DL rats with TAK-071 reduced falls from the rotating rod and the rotating zigzag rod, specifically when the angled part of the zigzag segment, upon entering, was at a steep, near vertical angle.

CONCLUSIONS

TAK-071 may benefit complex movement control, specifically in situations which disrupt the patterning of forward movement and require the interplay between cognitive and motor functions to modify movement based on information about the state of dynamic surfaces, balance, and gait.

Effects of aerobic fitness on cognitive motor interference during self-paced treadmill walking in older adults

BACKGROUND

Older adults experience greater cognitive motor interference (CMI) due to declines in cognitive and physical function. Although aerobic fitness has beneficial effects on cognition, its association with CMI is not clear.

AIMS

This study aims to investigate the effects of aerobic fitness on CMI during self-paced treadmill walking in older adults.

METHODS

Thirty participants (67.6 ± 10.34 years, 21 females) were included in a 2-day cross-sectional design study. Aerobic fitness was assessed with the Rockport 1-mile test. The dual-task paradigm consisted of walking only, and dual-task standing and dual-task walking (i.e., standing/walking while performing the Modified Stroop color word test) on a treadmill. To assess CMI, gait speed and accuracy rate were measured to later calculate the dual-task cost for each parameter.

RESULTS

Individuals with low aerobic fitness exhibited significantly greater gait speed dual-task cost than individuals with high aerobic fitness (p < 0.05). There were no significant findings for accuracy rate dual-task cost.

DISCUSSION

These study findings are the first to demonstrate increases in CMI in relation to low aerobic fitness. Results can be attributed to the relationship between aerobic fitness and cognition as well as theories related to attentional capacity.

CONCLUSION

Older adults with low aerobic fitness possess greater CMI when compared to older adults with high aerobic fitness. This provides a foundation of knowledge on how aerobic fitness in older adults may affect CMI which can lead researchers to examine the causal relationships between an aerobic exercise intervention program and CMI in older adults.

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).

Dual-tasking in older women: physical activity or else?

The interplay between gender, Physical Activity (PA), and Dual Tasking (DT) in older adults is unclear. This study aimed to address DT based on gender and PA level. One-hundred and twenty older adults (81 women and 39 men) participated. Timed up and go test and spatiotemporal gait measures were collected in single and DT conditions. Participants were grouped according to gender and PA level. Physical activity did not explain gender differences, women were slower and had shorter stride lengths when DT regardless of PA level. Findings indicate the necessity for tailored PA and functional interventions to improve women's performance.

Increased Q-Factor increases frontal-plane knee joint loading in stationary cycling

BACKGROUND

Q-Factor (QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment (KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.

METHODS

A total of 16 healthy participants (8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m², mean ± SD) participated. A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic (240 Hz) and pedal reaction force (PRF) (1200 Hz) data in 12 testing conditions: 4 QF conditions-Q1 (15.0 cm), Q2 (19.2 cm), Q3 (23.4 cm), and Q4 (27.6 cm)-under 3 workrate conditions-80 watts (W), 120 W, and 160 W. A 3 × 4 (QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions (p < 0.05).

RESULTS

Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.

CONCLUSION

Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.

Linear vs volume measures of ventricle size: Relation to present and future gait and cognition

OBJECTIVE

To compare the clinical utility of volume-based ratios with the standard linear ratio of Evans index (EI) by examining their associations with gait, cognition, and other patient and imaging variables.

METHODS

From MRI scans of 1,774 participants in the Mayo Clinic Study of Aging, we calculated 3 ventricle size measures: Evan index (frontal horn width divided by widest width of skull inner table), total ventricular volume, and frontal horn volume as ratios of total intracranial volume. Gait was measured by a timed 25-foot walk and cognition by a composite of psychometric tests. We also evaluated variables associated with the measures of ventricular size. Further, we evaluated gait and cognition associations with MRI of extraventricular findings seen in normal-pressure hydrocephalus: disproportionate enlargement of subarachnoid space (DESH) and focal sulcal dilations (FSD).

RESULTS

Ventricular volume measures had stronger association with gait and cognition measures than EI. In decreasing order of strength of association with ventricle size were DESH, FSD, white matter hyperintensity volume ratio, age, male sex, cortical thickness, and education. Modest evidence was observed that FSD was associated with future decline in gait and cognition.

CONCLUSION

Ventricular volume measures are clinically more useful than EI in indicating current and future gait and cognition. Multiple factors are associated with ventricle volume size, including FSD and DESH, suggesting that changes in CSF dynamics may go beyond simple ventriculomegaly.

Co-treatment with rivastigmine and idalopirdine reduces the propensity for falls in a rat model of falls in Parkinson's disease

RATIONALE

Falls in patients with Parkinson's disease (PD) are associated with cognitive, specifically attentional impairments and with losses in cholinergic projection systems. We previously established an animal model of the combined basal forebrain cholinergic-striatal dopaminergic losses of PD fallers (Dual Lesioned, DL, rats) and demonstrated that treating DL rats with an acetylcholinesterase inhibitor (AChEI), donepezil, together with a 5HT₆ receptor antagonist, idalopirdine, reduced fall frequency and improved associated aspects of the performance of DL rats traversing rotating rods.

OBJECTIVES

Here, we employed a longer and more taxing rotating beam apparatus to determine the potential therapeutic efficacy of idalopirdine when combined with the pseudo-irreversible, and thus relatively long-acting, AChE- and butyrylcholinesterase- (BuChE) inhibitor rivastigmine.

RESULTS

As before, vehicle-treated DL rats fell more frequently, committed more slips, and exhibited more movement stoppages than intact control rats. Repeated intermittent administration of rivastigmine and idalopirdine significantly improved the performance of DL rats. Rivastigmine alone also produced strong trends for reducing falls and slips. The combination treatment was more effective than rivastigmine alone in reducing stoppages and stoppage-associated falls. As before, idalopirdine treatment alone was ineffective.

CONCLUSIONS

These results extend the prediction that the combined treatment with idalopirdine and an AChEI improves complex movement control and reduces the propensity for falls in patients with movement disorders. Because of the importance of finding better treatments for gait and balance deficits in PD, the present results may further motivate a clinical exploration of the usefulness of this combination treatment.

Role of Gender in Dual-Tasking Timed Up and Go Tests: A Cross-Sectional Study

Gender plays a role in cognitive performance. Yet the selection of a secondary task, an important paradigm in studies of posture control, has not considered gender as a variable. We explored whether different cognitive tasks differentially influence performance during the Timed Up and Go (TUG) test in men and women. Twenty young adults performed five cognitive tasks while seated and during the TUG test. Men exhibited a slower normalized cadence than women. When seated, women recalled more items than men and men were more accurate in mental calculation task. There were no changes in spatiotemporal measures. We conclude that gender did not play a major role in motor-cognitive interference during dual task TUG test.

The role of gender in the association between personality and task priority in older adults' dual-tasking while walking

BACKGROUND

Falls are a major problem for older adults. Many falls occur when a person's attention is divided between two tasks, such as a dual task (DT) involving walking. Most recently, the role of personality in walking performance was addressed; however, its association with DT performance remains to be determined.

METHODS

This cross-sectional study of 73 older, community-dwelling adults explores the association between personality and DT walking and the role of gender in this relationship. Personality was evaluated using the five-factor model. Single-task (ST) and DT assessment of walking-cognitive DT performance comprised a 1-min walking task and an arithmetic task performed separately (ST) and concurrently (DT). Dual-task costs (DTCs), reflecting the proportional difference between ST and DT performance, were also calculated.

RESULTS

Gender plays a role in the relationship between personality and DT. Extraversion was negatively associated with DTC-motor for men (ΔR² = 0.06, p < 0.05). Conscientiousness was positively associated with DTC-cognition for women (ΔR² = 0.08, p < 0.01).

CONCLUSION

These findings may lead to effective personality-based early detection and intervention for fall prevention.

Stress and gender effects on prefrontal cortex oxygenation levels assessed during single and dual-task walking conditions

The ability to walk is critical for functional independence and wellbeing. The pre-frontal cortex (PFC) plays a key role in cognitive control of locomotion, notably under attention-demanding conditions. Factors that influence brain responses to cognitive demands of locomotion, however, are poorly understood. Herein, we evaluated the individual and combined effects of gender and perceived stress on stride velocity and PFC Oxygenated Hemoglobin (HbO₂ ) assessed during single and dual-task walking conditions. The experimental paradigm included Normal Walk (NW); Cognitive Interference (Alpha); and Walk-While-Talk (WWT) tasks. An instrumented walkway was used to assess stride velocity in NW and WWT conditions. Functional Near-Infrared-Spectroscopy (fNIRS) was used to quantify PFC HbO₂ levels during NW, Alpha and WWT. Perceived task-related stress was evaluated with a single 11-point scale item. Participants were community residing older adults (age = 76.8 ± 6.7 years; %female = 56). Results revealed that higher perceived stress was associated with greater decline in stride velocity from single to dual-task conditions among men. Three-way interactions revealed that gender moderated the effect of perceived stress on changes in HbO₂ levels comparing WWT to NW and Alpha. Attenuation in the increase in HbO₂ levels, in high compared to low perceived stress levels, from the two single task conditions to WWT was observed only in men. Thus, older men may be more vulnerable to the effect of perceived stress on the change in PFC oxygenation levels across walking conditions that vary in terms of cognitive demands. These findings confer important implications for assessment and treatment of individuals at risk of mobility impairments.

Precision Grip Control while Walking Down a Stair Step

The aim of this study was to determine whether the internal model regulating grip force (GF)/load force (LF) coordination during a brisk load increase is preserved when the lower extremities produce a perturbation during a single step-down task. We observed the coordination of the vertical ground reaction force (vGRF), GF and LF while holding a handheld object during a single step-down task. The 3 forces (vGRF, GF and LF) decreased during the start of the task. While the subject was descending, LF and GF became dissociated from vGRF and increased in value, probably to anticipate the first foot contact. Coordination of LF and GF was maintained until the maximal vGRF (knee extension). LF peaked in the same time window as vGRF, whereas GF peaked about 70 ms later. This desynchronization, which was previously observed in direct load increase on a handheld object, was interpreted to be a predictive action to ensure the smooth management of the brisk increase in load induced by the lower extremities. Incidentally, in this group, kinematic and dynamic differences were observed between men and women, which may highlight a gender-specific strategy to perform the step-down task. In conclusion, these results suggest that the internal model of precision grip is able to integrate a brisk load change, whatever its origin, and regulate the forces to provide an ideal GF to dampen a brisk load increase and secure the object.

Reducing falls in Parkinson's disease: interactions between donepezil and the 5-HT6 receptor antagonist idalopirdine on falls in a rat model of impaired cognitive control of complex movements

Falls are a leading cause of death in the elderly and, in a majority of patients with Parkinson's disease (PD), the leading levodopa-insensitive cause of hospitalization and long-term care. Falling in PD has been attributed to degeneration of forebrain cholinergic neurons that, in interaction with striatal dopamine losses, impairs the cognitive control of balance, gait, and movement. We previously established an animal model of these dual cholinergic-dopaminergic losses ("DL rats") and a behavioral test system (Michigan Complex Motor Control Task, MCMCT) to measure falls associated with traversing dynamic surfaces and distractors. Because the combined treatment of the acetylcholinesterase inhibitor donepezil and the 5-HT₆ receptor antagonist idalopirdine (Lu AE58054) was reported to exhibit synergistic pro-cholinergic activity in rats and improved cognition in patients with moderate Alzheimer's disease, here we assessed the effects of this treatment on MCMCT performance and attention in DL rats. Compared with the vehicle-treated group, the combined treatment greatly reduced (Cohen's d = 0.96) falls in DL rats when traversing dynamic surfaces and when exposed to a passive distractor. However, falls associated with a dual task distractor and sustained attentional performance did not benefit from this treatment. Analyses of the behavior in fall-prone moments suggested that this treatment improved the efficacy and speed of re-instating forward movement after relatively short stoppages. This treatment may reduce fall propensity in PD patients via maintaining planned movement sequences in working memory and improving the vigor of executing such movements following brief periods of freezing of gait.

Greater Fall Risk in Elderly Women Than in Men Is Associated With Increased Gait Variability During Multitasking

OBJECTIVE

As 90% of fractures are caused by falls, and as fractures are more common in elderly women than in elderly men, a better understanding of potential sex differences in fall rates and underlying mechanisms is needed. The purpose of this study was to determine whether women are more prone than men to falling, and to evaluate whether the risk of falling is associated with variations in gait patterns.

DESIGN, SETTING, AND PARTICIPANTS

The cohort for this prospective observational study consisted of 1390 community-dwelling men and women aged 70 years, examined in a health survey between July 2012 and November 2014.

MEASUREMENTS

Gait patterns were measured using a computerized walkway system during normal-speed, fast-speed, and dual-task trials. Triaxial accelerometers were used to collect objective data on physical activity, and self-reported fall data were collected by telephone 6 and 12 months after examination. Incident low-energy falls were defined as unexpected events in which participants came to rest on the ground.

RESULTS

During the follow-up period, 148 study participants (88 women, 60 men; P = .01) reported falls. After adjusting for multiple confounders, including objective measures of physical activity, socioeconomic factors, cardiovascular disease, and cognitive function, the odds ratio for falling in women was 1.49 (95% confidence interval [CI] 1.02-2.19). Variations in gait pattern were significantly (20%-40%) increased in fallers compared with nonfallers during the dual-task trial for step width, step length, stride length, step time, stance time, stride velocity, and single support time (all P < .05). Furthermore, women showed 15% to 35% increased variability in all of these gait parameters during the dual-task trial compared with men (all P < .01).

CONCLUSION

In the present cohort, 70-year-old women were at greater risk of falls compared with their male counterparts. This increased risk was associated with increased variation in gait pattern during dual-task activities, and may contribute to women's greater fracture risk compared with men.

Gait performance of the elderly under dual-task conditions: Review of instruments employed and kinematic parameters

Introduction The physiological deterioration associated with ageing exposes elderly persons to greater risks of falls, especially during the performance of simultaneous tasks during gait. Objectives To evaluate the effects of dual tasks (DT) on spatiotemporal gait parameters and to identify the tools and tasks most commonly used to assess the performance of DT among the elderly. Method Searches of the MEDLINE, PsycINFO, CINAHL, and SciELO databases were conducted. Observational studies, which evaluated gait changes during the performance of DT, published up to April 2014, were selected. Results A total of 385 articles were found, of which 28 were selected. Decreases in speed and increases in stride variability, stride time, step width, and double support time were observed under DT conditions. Motion analysis systems, such as the GAITRite walkway(r) system were the mostly commonly used instruments for the analyses of kinematic parameters (16 studies). DT was most commonly assessed by arithmetic calculations in 20 studies, followed by verbal fluency, in nine studies. The gait parameters most commonly assessed were speed (19 studies), followed by stride variability (14 studies). Conclusion The elderly showed changes in spatiotemporal gait parameters under DT conditions. Gait speed and stride variability were often assessed and, together, were considered good indicators of risks of falls.

Japanese elderly persons walk faster than non-Asian elderly persons: a meta-regression analysis

[Purpose] The purpose of this study was to clarify ethnic differences in walking speed by comparing walking speed in both Japanese and non-Asian elderly individuals and to investigate the necessity of consideration of ethnic differences in walking speed. [Subjects and Methods] Articles that reported comfortable walking speeds for community-dwelling elderly individuals were identified from electronic databases. Articles that involved community-dwelling individuals who were 60 years old or older and well functioning were included in the study. Articles that involved Asians were excluded. Weighted means for 5-m walking times were calculated as walking speeds from the Japanese and non-Asian sample data. The effects of age, gender, and ethnicity on 5-m walking times were then investigated using meta-regression analysis. [Results] Twenty studies (34 groups) were included for Japanese, and 16 studies (28 groups) were included for non-Asians. The weighted mean 5-m walking time was estimated to be 4.15 sec (95% confidence interval [CI]: 3.87-4.44) for Japanese and 4.24 sec (95% CI: 4.09-4.40) for non-Asians. Furthermore, using meta-regression analysis adjusted for age and gender, the 5-m walking time was 0.40 sec faster (95% CI: 0.03-0.77) for Japanese than for non-Asian elderly individuals. [Conclusion] Walking speed appeared faster for Japanese community-dwelling elderly individuals than for non-Asian elderly individuals.

Executive functions in men and postmenopausal women

INTRODUCTION

This study was designed to assess sex differences in older adults (55-65 years old) in executive functions and to examine the influence of hormone therapy (HT) in postmenopausal women.

METHOD

We have assessed task performance in memory, visuospatial, and executive functions in 29 women using HT, 29 women who never used HT, and 30 men.

RESULTS

Men outperformed never users in task switching and updating. HT users outperformed never users in updating. HT users outperformed never users and men in visual divided attention.

DISCUSSION

The present study support previous findings that sex and HT impact cognition and bring new insights on sex and HT-related differences in executive functions.

EEG measures reveal dual-task interference in postural performance in young adults

The study used a dual-task (DT) postural paradigm (two tasks performed at once) that included electroencephalography (EEG) to examine cortical interference when a visual working memory (VWM) task was paired with a postural task. The change detection task was used, as it requires storage of information without updating or manipulation and predicts VWM capacity. Ground reaction forces (GRFs) (horizontal and vertical), EMG, and EEG elements, time locked to support surface perturbations, were used to infer the active neural processes underlying the automatic control of balance in 14 young adults. A significant reduction was seen between single task (ST) and DT conditions in VWM capacity (F(1,13) = 6.175, p < 0.05, r = 06) and event-related potential (ERP) N1 component amplitude over the L motor (p < 0.001) and R sensory (p < 0.05) cortical areas. In addition, a significant increase in the COP trajectory peak (pkcopx) was seen in the DT versus ST condition. Modulation of VWM capacity as well as ERP amplitude and pkcopx in DT conditions provided evidence of an interference pattern, suggesting that the two modalities shared a similar set of attentional resources. The results provide direct evidence of the competition for central processing attentional resources between the two modalities, through the reduction in amplitude of the ERP evoked by the postural perturbation.

Your brain on speed: cognitive performance of a spatial working memory task is not affected by walking speed

When humans walk in everyday life, they typically perform a range of cognitive tasks while they are on the move. Past studies examining performance changes in dual cognitive-motor tasks during walking have produced a variety of results. These discrepancies may be related to the type of cognitive task chosen, differences in the walking speeds studied, or lack of controlling for walking speed. The goal of this study was to determine how young, healthy subjects performed a spatial working memory task over a range of walking speeds. We used high-density electroencephalography to determine if electrocortical activity mirrored changes in cognitive performance across speeds. Subjects stood (0.0 m/s) and walked (0.4, 0.8, 1.2, and 1.6 m/s) with and without performing a Brooks spatial working memory task. We hypothesized that performance of the spatial working memory task and the associated electrocortical activity would decrease significantly with walking speed. Across speeds, the spatial working memory task caused subjects to step more widely compared with walking without the task. This is typically a sign that humans are adapting their gait dynamics to increase gait stability. Several cortical areas exhibited power fluctuations time-locked to memory encoding during the cognitive task. In the somatosensory association cortex, alpha power increased prior to stimulus presentation and decreased during memory encoding. There were small significant reductions in theta power in the right superior parietal lobule and the posterior cingulate cortex around memory encoding. However, the subjects did not show a significant change in cognitive task performance or electrocortical activity with walking speed. These findings indicate that in young, healthy subjects walking speed does not affect performance of a spatial working memory task. These subjects can devote adequate cortical resources to spatial cognition when needed, regardless of walking speed.

Feasibility of dual-task gait training for community-dwelling adults after stroke: a case series

This case series explored the feasibility and efficacy of cognitive-motor dual-task gait training in community-dwelling adults within 12 months of stroke. A secondary aim was to assess transfer of training to different dual-task combinations. Seven male participants within 12 months of stroke participated in 12 sessions of dual-task gait training. We examined single and dual-task performance in four different dual-task combinations at baseline, after 6 and 12 sessions, and if possible, at 1-month followup. Feasibility was assessed by asking participants to rate mental and physical fatigue, perceived difficulty, anxiety, and fear of falling at the end of each session. Five of the seven participants demonstrated reduced dual-task cost in gait speed in at least one of the dual-task combinations after the intervention. Analysis of the patterns of interference in the gait and cognitive tasks suggested that the way in which the participants allocated their attention between the simultaneous tasks differed across tasks and, in many participants, changed over time. Dual-task gait training is safe and feasible within the first 12 months after stroke, and may improve dual-task walking speed. Individuals with a combination of physical and cognitive impairments may not be appropriate for dual-task gait training.

Prática habitual de atividade física afeta o equilíbrio de idosas?

INTRODUÇÃO: Os sistemas responsáveis pela manutenção do controle postural naturalmente entram em declínio com o avanço da idade, o que pode comprometer a capacidade de manter a postura nos limites de estabilidade, influenciando no equilíbrio das estruturas corporais e, consequentemente, aumentando os riscos de quedas. OBJETIVO: Verificar o impacto da prática habitual de atividade física sobre os parâmetros estabilográficos, equilíbrio estático e dinâmico de idosos fisicamente independentes. MATERIAIS E MÉTODOS: Trata-se de um estudo transversal e descritivo. A amostra foi composta de 77 mulheres com idade entre 60 a 75 anos estratificadas em cinco grupos de acordo com a prática de atividade física classificada pelo International Physical Activity Questionnaire (IPAQ). Foi utilizada a plataforma de força para avaliação estabilográfica, Teste de Apoio Unipodal (TAU) - equilíbrio estático, e o Timed Up and Go (TUG) - equilíbrio dinâmico. RESULTADOS: Foram observadas diferenças estatisticamente significantes em todos os parâmetros estabilométricos analisados exceto na velocidade de oscilação no eixo X. Por outro lado, os resultados referentes aos testes funcionais não apresentaram diferenças significativas entre os grupos, entretanto, para o TUG verificou-se uma tendência à boa mobilidade funcional com o aumento da prática habitual de atividade física. CONCLUSÃO: A prática habitual de atividade física mais elevada representa melhora na estabilidade corporal quantificada pela estabilometria, fato este não demonstrado nos testes neuromotores.

Increasing task complexity and ice hockey skills of youth athletes

The objective of this pilot study was to investigate the effects on cognitive performance of progressively adding tasks specific to ice hockey (skating, stick handling, and obstacle avoidance) during a visual interference task (Stroop Color Word Test-interference condition). In addition, the effects on locomotor performance of progressively adding tasks of stickhandling, visual interference, and obstacle avoidance related to maximal skating speed and minimal obstacle clearance were investigated in eight male athletes ages 10 to 12 years. Results revealed decreased performance on both cognitive and physical measures with increased task complexity, suggesting that adding complexity to an environment influences hockey skill performance.

Dual-task effects of spontaneous speech and executive function on gait in aging: exaggerated effects in slow walkers

This study compared the effects of spontaneous speech and executive function on gait and investigated the effects of single-task gait speed on dual-task costs. Twenty-one older adults (74.7 years, SD 5.9) and 23 younger adults (22 years, SD 1.2) walked for 60s while performing an auditory Stroop task and a spontaneous speech task; they also performed each task in isolation. Walking while talking significantly reduced gait speed in both groups; however, only older adults experienced significant cognitive-motor interference during the Stroop task. Stride duration variability and gait symmetry were also affected by the speech task in older but not younger adults. Dual-task costs on gait speed were greater in slow-walking older adults than fast walkers. These results demonstrate that spontaneous speech is a highly demanding task that has a profound impact on gait in older adults, especially those with gait speed <1 m/s.