Consistency and cost of dual-task gait balance measure in healthy adolescents and young adults

Matched control data are commonly used to examine recovery from concussion. Limited data exist, however, examining dual-task gait data consistency collected over time in healthy individuals. The study purposes were to: 1) assess the consistency of single-task and dual-task gait balance control measures, 2) determine the minimal detectable change (MDC) of gait balance control measures, and 3) examine the extent to which age and task complexity affect dual-task walking costs in healthy adolescents and young adults. Twenty-four adolescent (mean age = 15.5 ± 1.1 years) and 21 young adult (mean age = 21.2 ± 4.5 years) healthy participants completed 5 testing sessions across a two-month period, which involved analyses of gait balance control and temporal-distance variables during single-task and dual-task walking conditions in a motion analysis laboratory. Cronbach’s α and MDCs were used to determine the consistency of the gait balance control variables and the smallest amount of change required to distinguish true performance from change due to the performance/measurement variability, respectively. Dual-task costs were evaluated to determine the effect of task complexity and age across time using 3-way ANOVAs. Good to excellent test-retest consistency was found for all single-task and dual-task walking (Cronbach’s α range: 0.764–0.970), with a center-of-mass medial-lateral displacement MDC range of 0.835–0.948 cm. Greater frontal plane dual-task costs were observed during more complex secondary tasks (p < 0.001). The results revealed good-excellent consistency across testing sessions for all variables and indicated dual-task costs are affected by task complexity. Thus, healthy controls can be effective comparators when assessing injured subjects.     

Home-based interventions improve trained,but not novel,dual-task balance performance in older adults: A randomized controlled trial

The purpose of this study was to compare the efficacy of four different home-based interventions on dual-task balance performance and to determine the generalizability of the four trainings to untrained tasks. Sixty older adults, aged 65 and older, were randomly assigned to one of four home-based interventions: single-task motor training, single-task cognitive training, dual-task motor-cognitive training, and dual-task cognitive–cognitive training. Participants received 60-min individualized training sessions, 3 times a week for 4 weeks. Prior to and following the training program, participants were asked to walk under two single-task conditions (i.e. narrow walking and obstacle crossing) and two dual-task conditions (i.e. a trained narrow walking while performing verbal fluency task and an untrained obstacle crossing while counting backward by 3 s task). A nine-camera motion capture system was used to collect the trajectories of 32 reflective markers placed on bony landmarks of participants. Three-dimensional kinematics of the whole body center of mass and base of support were computed. Results from the extrapolated center of mass displacement indicated that motor-cognitive training was more effective than the single-task motor training to improve dual-task balance performance (p = 0.04, ES = 0.11). Interestingly, balance performance under both single-task and dual-task conditions can also be improved through a non-motor, single-task cognitive training program (p = 0.01, ES = 0.13, and p = 0.01, ES = 0.11, respectively). However, improved dual-task processing skills during training were not transferred to the novel dual task (p = 0.15, ES = 0.09). This is the first study demonstrating that home-based dual-task training can be effectively implemented to improve balance performance during gait in older adults.     

Objective clinical tests of dual-task dynamic postural control in youth athletes with concussion

Objectives

To prospectively evaluate single/dual-task timed-up-and-go (TUG) and tandem gait performance among children and adolescents with concussion and healthy controls.

No differences in tandem gait performance between male and female athletes acutely post-concussion

ObjectivesTo test whether 1) concussed athletes demonstrate slower tandem gait times compared to controls and 2) concussed female athletes display greater post-injury deficits than males.DesignProspective longitudinalMethodFifty concussed collegiate student-athletes (32% female, age = 20.18 ± 1.27 years) completed tandem gait tests during pre-season (Time 1) and acutely (<72 hours) post-concussion (Time 2), and twenty-five controls (52% female, age = 21.08 ± 2.22 years) completed tandem gait at two time points, 1.96 ± 0.46 days apart. Participants completed four single-task (ST) and dual-task (DT) trials. During DT trials, they simultaneously completed a cognitive assessment. The best ST and DT times were recorded, along with cognitive accuracy, and the change score between the two assessments was calculated. A positive change in tandem gait time was indicative of worsening performance. A 2 × 2 (group*sex) ANOVA was used to examine change between pre-injury and post-injury tests for ST/DT tandem gait time and DT cognitive accuracy.ResultsThe change in tandem gait time from Time 1 to Time 2 was significantly higher for the concussion group relative to controls during both ST (Concussion: 1.36 ± 2.6 seconds, Controls: -1.16 ± 0.8 seconds, p < 0.001) and DT (Concussion: 1.70 ± 3.8 seconds, Controls: -0.94 ± 1.7 seconds, p = 0.002) tandem gait. There were no interactions or main effects of sex for tandem gait time or cognitive accuracy.ConclusionsThere were no sex-specific differences in the change in tandem gait performance among concussed collegiate athletes or controls. However, all concussed participants, regardless of sex, performed significantly worse on tandem gait than male and female controls, who both improved between testing time points.     

Different cognitive functions discriminate gait performance in younger and older women: A pilot study

AimCognitive dysfunction is associated with slower gait speed in older women, but whether cognitive function affects gait performance earlier in life has yet to be investigated. Thus, the objective of this study was to test the hypothesis that cognitive function will discriminate gait performance in healthy younger women.MethodsFast-pace and dual-task gait speed were measured in 30 young to middle-aged (30–45 y) and 26 older (61–80 y) women without mild cognitive impairment. Visuoperceptual ability, working memory, executive function, and learning ability were assessed using neuropsychological tests. Within each age group, women were divided by the median into lower and higher cognitive function groups to compare gait performance.ResultsYounger women with higher visuoperceptual ability had faster fast-pace (2.25 ± 0.30 vs. 1.98 ± 0.18 m/s, p ≤ 0.01) and dual-task gait speed (2.02 ± 0.27 vs. 1.69 ± 0.25 m/s, p ≤ 0.01) than women with lower visuoperceptual ability. The difference in dual-task gait speed remained significant (p = 0.02) after adjusting for age, years of education, and other covariates. Dividing younger women based on other cognitive domains showed no difference in gait performance. In contrast, working memory and executive function discriminated dual-task gait speed (p < 0.05) in older women after adjusting for age and education.ConclusionTo our knowledge, this is the first study to show that poorer cognitive function even at a relatively young age can negatively impact mobility. Different cognitive functions discriminated gait performance based on age, highlighting a possible influence of aging in the relationship between cognitive function and mobility in women.     

Residual standard deviation: Validation of a new measure of dual-task cost in below-knee prosthesis users

We developed and evaluated properties of a new measure of variability in stride length and cadence, termed residual standard deviation (RSD). To calculate RSD, stride length and cadence are regressed against velocity to derive the best fit line from which the variability (SD) of the distance between the actual and predicted data points is calculated. We examined construct, concurrent, and discriminative validity of RSD using dual-task paradigm in 14 below-knee prosthesis users and 13 age- and education-matched controls. Subjects walked first over an electronic walkway while performing separately a serial subtraction and backwards spelling task, and then at self-selected slow, normal, and fast speeds used to derive the best fit line for stride length and cadence against velocity. Construct validity was demonstrated by significantly greater increase in RSD during dual-task gait in prosthesis users than controls (group-by-condition interaction, stride length p = 0.0006, cadence p = 0.009). Concurrent validity was established against coefficient of variation (CV) by moderate-to-high correlations (r = 0.50–0.87) between dual-task cost RSD and dual-task cost CV for both stride length and cadence in prosthesis users and controls. Discriminative validity was documented by the ability of dual-task cost calculated from RSD to effectively differentiate prosthesis users from controls (area under the receiver operating characteristic curve, stride length 0.863, p = 0.001, cadence 0.808, p = 0.007), which was better than the ability of dual-task cost CV (0.692, 0.648, respectively, not significant). These results validate RSD as a new measure of variability in below-knee prosthesis users. Future studies should include larger cohorts and other populations to ascertain its generalizability.     

The utility of instrumented dual-task gait and tablet-based neurocognitive measurements after concussion

Objectives

Quantitative and non-invasive measurements acquired by neurocognitive or gait evaluations are useful concussion management components. Emerging technology has allowed for the development of portable and objective tests which may be potentially useful across many settings where evaluations take place. Our aim was to examine the association between instrumented dual-task gait and tablet-based neurocognitive outcome variables with an acute concussion.

Spatial and temporal gait parameters in Alzheimer's disease and aging

Spatial and temporal gait parameters in 40 patients with early Alzheimer's disease (AD) were compared to that of 34 normal controls (NC) on a level ground and on a treadmill. Over-ground velocity, cycle-time, cadence, stride-length, stride-width and double-support time were captured on an electronic walkway. On the treadmill, cadence, cycle-time and double-support time were recorded at a preferred velocity using footswitches. The AD group were significantly slower on the Timed Up and Go task compared to NC (p < 0.05). AD patients differed significantly from the NC on their over-ground gait velocity (99 ± 19 cm/s vs 119 + 15 cm/s, p < 0.001), cadence (101 ± 9 steps/min vs 109 ± 9 steps/min, p = 0.001) and stride-length (118 ± 18 cm vs 131 ± 17 cm, p < 0.01). On the treadmill, only preferred speed was significantly different in the AD group compared to the NC group (60 ± 20 cm/s vs 74 ± 23 cm/s, p = 0.02). These results indicate that patients with early AD walk slower and with shorter strides than healthy older adults.     

The effect of a dual task on gait speed in community dwelling older adults: A systematic review and meta-analysis

Background and purposeReduced walking speed in older adults is associated with adverse health outcomes. This review aims to examine the effect of a cognitive dual-task on the gait speed of community-dwelling older adults with no significant pathology affecting gait.Data sources and study selectionElectronic database searches were performed in, Web of Science, PubMed, SCOPUS, Embase and psychINFO. Eligibility and methodological quality was assessed by two independent reviewers. The effect size on gait speed was measured as the raw mean difference (95% confidence interval) between single and dual-task performance. Pooled estimates of the overall effect were computed using a random effects method and forest plots generated.Data extraction and data synthesis22 studies (27 data sets) with a population of 3728 were reviewed and pooled for meta-analysis. The mean walking speed of participants included in all studies was >1.0 m/s and all studies reported the effect of a cognitive dual-task on gait speed. Sub-analysis examined the effect of type of cognitive task (mental-tracking vs. verbal-fluency). Mean single-task gait speed was 1.21 (0.13) m/s, the addition of a dual-task reduced speed by 0.19 m/s to 1.02 (0.16) m/s (p < 0.00001), both mental-tracking and verbal-fluency tasks resulted in significant reduction in gait speed.Limitations and conclusionThe cross-sectional design of the studies made quality assessment difficult. Despite efforts, high heterogeneity remained, possibly due to participant characteristics and testing protocols. This meta-analysis shows that in community-dwelling older adults, the addition of a dual-task significantly reduces gait speed and may indicate the value of including dual-task walking as part of the standard clinical assessment of older people.     

Cognitive motor interference during dual-task gait in essential tremor

BackgroundFunctional ambulation requires concurrent performance of motor and cognitive tasks, which may create interference (degraded performance) in either or both tasks. People with essential tremor (ET) demonstrate impairments in gait and cognitive function. In this study we examined the extent of interference between gait and cognition in people with ET and controls during dual-task gait.MethodsWe tested 62 controls and 151 ET participants (age range: 72–102). ET participants were divided into two groups based on median score on the modified Mini Mental State Examination. Participants walked at their preferred speed, and performed a verbal fluency task while walking. We analyzed gait velocity, cadence, stride length, double support time, stride time, step width, step time difference, coefficient of variation (CV) of stride time and stride length.ResultsVerbal fluency performance during gait was similar across groups (p = 0.68). Velocity, cadence and stride length were lowest whereas step time difference (p = 0.003), double support time (p = 0.009), stride time (p = 0.002) and stride time CV (p = 0.007) were highest for ET participants with lower cognitive scores (ETp-LCS), compared with ET participants with higher cognitive scores (ETp-HCS) and controls. ETp-LCS demonstrated greatest interference for double support time (p = 0.005), step time difference (p = 0.013) and stride time coefficient of variation (p = 0.03).ConclusionsETp-LCS demonstrated high levels of cognitive motor interference. Gait impairments during complex tasks may increase risk for falls for this subgroup and underscore the importance of clinical assessment of gait under simple and dual-task conditions.     

Using a dual-task protocol to investigate motor and cognitive performance in healthy children and youth

ObjectivesMild traumatic brain injury (or concussion) is a prevalent yet understudied health concern in children and youth. This injury can cause dysfunction in both motor and cognitive domains; however, most literature focuses on single-task neuropsychological tests which only assess cognition. Although dual-task research on concussed children and youth is needed as many daily activities require both motor and cognitive domains, we must first investigate whether performing simultaneous motor and cognitive tasks of varied complexity impact these domains in healthy children and youth.Participants and designData collected from 106 healthy children and youth (5–18 years) created a normative dataset. Participants performed motor (postural stability) and cognitive (visual attention) tasks under single- and dual-task conditions. The cognitive task difficulty remained constant while the motor task had four conditions of increasing difficulty. The relationship between the number of correct responses (cognitive performance) and sway index (motor performance) was determined using two repeated measures ANOVAs (p < 0.05).ResultsDual-task conditions resulted in reduced postural stability, with greater differences on the foam surface (F_2,206 = 16.070, p < 0.0005). No statistically significant differences were observed in attention (F_4,101 = 0.713, p = 0.584).ConclusionsPostural stability decreased under dual-task conditions, but attention was maintained or improved. Consequently, attention took precedence over postural control when performing tasks concurrently, demonstrating the ability for dual-task methodology to isolate specific processes. This study provides a normative dataset to be used during clinical management to identify functional deficits following concussion and acts as a starting point to explore dual-task protocols in children and youth following concussion.     

Balance and cognitive performance during a dual-task: Preliminary implications for use in concussion assessment

ObjectivesTo determine the reliability and effects of a dual-task paradigm on balance and cognitive function compared to a single-task paradigm.DesignRepeated measures.MethodsHealthy participants (n = 23) completed a variation of the Sensory Organization Test and the incongruent Stroop test individually (single-task) and concurrently (dual-task) during two testing sessions.ResultsThe Sensory Organization Test and incongruent Stroop test had moderate to high reliability (1.00 > ICC_2,k > 0.60) under the dual-task conditions. Reaction time was significantly longer (t₂₁ = ?2.54, p = 0.019) under the dual-task conditions, while balance scores under one of the four conditions of the Sensory Organization Test (sway floor/fixed wall) were statistically better (t₂₂ = ?3.03, p = 0.006) under the dual-task conditions. However, this difference in balance scores may not be clinically meaningful.ConclusionsThese findings illustrate that the Sensory Organization Test and incongruent Stroop task can be reliably incorporated into a dual-task assessment paradigm. The slowed reaction time under the dual-task paradigm indicates that the dual-task provided an additional cost to cognitive function. Dual-task concussion assessment paradigms involving these two tasks are psychometrically appropriate as well as more representative of actual sporting situations. However, more research should be conducted in a concussed population to further validate this claim.     

Sleep quality is associated with walking under dual-task,but not single-task performance

ObjectivesThe objective of this study was to assess the relationship between sleep behavior and gait performance under single-task (ST) and dual-task (DT) walking conditions in community- dwelling older adults.MethodsWalking under ST and DT conditions was evaluated in 34 community-dwelling older adults, 64.7% women, mean age 71.5 (SD ± 5.8). Gait-speed and gait-variability data were collected using the OPAL wearable sensors of the Mobility Lab. Sleep behavior (sleep efficiency [SE] and sleep latency [SL]) was assessed using actigraphy, over 5 consecutive nights.ResultsLower SE was associated with decreased gait speed and increased stride-length variability during DT (rs = 0.35; p = 0.04; rs = −0.36; p = 0.03, respectively), whereas longer SL was associated with increased stride-length variability during DT (rs = 0.38; p = .03). After controlling for age and cognition, SE accounted for 24% and 33% of the variability in stride length and stride time. No associations were found between sleep and gait measures under ST walking.ConclusionsLower SE is associated with decreased gait speed and increased gait variability under DT conditions that are indicative of an increased risk for falls in older adults. Our findings support clinical recommendations to incorporate the evaluation of sleep quality in the context of risk assessment for falls.     

Tandem gait test performance in healthy,physically active adults: Clinical implications for concussion evaluation

ObjectivesTo identify factors affecting performance on the tandem gait test in healthy, physically active adults.DesignCross-sectional.MethodsParticipants completed the tandem gait test according to Sport Concussion Assessment Tool 3 (SCAT3) guidelines. Dependent variables included time for best trial (initial 3 m, turn, final 3 m and total) and whether the trial was “pass” or “fail”. Independent variables included sex, concussion history, foot length, height and total number of trials.Results55% (35/64) of participants passed the first trial of the tandem gait test; 19% (12/64) had a best time <14 s. Sex and concussion history did not affect performance (p > 0.05). There were no differences in turn times for those with and without a history of concussion (t = 0.26, p = 0.80). The number of trials was not significantly correlated with best time (þ = ?0.04, p = 0.74). There were low (þ = ?0.31) to negligible (þ < 0.30) correlations between foot length, height and all portions of the test. There was more variability in times for the turn (COV = 27%) than during the straight portions (COV = 18%).ConclusionsCurrent recommendations for the tandem gait test led to a high false-positive rate in healthy, physically active adults. Sex, concussion history, number of trials and foot length had little to no influence on scores on the test. Turning times were more variable than times on the straight portions of the test. Clinicians may use these results as a guideline when interpreting performance on the tandem gait test in healthy physically active adults.     

The use of the dual-task paradigm in detecting gait performance deficits following a sports-related concussion: A systematic review and meta-analysis

ObjectivesThe purpose of this systematic review was to determine the viability of the dual-task paradigm in the evaluation of a sports-related concussion.DesignSystematic review and meta-analysis.MethodsEight electronic databases were searched from their inception until the 11^th of April 2011. Studies were grouped according to their reported gait performance variables and their time(s) of assessment(s). Raw mean differences (MD) and 95% confidence intervals (CI) were calculated based on raw means and standard deviations for gait performance measures in both single- and dual-task conditions. Dual-task deficits were pooled using a random effects model and heterogeneity (I²) between studies was assessed.ResultsTen studies representing a total sample of 168 concussed and 167 matched (age and gender) non-concussed participants met the inclusion criteria. Meta-analysis demonstrated that dual-task performance deficits were detected (p < 0.05) in the concussed group for gait velocity (GV) (MD = ?0.133; 95% CI ?0.197, ?0.069) and range of motion of the centre of mass in the coronal plane (ML-ROM) (MD = 0.007; 95% CI 0.002, 0.011), but not in the non-concussed group; GV (MD = ?0.048; 95% CI ?0.101, 0.006), ML-ROM (MD = 0.002; 95% CI ?0.001, 0.005).ConclusionsThe results of this study indicate that GV and ML-ROM are sensitive measures of dual-task related changes in concussed patients and should be considered as part of a comprehensive assessment for a sports-related concussion.     

Gait initiation time is associated with the risk of multiple falls—A population-based study

AimsIn a population-based study of older people to examine whether 1) overall gait initiation (GI) time or its components are associated with falls and 2) GI under dual-task is a stronger predictor of falls risk than under single-task.MethodsParticipants aged 60–85 years were randomly selected from the electoral roll. GI was obtained with a force platform under both single and dual-task conditions. Falls were ascertained prospectively over a 12-month period. Log multinomial regression was used to examine the association between GI time (total and its components) and risk of single and multiple falls. Age, sex and physiological and cognitive falls risk factors were considered as confounders.ResultsThe mean age of the sample (n = 124) was 71.0 (SD 6.8) years and 58.9% (n = 73) were male. Over 12 months 21.8% (n = 27) of participants reported a single fall and 16.1% (n = 20) reported multiple falls. Slower overall GI time under both single (RR all per 100 ms 1.28, 95%CI 1.03, 1.58) and dual-task (RR 1.14, 95%CI 1.02, 1.27) was associated with increased risk of multiple, but not single falls (p < 0.05). Multiple falls were also associated with slower time to first lateral movement under single-task (RR 1.90 95%CI 0.59, 1.51) and swing time under dual-task condition (RR 1.44 95%CI 1.08, 1.94).ConclusionSlower GI time is associated with the risk of multiple falls independent of other risk factors, suggesting it could be used as part of a comprehensive falls assessment. Time to the first lateral movement under single-task may be the best measures of this risk.     

The association between intersegmental coordination in the lower limb and gait speed in elderly females

Human multi-segmental motion is a complex task requiring motor coordination. Uncoordinated motor control may contribute to the decline in mobility; however, it is unknown whether the age-related decline in intersegmental coordination relates to the decline in gait performance. The aim of this study was to clarify the association between intersegmental coordination and gait speed in elderly females. Gait measurements were performed in 91 community-dwelling elderly females over 60 years old. Foot, shank, and thigh sagittal motions were assessed. Intersegmental coordination was analyzed using the mean value of the continuous relative phase (mCRP) during four phases of the gait cycle to investigate phase differences in foot–shank and shank–thigh motions during a normal gait. The results showed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.53) and cadence (r = −0.54) and a positive correlation with age (r = 0.25). In contrast, shank–thigh mCRP at late stance had positive correlations with gait speed (r = 0.37) and cadence (r = 0.56). Moreover, partial correlation, controlling age, height, and weight, revealed that foot–shank mCRP at late stance had negative correlations with gait speed (r = −0.52) and cadence (r = −0.54). Shank–thigh mCRP at late stance had a positive correlation with gait speed (r = 0.28) and cadence (r = 0.51). These findings imply that the foot–shank and shank–thigh coordination patterns at late stance relate to gait speed, and uncoordinated lower limb motion is believed to be associated with the age-related decline in cadence.     

Dynamic joint stiffness of the ankle during walking: Gender-related differences

ObjectivesTo characterize and compare dynamic joint stiffness (DJS) of the ankle in the sagittal plane during natural cadence walking in both genders.DesignObservation, cross-sectional and matched pairs.ParticipantsTwenty-one males (mean age=27±4.2 years) and 18 females (mean age=22.9±4.1 years).SettingLaboratory at the University de Trás-os-Montes and Alto Douro. The DJS of the ankle was assessed while participants performed barefoot walking at a natural cadence, was measured using a force platform (1000 Hz), and synchronized with a high-speed camera (200 Hz).Main outcome measuresDJS of the ankle in males and females was calculated in two sub-phases (the second and the fourth sub-phases) of the stance phase. The Wilcoxon non-parametric matched-pairs test and the Mann–Whitney U non-parametric test were used to analyse difference of DJS of the ankle within and between the groups with p⩽0.05 regarded as significant.ResultsMale and female participants demonstrated significantly (p<0.005) less DJS during the second sub-phase. DJS was not significantly (p>0.063) different between females (0.0511 N m/kg/°) and males (0.0596 N m/kg/°) during the second sub-phase. DJS was significantly (p<0.001) higher in males (0.0844 N m/kg/°) than females (0.0691 N m/kg/°) during the fourth sub-phase.ConclusionsGender-specific DJS characteristics demonstrated by females in this study may be used in preventative training programs designed to promote a greater ability to use contractile components to produce mechanical energy through the ankle.     

Functional balance assessment in recreational college-aged individuals with a concussion history

Objectives

Despite evidence for increased musculoskeletal injury after concussion recovery, there is a lack of dynamic balance assessments that could inform management and research into this increased injury risk post-concussion. Our purpose was to identify tandem gait dynamic balance deficits in recreational athletes with a concussion history within the past 18-months compared to matched controls.

A comparison of two walking while talking paradigms in aging

BackgroundOur study aimed to [1] compare dual-task costs in gait and cognitive performance during two dual-task paradigms: walking while reciting alternate letters of the alphabet (WWR) and walking while counting backward by sevens (WWC); [2] examine the relationship between the gait and cognitive interference tasks when performed concurrently.ScopeGait and cognitive performance were tested in 217 non-demented older adults (mean age 76 ± 8.8 years; 56.2% female) under single and dual-task conditions. Velocity (cm/s) was obtained using an instrumented walkway. Cognitive performance was assessed using accuracy ratio: [correct responses]/[total responses]. Linear mixed effects models revealed significant dual-task costs, with slower velocity (p < .01) and decreased accuracy ratio (p < .01) in WWR and WWC compared to their respective single task conditions. Greater dual-task costs in velocity (p < .01) were observed in WWC compared to WWR. Pearson correlations revealed significant and positive relationships between gait and cognitive performance in WWR and WWC (p < .01); increased accuracy ratio was associated with faster velocity.ConclusionsOur findings suggested that dual-task costs in gait increase as the complexity of the cognitive task increases. Furthermore, the positive association between the gait and cognitive tasks suggest that dual-task performance was not influenced by task prioritization strategies in this sample.