scholarly journals Do Functionally Fit Elderly Community-Dwelling Subjects Have Enough Time to Safely Cross the Road?

1970 ◽  
Vol 25 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Darija Rugelj ◽  
Marija Tomšič ◽  
France Sevšek
Keyword(s):  
Dual Task ◽  
Walking Speed ◽  
Community Dwelling ◽  
Urban Traffic ◽  
Gait Velocity ◽  
Dual Task Condition ◽  
Traffic Lights ◽  
The Road ◽  
Spatio Temporal ◽  
Task Conditions

Elderly people are the most vulnerable group in urban traffic and a large proportion of them are as pedestrians victims of traffic accidents. The majority of these happen while crossing the road. Crossing a busy road at an intersection with traffic lights or without them is a typical dual task condition requiring a motor task i.e. walking and a cognitive task such as monitoring traffic. The purpose of present study was to compare the walking speed and the related spatio-temporal gait variables of fallers and non-fallers in three walking conditions against the speeds required by regulations in Slovenia for safe street crossing. To assess the spatio-temporal characteristics of gait we used a 7m instrumented walkway.The general results showed that the spatio-temporal gait parameters did not differ between the two groups at the self-selected speed. But as soon as a constraint, such as fast walking speed, was imposed on the subjects the differences between the groups became evident. Fallers demonstrated a significantly slower mean gait velocity and shorter stride length while the cadence and the base of support did not differ between the two groups. In dual task conditions the difference between the two groups reached 25 percent. The fallers group gait velocity dropped to 0.99 m/s. The observed walking speed was slower than considered by the guidelines for the design of traffic light equipped road crossing.In conclusion, the results of walking speed under dual task conditions could be a useful parameter for planning of optimal pedestrian crossing in urban areas. These results will serve for the design of a population based study in Ljubljana.

scholarly journals Association of Affect and Gait Performance in Dual-Task Walking in Non-Demented Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 287-287
Author(s):  
Deepan Guharajan ◽  
Roee Holtzer
Keyword(s):  
Older Adults ◽  
Negative Affect ◽  
Positive Affect ◽  
Dual Task ◽  
Task Demands ◽  
Gait Velocity ◽  
Positive And Negative Affect ◽  
Increased Risk ◽  
Aging Populations ◽  
Task Conditions

Abstract Aging populations are at increased risk to experience mobility disability, which is associated with falls, frailty, and mortality. Previous studies have not examined the concurrent associations of both positive and negative affect with gait velocity. We examined whether individual differences in positive and negative affect predicted dual-task performance decrements in velocity in a dual-task (DT) paradigm in non-demented older adults. We hypothesize that positive affect would be associated with lower DT costs, and negative affect would be associated with higher DT costs. Participants (N = 403; mean age, = 76.22 (6.55); females = 56%) completed the Positive and Negative Affect Schedule (PANAS) and a DT paradigm that involved three task conditions: Single-Task-Walk (STW), Alpha (cognitive interference requiring participants to recite alternate letters of the alphabet), and Dual-Task-Walk (DTW) requiring participant to perform the two single tasks concurrently. Gait velocity was assessed via an instrumented walkway. As expected, results of a linear mixed effects model (LME) showed a significant decline in gait velocity (cm/s) from STW to DTW (estimate = -11.79; 95%CI = -12.82 to -10.77). LME results further revealed that negative affect was associated with greater decline in gait velocity from STW to DTW (ie., worse DT cost) (estimate = -0.38; 95%CI = -0.73 to -0.03). Positive affect did not, however, predict DT costs in gait velocity (estimate = -0.09; 95%CI = -0.23 to 0.05). These findings suggest that increased negative affect interferes with the allocation of attentional resources to competing task demands inherent in the DT paradigm.

scholarly journals Effects of a Dual-Task Paradigm and Gait Velocity on Dynamic Gait Stability during Stair Descent

2020 ◽  
Vol 10 (6) ◽  
pp. 1979 ◽  
Author(s):  
Qipeng Song ◽  
Wei Sun ◽  
Cui Zhang ◽  
Min Mao ◽  
Li Li
Keyword(s):  
Dual Task ◽  
Center Of Pressure ◽  
Force Plate ◽  
Gait Velocity ◽  
Task Condition ◽  
Dual Task Condition ◽  
Gait Stability ◽  
Single Task ◽  
Dual Task Paradigm ◽  
Dynamic Gait

Falls during stair negotiation have become one of the leading causes of accidental death. The effects of a concurrent cognitive or manual dual-task paradigm on dynamic gait stability remain uncertain. How much dynamic gait stability is influenced by gait velocity is also not clear. A total of 16 healthy young females descended a staircase under three different walking conditions: descend stairs only (single task), descend stairs while performing subtraction (cognitive dual-task), and descend stairs while carrying a glass of water (manual dual-task). An eight-camera Vicon motion analysis system and a Kistler force plate embedded into the third step of the staircase were used synchronously to collect kinematic and kinetic data. Gait velocity decreased and dynamic gait stability increased with both cognitive and manual dual-task conditions. The center of mass–center of pressure inclination angle increased with gait velocity but decreased with the manual dual-task condition compared to the single-task condition. Changes in gait velocity caused by the dual-task paradigm can partially explain the effects of dual-task dynamic gait stability. The influence of gait velocity should be considered in the assessment of dual-task effects.

scholarly journals The use of a simulation model to analyze the impact of heavy transport generated by the port to the city traffic.

2017 ◽  
Vol 42 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Natalia Stasiak ◽  
Leszek Smolarek
Keyword(s):  
Average Length ◽  
Autonomous Vehicle ◽  
Urban Traffic ◽  
Microscopic Simulation ◽  
Traffic Lights ◽  
The Road ◽  
Time Of Travel ◽  
The Impact ◽  
The City ◽  
The Web

Abstract The article presents an analysis of the impact of transport on heavy urban traffic on Wharf Kwiatkowski using program PTV Vissim. The data for analysis were taken from the Road and Greenery in Gdynia from program PTV Visum. Attention has been focused on vehicle traffic in the afternoon the top of its intensity. Model of Kwiatkowskiego Wharf, made entirely in the PTV VISSIM, was used for microscopic simulation of traffic. With its help, it was possible to find and analyze the behavior of each autonomous vehicle and interactions on the Web. For the analysis was used as a program of traffic lights currency at these junctions. The analysis results of simulation in the PTV VISSIM are related to the movement of the two structures. The first assumes that the route will move cars and trucks, taking into account their share in the network based on the intensity of traffic during peak hours of the afternoon, the second consisted only of cars. The results presented are based on measuring the time of travel and delays on specific relationships and the average length of queues at selected inlets. The results of analysis and simulation tests were subjected to statistical analysis.

Obstacle Avoidance and Dual-Tasking During Reaching While Standing in Patients With Mild Chronic Stroke

2021 ◽  
pp. 154596832110231
Author(s):  
Aditi A. Mullick ◽  
Melanie C. Baniña ◽  
Yosuke Tomita ◽  
Joyce Fung ◽  
Mindy F. Levin
Keyword(s):  
Obstacle Avoidance ◽  
Dual Task ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Avoidance Task ◽  
Success Rates ◽  
Task Condition ◽  
Dual Task Condition ◽  
Single Task ◽  
Task Conditions

Background. Poststroke individuals use their paretic arms less often than expected in daily life situations, even when motor recovery is scored highly in clinical tests. Real-world environments are often unpredictable and require the ability to multitask and make decisions about rapid and accurate arm movement adjustments. Objective. To identify whether and to what extent cognitive–motor deficits in well-recovered individuals with stroke affect the ability to rapidly adapt reaching movements in changing cognitive and environmental conditions. Methods. Thirteen individuals with mild stroke and 11 healthy controls performed an obstacle avoidance task in a virtual environment while standing. Subjects reached for a virtual juice bottle with their hemiparetic arm as quickly as possible under single- and dual-task conditions. In the single-task condition, a sliding glass door partially obstructed the reaching path of the paretic arm. A successful trial was counted when the subject touched the bottle without the hand colliding with the door. In the dual-task condition, subjects repeated the same task while performing an auditory–verbal working memory task. Results. Individuals with stroke had significantly lower success rates than controls in avoiding the moving door in single-task (stroke: 51.8 ± 21.2%, control: 70.6 ± 12.7%; P = .018) and dual-task conditions (stroke: 40.0 ± 27.6%, control: 65.3 ± 20.0%; P = .015). Endpoint speed was lower in stroke subjects for successful trials in both conditions. Obstacle avoidance deficits were exacerbated by increased cognitive demands in both groups. Individuals reporting greater confidence using their hemiparetic arm had higher success rates. Conclusion. Clinically well-recovered individuals with stroke may have persistent deficits performing a complex reaching task.

scholarly journals Real Life Does Not Always Get in the Way: Verbal Memory and the Sustained Attention to Response Task

2020 ◽  
Vol 64 (1) ◽  
pp. 234-238
Author(s):  
Samantha L. Smith ◽  
Graham K. Edgar ◽  
Paul N. Russell ◽  
William S. Helton
Keyword(s):  
Sustained Attention ◽  
Dual Task ◽  
Verbal Memory ◽  
Ecological Validity ◽  
Memory Task ◽  
Real Life ◽  
Future Research ◽  
Dual Task Condition ◽  
Response Task ◽  
Task Conditions

The Sustained Attention to Response Task (SART) is a go/no-go task where participants must respond frequently to target stimuli and withhold responses from infrequent neutral stimuli. Researchers have shown that the fast and frequent responding characteristic of SART is typically associated with difficulty withholding responses to no-go stimuli. Imposing additional cognitive demands has been shown to further impair task performance. In the present research, participants completed a modified SART task, a narrative memory task, and a dual-task condition where both were done simultaneously. No significant performance impairments were found in the dual- compared to single-task conditions. The tasks’ non-overlapping resource demands, alongside a potential arousing benefit of the memory task, may explain the lack of notable dual-task interference. Future research is needed to better understand the effects of arousal and other factors that may help to uncouple errors of commission from response time, particularly in tasks with high ecological validity.

scholarly journals Localization of Executive Functions in Dual-Task Performance with fMRI

2002 ◽  
Vol 14 (8) ◽  
pp. 1184-1199 ◽  
Author(s):  
André J. Szameitat ◽  
Torsten Schubert ◽  
Karsten Müller ◽  
D. Yves von Cramon
Keyword(s):  
Executive Functions ◽  
Task Performance ◽  
Dual Task ◽  
Task Difficulty ◽  
Task Condition ◽  
Subtraction Method ◽  
Dual Task Condition ◽  
Single Task ◽  
Dual Task Performance ◽  
Task Conditions

We report a study that investigated the neuroanatomical correlates of executive functions in dual-task performance with functional magnetic resonance imaging. Participants performed an auditory and a visual three-choice reaction task either separately as single tasks or concurrently as dual tasks. In the dual-task condition, two stimuli were presented in rapid succession to ensure interference between the component tasks (psychological refractory period). The behavioral data showed considerable performance decrements in the dual-task compared to the single-task condition. Dual-task-related activation was detected with two different neuroimaging methods. First, we determined dual-task-related activation according to the method of cognitive subtraction. For that purpose, activation in the dual-task was compared directly with activation in the single-task conditions. This analysis revealed that cortical areas along the inferior frontal sulcus (IFS), the middle frontal gyrus (MFG), and the intraparietal sulcus (IPS) are involved in dual-task performance. The results of the subtraction method were validated with the method of parametric manipulation. For this purpose, a second dual-task condition was introduced, where the difficulty of the dual-task coordination was increased compared with the first dual-task condition. As expected, behavioral dual-task performance decreased with increased dual-task difficulty. Furthermore, the increased dual-task difficulty led to an increase of activation in those cortical regions that proved to be dual-task related with the subtraction method, that is, the IFS, the MFG, and the IPS. These results support the conclusion that dorsolateral prefrontal and superior parietal cortices are involved in the coordination of concurrent and interfering task processing.

scholarly journals Reduced Sway During Dual Task Balance Performance Among People With Stroke at 6 and 12 Months After Discharge From Hospital

2009 ◽  
Vol 23 (8) ◽  
pp. 847-854 ◽  
Author(s):  
Dorit Hyndman ◽  
Ruth M. Pickering ◽  
Ann Ashburn
Keyword(s):  
Dual Task ◽  
Postural Sway ◽  
Force Plate ◽  
Balance Performance ◽  
Dual Task Condition ◽  
Eyes Closed ◽  
Balance Task ◽  
Balance Ability ◽  
Task Conditions ◽  
Discharge From Hospital

Background. Cognitive motor interference has been linked to poor recovery and falls. Little is known about recovery of dual-task balance ability poststroke. Methods. In this experimental study, postural sway was examined while standing on a force plate in preferred stance, with feet together, and with eyes closed, at 6 and 12 months postdischarge from hospital. Sway was assessed in isolation and while participants performed a cognitive (shopping list) task. Results . Seventy-six people with stroke (mean age 67 years; range, 21-91 years) took part. Fifty-four completed both assessments. When compared with the single task, sway during the dual-task condition was significantly lower in both the medial lateral (ML) and anterior posterior (AP) directions (both P < .0001). Sway in both directions was influenced by the difficulty of the balance task (both P < .0001). There was a trend of reduced sway at the 12-month assessment compared with the 6-month assessment: significant only in the ML direction ( P = .0056). Repeat fallers swayed more than non—repeat fallers, with increases of 48% and 44% in the ML ( P = .0262) and AP ( P = .0134) directions, respectively. No significant variation in the dual-task reduction in sway was found: the dual-task effect was remarkably consistent over all the conditions tested, particularly in the AP direction. Conclusions. Sway decreased under dual-task conditions and changed as the difficulty of the balance task changed. Stroke fallers swayed more than nonfallers and there was evidence of a reduction in sway over time, particularly in the ML direction.

scholarly journals Cognitive Load and Dual-Task Performance During Locomotion Poststroke: A Feasibility Study Using a Functional Virtual Environment

2010 ◽  
Vol 90 (2) ◽  
pp. 252-260 ◽  
Author(s):  
Rachel Kizony ◽  
Mindy F. Levin ◽  
Lucinda Hughey ◽  
Claire Perez ◽  
Joyce Fung
Keyword(s):  
Older Adults ◽  
Virtual Environment ◽  
Dual Task ◽  
Gait Speed ◽  
Stride Length ◽  
Community Dwelling ◽  
Control Group ◽  
Dual Task Condition ◽  
Dual Tasking ◽  
Stroke Group

Background Gait and cognitive functions can deteriorate during dual tasking, especially in people with neurological deficits. Most studies examining the simultaneous effects of dual tasking on motor and cognitive aspects were not performed in ecological environments. Using virtual reality technology, functional environments can be simulated to study dual tasking. Objectives The aims of this study were to test the feasibility of using a virtual functional environment for the examination of dual tasking and to determine the effects of dual tasking on gait parameters in people with stroke and age-matched controls who were healthy. Design This was a cross-sectional observational study. Methods Twelve community-dwelling older adults with stroke and 10 age-matched older adults who were healthy participated in the study. Participants walked on a self-paced treadmill while viewing a virtual grocery aisle projected onto a screen placed in front of them. They were asked to walk through the aisle (single task) or to walk and select (“shop for”) items according to instructions delivered before or during walking (dual tasking). Results Overall, the stroke group walked slower than the control group in both conditions, whereas both groups walked faster overground than on the treadmill. The stroke group also showed larger variability in gait speed and shorter stride length than the control group. There was a general tendency to increase gait speed and stride length during dual-task conditions; however, a significant effect of dual tasking was found only in one dual-task condition for gait speed and stride duration variability. All participants were able to complete the task with minimal mistakes. Limitations The small size and heterogeneity of the sample were limitations of the study. Conclusions It is feasible to use a functional virtual environment for investigation of dual tasking. Different gait strategies, including an increase or decrease in gait speed, can be used to cope with the increase in cognitive demands required for dual tasking.

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