Initial development and testing of a novel foam-based pressure sensor for wearable sensing

Background

The ability to maintain a steady gait rhythm is impaired in patients with Parkinson's disease (PD). This aspect of locomotor dyscontrol, which likely reflects impaired automaticity in PD, can be quantified by measuring the stride-to-stride variability of gait timing. Previous work has shown an increase in both the variability of the stride time and swing time in PD, but the origins of these changes are not fully understood. Patients with PD also generally walk with a reduced gait speed, a potential confounder of the observed changes in variability. The purpose of the present study was to examine the relationship between walking speed and gait variability.

Methods

Stride time variability and swing time variability were measured in 36 patients with PD (Hoehn and Yahr stage 2–2.5) and 30 healthy controls who walked on a treadmill at four different speeds: 1) Comfortable walking speed (CWS), 2) 80% of CWS 3) 90% of CWS, and 4) 110% of CWS. In addition, we studied the effects of walking slowly on level ground, both with and without a walker.

Results

Consistent with previous findings, increased variability of stride time and swing time was observed in the patients with PD in CWS, compared to controls. In both groups, there was a small but significant association between treadmill gait speed and stride time variability such that higher speeds were associated with lower (better) values of stride time variability (p = 0.0002). In contrast, swing time variability did not change in response to changes in gait speed. Similar results were observed with walking on level ground.

Conclusion

The present results demonstrate that swing time variability is independent of gait speed, at least over the range studied, and therefore, that it may be used as a speed-independent marker of rhythmicity and gait steadiness. Since walking speed did not affect stride time variability and swing time variability in the same way, it appears that these two aspects of gait rhythmicity are not entirely controlled by the same mechanisms. The present findings also suggest that the increased gait variability in PD is disease-related, and not simply a consequence of bradykinesia.     

Gait variability and fall risk in community-living older adults: a 1-year prospective study

OBJECTIVE: To test the hypothesis that increased gait variability predicts falls among community-living older adults attending an outpatient clinic. DESIGN: Prospective, cohort study. SETTING: Three outpatient geriatric clinics. PARTICIPANTS: Fifty-two community-living, ambulatory men and women aged > or = 70 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects walked at a normal pace for up to 6 minutes wearing force-sensitive insoles that measured the gait rhythm on a stride-to-stride basis. Afterward, subjects reported fall status on a weekly basis for 1 year. The primary outcomes were the association between measures of the stride-to-stride fluctuations in gait rhythm and (1) subsequent falls during a 12-month follow-up period and (2) potential contributing factors. RESULTS: Almost 40% of the subjects reported falling during the 12-month follow-up period. Stride time variability was 106 +/- 30 ms in subjects who subsequently fell (n = 20) and 49 +/- 4 ms in those who did not experience a fall (n = 32) during the 12-month follow-up period (p <.04). Logistic regression also showed that stride time variability predicted falls (p <.05). Stride time variability correlated significantly with multiple factors including strength, balance, gait speed, functional status, and even mental health, but these other measures did not discriminate future fallers from nonfallers. CONCLUSIONS: These findings show both the feasibility of obtaining stride-to-stride measures of gait timing in the ambulatory setting and the potential use of gait variability measures in augmenting the prospective evaluation of fall risk in community-living older adults.     

Lesser magnitudes of lower extremity variability during terminal swing characterizes walking patterns in children with autism

BackgroundAnecdotally, children with Autism Spectrum Disorder have highly variable lower extremity walking patterns, yet, this has not been sufficiently quantified. As such, the purpose of this study was to examine walking pattern variability by way of lower extremity coordination and spatio-temporal characteristics in children with autism compared with individuals with typical development during over-ground walking.MethodsBilateral continuous relative phase variability was computed for the thigh-leg, leg-foot, and thigh-foot segment couples for 11 children with autism and 9 children with typical development at each gait sub-phase. Furthermore, left and right stride lengths and stride width were computed and compared. The Model Statistic was utilized to test for statistical differences in variability between each child with autism to an aggregate group with typical development. Effect sizes were computed to determine the meaningfulness between responses for children with autism and typical development. Coefficient of variation and effect sizes were computed for stride lengths and stride width.FindingsAnalysis revealed that children with autism exhibited differences in variability in each gait sub-phase. Notably, all but two children with autism exhibited lesser variability in all segment couples during terminal swing. Differences in stride lengths were relatively minimal, however, greater coefficient of variation magnitudes in stride width were observed in children with autism.InterpretationThis finding reveals that children with autism may have limited or a preferred movement strategy when preparing the foot for ground contact. The findings from this study suggest variability may be an identifiable characteristic during movement in children with autism.     

Age-related changes in spatial and temporal gait variables

OBJECTIVE: To extend recent findings describing the effect of age on spatial and temporal gait variables. DESIGN: Experimental. SETTING: A gait analysis laboratory. PARTICIPANTS: Two experiments with healthy nonfallers were conducted. Experiment 1 included 33 subjects (n = 15, 72.13 +/- 3.96yr; n = 18, 25.06 +/- 4.02yr); and experiment 2 included 24 subjects (n = 14, 75.57 +/- 6.15yr; n = 10; 28.10 +/- 3.48yr). INTERVENTIONS: The effect of age, walking velocity, shoe condition, and performance of an attention-splitting task on gait variables was investigated. MAIN OUTCOME MEASURES: Temporal and spatial gait variables were quantified using an instrumented surface across which subjects walked. The independent variables were walking velocity variability, stride length variability, stride width variability, and stride time variability. RESULTS: Stride width variability of older adults was significantly larger than that of younger adults in both experiments. The remaining gait variables demonstrated nonsystematic or no age-related differences. CONCLUSIONS: With the exception of stride width variability, the variability of the remaining gait variables of interest were insensitive to the speed at which subjects walked, whether the subjects were wearing shoes or not, and performing an attention-splitting task while walking. These findings contribute to an emerging interpretive framework established by similar work published by others regarding gait variability.     

Gait stability and variability measures show effects of impaired cognition and dual tasking in frail people

Background  

Falls in frail elderly are a common problem with a rising incidence. Gait and postural instability are major risk factors for falling, particularly in geriatric patients. As walking requires attention, cognitive impairments are likely to contribute to an increased fall risk. An objective quantification of gait and balance ability is required to identify persons with a high tendency to fall. Recent studies have shown that stride variability is increased in elderly and under dual task condition and might be more sensitive to detect fall risk than walking speed. In the present study we complemented stride related measures with measures that quantify trunk movement patterns as indicators of dynamic balance ability during walking. The aim of the study was to quantify the effect of impaired cognition and dual tasking on gait variability and stability in geriatric patients.     

认知负荷任务对帕金森病患者步态的干扰效应

目的:探讨认知负荷任务对帕金森病患者步态的影响。方法:8例帕金森病患者和6例健康对照受试者参与本研究。要求受试者完成以下2种条件下的步行:一是以自己感觉最舒适的速度自由步行2min;二是步行的同时执行一个计算任务。采用三维运动分析仪记录2种条件下的步态参数。此外,要求两组受试者在安静坐位条件下完成2min的计算任务,记录2种条件下的计算完成数和错误率。结果:自由步行条件下,帕金森病组的步幅、步长和步速低于对照组。计算负荷条件下,帕金森病组的步长、步幅、步速、步频、摆动相和单支撑相均显著减低,双支撑相和总支撑相时间显著延长。在加载计算任务后,帕金森病组的步速和步幅变异较其自由步行时显著增加,且步幅变异亦明显高于对照组。帕金森病组安静坐位时计算完成数显著低于对照组,在步行的同时加载计算任务后其计算完成数显著高于对照组。结论:健康老年人的步态对认知调控的依赖程度不高,帕金森病患者的步态明显受认知负荷的干扰,并存在认知资源配置的不合理。     

Reliability of the biceps brachii M-wave

Background

Decreased gait speed and increased stride time, stride length, double support time, and stance time variability have consistently been associated with falling whereas step width variability has not been strongly related to falls. The purpose was to examine the linear and nonlinear associations between gait variability and fall history in older persons and to examine the influence of gait speed.

Methods

Gait characteristics and fall history were obtained in 503 older adults (mean age = 79; 61% female) participating in the Cardiovascular Health Study who could ambulate independently. Gait characteristics were recorded from two trials on a 4 meter computerized walkway at the subject's self-selected walking speed. Gait variability was calculated as the coefficient of variation. The presence of a fall in the past 12 months was determined by interview. The nonlinear association between gait variability and fall history was examined using a simple three level classification derived from the distribution of the data and from literature based cut-points. Multivariate logistic regression was used to examine the association between step width variability (extreme or moderate) and fall history stratifying by gait speed (1.0 m/s) and controlling for age and gender.

Results

Step length, stance time, and step time variability did not differ with respect to fall history (p > .33). Individuals with extreme step width variability (either low or high step width variability) were more likely to report a fall in the past year than individuals with moderate step width variability. In individuals who walked ≥ 1.0 m/s (n = 281), after controlling for age, gender, and gait speed, compared to individuals with moderate step width variability individuals with either low or high step width variability were more likely to have fallen in the past year (OR and 95% CI 4.38 [1.79–10.72]). The association between step width variability and fall history was not significant in individuals who walked < 1.0 m/s (n = 224).

Conclusion

Extreme (either too little or too much) step width variability is associated with falls in the past year in older persons who walk at or near normal gait speed and not in older persons who walk slowly (<1.0 m/s).     

Gait characteristics of elderly people with a history of falls: a dynamic approach

BACKGROUND AND PURPOSE: This study investigated changes in the kinematics of elderly people who experienced at least one fall 6 months prior to data collection. The authors hypothesized that, in order to decrease variability of walking, people with a history of falls would show different kinematic adaptations of their walking patterns compared with elderly people with no history of falls. SUBJECTS AND METHODS: Twenty-one elderly people who had fallen within the previous 6 months ("fallers"; mean age=72.1 years, SD=4.9) and 27 elderly people with no history of falls ("nonfallers"; mean age=73.8 years, SD=6.4) walked at their preferred stride frequency (STF) as treadmill speed was gradually increased (from 0.18 m/s to 1.52 m/s) and then decreased in steps of 0.2 m/s. Gait parameter measurements were recorded, and statistical analysis was applied using walking speed and STF as independent variables. RESULTS: Fifty-seven percent of the fallers were unable to walk at the fastest speed, whereas all nonfallers walked comfortably at all walking speeds. Although the fallers showed significantly greater STF, smaller stride lengths, smaller center-of-mass lateral sway, and smaller ankle plantar flexion and hip extension during push-off, they showed increased variability of kinematic measures in their coordination of walking compared with the nonfallers. DISCUSSION AND CONCLUSION: Although the fallers' adaptations were expected to reduce variability in the coordination of walking, they showed less stable gait patterns (ie, greater variability) compared with the nonfallers. Increased variability of walking patterns may be an important gait risk factor in elderly people with a history of falls.     

Effects of aging and Parkinson's disease on joint coupling,symmetry, complexity and variability of lower limb movements during gait

BackgroundNatural aging and disease processes such as Parkinson's disease often lead to gait impairment. This impairment often manifests as changes in symmetry, complexity, and variability of lower limb joint movements during gait as compared to young healthy adults. Current gait assessment tools primarily focus on discrete events during gait or are based on univariate statistical techniques. Therefore, they fall short in examining spatiotemporally complex gait characteristics including interactions across multiple segments and joints.MethodsTreadmill walking data from ten healthy older adults and ten individuals with idiopathic Parkinson's disease were collected at their self-selected speed. Additionally treadmill walking data from previously collected gait studies on 20 young adults were also used. This study utilized new gait assessment techniques that quantitatively examined joint coupling characteristics (via Condition Signature Analysis), variability and complexity of joint variables (via Phase Portrait Analysis), and movement asymmetry (via Regions of Deviation analysis) of the three different groups.FindingsPeople with Parkinson's disease had the highest asymmetry among the three groups. Aging and Parkinson's disease significantly decreased complexity of hip and ankle joint movements, respectively, while there were no significant differences in variability measures among the three groups. The Condition Signature Analysis method suggested significant differences of joint coupling patterns due to aging and Parkinson's disease.InterpretationThese new gait assessment techniques successfully captured changes in asymmetry, variability, complexity, and joint coupling patterns. Quantitative gait assessment using these tools can be used to detect various types of gait impairments.     

The effects of head movement and walking speed on gait parameters in patients with chronic neck pain

It has been documented that neck pain can influence sensorimotor function. However, little is known about the effects of head movement and walking speed on gait characteristics in patients with neck pain. The aim of this study was to determine gait characteristics of patients with neck pain during walking with different head movements and gait speeds as compared to a control group without neck pain. Twenty women aged between 18 and 59 years with chronic neck pain (>3 months) and 20 healthy controls of similar age, weight and height were recruited into the study. Participants with neck pain completed the Neck Disability Index and Visual Analogue Pain Scale. The experiment consisted of two walking sessions. The first session included walking with head straight, head up-down, and head turns from side to side. The second session included walking at comfortable and maximum speeds. Each trial was performed twice. Gait parameters measured using GAITRite walkway system were step length, stride length, step time, stride time, step width, cadence and gait speed. Patients with chronic neck pain demonstrated a narrower step width, a shorter step length and a slower gait speed during walking with the head movements and at maximum speed compared to the control group (all p < 0.05). Maximum gait speed was moderately correlated with pain intensity and disability (p < 0.01). The results suggest that patients with chronic neck pain have gait disturbances. This supports the notion that assessment of gait should be addressed in patients with persistent neck pain.     

The effect of cognitive dual tasks on balance during walking in physically fit elderly people

OBJECTIVE: To evaluate the effect on balance of 3 different cognitive dual tasks performed while walking without and with standardization for gait velocity, and measured with both foot placements and trunk movements. DESIGN: Cross-sectional study. SETTING: Community. PARTICIPANTS: Fifty-nine physically fit elderly people (mean age, 73.5y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Stride length and time variability measured with an electronic walkway, body sway measured with an angular velocity instrument, and gait velocity. RESULTS: Overall, dual tasks resulted in decreased gait velocity (1.46 to 1.23m/s, P<.001), increased stride length (1.4% to 2.6%), and time variability (1.3% to 2.3%) (P<.001), and had no significant effect on body sway. After standardization for gait velocity, the dual tasks were associated with increased body sway (111% to 216% of values during walking without dual task, P<.001) and increased stride length and time variability (41% to 223% increase, P<.001). CONCLUSIONS: In physically fit elderly people, cognitive dual tasks influence balance control during walking directly as well as indirectly through decreased gait velocity. Dual tasks increase stride variability with both mechanisms, but the increase in body sway is only visible after standardization for gait velocity. The decreased gait velocity can be a strategy with which to maintain balance during walking in more difficult circumstances.     

Age-related differences in dual task walking: a cross sectional study

Background  

Variability in stride velocity during walking characterizes gait instability and predicts falling in older individuals. Walking while executing a cognitive task is also associated with increased risk of falling, particularly in older adults. Variability in stride velocity, particularly during dual task walking conditions, may differ between younger and older individuals. The purpose of this study was to examine whether gait velocity and variability in stride velocity differ between older community-dwelling women and younger women during dual task walking.     

Effects of Dual Task Training on Dual Task Gait Performance and Cognitive Function in Individuals With Parkinson Disease: A Meta-analysis and Meta-regression

ObjectiveTo explore the effects of dual task (DT) training on DT gait performance and cognitive function in individuals with Parkinson disease (PD) and to examine factors that might influence the effects of DT training.Data SourcesPubMed, Wiley Online Library, Cochrane Library, CINAHL, and Medline were searched for articles published from January 2006 to December 2021.Study SelectionRandomized controlled trials comparing DT training with usual care or general exercise were included.Data ExtractionThe outcomes studied were DT gait parameters including speed, step and stride length, cadence, step and stride time variability, dual-task cost on gait speed, and Trail Making Tests presented as standardized mean differences (SMDs). The Grading of Recommendations, Assessment, Development, and Evaluation was used to evaluate the quality of evidence.Data SynthesisTen randomized controlled trials with 466 participants were included in the meta-analysis. The included studies presented, in general, with a low to high risk of bias. Meta-analyses used a random-effects model for all analyses. The meta-analysis showed the DT training effects on DT gait speed (SMD=0.825, P=.012), DT step and stride length (SMD=0.400, P=.015), Trail Making Tests-part A (TMT-A; SMD=0.533, P=.010), and Trail Making Tests-part B (SMD=0.516, P=.012) compared with the control group. Only the effect on TMT-A was maintained at the follow-up assessment. The results of meta-regression showed that participants with slower initial single task gait speed improved more after DT training on DT step and stride length.ConclusionsThe DT training improved more in DT gait speed with moderate-quality evidence as compared with usual care or conventional physical training in individuals with PD. The beneficial effects of DT training on DT step and stride length, attention, and executive function were also demonstrated in this meta-analysis. Furthermore, the improvement in the DT walking step and stride length was related to the participant's initial single task gait speed.     

Six weeks of intensive treadmill training improves gait and quality of life in patients with Parkinson's disease: a pilot study

OBJECTIVE: To evaluate the effects of 6 weeks of intensive treadmill training on gait rhythmicity, functional mobility, and quality of life (QOL) in patients with Parkinson's disease (PD). DESIGN: An open-label, before-after pilot study. SETTING: Outpatient movement disorders clinic. PARTICIPANTS: Nine patients with PD who were able to ambulate independently and were not demented. Mean age was 70+/-6.8 years. Patients had mild to moderate PD (Hoehn and Yahr stage range, 1.5-3). INTERVENTIONS: Patients walked on a treadmill for 30 minutes during each training session, 4 training sessions a week, for 6 weeks. Once a week, usual overground walking speed was re-evaluated and the treadmill speed was adjusted accordingly. MAIN OUTCOME MEASURES: The 39-item Parkinson's Disease Questionnaire (PDQ-39), motor part of the Unified Parkinson's Disease Rating Scale (UPDRS), gait speed, stride time variability, swing time variability, and the Short Physical Performance Battery (SPPB). RESULTS: A comparison of the measures taken before and after the treadmill intervention indicates general improvement. QOL, as measured by the PDQ-39, was reduced (improved) from 32 to 22 (P<.014). Parkinsonian symptoms, as measured by the UPDRS, decreased (improved) from 29 to 22 (P<.043). Usual gait speed increased from 1.11 to 1.26 m/s (P<.014). Swing time variability was lower (better) in all but one patient, changing from 3.0% to 2.3% (P<.06). Scores on the SPPB also improved (P<.008). Interestingly, many of the improvements persisted even 4 weeks later. CONCLUSIONS: These results show the potential to enhance gait rhythmicity in patients with PD and suggest that a progressive and intensive treadmill training program can be used to minimize impairments in gait, reduce fall risk, and increase QOL in these patients.     

Gait parameters and stride-to-stride variability during familiarization to walking on a split-belt treadmill

Background

Subjects unfamiliar to walking on a split-belt treadmill may initially demonstrate an altered gait pattern or increased variability of gait parameters. While previous investigations have examined kinematic variables associated with familiarization time, the objective of this study was to determine the familiarization period required to obtain the most reproducible gait pattern through the assessment of kinetic, kinematic and spatio-temporal parameters during a single session of treadmill walking.

Methods

Eleven healthy subjects participated in a single bout of treadmill walking which lasted 9 min. Kinematic and kinetic data were collected from the first 30 s of each minute, beginning when the treadmill reached full speed. Means and standard deviations for knee flexion at heel strike, ground reaction forces, step width and step length were obtained to examine the changes in each variable over the 9 min. Mean r² values were evaluated for changes in variability from one stride to the subsequent stride for sagittal plane hip, knee and ankle joint angles and moments, as well as for vertical and horizontal ground reaction forces.

Findings

Significant reductions in variability were found for vertical and horizontal ground reaction forces, knee flexion at heel strike and step length over 9 min. Only step width showed a change in the mean value across trials. There were no increases in r² values after the 5th min for any of the gait variables.

Interpretation

The results suggest that in order to collect accurate data for gait analysis, subjects should be familiarized to the split-belt treadmill for at least 5 min prior to data collection.     

Use of a video time display in determining general gait measures

By superimposing a video time display (VTD) onto videotapes of patients walking, and using pause-motion replay, precise measures of walking speed, cadence and stride length may be obtained. Five groups of 10 subjects were used to investigate VTD-based gait analysis under different test conditions. An additional 20 healthy subjects were retested on two occasions on average 10.2 weeks apart. These subjects demonstrated moderate reliability for cadence and poor reliability for speed and stride length. It is recommended that progress be assessed by serial testing with regular time intervals. The results from healthy subjects were comparable with results from studies using other instruments. VTD-based gait analysis is a simple, accurate and inexpensive test procedure under a variety of clinical conditions.     

Effects of attention on the control of locomotion in individuals with chronic low back pain

Background  

People who suffer from low back pain (LBP) exhibit an abnormal gait pattern, characterized by shorter stride length, greater step width, and an impaired thorax-pelvis coordination which may undermine functional walking. As a result, gait in LBP may require stronger cognitive regulation compared to pain free subjects thereby affecting the degree of automaticity of gait control. Conversely, because chronic pain has a strong attentional component, diverting attention away from the pain might facilitate a more efficient walking pattern.     

Nonlinear dynamics indicates aging affects variability during gait

OBJECTIVE: To investigate the nature of variability present in time series generated from gait parameters of two different age groups via a nonlinear analysis. DESIGN: Measures of nonlinear dynamics were used to compare kinematic parameters between elderly and young females. BACKGROUND: Aging may lead to changes in motor variability during walking, which may explain the large incidence of falls in the elderly. METHODS: Twenty females, 10 younger (20-37 yr) and 10 older (71-79 yr) walked on a treadmill for 30 consecutive gait cycles. Time series from selected kinematic parameters of the right lower extremity were analyzed using nonlinear dynamics. The largest Lyapunov exponent and the correlation dimension of all time series, and the largest Lyapunov exponent of the original time series surrogated were calculated. Standard deviations and coefficient of variations were also calculated for selected discrete points from each gait cycle. Independent t-tests were used for statistical comparisons. RESULTS: The Lyapunov exponents were found to be significantly different from their surrogate counterparts. This indicates that the fluctuations observed in the time series may reflect deterministic processes by the neuromuscular system. The elderly exhibited significantly larger Lyapunov exponents and correlation dimensions for all parameters evaluated indicating local instability. The linear measures indicated that the elderly demonstrated significantly higher variability. CONCLUSIONS: The nonlinear analysis revealed that fluctuations in the time series of certain gait parameters are not random but display a deterministic behavior. This behavior may degrade with physiologic aging resulting in local instability. RELEVANCE: Elderly show increased local instability or inability to compensate to the natural stride-to-stride variations present during locomotion. We hypothesized that this may be the one of the reasons for the increases in falling due to aging. Future efforts should attempt to evaluate this hypothesis by making comparisons to pathological subjects (i.e. elderly fallers), and examine the sensitivity and specificity of the nonlinear methods used in this study to aid clinical assessment.     

Effects of prosthetic mass and mass distribution on kinematics and energetics of prosthetic gait: a systematic review

OBJECTIVE: To introduce the theoretical models used in literature that describe the relation between prosthetic inertial loading and amputee gait and to derive specific predictions from these models: to systematically review experimental studies on the relation between prosthetic inertial loading and energetics and kinematics of lower-limb prosthetic gait; and to compare the review outcomes with predictions derived from theoretical models. DATA SOURCES: Studies selected from Medline and from examining references in the selected Medline publications. STUDY SELECTION: Theoretical models were selected that are used in the present literature to predict the effects of prosthetic mass and mass distribution on kinematics and energetics of prosthetic gait. Experimental studies were selected that investigated the effects of prosthetic mass or center of mass location on the economy, self-selected walking speed, stride length, or stride frequency of lower limb amputee patients. DATA EXTRACTION: The design and methodologic quality was assessed using a checklist of nine criteria. Data on economy, self-selected walking speed, stride frequency, and stride length were extracted from the studies selected. DATA SYNTHESIS: The predictions of the theoretical models suggest that inertial loading of the present lightweight prostheses need not be decreased and sometimes may need to be increased to improve the gait of amputee patients. The methodologic quality of most of the experimental studies was limited. Review of the experimental studies suggests that the inertial loading of the present lightweight prostheses need not be further reduced. The discrepancy between theoretical models and experimental findings may be related to both the poor methodologic quality of the experiments as well as to the limited predictive value of the existing models.     

Structures promoting research, training, and technology transfer in mobility: lessons learned from a visit to European centers

Background

Few studies looked at the association between gait variability and executive subdomains (ESD). The aim of this study was to examine the association between ESD (i.e., information updating and monitoring) and stride time variability among healthy older adults.

Methods

Seventy-eight healthy older adults (mean age 69.9 ± 0.9 years, 59% women) were divided into 3 groups according to stride time variability (STV) tertiles while steady state walking. Coefficient of variation of stride time was used as a marker of STV. Scores on cognitive tests evaluating information updating and monitoring (Digit Span test), mental shifting (Trail Making Test part A and part B) and cognitive inhibition (Stroop Color Word test) were used as measures of ESD.

Results

The full adjusted and the stepwise backward logistic regression models showed that the highest tertile (i.e., the worst performance) of STV was only associated with lower Digit Span performance (Odds ratio = 0.78 with P = 0.020 and Odds ratio = 0.81 with P = 0.019).

Conclusions

Information updating and monitoring are associated with STV in the sample of studied participants, suggesting that walking may be a complex motor task depending specifically of this subdomain of executive functions.