Dual-task training reduces impact of cognitive task on postural sway

Multimodal training with dual-task enhances immediate and retained effects on dual-task effects of gait speed not by cognitive-motor trade-offs in stroke survivors: a randomized controlled trial

PURPOSE

Individuals who have experienced stroke may benefit from dual-task related training to improve gait speed performance. Whether noted improvements reflect true effects on gait or cognitive-motor trade-offs still remains unclear. Therefore, this study aimed to investigate the effects of dual-task training on dual-task effects of both walking and cognitive domains in stroke survivors.

MATERIALS AND METHODS

Forty-four individuals with stroke were randomized to dual-task or single-task training groups. Both groups exercised three 60-minute sessions per week for 4 weeks. The primary outcomes were dual-task effects on gait speed and cognitive score. Outcomes were assessed before and after the intervention and 1-month follow-up.

RESULTS

While both groups exhibited improvement in absolute gait speed under dual-task conditions, the dual-task training group demonstrated superior results by providing an additional gain on dual-task effects of gait speed. Compared to single-task training, dual-task training exhibited a significant improvement in dual-task effects of gait speed at post-treatment and follow-up. Regarding the dual-task effects on cognitive scores, no significant differences within and between groups after training were observed.

CONCLUSION

Dual-task training enhances immediate and retained effects on the dual-task effects of gait speed in individuals with stroke, not by cognitive-motor trade-offs.

TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov.

CLINICALTRIALS.GOV IDENTIFIER

NCT02686515.

The effect of visual sensory interference during multitask obstacle crossing in younger and older adults

When older adults step over obstacles during multitasking, their performance is impaired; the impairment results from central and/or sensory interference. The purpose was to determine if sensory interference alters performance under low levels of cognitive, temporal, and gait demand, and if the change in performance is different for younger versus older adults. Participants included 17 younger adults (20.9±1.9 years) and 14 older adults (69.7±5.4 years). The concurrent task was a single, simple reaction time (RT) task: depress button in response to light cue. The gait task was stepping over an obstacle (8 m walkway) in three conditions: (1) no sensory interference (no RT task), (2) low sensory interference (light cue on obstacle, allowed concurrent foveation of cue and obstacle), or (3) high sensory interference (light cue away from obstacle, prevented concurrent foveation of cue and obstacle). When standing, the light cue location was not relevant (no sensory interference). An interaction (sensory interference by task, p<0.01) indicated that RT was longer for high sensory interference during walking, but RT was not altered for standing, confirming that sensory interference increased RT during obstacle approach. An interaction (sensory interference by age, p<0.01) was observed for foot placement before the obstacle: With high sensory interference, younger adults placed the trail foot closer to the obstacle while older adults placed it farther back from the obstacle. The change increases the likelihood of tripping with the trail foot for younger adults, but with the lead limb for older adults. Recovery from a lead limb trip is more difficult due to shorter time for corrective actions. Overall, visual sensory interference impaired both RT and gait behavior with low levels of multitask demand. Changes in foot placement increased trip risk for both ages, but for different limbs, reducing the likelihood of balance recovery in older adults.

Different types of combined training programs to improve postural balance in single and dual tasks in children with intellectual disability

The study explored the effects of two combined training (Strength-Proprioceptive versus Cognitive-Balance) programs on postural balance during single-task and dual-task conditions in children with intellectual disability. The postural balance and the second cognitive-task performances were evaluated before and after 8-week of training in two groups: Strength-Proprioceptive Group (n = 12) and Cognitive-Balance Group (n = 10). Results showed that, in both groups and regardless of the training effect, the postural balance performance was significantly (p < 0.05) altered in the dual-task condition compared to the single-task one. After-training session, postural balance performance was improved significantly (p < 0.001) for all task conditions. After training session, the second cognitive-task performance was improved in the Strength-Proprioceptive Group (p < 0.001) and Cognitive-Balance Groupe (p < 0.05). In conclusion, the combined training programs, Strength-Proprioceptive and Cognitive-Balance, improved postural balance performance in single-task and dual-task conditions in children with intellectual disability.

Dual task impact on functional mobility and interaction of functional level and balance in patients with Duchenne muscular dystrophy

BACKGROUND

Dystrophin, a protein crucial for various brain regions governing higher-order functions like learning and memory is notably absent in individuals with Duchenne muscular dystrophy (DMD). This absence of dystrophin in the brain is believed to underlie cognitive challenges in DMD. Cognitive and motor challenges observed in DMD could potentially hinder the execution of dual tasks.

RESEARCH QUESTION

Is there a significant correlation between dual-task performance, functional mobility, and balance in children with DMD?

METHOD

The study included 28 participants (14 DMD, 14 typical development). Timed Up and Go (TUG) test results were recorded for single and dual-task conditions (motor-motor, cognitive-motor). Functional level was assessed using Motor Function Measurement-32 (MFM-32), Brooke Upper Extremity Scale, and Vignos Scale. Balance was evaluated using Balance Master System and Pediatric Functional Reach Test (PFRT).

RESULTS

Significant differences in TUG test scores across conditions were observed in both DMD and typical development groups (p < 0.05). Children with DMD exhibited longer completion times compared to typical development children (p < 0.05). Among children with DMD, there was a significant correlation between TUG scores in different task conditions and balance assessment (p < 0.05, r = 0.571 to -0.819). Lower MFM-32 scores in DMD children were correlated with worse TUG performance across conditions (p < 0.05, r = 0.586 to -0.868).

SIGNIFIANCE

This study sheds light on the multifaceted nature of dual-tasking challenges in individuals with DMD, thereby contributing to a deeper understanding of the implications for rehabilitation strategies.

The Effects of Various Cognitive Tasks Including Working Memory, Visuospatial, and Executive Function on Postural Control in Patients With Anterior Cruciate Ligament Injury

Anterior cruciate ligament (ACL) rupture can impair balance performance, particularly during cognitive motor dual-tasks. This study aimed to determine the effects of various modalities of cognitive load (working memory, and visuospatial and executive function) on postural control parameters in individuals with ACL injury. Twenty-seven ACL-injured and 27 healthy participants were evaluated doing different cognitive tasks (silent backward counting, Benton's judgment of line orientation, and Stroop color-word test) while standing on a rigid surface or a foam. Each task was repeated three times and then averaged. Center of pressure variables used to measure postural performance included sway area and sway velocity in anterior-posterior and medial-lateral directions. Cognitive performance was also assessed by calculating errors and the score of cognitive tasks. A mixed model analysis of variance for center of pressure parameters indicated that patients had more sways than the healthy group. The interaction of group by postural difficulty by cognitive tasks was statistically significant for cognitive errors (p < .01), and patients with ACL injury indicated more cognitive errors compared to healthy controls while standing on the foam. The main effect of cognitive task was statistically significant for all postural parameters, representing reduced postural sways in both groups with all cognitive tasks. However, ACL-injured patients showed more cognitive errors in difficult postural conditions, suggesting that individuals with ACL injury may prioritize postural control over cognitive task accuracy and adopt the posture-first strategy to maintain balance under dual-task conditions.

An investigation of the effects of dual-task balance exercises on balance, functional status and dual-task performance in children with Down syndrome

PURPOSE

To investigate the effects of dual task (DT) balance exercises on functional status, balance, and DT performance in children with Down Syndrome (DS).

METHODS

Participants were divided into two groups: intervention group (IG; n = 13) and control group (CG;n = 14). WeeFIM was used to measure the functional independence level and balance was evaluated using the Pediatric Balance Scale. DT performance was assessed using Timed Up and Go, Single Leg Stance, Tandem-Stance and 30 s Sit to Stand tests without concomitant task, with motor task or cognitive task. The IG received 16 sessions of DT training twice a week for 8 weeks.

RESULTS

Functional level, balance, and DT performance improved significantly in the IG, whereas only balance improved in the CG. Significantly better results were achieved in the IG, as demonstrated by greater pre/post-treatment changes.

CONCLUSION

DT balance exercises improved functional level, balance and DT performance of children with DS.

Dual-Task Training Effects on the Cognitive-Motor Interference in Individuals with Intellectual Disability

This study explored the effect of dual task (DT) training compared to single task (ST) training on postural and cognitive performances in DT conditions in individuals with intellectual disability (ID). Postural sways and cognitive performances were measured separately and simultaneously before and after 8 weeks in the ST training group (STTG), the DT training group (DTTG) and the control group (CG) that did not received any training. Before training, postural sways and cognitive performances were higher in the DT condition compared to ST one in all groups. After training, postural sways were higher in the DT condition compared to the ST only in the STTG and the CG. The cognitive performance increased after training only in the DTTG.

Quick on Your Feet: Modifying the Star Excursion Balance Test with a Cognitive Motor Response Time Task

The Star Excursion Balance Test (SEBT) is a common assessment used across clinical and research settings to test dynamic standing balance. The primary measure of this test is maximal reaching distance performed by the non-stance limb. Response time (RT) is a critical cognitive component of dynamic balance control and the faster the RT, the better the postural control and recovery from a postural perturbation. However, the measure of RT has not been done in conjunction with SEBT, especially with musculoskeletal fatigue. The purpose of this study is to examine RT during a SEBT, creating a modified SEBT (mSEBT), with a secondary goal to examine the effects of muscular fatigue on RT during SEBT. Sixteen healthy young male and female adults [age: 20 ± 1 years; height: 169.48 ± 8.2 cm; weight: 67.93 ± 12.7 kg] performed the mSEBT in five directions for three trials, after which the same was repeated with a response time task using Blazepod™ with a random stimulus. Participants then performed a low-intensity musculoskeletal fatigue task and completed the above measures again. A 2 × 2 × 3 repeated measures ANOVA was performed to test for differences in mean response time across trials, fatigue states, and leg reach as within-subjects factors. All statistical analyses were conducted in JASP at an alpha level of 0.05. RT was significantly faster over the course of testing regardless of reach leg or fatigue state (p = 0.023). Trial 3 demonstrated significantly lower RT compared to Trial 1 (p = 0.021). No significant differences were found between fatigue states or leg reach. These results indicate that response times during the mSEBT with RT is a learned skill that can improve over time. Future research should include an extended familiarization period to remove learning effects and a greater fatigue state to test for differences in RT during the mSEBT.

Effects of fixed versus variable task prioritization during short-term dual task practice on motor and cognitive task performance in young adults

OBJECTIVE

It has been shown that variable compared to fixed task prioritization during dual task practice more effectively improves motor (i.e., postural control) and cognitive (i.e., memory) performance in older adults. However, it is unclear whether this finding is also valid in young adults. Thus, the present study examined the effect of fixed (allocate equal priority on both tasks) versus variable (vary priority between both tasks) priority during short-term motor-cognitive dual task practice on single and dual task performance in healthy young adults (age range: 20-30 years).

RESULTS

During two days of practice, significant improvements of motor (i.e., balance task: reduced root mean square error; p < 001, η_p² = .72) and cognitive (i.e., arithmetic task: increased serial three subtractions; p < .001, η_p² = .78) task performance were observed and that was irrespective of group ("fixed priority" and "variable priority"). Further, the statistical analysis of post-practice single and dual task performance revealed no significant differences between groups, irrespective of task (i.e., motor or cognitive). This indicates that in young as opposed to old adults, single and dual task performance improvements are independent of task prioritization (i.e., fixed or variable priority) during short-term motor-cognitive dual task practice.

The effect of a concomitant stroop task during sit-to-stand tasks on postural control

[Purpose] This study aimed to explain the effect of a dual-task technology that utilizes motor and/or cognitive skills on the performance of major tasks, postural control, and gait consistency. [Participants and Methods] Eighteen healthy adults were divided into two groups: the single-word dual-task group and the control group (study 1). We enrolled 32 healthy adults to perform four-word Stroop (study 2) and sit-to-stand tasks simultaneously to determine the attentional demand for postural control and locomotion. [Results] The dynamic condition of postural control differed significantly between the single-task and single-word dual-task groups in Study 1. In Study 2, postural control in the four-word dual-task condition improved under both static and dynamic conditions. On comparing the results of studies 1 and 2, we found that during a four-word dual-task, healthy participants experienced a more significant decrease in postural sway than that experienced during the single-word dual-task. [Conclusion] Dual task of Stroop task with sit-to-stand could improve a postural control.

Could emotional and sensitization status affect postural sway in adults with knee osteoarthritis?

BACKGROUND AND PURPOSE

The manipulation of sensory conditions and attentional demand affect the postural sway in older adults with knee osteoarthritis (KOA). However, it is not known if emotional and sensitization status affects postural sway in this population. This study aimed to test if older adults with mild and moderate knee osteoarthritis with symptoms of depression and high sensitization would change the profile of postural sway.

METHODS

Design: A cross-sectional study was undertaken.

PARTICIPANTS

The center of pressure parameters of 30 older adults with mild and moderate knee osteoarthritis and 15 healthy controls were evaluated under different conditions manipulating the visual and attentional demand. We used the pressure pain threshold to measure the sensitization status. Furthermore, we applied the Beck Depression Inventory index to assess emotional status.

RESULTS

Manipulating the visual demand affected the center of pressure parameters for both groups, without differences between them. Compared to the healthy control group, the knee osteoarthritis group presented with worse scores on the Beck Depression Inventory, lower pressure pain threshold scores, and the correlations between the symptoms of depression and sensitization status ranged from weak to moderate. Finally, in the knee osteoarthritis group, we observed few and weak significant associations between the center of pressure parameters and the Beck Depression Inventory and the pressure pain threshold scores.

DISCUSSION

Emotional and sensitization status seem not to be more associated with the center of pressure of older adults with mild to moderate KOA than healthy adults. Thus, it suggests that this population can safely maintain postural sway, irrespective of depression symptoms and high sensitization.

Effects of Dual-Task Training on Gait Parameters in Elderly Patients with Mild Dementia

This study aimed to investigate the effectiveness of dual-task training (DTT) compared to single-task training (STT), on gait parameters in elderly patients with mild dementia (MD). Twenty-four elderly patients with MD were randomly assigned to the DTT (n = 13) or the STT group (n = 11). The DTT group performed a specific cognitive-motor DTT, while the STT group received only motor task training. Both training sessions lasted 8 weeks, with a frequency of 3 days per week, and the cognitive functions and gait parameters were measured. A statistically significant interaction effect was found between the two groups in stride length, stride velocity, cadence, step length, swing phase, stance phase, and double support phase (p < 0.05). After 8 weeks, the DTT group showed significant improvement in spatiotemporal parameters, except for the kinematic parameters (p < 0.05). In the between-group analysis, the DTT group showed more improvement than the STT group in stride velocity, step length, swing phase, stance phase, and double support (p < 0.05). These findings suggest that improvements in spatiotemporal gait parameters after DTT are reported in patients with MD. Our results can guide therapists to include dual tasks in their gait rehabilitation programs for the treatment of mild dementia.

Evaluating a new verbal working memory-balance program: a double-blind, randomized controlled trial study on Iranian children with dyslexia

BACKGROUND

It is important to improve verbal Working Memory (WM) in reading disability, as it is a key factor in learning. There are commercial verbal WM training programs, which have some short-term effects only on the verbal WM capacity, not reading. However, because of some weaknesses in current verbal WM training programs, researchers suggested designing and developing newly structured programs that particularly target educational functions such as reading skills. In the current double-blind randomized clinical trial study, we designed a new Verbal Working Memory-Balance (VWM-B) program which was carried out using a portable robotic device. The short-term effects of the VWM-B program, on verbal WM capacity, reading skills, and postural control were investigated in Iranian children with developmental dyslexia.

RESULTS

The effectiveness of the VWM-B program was compared with the VWM-program as a traditional verbal WM training. In comparison with VWM-program, the participants who received training by the VWM-B program showed superior performance on verbal WM capacity, reading skills, and postural control after a short-term intervention.

CONCLUSIONS

We proposed that the automatized postural control resulting from VWM-B training had a positive impact on improving verbal WM capacity and reading ability. Based on the critical role of the cerebellum in automatizing skills, our findings support the cerebellar deficit theory in dyslexia.

TRIAL REGISTRATION

This trial was (retrospectively) registered on 8 February 2018 with the Iranian Registry of Clinical Trials (IRCT20171219037953N1).

Video game and motor-cognitive dual-task training could be suitable treatments to improve dual-task interference in older adults

The objective of study was to investigate the effects of video game training in comparison with traditional motor-cognitive dual-task training on dual-task interference in older adults. Sixty older adults were allocated to the video game (intervention group) or the motor-cognitive dual-task training (control group). The outcome measures were dual-task cost (DTC) of linear metrics (Standard deviation (SD) of amplitude and velocity) and DTC of nonlinear metrics (approximate entropy, Lyapunov and correlation dimension) acquired from postural sway time series from both the mediolateral (ML) and anteroposterior (AP) directions. The results revealed in both groups, dual-task cost of SD of amplitude and velocity as well as Lyapunov were significantly decreased in post-training and follow-up compared with pre-training (p < 0.017), while there was no significant difference between the groups. Video game and motor-cognitive dual-task training could be recommended as suitable treatments to improve dual-task interference.

Cognitive and motor task performance under single- and dual-task conditions: effects of consecutive versus concurrent practice

The concurrent execution of two or more tasks simultaneously results in performance decrements in one or both conducted tasks. The practice of dual-task (DT) situations has been shown to decrease performance decrements. The purpose of this study was to investigate the effects of consecutive versus concurrent practice on cognitive and motor task performance under single-task (ST) and DT conditions. Forty-five young adults (21 females, 24 males) were randomly assigned to either a consecutive practice (INT consecutive) group, a concurrent practice (INT concurrent) group or a control (CON) group (i.e., no practice). Both INT groups performed 2 days of acquisition, i.e., practicing a cognitive and a motor task either consecutively or concurrently. The cognitive task required participants to perform an auditory stroop task and the number of correct responses was used as outcome measure. In the motor task, participants were asked to stand on a stabilometer and to keep the platform as close to horizontal as possible. The time in balance was calculated for further analysis. Pre- and post-practice testing included performance assessment under ST (i.e., cognitive task only, motor task only) and DT (i.e., cognitive and motor task simultaneously) test conditions. Pre-practice testing revealed no significant group differences under ST and DT test conditions neither for the cognitive nor the motor task measure. During acquisition, both INT groups improved their cognitive and motor task performance. The post-practice testing showed significantly better cognitive and motor task values under ST and DT test conditions for the two INT groups compared to the CON group. Further comparisons between the two INT groups revealed better motor but not cognitive task values in favor of the INT consecutive practice group (ST: p = 0.022; DT: p = 0.002). We conclude that consecutive and concurrent practice resulted in better cognitive (ST condition) and motor (ST and DT test conditions) task performance than no practice. In addition, consecutive practice resulted in superior motor task performance (ST and DT test conditions) compared to concurrent practice and is, therefore, recommended when executing DT practice schedules.

Multi-Component Intervention Program on Habitual Physical Activity Parameters and Cognitive Function in Patients with Mild Cognitive Impairment: A Randomized Controlled Trial

Age-related dementia refers to a state in which someone experiences multiple cognitive function impairment due to degenerative brain disease, and which causes difficulties in their daily life or social life. Dementia is the most common and serious obstacle in later life. Early intervention in the case of patients who are in the mild cognitive impairment (MCI) stage among the high-risk group can maintain and improve their cognitive function. The purpose of the current trial is aimed at investigating the association between a multi-component (exercise with cognitive) intervention program and habitual physical activity parameters on cognitive functions in MCI patients. Neuropsychological cognitive and depression assessments were performed by neuropsychologists according to normalized methods, including the Korean mini-mental State examination (K-MMSE) and modified Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog) and cognitive assessment tool (attention, processing speed), and the Korean version of the geriatric depression scale (SGDS-K), both at baseline and at a 12 weeks follow-up. The 12-week multi-component intervention improved cognitive function and habitual physical activity parameters in patients with MCI relative to controls. A multi-component intervention program for patients with MCI is considered to be an effective method of dementia prevention by improving global (ADAS-Cog) and frontal (trail-making test, digit symbol substitution test) cognition and habitual physical activity parameters such as moderate to vigorous physical activity and step count. In addition, it is important to encourage habitual physical activities to ensure that exercise intervention strategies are carried out at the duration and intensity required for improving physical and cognitive wellbeing and obtaining health benefits.

Anxiety does not always affect balance: the predominating role of cognitive engagement in a video gaming task

Scientists have predominantly assessed anxiety's impact on postural control when anxiety is created by the need to maintain balance (e.g., standing at heights). In the present study, we investigate how postural control and its mechanisms (i.e., vestibular function) are impacted when anxiety is induced by an unrelated task (playing a video game). Additionally, we compare watching and playing a game to dissociate postural adaptations caused by increased engagement rather than anxiety. Participants [N = 25, female = 8, M (SD) age = 23.5 (3.9)] held a controller in four standing conditions of varying surface compliance (firm or foam) and with or without peripheral visual occlusion across four blocks: quiet standing (baseline), watching the game with a visual task (watching), playing the game (low anxiety), and playing under anxiety (high anxiety). We measured sway area, sway frequency, root mean square (RMS) sway, anxiety, and mental effort. Limited sway differences emerged between anxiety blocks (only sway area on firm surface). The watching block elicited more sway than baseline (greater sway area and RMS sway; lower sway frequency), and the low anxiety block elicited more sway than the watching block (greater sway area and RMS sway; higher sway frequency). Mental effort was associated with increased sway area and RMS sway. Our findings indicate that anxiety, when generated through competition, has minimal impact on postural control. Postural control primarily adapts according to mental effort and more cognitively engaging task constraints (i.e., playing versus watching). We speculate increased sway reflects the prioritization of attention to game performance over postural control.

The performance of balance exercises during daily tooth brushing is not sufficient to improve balance and muscle strength in healthy older adults

Background

High prevalence rates have been reported for physical inactivity, mobility limitations, and falls in older adults. Home-based exercise might be an adequate means to increase physical activity by improving health- (i.e., muscle strength) and skill-related components of physical fitness (i.e., balance), particularly in times of restricted physical activity due to pandemics.

Objective

The objective of this study was to examine the effects of home-based balance exercises conducted during daily tooth brushing on measures of balance and muscle strength in healthy older adults.

Methods

Fifty-one older adults were randomly assigned to a balance exercise group (n = 27; age: 65.1 ± 1.1 years) or a passive control group (n = 24; age: 66.2 ± 3.3 years). The intervention group conducted balance exercises over a period of eight weeks twice daily for three minutes each during their daily tooth brushing routine. Pre- and post-intervention, tests were included for the assessment of static steady-state balance (i.e., Romberg test), dynamic steady-state balance (i.e., 10-m single and dual-task walk test using a cognitive and motor interference task), proactive balance (i.e., Timed-Up-and-Go Test [TUG], Functional-Reach-Test [FRT]), and muscle strength (i.e., Chair-Rise-Test [CRT]).

Results

Irrespective of group, the statistical analysis revealed significant main effects for time (pre vs. post) for dual-task gait speed (p < .001, 1.12 ≤ d ≤ 2.65), TUG (p < .001, d = 1.17), FRT (p = .002, d = 0.92), and CRT (p = .002, d = 0.94) but not for single-task gait speed and for the Romberg-Test. No significant group × time interactions were found for any of the investigated variables.

Conclusions

The applied lifestyle balance training program conducted twice daily during tooth brushing routines appears not to be sufficient in terms of exercise dosage and difficulty level to enhance balance and muscle strength in healthy adults aged 60–72 years. Consequently, structured balance training programs using higher exercise dosages and/or more difficult balance tasks are recommended for older adults to improve balance and muscle strength.

People with persistent postural-perceptual dizziness demonstrate altered postural strategies in complex visual and cognitive environments

BACKGROUND

People with PPPD report imbalance, increase in symptoms and impaired function within complex visual environments, but understanding of the mechanism for these behaviors is still lacking.

OBJECTIVE

To investigate postural control in PPPD we compared changes in center of pressure (COP) and head kinematics of people with PPPD (N = 22) and healthy controls (N = 20) in response to different combinations of visual and cognitive perturbations during a challenging balance task.

METHODS

Participants stood in a tandem position. Static or moving stars (0.2 Hz, 5 mm or 32 mm amplitude, anterior-posterior direction) were displayed through a head-mounted display (HTC Vive). On half the trials, participants performed a serial-3 subtraction task. We measured medio-lateral and anterior-posterior path and acceleration of COP and head.

RESULTS

Controls significantly increased all COP and head parameters with the cognitive task whereas PPPD increased only COP ML path and acceleration. Only controls significantly increased head anterior-posterior & medio-lateral acceleration with moving visual load. Cognitive task performance was similar between groups.

CONCLUSIONS

We observed altered postural strategies in people with PPPD, in the form of reduced movement with challenge, particularly around the head segment. The potential of this simple and portable head-mounted display setup for differential diagnosis of vestibular disorders should be further explored.

DUAL-TASK ASSESSMENT IMPLICATIONS FOR ANTERIOR CRUCIATE LIGAMENT INJURY: A SYSTEMATIC REVIEW

Background

Several systematic reviews have evaluated the role of dual-task assessment in individuals with concussion. However, no systematic reviews to date have investigated dual-task protocols with implications for individuals with anterior cruciate ligament (ACL) injury or ACL reconstruction (ACLR).

Purpose

To systematically review the evidence on dual-task assessment practices applicable to those with ACL deficiency/ACLR, specifically with the aim to identify motor-cognitive performance costs.

Study Design

Systematic review.

Methods

A systematic literature review was undertaken on those with ACL-deficient or ACL-reconstructed knees performing dual-task activities. The following databases were searched from inception to June 8, 2018 including CINAHL, PsychInfo, PubMed, SPORTDiscus, Web of Science, and gray literature. Three primary search categories (knee, cognition, and motor task) were included. Only one reviewer independently performed the database search, data extraction, and scored each article for quality. All studies were assessed for quality and pertinent data were extracted, examined and synthesized.

Results

Ten studies were included for analysis, all of which were published within the prior ten years. Performance deficits were identified in those with either ACL deficiency or ACLR while dual-tasking, such as prioritization of postural control at the expense of cognitive performance, impaired postural control in single limb stance, greater number of cognitive errors, and increased step width coefficient of variation while walking. No studies examined those with prior ACL injury or ACLR during tasks that mimicked ACL injury mechanisms such as jump-landing or single-leg cutting.

Conclusion

The results of the current systematic review suggests that postural control, gait, and/or cognitive deficits exist when evaluated under a dual-task paradigm in those with ACL deficiency or ACLR. This systematic review highlights the need for future research on dual-task assessment for individuals who have sustained an ACL injury or undergone ACLR, specifically utilizing more difficult athletic movements.

Level of Evidence

Level 3a.

Effects of Motor Versus Cognitive Task Prioritization During Dual-Task Practice on Dual-Task Performance in Young Adults

Background: Previous studies have reported positive effects of concurrent motor and cognitive task practice compared to motor or cognitive task practice only on dual-task performance in young adults. Knowledge about the effect of motor vs. cognitive task prioritization during practice on dual-task performance remains unclear and has not been investigated in depth so far. Thus, we examined the effects of motor task compared to cognitive task prioritization during dual-task practice on motor-cognitive performance in healthy young adults.

Methods: Healthy young adults were randomly assigned to dual-task (DT; i.e., concurrent motor and cognitive practice) or single-task (ST; i.e., motor or cognitive task practice only) practice groups. In DT practice, subjects were instructed to either prioritize the motor or the cognitive task. The motor task required subjects to keep a stabilometer in a horizontal position. The cognitive task involved serial three subtractions. Outcome variables were the root-mean-square error (RMSE) for the motor task and the total number of correct calculations for the cognitive task. All participants practiced for 2 consecutive days under their respective treatment condition and were tested under DT condition 24 h later (i.e., retention on day 3) without providing instructions on task prioritization.

Results: Irrespective of prioritization (i.e., prioritize the motor task or the cognitive task), the DT practice groups similarly improved their DT motor and cognitive task performance. The ST groups also improved motor or cognitive performance depending on their respective training contents (i.e., motor practice improved RMSE and cognitive practice improved number of correct calculations but not vice versa).

Conclusion: We conclude that DT compared to ST practice is well-suited to improve DT performance, irrespective of task-prioritization. DT but not ST practice resulted in an improved modulation of both domains (i.e., motor and cognitive) during DT performance. Our findings might be explained by freeing up central resources following DT practice that can be used to effectively perform the concurrent execution of motor and cognitive processing demands. However, this process is not further enhanced by the prioritized task domain.

The development of a cognitive rehabilitation task for mice

Obesity, neurodegenerative diseases, and injury can all lead to cognitive deficits, which can be improved clinically with the implementation of cognitive rehabilitation. Due to a lack of effective cognitive rehabilitation tools in mice, we re-designed a cognitive task utilized to detect problem-solving deficits, to develop a cognitive rehabilitation paradigm for mice. In this study, we developed a modified the Puzzle Box task by exposing B6 mice to a variety of obstacles and assessing the escape latencies. We then combined obstacles in order to create a "complex obstacle" for the problem-solving task. We determined that our task was reproducible in different cohorts of mice. Furthermore, with repetition the mice display an improvement in the performance, evident by a shorter escape latency and the ability to maintain this improvement in performance, indicative of long-term memory. Given that this approach is new, we validated whether this task could successfully detect deficits in a mouse model of cognitive impairment, the high-fat diet mouse. We demonstrate that high-fat diet mice have longer escape latencies when exposed to the complex obstacle compared to standard diet control mice. Taken together, these data suggest that the Puzzle Box is a valid task for cognitive rehabilitation in mice.

Effects of smart phone use on lower limb joint angle and dynamic balance during gait

BACKGROUND

Cognitive tasks influence gait by reducing balancing abilities. Diverse studies to date have examined dual-tasking and gait.

OBJECTIVE

This study aimed to determine the influences of smart phone use while walking on lower limb joint angle and dynamic balancing ability.

METHODS

Thirty healthy subjects were voluntarily recruited from the university population. All subjects were required to perform the tasks under three conditions: not using a smart phone, having a conversation by phone, and playing a smart phone game. Lower limb joint angle and dynamic balance ability related to smart phone use during gait were measured. Motion analysis was used to measure lower limb joint angle changes during gait, while balance measuring equipment was used to measure the dynamic balancing ability.

RESULTS

In the stability limit test to measure the changes in dynamic balancing abilities, significant differences were found among the different smart phone use conditions.

CONCLUSIONS

Smart phone use during movements that are required for balance requires special attention, and this study provides important basic data for follow-up studies.

The execution of the Grooved Pegboard test in a Dual-Task situation: A pilot study

Background

Manual dexterity is an important aspect in everyday life, which is widely studied through the Grooved Pegboard Test (GPT). Since Dual-Tasks (DT) activities are widely investigated and important to simulate everyday life situations, the objectives of the present pilot study were the evaluation of the effect of a cognitive task and a motor task during the performance of the GPT and the feasibility of the GPT in a DT contest. A secondary objective was to evaluate the training effect of the GPT.

Methods

A total of 31 young adults (20 man and 11 woman, age (SD): 27.7 (2.5)) performed the GPT eight times to understand the presence of a training effect before performing the GPT in DT. The additional tasks were a secondary cognitive task and a secondary motor task.

Results

All participants were able to complete the required conditions. The GPT performed in motor DT were significantly slower than those performed singularly (p < 0.01). The GPT performed with the cognitive task was slower than the secondary motor task (p < 0.05). A training effect was present up to the 4^th consecutive trial.

Conclusions

The GPT can be executed with a cognitive or motor task to increase the difficulty of the trial to better evaluate manual dexterity and cognitive capacities.

Postural sway changes during static standing with concurrent task in children with traumatic brain injury

OBJECTIVE

To investigate the effects of concurrent tasks (motor and cognitive) on postural control performance in children with traumatic brain injury (TBI) compared to typically developing (TD) control subjects.

METHODS

Sixteen children with TBI (aged 11.63+/-1.89 years) and 22 TD controls (aged 11.41+/-2.24 years) participated in this case-control study. This study was conducted between May 2016 and March 2017. Each child performed static standing under 3 different conditions: single, concurrent motor, and concurrent cognitive task. Postural control performance measure includes sway area, anterior-posterior (AP) sway velocity, medio-lateral (ML) sway velocity, AP sway distance and ML sway distance as measured using the APDM Mobility Lab (Oregon, Portland). A repeated-measure analysis of variance was used to analyse the data.

RESULTS

We found that children with TBI showed significantly more deterioration in postural control performance than TD children (p<0.05). Both concurrent tasks (motor and cognitive) significantly decreased postural control performance in both groups with more pronounced changes in children with TBI than that of the TD controls.

CONCLUSION

The results demonstrated that, performing concurrent tasks (motor and cognitive) during upright standing resulted in deterioration of postural control performance. The existence of cognitive and balance impairment in children with TBI will possibly cause concurrent tasks to be more complex and demands greater attention compared to single task.

Toward Objective Evaluation of Working Memory in Visualizations: A Case Study Using Pupillometry and a Dual-Task Paradigm

Cognitive science has established widely used and validated procedures for evaluating working memory in numerous applied domains, but surprisingly few studies have employed these methodologies to assess claims about the impacts of visualizations on working memory. The lack of information visualization research that uses validated procedures for measuring working memory may be due, in part, to the absence of cross-domain methodological guidance tailored explicitly to the unique needs of visualization research. This paper presents a set of clear, practical, and empirically validated methods for evaluating working memory during visualization tasks and provides readers with guidance in selecting an appropriate working memory evaluation paradigm. As a case study, we illustrate multiple methods for evaluating working memory in a visual-spatial aggregation task with geospatial data. The results show that the use of dual-task experimental designs (simultaneous performance of several tasks compared to single-task performance) and pupil dilation can reveal working memory demands associated with task difficulty and dual-tasking. In a dual-task experimental design, measures of task completion times and pupillometry revealed the working memory demands associated with both task difficulty and dual-tasking. Pupillometry demonstrated that participants' pupils were significantly larger when they were completing a more difficult task and when multitasking. We propose that researchers interested in the relative differences in working memory between visualizations should consider a converging methods approach, where physiological measures and behavioral measures of working memory are employed to generate a rich evaluation of visualization effort.

Combined Intervention of Physical Activity, Aerobic Exercise, and Cognitive Exercise Intervention to Prevent Cognitive Decline for Patients with Mild Cognitive Impairment: A Randomized Controlled Clinical Study

This study aimed to investigate the association between a dual-task intervention program and cognitive and physical functions. In a randomized controlled trial, we enrolled 49 individuals with MCI. The MCI diagnosis was based on medical evaluations through a clinical interview conducted by a dementia specialist. Cognitive assessments were performed by neuropsychologists according to standardized methods, including the MMSE and modified Alzheimer’s disease Assessment Scale-Cognitive Subscale (ADAS-Cog), both at baseline and at 3 months follow-up. The program comprised physical activity and behavior modification, aerobic exercise, and a cognitive and exercise combined intervention program. Analysis of the subjects for group-time interactions revealed that the exercise group exhibited a significantly improved ADAS-Cog, working memory, and executive function. Total physical activity levels were associated with improvements in working memory function and the modified ADAS-Cog score, and the associations were stronger for daily moderate intensity activity than for daily step count. The 24-week combined intervention improved cognitive function and physical function in patients with MCI relative to controls. Encouraging participants to perform an additional 10 min of moderate physical activity under supervision, during ongoing intervention, may be more beneficial to prevent cognitive decline and improve exercise adherence.

Dual Task Training Effects on Upper Extremity Functions and Performance of Daily Activities of Chronic Stroke Patients

Objectives

The purpose of this research was to study the influences of dual task training on upper extremity function and performance of daily activities of chronic stroke patients.

Methods

Dual task training was performed on 21 patients who had suffered a chronic stroke with hemiplegia. The dual task training was performed for 30 minutes per session, for 5 days a week, for 3 weeks. There were 5 evaluations carried out over 3 weeks before and after the intervention. Changes in upper extremity function were measured by using the Box and block test. Changes in the performance of daily activities were measured using the Korea-Modified Barthel Index.

Results

The mean upper limb function score of the chronic stroke patients increased significantly from 21.88 ± 19.99 before the intervention, to 26.22 ± 15.65 after the intervention (p < 0.05), and the mean daily activities score increased significantly from 65.82 ± 12.04, to 67.29 ± 12.90 (p < 0.05).

Conclusion

Dual task training effectively improved upper extremity function, and the performance of daily activities in chronic stroke patients.

A randomized controlled trial protocol to test the efficacy of a dual-task multicomponent exercise program in the attenuation of frailty in long-term nursing home residents: Aging-ONDUAL-TASK study

Background

The purpose of the Aging-ON_DUAL-TASK study is to determine if a supervised dual-task program carried out in long-term nursing homes is able to attenuate frailty in a greater extent than the same multicomponent exercise program alone.

Methods

This multicenter randomized controlled trial will include 188 participants who will be randomly allocated to either a multicomponent exercise program or to the same multicomponent program with simultaneous cognitive training (dual-task training). Inclusion criteria are as follows: ≥ 70 years, ≥ 50 on the Barthel Index, ≥ 20 on the Mini Examen Cognoscitivo (MEC-35) who are able to stand up and walk independently for 10 m. Subjects in the multicomponent group will attend a twice-a-week multicomponent exercise program of 1-h duration per session, consisting of strength and balance exercises. Participants in the dual-task group will perform the same multicomponent exercise program with concurrent individually tailored cognitive tasks. Study assessments will be conducted at baseline and at 3 months. The primary outcome measure will be gait speed under dual-task conditions and secondary outcomes will include physical fitness measurements, gait spatiotemporal parameters, cognition and emotional assessments, several frailty scales and objectively measured physical activity.

Discussion

The present research will add valuable information to the knowledge around the effects of the dual-task program in long-term nursing home residents, taking altogether physical, cognitive and emotional variables linked to frailty.

Trial registration

Australian and New Zealand Clinical Trials Registry (ANZCTR) with the identifier: ACTRN12618000536268. Registration date: 11/04/2018.

Progressive treadmill cognitive dual-task gait training on the gait ability in patients with chronic stroke

The purpose of this study was to investigate the effects of progressive treadmill cognitive dual-task training on gait performance in individuals with chronic stroke patients. Twenty-six participants with chronic hemiparesis were recruited to this study and randomly distributed into two groups: progressive treadmill cognitive dual-task gait training (PTCDG group, 13 patients), conventional treadmill gait training (CTG group, 13 patients). All patients underwent 20 sessions of treadmill gait training with a harness (5 times per week, for a total of 4 weeks). The GAITRite was used to analyze gait kinematics, and 10-m walking test (10MWT) wear used as the clinical evaluation indicators. After training, PTCDG group showed significant improvement in gait velocity, cadence, single support time, and 10MWT compared to the control group. However there was no significant difference between the groups in the stride lengths in the affected and unaffected sides. The study verified that progressive treadmill cognitive dual-task gait training had a positive influence on the gait and clinical gait index in chronic stroke patients.

Effects of Single Compared to Dual Task Practice on Learning a Dynamic Balance Task in Young Adults

Background: In everyday life, people engage in situations involving the concurrent processing of motor (balance) and cognitive tasks (i.e., “dual task situations”) that result in performance declines in at least one of the given tasks. The concurrent practice of both the motor and cognitive task may counteract these performance decrements. The purpose of this study was to examine the effects of single task (ST) compared to dual task (DT) practice on learning a dynamic balance task.

Methods: Forty-eight young adults were randomly assigned to either a ST (i.e., motor or cognitive task training only) or a DT (i.e., motor-cognitive training) practice condition. The motor task required participants to stand on a platform and keeping the platform as close to horizontal as possible. In the cognitive task, participants were asked to recite serial subtractions of three. For 2 days, participants of the ST groups practiced the motor or cognitive task only, while the participants of the DT group concurrently performed both. Root-mean-square error (RMSE) for the motor and total number of correct calculations for the cognitive task were computed.

Results: During practice, all groups improved their respective balance and/or cognitive task performance. With regard to the assessment of learning on day 3, we found significantly smaller RMSE values for the ST motor (d = 1.31) and the DT motor-cognitive (d = 0.76) practice group compared to the ST cognitive practice group but not between the ST motor and the DT motor-cognitive practice group under DT test condition. Further, we detected significantly larger total numbers of correct calculations under DT test condition for the ST cognitive (d = 2.19) and the DT motor-cognitive (d = 1.55) practice group compared to the ST motor practice group but not between the ST cognitive and the DT motor-cognitive practice group.

Conclusion: We conclude that ST practice resulted in an effective modulation of the trained domain (i.e., motor or cognitive) while only DT practice resulted in an effective modulation of both domains (i.e., motor and cognitive). Thus, particularly DT practice frees up central resources that were used for an effective modulation of motor and cognitive processing mechanisms.

Dual-task training in older adults: The effect of additional motor tasks on mobility performance

OBJECTIVES

Dual-task (DT) performance is common to most activities of daily living and difficulties in DT activities may reduce quality of life in older adults. This study investigated the effect of DT training in a sample of older adults.

METHODS

Sixty older adults (mean=74.4±3.1years) participated in the study. Twenty-two older adults were included in the control (CG), 19 in the single-task (ST) training and 19 in DT training group. ST group received balance and walking training twice a week for16 weeks, while DT training group performed the same training with additional motor tasks. Data were gathered on 6m timed walk (6MTW), timed up and go test (TUG) and four square step test (FSST). DT conditions required participants to complete 6MTW, TUG and FSST, either (i) while carrying a glass of water or (ii) while carrying a ball on a round tray.

RESULTS

A significant Group x Time interaction was found in TUG (F [2,57]=29.5; p<0.01; partial η²=0.51) and in FSST (F [2,57]=23.2; p<0.01; partial η²=0.44). After intervention DT showed better scores in overall TUG (mean difference=1.21s [95% CI, 0.82-1.60]; p<0.05) and FSST (mean difference=2.51s [95% CI, 1.67-3.35]; p<0.01), whereas CG and ST did not exhibit significant changes.

CONCLUSION

Our results suggested that 16 weeks of motor DT training, using motor additional tasks as manipulation of common objects of everyday life, could improve mobility in older age.

Dual task training effects on balance and hand functions of stroke patients

[Purpose] The purpose of this research is to take a look at the influences of the dual task training on the hand function and the balance ability of the stroke patients. [Subjects and Methods] The dual task training was applied to 2 stroke hemiplegia patients. The dual task training had been carried out for 30 minutes by each session for 5 days a week for 3 weeks. The evaluations had been carried out 5 times for 3 weeks before and after the intervention. And the changes of the hand function had been measured by using the box and block test. And, for the changes of the balancing ability, the Berg Balance Scale was used. [Results] Both the hand function and the balancing ability of the subjects were improved after the dual task training. [Conclusion] Through the results of the research, it was able to confirm that the dual task training is effective for the enhancements of the hand function and the balancing ability of the stroke patients.

Examining Transfer Effects of Dual-Task Training Protocols for a Complex Locomotor Task

Training protocols designed to improve dual-task performance of an obstacle crossing and auditory Stroop task (OBS+Stroop) were tested. In Experiment  1 , following baseline collection of OBS+Stroop trials, proximally related walking training was performed, and participants were then retested on the OBS+Stroop test. After training, participants adopted a more cautious obstacle crossing strategy, indicating a potentially safer navigation strategy. Transfer effects from distally related training were then examined (Experiment  2 ); a computer game training paradigm was examined using the same testing protocol as Experiment  1 . Computer training demonstrated improved dual-task performance on some measures, but did not induce a more cautious stepping strategy. Results indicate that dual-task training needs to be similar to targeted tasks to yield reliable, positive training outcomes.

Fatigue does not conjointly alter postural and cognitive performance when standing in a shooting position under dual-task conditions

This study investigated the effects of fatigue on balance control and cognitive performance in a standing shooting position. Nineteen soldiers were asked to stand while holding a rifle (single task - ST). They also had to perform this postural task while simultaneously completing a cognitive task (dual task - DT). Both the ST and DT were performed in pre- and post-fatigue conditions. In pre-fatigue, participants achieved better balance control in the DT than in the ST, thus suggesting that the increased cognitive activity associated with the DT improves balance control by shifting the attentional focus away from a highly automatised activity. In post-fatigue, balance control was degraded in both the ST and DT, while reaction time was enhanced in the first minutes following the fatiguing exercise without affecting the accuracy of response in the cognitive task, which highlights the relative independent effects of fatigue on balance control and cognitive performance.

Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10) and in patients suffering from chronic stroke (−0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (−0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive–motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings.

Task oriented training improves the balance outcome & reducing fall risk in diabetic population

Objectives:

The objective was to determine the balance impairments and to compare task oriented versus traditional balance training in fall reduction among diabetic patients.

Methods:

The randomized control trial with descriptive survey and 196 diabetic patients were recruited to assess balance impairments through purposive sampling technique. Eighteen patients were randomly allocated into two groups; task oriented balance training group TOB (n=8) and traditional balance training group TBT (n=10). The inclusion criteria were 30-50 years age bracket and diagnosed cases of Diabetes Mellitus with neuropathy. The demographics were taken through standardized & valid assessment tools include Berg Balance Scale and Functional Reach Test. The measurements were obtained at baseline, after 04 and 08 weeks of training.

Results:

The mean age of the participants was 49 ±6.79. The result shows that 165(84%) were at moderate risk of fall and 31(15%) were at mild risk of fall among total 196 diabetic patients. There was significant improvement (p <0.05) in task oriented balance training group for dynamic balance, anticipatory balance and reactive balance after 8 weeks of training as compare to traditional balance training.

Conclusion:

Task oriented balance training is effective in improving the dynamic, anticipator and reactive balance. The task oriented training reduces the risk of falling through enhancing balance outcome.

Motor-Cognitive Dual-Task Training in Persons With Neurologic Disorders: A Systematic Review

BACKGROUND AND PURPOSE

Deficits in motor-cognitive dual tasks (eg, walking while talking) are common in individuals with neurologic conditions. This review was conducted to determine the effectiveness of motor-cognitive dual-task training (DTT) compared with usual care on mobility and cognition in individuals with neurologic disorders.

METHODS

Databases searched were Biosis, CINAHL, ERIC, PsychInfo, EBSCO Psychological & Behavioral, PubMed, Scopus, and Web of Knowledge. Eligibility criteria were studies of adults with neurologic disorders that included DTT, and outcomes of gait or balance were included. Fourteen studies met inclusion criteria. Participants were subjects with brain injury, Parkinson disease (PD), and Alzheimer disease (AD). Intervention protocols included cued walking, cognitive tasks paired with gait, balance, and strength training and virtual reality or gaming. Quality of the included trials was evaluated with a standardized rating scale of clinical relevance.

RESULTS

Results show that DTT improves single-task gait velocity and stride length in subjects with PD and AD, dual-task gait velocity and stride length in subjects with PD, AD, and brain injury, and may improve balance and cognition in those with PD and AD. The inclusion criteria of the studies reviewed limited the diagnostic groups included.

DISCUSSION AND CONCLUSIONS

While the range of training protocols and outcome assessments in available studies limited comparison of the results across studies motor-cognitive dual-task deficits in individuals with neurologic disorders appears to be amenable to training. Improvement of dual-task ability in individuals with neurologic disorders holds potential for improving gait, balance, and cognition.Video Abstract available for additional insights from the authors (Supplemental Digital Content, http://links.lww.com/JNPT/A104).

Neurofeedback training improves the dual-task performance ability in stroke patients

Owing to the reduced capacity for information processing following a stroke, patients commonly present with difficulties in performing activities of daily living that combine two or more tasks. To address this problem, in the present study, we investigated the effects of neurofeedback training on the abilities of stroke patients to perform dual motor tasks. We randomly assigned 20 patients who had sustained a stroke within the preceding 6 months to either a pseudo-neurofeedback (n = 10) or neurofeedback (n = 10) group. Both groups participated in a general exercise intervention for 8 weeks, three times a week for 30 min per session, under the same conditions. An electrode was secured to the scalp over the region of the central lobe (Cz), in compliance with the International 10-20 System. The electrode was inactive for the pseudo-training group. Participants in the neurofeedback training group received the 30-min neurofeedback training per session for reinforcing the sensorimotor rhythm. Electroencephalographic activity of the two groups was compared. In addition, selected parameters of gait (velocity, cadence [step/min], stance phase [%], and foot pressure) were analyzed using a 10-m walk test, attention-demanding task, walk task and quantified by the SmartStep system. The neurofeedback group showed significantly improved the regulation of the sensorimotor rhythm (p < 0.001) and ability to execute dual tasks (p < 0.01). Significant improvements on selected gait parameters (velocity and cadence; p < 0.05) were also observed. We thus propose that the neurofeedback training is effective to improve the dual-task performance in stroke patients.

The effect of dual-task difficulty on the inhibition of the motor cortex

Dual-tasking is intrinsic to many daily activities, including walking and driving. However, the activity of the primary motor cortex (M1) in response to dual-tasks (DT) is still not well characterised. A recent meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014) demonstrated a reduction in M1 inhibition during dual-tasking, yet responses were not consistent between studies. It was suggested that DT difficulty might account for some of this between-study variability. The aim of this study was to investigate whether corticospinal excitability and M1 inhibition differed between an easier and more difficult dual-task. Transcranial magnetic stimulation (TMS) was applied to participants' abductor pollicis brevis muscle representation during a concurrent pincer grip task and stationary bike-riding. The margin of error in which to maintain pincer grip force was reduced to increase task difficulty. Compared to ST conditions, significantly increased M1 inhibition was demonstrated for the easier, but not more difficult, DT. However, there was no significant difference in M1 inhibition between easy and difficult DTs. The difference in difficulty between the two tasks may not have been wide enough to result in significant differences in M1 inhibition. Increased M1 inhibition for the easy DT condition was in opposition to the reduction in M1 inhibition found in our meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014). We propose that this may be partially explained by differences in the timing of the TMS pulse between DT studies.

Effect of dual tasks on balance ability in stroke patients

[Purpose] The purpose of this study was to determine the effects of training using dual tasks on balance ability in stroke patients. [Subjects] Forty stroke patients were divided into a dual-task training group (N = 20) and a single task training group (N = 20) randomly. [Methods] The subjects in the single-task traing group stood in a comfortable position, faced a therapist, then threw a Swiss ball back and forth. They then performed balance training in which they raised and lowered their ankles while facing forward or moved objects from one table to another. The DTG performed dual tasks, which involved performing a task on an unstable surface using a balance pad. Both groups received training 30 min per day, five times per week, for eight weeks. [Results] The DTG showed significant increases in weight distribution rate, anterior limit of stability, posterior limit of stability, and BBS scores compared with the STG. [Conclusion] According to the results of this study, dual-task training and single-task training were effective in improving balance in stroke patients, dual task training is more effective for increasing balance ability.

Static Foot Posture and Mobility Associated With Postural Sway in Elderly Women Using a Three-dimensional Foot Scanner

BACKGROUND

Maintaining balance is a complex phenomenon that is influenced by a range of sensorimotor factors. Foot posture and mobility may also influence balance and postural sway. Recently, three-dimensional foot scanners have been used to assess foot posture. This tool allows many individuals to be scanned quickly and easily and helps eliminate patients' radiation exposure. The objective of this study was to determine whether static foot posture and mobility are independently associated with postural sway in a large community sample of older women using objective measures of balance status and the recently launched technology of three-dimensional foot scanning.

METHODS

This cross-sectional study included 140 community-dwelling elderly women (mean ± SD age, 73.9 ± 5.1 years) recruited in Kasama City, Japan. The postural sway variables were total path length and area and were measured by force plate. We measured static foot posture, sitting and standing navicular height, and mobility using a three-dimensional foot scanner. Foot mobility was determined as the amount of vertical navicular excursion between the positions of the subtalar joint, from neutral in sitting position to relaxed bilateral standing.

RESULTS

After adjusting for potential cofounders, analysis of covariance revealed that sitting navicular height was associated with total path length (P = .038) and area (P = .031). Foot mobility was associated with total path length (P = .018).

CONCLUSIONS

These findings suggest that sitting navicular height and foot mobility are associated with postural sway in elderly women and might be an important factor in defining balance control in older adults.

Improvements in dizziness and imbalance results from using a multi disciplinary and multi sensory approach to Vestibular Physical Therapy - a case study

This paper discusses a case study of a 41-year-old active duty male service member who sustained head trauma from a motorcycle accident and underwent multidisciplinary vestibular physical therapy rehabilitation. He was initially treated with traditional physical therapy applications of treadmill walking and standing balance with some symptom improvements, but was not able to maintain a running speed that would allow him to return to full active duty status. Further treatment utilizing a Computer Assisted Rehabilitation Environment was performed in order to increase level of difficulty and further enhance function. This treatment is able to elicit vestibular deficits seen in the community as it requires subjects to walk and balance while performing tasks within a virtual scenario incorporating platform motion, visual surround and flow, and cognitive processing. After 6 weeks of therapy, twice weekly, improvements in clinical vestibular measures were observed as well as walking speed and patient confidence. The patient was able to return to full duty after treatment. This case study provides supportive evidence that multidimensional tasking in a virtual environment provides a safe but demanding form of vestibular therapy for patients needing more challenging tasks than those provided with traditional therapy techniques. Those persons requiring higher levels of performance before returning to full duty (e.g., pilots, special operators, etc.) may find this type of therapy beneficial.