جستجوی مقالات مرتبط با کلیدواژه « dual task » در نشریات گروه « پزشکی »

Several studies have investigated gait biomechanics in people with functional ankle instability (FAI). However, the potential role of information processing (attention) in the gait control of these patients is still unknown. Therefore, this study aimed to investigate the effect of cognitive load on the range of motion (ROM) of lower limb joints during walking in men with and without FAI.

The study was a non-randomized controlled clinical trial. Eighteen male subjects with FAI and 19 healthy subjects participated in this study and completed three randomized conditions (three trials per condition): normal walking on a treadmill (single task), normal walking while performing a cognitive task (dual task), and (3) performing cognitive task while sitting. Three-dimensional information of hip, knee, and ankle joint ROM in the sagittal, frontal, and transverse planes were measured as gait kinematic components, and the error ratio and average reaction time were measured as cognitive task indicators. The intraclass correlation coefficient (ICC) was used to determine the intrasession reliability of kinematic and cognitive measures.

The ICC of kinematic variables, including the hip, knee, and ankle joint ROM, with and without applying cognitive tasks in three planes was more than 0.70. During the single task, the group with FAI showed a significantly decreased knee ROM in the transverse plane and a decreased hip ROM in the sagittal plane compared to the healthy group. During the dual task, the group with FAI showed a significantly increased hip ROM in the sagittal plane compared to the healthy group. The results of the cognitive task showed that the group with FAI had a longer reaction time in the auditory Stroop test during dual-task walking than in the sitting position.

FAI can be an important factor in motor-cognitive interactions. Using a cognitive task may be an effective strategy in the rehabilitation program of men with FAI.

This study aimed to investigate the effect of motor dual task on the electromyographic activity of lower limb and trunk muscles during gait in cerebral palsy (CP) and healthy subjects.

10 patients with CP and 10 healthy matched subjects participated in this study voluntarily. Using an EMG USB2+ system and bipolar electrodes, the electromiyographic activity of biceps femoris (BF), rectus femoris (RF), and erector spinea at L3 level (L3) was recorded during gait with and without motor dual task. The gathered signals were processed using OT Biolab software. SPSS 22 software and ANOVA with significance level of 0.05 were used for statistical analysis.

Results showed that CP patients had greater normalized EMG of right and left L3 and left BF and RF muscle than control group. Motor dual task increased muscle activity in both groups (p=0.001) and had the same effect on the EMG of both right and left sides of healthy subjects. However, in the CP patients, motor dual task resulted in a higher muscle activity on the left side than the right side (p=0.01).

Motor dual task increases EMG activity of RF, BF, and L3 muscle of CP patientchr('39')s more than healthy subjects. This increase can be attributed to the greater attempt of these subjects to maintain body posture and dynamic balance. So, focus on the motor dual task can be recommended in evaluating and designing an appropriate exercise program for CP patients.

Visual impairment is blindness and low vision. Besides, it is among the most common disabilities and causes of functional disability among individuals with profound effects on functioning. Visual impairments cause some problems in visual receptors that include disorders in spatial orientation, balance, performing motor skills, cognitive skills, and learning. Balance control and injuries/falling are in diverse relations. Simultaneously, the issue of balance in the blinds' lives occurs in a more complicated manner, e.g., when cognitive attention is focused on something else. Considering the importance of balance for the blind to reduce falls and injuries and the effect of dual concentration and activity on balance and reduce the executive performance of the blind, compared with others. This study aimed to investigate the impact of Brailletonik cognitive–motor exercises on postural control and cognitive abilities in blind women. 

The was a quasi–experimental study with pretest–posttest and a control group design. The sample consisted of 21 blind women (age: 20–35 years) that lived in Isfahan Province, Iran, in 2018 and selected by convenience sampling technique. The study participants were randomly assigned into the experimental (n=12) and control (n=9) groups. The inclusion criteria of the study were absolute or very severe blindness; awareness in Braille for the blind; being in the age range of 20 to 35 years; no history of lower limb fractures or sprains in the past 6 months; no substance dependence and use of sedatives, alcohol, etc.; having certain diseases, such as inflammation, osteoporosis, diabetes, cardiovascular, specific orthopedic problems; presenting dizziness, hearing problems, and any factors that interfere with exercise or affect balance, and no regular sports activity during the last 3 months. The exclusion criteria were lower extremity problems, dizziness, physical weakness, and absence from>4 consecutive sessions or 3 non–consecutive sessions during the course. The experimental group participated in Brailletonik exercise sessions for 2 months 3 times a week; however, the control group participated in usual aerobic exercises. The study subjects were instructed quiet upright standing on a Kistler force platform under the following conditions: quiet upright standing (single task) and quiet upright standing while performing a cognitive activity (dual–task). Postural control was evaluated before and after Brailletonik exercises.</span> Each test was repeated 3 times for 60 seconds. The rest between the two trials was considered 60 seconds, and the test sequences were random. The parameters of mean velocity, the standard deviation of velocity in both anterior–posterior and medio–lateral plans, and standard deviation of amplitude in both anterior–posterior and medio–lateral plans from the center of foot pressure have recorded the device (for both pretest and posttest). Analysis of Covariance (ANCOVA) analyzed the obtained data in SPSS at a significance level of α=0.05.

The ANCOVA results for both single tasks suggested that the mean value of the mean velocity (p</em>=0.002), the standard deviation of the velocity in the lateral view (p</em>=0.004), and the standard deviation of the velocity in the anterior–posterior view (p</em>=0.05) in the experimental group was significantly less than the control group; however, the standard deviation of displacement in two lateral (p</em>=0.416) and anterior–posterior (p</em>=0.539) views was not significantly different between the two groups. Moreover, the ANCOVA results for dual–task indicated that the mean value of the mean velocity (p</em><0.001), the standard deviation of the velocity in the lateral view (p</em><0.001), and standard deviation of the velocity in the anterior–posterior view (p</em><0.001) in the experimental group was significantly smaller than the control group; however, the standard deviation of displacement in two lateral (p</em>=0.165) and anterior–posterior (p</em>=0.469) views did not significantly differ between the research groups.

The present study data revealed that the cognitive–motor exercises of brailletonik in dual tasks and single tasks effectively improve postural control of the blinds. Related centers, such as the State Welfare Organization, Exceptional Education, Rehabilitation Centers, and Families of the Blinds, are encouraged to include Brighton exercises in the weekly blinds Schedule.

Since walking and other tasks are simultaneously among the most common human activities, and considering the fact that that a large part of the elderly falls are during two tasks, the purpose of the present study was to examine the effect of walking speed and cognitive load on gait stability in the elderly.

A total of 10 healthy volunteer elderly (5 males and 5 females) without a history of falls took part in the study. They were asked to perform 3 walking trails on a treadmill, including walking at 3 paces (preferred, fast, and slow) with/without cognitive load. Cognitive task was performed by subtracting 3's from a random three digit number. The gait-stability ratio (GSR) was calculated for each of the above conditions. Two-way repeated measures ANOVA was used to examine the mean differences at the significance level of 0.05.

The findings showed that the cognitive performance score decreases with increasing speed and at faster speeds, compared with speed with cognitive load, GSR was found to be higher (p<0.01).

The results showed that the elderly, through different walking strategies, especially the shorter phase, provide more dual support while walking, so that they will fall less with increasing steadiness.

The wrong posture of head in patients with Forward Head Posture (FHP) could affect their visual and attention demands of postural control. The present study was carried out to investigate the effects of cognitive loading and visual occlusion on the static stability in patients with FHP compared to healthy participants.

A total of 17 individuals with FHP and 15 healthy people participated in the study. The center of pressure parameters were evaluated, including the standard deviation of displacement and velocity in anteroposterior and mediolateral directions, mean velocity, 95% Confidence Ellipse Area, and displacement range in anteroposterior and mediolateral directions. The postural task was conducted in eight conditions, two cognitive conditions (with and without cognition task), two postural task difficulties (standing on one foot and both feet), and two visual conditions (open and closed eyes) in both groups.

The main effects of group and cognitive conditions had no significant effect on almost none of the dependent variables, but the main effects of visual and postural conditions showed significant effects on all the dependent variables (p<0.05). The interaction effects of group and other factors, including visual, postural difficulties, and cognitive conditions, showed no significant effect on any of the center of pressure variables. On the other hand, the interaction of all factors together showed significant effects in some of the postural sway parameters.

The visual demand of postural control is not different in the people with forward head posture. The attention demand in these individuals, however, is higher when a difficult postural task is coincided with a cognitive task.

Studies report that mobility changes could be present in early stages of Alzheimer’s disease (AD) or even in previous stages, such as mild cognitive impairment (MCI). The use of motor tests, involving dual task, could facilitate screening and differentiation between elderly with AD and MCI. The goal of this research was to design and validation of dual-tasks based on Kinect sensor in a Virtual Reality environment to evaluate cognitive disorders in elderly.

The study was a validating research. The statistical society was the psychologists that were expert in the field of AD treatment, cognitive disorders, and the educational technologies, among which ten people were purposefully selected. A package of dual tasks based on Kinect sensor in a virtual reality environment was developed and evaluated for assessing cognitive disorders in geriatrics. The tools used in this research included a three dimensional game made by Unity, a Kinect sensor and a virtual reality headset. To determine the content validity of the software, a questionnaire was prepared by the technical team concerning the software content, and then was filled by the psychologists. Software validity was determined using the Kappa coefficient

Applying the revisions based on received comments, the evaluation of the experts’ opinions were analyzed and resulted in the Kappa coefficient of 93.4% .

The developed software seems to have the acceptable content validity. Dual tasks based on Kinect sensor may be used to accurately evaluate the cognitive function in elderly

Some individuals, copers, despite of an acute lateral ankle sprain could return to high-level physical activities, without development of functional ankle instability (FAI). Study about differences between copers and FAI groups results in identify factors that cause FAI. The aim of this study was to compare the effect of cognitive demands on dynami postural control in FAI, copers and uninjured controls. 42 individuals in three groups with FAI, copers and uninjured controls participated in this study. Dynamic postural stability with and without cognitive demands, was assessed. Repeated measure ANOVAs was used to determine possible significant interactions for the 2 factors. Interaction of group by cognitive difficulty was significant for Overal stability index (OSI) (P<0.001) and mediolateral stability index (MLSI) (P=0.005). A significant increase in OSI and MLSI observed in FAI group during dual task compared to the single task performance (p<0.05). However, a significant decrease in OSI was demonstrated in copers during dual task condition (p=0.004). The results showed that concurrent performance of cognitive task could effect on postural control after first lateral ankle sprain. responses to cognitive perturbations can consider as an important factor to identify adaptation mechanisms in copers and distinguish between copers and FAI groups.

The ability of the elderly to maintain balance during cognitive activity changes. Given the importance of recognizing the nature of the balance disorder among the elderly and the importance of verbal commands in rehabilitating such disorders, the purpose of this study was to investigate the Effectiveness of Dual Task and Focus of Attention Intervention on Balance in Elderly in Ahvaz.

The research method is semi-experimental and applied in terms of purpose. The statistical population was the elderly men of Salehin House in Ahvaz in 1397. 40 people were selected by available method. First, a static and dynamic equilibrium test was taken. Participants were randomly assigned to four groups of 10: dual task, internal attention, external attention, and control. The intervention was performed for 3 consecutive days. The dual task group performed a cognitive secondary task while performing a static and dynamic balance. The inner focus group focused on their feet during the performance. While performing the dynamic balance, the external focus group focused on the end of the path and focused on the static balance at a distance of 3 meters. An hour after the end of the training phase, the post-test was taken. Data analysis was performed using the statistical analysis of one-way variance analysis with SPSS software version 22.

The results showed that the groups did not differ in demographic characteristics (P <0.05). In the pre-test phase, there is no significant difference between groups (P <0.05), but in the post-test period, there is a significant difference between groups in both static and dynamic equilibrium (P <0.05).

The results of this study confirmed that the exercises of the instruction of the focus of internal attention weaken the static and dynamic balance. Exercises of the external focus guide improve static and dynamic balance, and the dual task attention guideline improves static balance in the elderly, but has a weakening effect on the dynamic balance of the elderly.

As the population of older people grows, the rate of falling among them increases significantly. This may lead to serious damage to the health status of the older people, their families and the society. One of the conditions that may result in falling in older people is when they walk and simultaneously perform another cognitive or motor task, known as dual-task walking (DTW). DTW is an interesting issue in the fields of geriatrics, cognitive and motor sciences and it is important for the researchers to decide how to design their studies on DTW paradigm. Thus, the aim of this study was to review the methodologies of DTW studies in older people.
We searched Scopus, PubMed, Embase and Index Copernicus since, 1998 till 2016. The keywords were a combination of three categories: 1) Elderly/ Older people/ aged people/ Aging; 2) Walking/ gait and 3) Cognitive/ executive function/ Memory/ Working memory/ Attention/ Processing speed/ Visuospatial/ Language/ Psychomotor speed.
Sixty-four articles met our inclusion criteria. The cognitive, motor and/or cognitive-motor tasks as the concurrent task while walking, the instrumentation for evaluating gait performance and the effects of dual-tasking on both gait properties and the quality of performing the concurrent task, were considered in our study.
While several cognitive and motor tasks are available to be used in the DTW and they need to be chosen based on the objectives of the studies, cognitive tasks are more prevalent. It may be attributed to the safety of the tasks since the hands are free to protect the elderly from possible falling during walking. Moreover, the speed of walking and other linear properties of walking were assessed in most of the studies.

Alzheimer's is a progressive brain disease that destroys brain cells to be causing impairment in memory and cognitive processes. Accordingly, the purpose of this study was the evaluation of cognitive function deficit in elderly patients with and without Alzheimer's disease using the dual task.
Material and This study was a quasi-experimental and between subject and within subject design was used in it. The 23 subjects (11 females and 12 males) with an age range of 62 to 81 years; 13 patients with Alzheimer's disease (AD) and 10 healthy elderly subjects (EC) with normal cognitive function participated in this study. Identifying people with Alzheimer's disease and healthy people was performed based on physician diagnoses and the Short Portable Mental Status Questionnaire (SPMSQ). After obtaining the average number of correct counting of months of the year in both simple and difficult cognitive task, each person was performed 10 tasks simultaneously (under Dual-task) in both simple and difficult condition.
The results showed that the AD group compared to the matched controls (EC) in the difficult condition of cognitive task, more errors were committed. Also level of difficulty and AD disease effect on drop in the average number of months counted at dual-task condition was significant (p It seems that attentional tasks is appropriate to separate patients with AD and healthy elderly individuals. But for a more detailed explanation of this issue, there is a need for further researches.

The inability to allocate attention to balance when performing concurrent tasks may cause the older adults to fall. Therefore, thisstudy aimed to investigate the effect of 2 types of dual-task training on the balance of older adults.
Methods & Materials :This quasi-experimental study included 36 eligible older adults (aged > 65 years) living in Kerman City, Iran. The selected participants were randomly divided into 3 groups based on the Berg balance scale scores, and each group consisted of 12 older adults. Our training groups comprised dual-task group under fixed priority, dual-task group under variable priority balance training, and control group. The experimental groups received 45-minute individualized training session, 3 times a week for 1 month (4 weeks). The training comprised of 3 kinds of activities: standing, transferring, and walking. The training was administered based on 2 principles of difficulty of moving task and individual’s safety as well as corresponding with the classification of Gentile’s moving task. We used the Berg balance test and sitting and walking times test for 2 conditions of single and dual tasks to evaluate balance in older people. For data analysis, we performed analysis of covariance and Bonferroni post hoc test with SPSS version 18 (PIt was found that there were significant differences (P≤0.05) between the control group and dual-task groups with fixed and variable priorities with regard to the balance performance test and the time of walking and sitting under single-task condition. In other words, 2 dual-task groups had better performance than the control group. However, no significant difference was seen between the 2 training groups of dual-task (P>0.05) with fixed and variable priorities in the test of the single-task condition. Moreover, the results of tests of sitting and walking time under dual-task condition showed significant differences between the control group and the dual-task groups with fixed or variable priorities and also between the 2 dual-task training groups with fixed and variable priorities (P≤0.05). Thus, this indicates that the training groups with dual tasks (fixed or variable priority) had better performance than the control group. In addition, the training dual-task group with variable priority had better performance than the same group with fixed priority.
The superiority of training with dual-task over single one and the superiority of dual-task training with variable priority over the fixed one (under dual-task condition) may be due to the “limited capacity of attention” theory, which explains the reduction in performance when performing imultaneous tasks. This difference and dominance may also be explained by other mechanisms, such as the capability of attention and focus on doing tasks simultaneously, involved in this process. Therefore, by designing balance training based on dual-task methods, especially training based on the ability to turn the focus of cognitive capabilities and their suitable allocation, the attention to these tasks improves and consequently, the risk of falling decreases in the older adults.

Multiple sclerosis is a progressive degenerative disease of myelin in the central nervous system. One of the main complications of the disease is development of balance disorder. Since considerable attention is needed to the balance issue, this study aimed to compare the two methods of single and dual task balance training on balance in the women with multiple sclerosis. 20 women between 25 to 45 years of age participated in this study. They were members of the MS association of Khorasn Razavi province with disability scores of (1-4). The patients were randomly assigned to two equal groups (single and dual balance groups) and conducted balance exercises three sessions per week for 8 weeks. The dual training group performed a cognitive task in addition to the balance training exercises. Using the Biodex balance analyzer instrument, we evaluated the indices of patients’ balance.Using SPSS software, data analysis was performed by analysis of covariance. Covariate effects were significant for all three variables (p<0.01). The indices of overall and anterior - posterior balance were significantly different between the two groups (p<0.01, p<0.02). The mean values for the overall and anterior-posterior balance indices decreased in the dual training group, but no significant differences were found in the medial-lateral index (p<0.4). According to the results of this study, dual training exercises were suitable methods to improve balance disorders in the women with MS.

Knee osteoarthritis is one of the most common musculoskeletal problems that can affect activity daily living of patients. Many studies have indicated postural control deficits in these patients; but the effect of dual tasking on postural control has not been examined yet. The aim of this study is to investigat the effect of cognitive task on postural control in the female patients with knee osteoarthritis. Postural stability in knee OA patients and healthy subjects (20 subjects in each group) in four positions was measured using the Force plate. Positions included double leg stance with closed or opened eyes with and without cognitive task. Area of COP and mean velocity (Vm) were measured for as static postural stability. Area under the curve increased in the double leg stance position in the patients significantly (P<0. 05). While mean velocity decreased by performing a dual task (P<0. 05). The response to dual-tasking was not significant between the 2 groups (P>0. 05). Postural control deficits and increased of center of pressure’s sway were identified in participants with Knee osteoarthritis. Also performance of a cognitive task resulted in decrease of postural sway، but the dual- tasking did not change the postural performance of knee OA patients compared to healthy subjects.