Does the walking task matter? Influence of different walking conditions on dual-task performances in young and older persons

Previous literature suggests that age-related deficits of dual-task walking are particularly pronounced with second tasks that require continuous visual processing. Here we evaluate whether the difficulty of the walking task matters as well. To this end, participants were asked to walk along a straight pathway of 20 m length in four different walking conditions: (a) wide path and preferred pace; (b) narrow path and preferred pace, (c) wide path and fast pace, (d) obstacled wide path and preferred pace. Each condition was performed concurrently with a task requiring visual processing or fine motor control, and all tasks were also performed alone which allowed us to calculate the dual-task costs (DTC). Results showed that the age-related increase of DTC is substantially larger with the visually demanding than with the motor-demanding task, more so when walking on a narrow or obstacled path. We attribute these observations to the fact that visual scanning of the environment becomes more crucial when walking in difficult terrains: the higher visual demand of those conditions accentuates the age-related deficits in coordinating them with a visual non-walking task.     

Developmental continuity? Crawling,cruising, and walking

This research examined developmental continuity between "cruising" (moving sideways holding onto furniture for support) and walking. Because cruising and walking involve locomotion in an upright posture, researchers have assumed that cruising is functionally related to walking. Study 1 showed that most infants crawl and cruise concurrently prior to walking, amassing several weeks of experience with both skills. Study 2 showed that cruising infants perceive affordances for locomotion over an adjustable gap in a handrail used for manual support, but despite weeks of cruising experience, cruisers are largely oblivious to the dangers of gaps in the floor beneath their feet. Study 3 replicated the floor-gap findings for infants taking their first independent walking steps, and showed that new walkers also misperceive affordances for locomoting between gaps in a handrail. The findings suggest that weeks of cruising do not teach infants a basic fact about walking: the necessity of a floor to support their body. Moreover, this research demonstrated that developmental milestones that are temporally contiguous and structurally similar might have important functional discontinuities.     

Does augmented feedback from pedometers increase adults' walking behavior?

This study investigated whether feedback from pedometers motivated adults to increase their walking behavior. Participants (n =26) were enrolled in one of two 8-wk. "Walking for Fitness" classes. The study used a crossover design, such that Group 1 wore pedometers for the first 3 weeks (Feedback Condition) and sealed "disguised" pedometers for the last 3 weeks (No-feedback Condition). The order of feedback was reversed for Group 2. Analysis indicated that (a) neither group increased their walking behavior significantly over time and, (b) interactions between groups were not significant at Week 3 or 6, indicating that groups did not respond differently to feedback from the pedometers. If a motivational effect from pedometers exists, it may be small, dissipate before 3 wk., only work in combination with goal setting, or only motivate certain types of individuals.     

Are daily fluctuations in perceived environment associated with walking?

The physical environment is thought to influence walking; however, daily variations in perceived environment have received little attention. The current study sought to examine if key within-person factors (i.e., implementation intentions, social support, affect and self-efficacy) would be associated with walking and if perceived access to supportive environments (e.g., access to nice walking paths) and perceived environmental barriers (e.g., bad weather and safety issues) were uniquely associated with walking after controlling for other constructs. Participants (N = 14, 50.0% men, 78.6% White, M age = 59.4 ± 6.4) were in the intervention arm of an 8-week controlled trial promoting walking via personal digital assistants. Participants completed electronic surveys twice a day (total entries = 804) in which they reported brisk walking levels and psychosocial and environmental factors. Multilevel modelling was used to examine within-person variations in constructs as determinants of walking. Results suggested that daily variations in implementation intentions, social support and positive affect were positively associated with walking. Further, perceived access to supportive environments, though not perceived environmental barriers, was positively associated with walking after controlling for other constructs (p < 0.05). Future research should explore intervention components that target context-specific information about perceived access to supportive environments as part of a broader perspective on intervention development.     

Do kinematic metrics of walking balance adapt to perturbed optical flow?

Visual (i.e., optical flow) perturbations can be used to study balance control and balance deficits. However, it remains unclear whether walking balance control adapts to such perturbations over time. Our purpose was to investigate the propensity for visuomotor adaptation in walking balance control using prolonged exposure to optical flow perturbations. Ten subjects (age: 25.4 ± 3.8 years) walked on a treadmill while watching a speed-matched virtual hallway with and without continuous mediolateral optical flow perturbations of three different amplitudes. Each of three perturbation trials consisted of 8 min of prolonged exposure followed by 1 min of unperturbed walking. Using 3D motion capture, we analyzed changes in foot placement kinematics and mediolateral sacrum motion. At their onset, perturbations elicited wider and shorter steps, alluding to a more cautious, general anticipatory balance control strategy. As perturbations continued, foot placement tended toward values seen during unperturbed walking while step width variability and mediolateral sacrum motion concurrently increased. Our findings suggest that subjects progressively shifted from a general anticipatory balance control strategy to a reactive, task-specific strategy using step-to-step adjustments. Prolonged exposure to optical flow perturbations may have clinical utility to reinforce reactive, task-specific balance control through training.     

Barriers to children’s walking to school in Iranian and Chinese samples

Factors that contribute to children’s walking to school have been investigated in previous research, which primarily focussed on socio-economic variables in high income countries. There is a general lack of studies which have examined mode choice differences on school trips in low and middle income countries. Focusing on parental social cognitive variables in addition to household socio-economic characteristics, the present study is among the first to compare barriers to children’s walking in daily commuting to schools across samples from two middle income countries: Iran and China. A self-administered questionnaire was devised and distributed among primary school pupils (7–9 years old) in Mashhad, Iran and Nanjing, China. The children were asked to take the questionnaires to their parents to complete and return the filled forms. A total of 671 (response rate of 90 percent) and 224 (response rate of 82 percent) completely filled questionnaires were returned in Mashhad and Nanjing, respectively. Multivariate analysis of covariance (MANCOVA) showed that parents in Mashhad perceived higher risk and reported more worry of children being involved in road crashes when walking to school. Analyses revealed more safety favourable parental attitudes in the Chinese sample, compared to the Iranian sample. Parental attitudes towards transport safety were safer in the sample from Nanjing as compared to Mashhad. Hierarchical binary logistic regression showed that walking time from home to school and parental worry about road crashes were negatively associated with children’s walking to school in both samples. In the Iranian sample, results suggested that while household car ownership and higher family income were associated with a decreased probability that a child walk to school, the total number of children in the household increased the probability of walking to school.     

Is optic flow used to guide walking while wearing a displacing prism?

Rushton et al (1998 Current Biology 8 1191 - 1194) recently showed that walkers wearing displacing prisms follow curved trajectories determined by the perceived direction of their target. This suggests that optic flow is not important in guidance, since flow cues are unaffected by the prism and should allow a straight, direct trajectory. We replicated Rushton et al's result but also tried to rule out an important artifact associated with the prism. Prisms restrict the field of view and, particularly, access to the foreground optic flow that is likely to be important in providing guidance cues. We found that performance did not improve when walkers directed their gaze to include the foreground flow, suggesting that Rushton et al's results were not due to this artifact. On the other hand, performance did reliably improve when subjects reduced their viewing height by crawling towards the target. This improvement may be due to coarsening of the visual texture or to increased salience of alignment and motion-parallax cues. Whatever its cause, the improvement demonstrates that guidance is not determined only by perceived target direction and that, under some conditions, flow may be important.     

Is it really too far? Overestimating walk time and distance reduces walking

In this paper we use an intercept survey of 1,297 people at seven locations in New Jersey to answer three questions about perceived distances and walk times to nearby destinations. First, we seek to clarify conflicting results from the literature by asking: what factors are associated with perceived distance and walk times? Like other studies, we find that people overestimate both walk times and distances. We find that characteristics of the route matter. People are more likely to overestimate in car-dependent locations, along routes with many turns or barriers, or for destinations that are relatively closer. In terms of personal characteristics, experience walking and familiarity with the area both lead to lower estimates, while concerns about crime, getting lost, or carrying something heavy increase estimates. Next, we explore whether overestimating walk times and distances reduces the likelihood of walking. We find that people who overestimate are less likely to walk, everything else equal. Together, these results suggest that wayfinding campaigns that clarify the travel time to nearby destinations and ease the fear of getting lost are likely to improve perceptions and increase walking. We make an additional contribution by highlighting important differences between our university and town center samples, which raises questions about the reliance on student samples in research.     

How do skeletal and postural parameters contribute to maintain balance during walking?

IntroductionMaintaining balance during gait allows subjects to minimize energy expenditure and avoid falls. Gait balance can be measured by assessing the relationship between the center of mass (COM) and center of pressure (COP) during gait. Demographics, skeletal and postural parameters are known to influence gait balance.PurposeWhat are the determinants of dynamic balance during gait in asymptomatic adults among skeletal and demographic parameters?Methods115 adults underwent 3D gait analysis and full-body biplanar X-rays. Angles between the COM-COP line and the vertical were calculated in frontal and sagittal planes during gait: maxima, minima, and ROM were evaluated. Full-body 3D reconstructions were obtained; skeletal and postural parameters of the spine (lumbar lordosis, thoracic kyphosis, sagittal vertical axis SVA), pelvis (pelvic tilt and incidence, acetabular orientation in the 3 planes) and lower limbs (neck shaft angle femoral and tibial torsions) were calculated. A univariate followed by a multivariate analysis were computed between the COM-COP parameters and skeletal and demographic parameters.ResultsThe univariate analysis showed that in the frontal plane, maximum (4.6°) of the COM-COP angle was significantly correlated with weight (r = 0.53), age (r = 0.28), height (r = 0.35), SVA (r = 0.23), T1T12 (r = 0.24) and pelvic width (r = 0.25).In the sagittal plane, maximum COM-COP (19.7 ± 2.8°) angle was significantly correlated to acetabular tilt (r = 0.25) and acetabular anteversion (r = 0.21). The multivariate analysis showed that, in the frontal plane, an increase in the maximum of the COM-COP angle was determined by a decreasing height (β = −0.28), an increasing weight (β = 0.48), being a male (β = −0.42), and an increasing posterior acetabular coverage (β = 0.22). In the sagittal plane, an increasing maximum COM-COP angle was determined by a decreasing height (β = −0.38) and an increasing SVA (β = 0.19).ConclusionFrontal imbalance appeared to be mainly correlated to demographic parameters. Sagittal imbalance was found to be correlated with weight, height, acetabular parameters and SVA. These results suggest that in addition to demographic parameters, acetabular parameters and SVA are important determinants of balance during gait.     

Are there common walking gait characteristics in patients diagnosed with late-onset Pompe disease?

Late-onset Pompe disease (LOPD) is a rare disease, defined as a progressive accumulation of lysosomal glycogen resulting in muscle weakness and respiratory problems. Anecdotally, individuals often have difficulties walking, yet, there is no three-dimensional data supporting these claims. We aimed to assess walking patterns in individuals with LOPD and compare with healthy individuals. Kinematic, kinetic and spatiotemporal data were compared during walking at a self-selected speed between individuals with LOPD (n = 12) and healthy controls (n = 12). Gait profile scores and movement analysis profiles were also determined to indicate gait quality. In comparison with healthy individuals, the LOPD group demonstrated greater thoracic sway (96%), hip adduction angles (56%) and pelvic range of motion (77%) and reduced hip extensor moments (36%). Greater group variance for the LOPD group were also observed. Individuals with LOPD had a slower (15%) walking speed and reduced cadence (7%). Gait profile scores were 37% greater in the LOPD group compared to the healthy group. Proximal muscular weakness associated with LOPD disease is likely to have resulted in a myopathic gait pattern, slower selected walking speeds and deviations in gait patterns. Although individuals with LOPD presented with some common characteristics, greater variability in gait patterns is likely to be a result of wide variability in phenotype spectrum observed with LOPD. This is the first study to examine walking in individuals with LOPD using instrumented gait analysis and provides an understanding of LOPD on walking function which can help orientate physiotherapy treatment for individuals with LOPD.     

Do attentional focus instructions affect real-time reinvestment during level-ground walking in older adults?

Cognitive Processing - This study represents the first attempt in exploring whether attentional focus instructions could affect real-time reinvestment (conscious movement processing) in older...     

Does direction of walking impact binocular rivalry between competing patterns of optic flow?

When dissimilar monocular images are viewed simultaneously by the two eyes, stable binocular vision gives way to unstable vision characterized by alternations in dominance between the two images in a phenomenon called binocular rivalry. These alternations in perception reveal the existence of inhibitory interactions between neural representations associated with conflicting visual inputs. Binocular rivalry has been studied since the days of Wheatstone, but one recent strategy is to investigate its susceptibility to influences caused by one’s own motor activity. This paper focused on the activity of walking, which produces an expected, characteristic direction of optic flow dependent upon the direction of one’s walking. In a set of experiments, we employed virtual reality technology to present dichoptic stimuli to observers who walked forward, backward, or were sitting. Optic flow was presented to a given eye, and was sometimes congruent with the direction of walking, sometimes incongruent, and sometimes random, except when the participant was sitting. Our results indicate that, while walking had a reliable influence on rivalry dynamics, the predominance of congruent or incongruent motion did not.     

Perceptually walking in another’s shoes: goals and memories constrain spatial perception

Psychological Research - Perceptual variables such as perceived distance contain information about future actions. Often our goals involve the integration of another’s goals, such as lifting...     

How does normal variability in trunk flexion affect lower limb muscle activity during walking?

A large proportion of the mass of the body is contained within the trunk segment. Therefore, small changes in the inclination of this segment have the potential to influence the direction of the ground reaction force and alter lower limb joint moments and muscle activation patterns during walking. The aim of this study was to investigate if variability in sagittal trunk inclination in healthy participants is associated with differences in lower limb biomechanics. Gait analysis data was collected on 41 healthy participants during walking. Two groups were defined based on habitual trunk flexion angle during normal walking, a forward lean group (n = 18) and a backward lean group (n = 17). Lower limb moments, muscle activation patterns and co-contraction levels were compared between the two groups using independent t-tests. The forward lean group walked with 5° more trunk flexion than the backward lean group. This difference was associated with a larger peak hip moment (effect size = 0.7) and higher activation of the lateral gastrocnemius (effect size =0.6) and the biceps femoris (effect size =0.7) muscles. The forward lean group also exhibited greater co-contraction in late stance (effect size =0.7). This is the first study to demonstrate that small differences in trunk flexion are associated with pronounced alterations in the activation of the lateral knee flexor muscles. This is important because people with knee osteoarthritis have been observed to walk with increased trunk flexion. It is possible that increased sagittal trunk inclination may be associated with elevated joint loads in people with knee osteoarthritis.     

“We’re a walking picket sign”: Management of a Stigmatized Religious Identity

This study analyzes qualitative data from interviews with 18 members of the Westboro Baptist Church (WBC) focusing on the group’s religious identity and relationships with “mainstream” society. Two primary themes emerged. First, the WBC religious identity appears to hinge on external conflict with society which is promoted by their core religious ideology and negotiated through various stigma management strategies. Second, members of the church enjoy strong internal group cohesion promoted by their religious ideology and symbolic boundaries that separate them from outside institutions. This study therefore suggests stigmatization offers social benefits to members of the WBC in addition to social consequences.     

Are there attentional demands associated with haptic modalities while walking in young,healthy adults?

Study designA prospective, observational study.ObjectivesTo assess the attentional demands of using haptic modalities during walking using a multi-task paradigm in young, healthy adults.SettingBiomechanics of Balance and Movement (BBAM) Lab, University of Saskatchewan.MethodsTwenty-two (12 male) young, healthy adults performed walking trials with and without a verbal reaction time (VRT) task, as well as with and without the use of haptic anchors and light touch on a railing. Walking performance was evaluated using normalized stride velocity and step width, and dynamic stability was evaluated using step width variability and medial-lateral margin of stability (ML MOS) and its variability.ResultsThere were no significant differences in VRT when walking with and without added haptic input and no interactions between the added VRT task and added haptic input. Step width increased and variability of the ML MOS increased during trials with the VRT task compared to trials without the VRT task. The ML MOS decreased when using both haptic tools with a greater decrease when using light touch on the railing compared to when using the haptic anchors. Normalized stride velocity and step width decreased when using light touch on the railing only.ConclusionBoth haptic tools affected stability during walking. Using the railing to add haptic input had a greater effect on walking stability and was the only haptic tool to affect walking performance. Attentional demands should be considered in future research and applications of adding haptic input during walking.     

How to improve the walking realm in a car-oriented city? (Dis)agreements between professionals

PurposeUrban environments and transport systems can enable and encourage walking, and therefore play a key role in climate action, public health, equity of access, and population wellbeing. The question, especially in cities that have been dominated by car traffic, is how? The challenge is heightened by the multidisciplinary involvements in the design, operation, and maintenance of urban infrastructure.This study examines the views of professionals from different disciplines involved in delivering walking environments in Auckland, New Zealand. The study examines agreements and disagreements regarding users’ needs, priorities, challenges, and evidence gaps for delivering quality walking environments in a car-dominated city.MethodsPrimary data were collected through an online survey (N = 28) and a focus group, both involving professionals active in urban design, road safety, transport planning, public health, urban development and strategy. Analysis involved content coding and comparing the frequency of responses across professional groups.ResultsThe results indicated a consensus on the complexity associated with providing walking environments, as well as the importance of the quality of street environments. The lack of priority given to walking, car-dominated environments, and the inability to deliver change were seen as challenges. The inputs suggested a negative chain reaction linking the low priority of walking and the lack of consensus relative to users’ experience. There appeared to be a lack of common understanding of users’ needs and experiences and a paucity of evidence on this topic.ConclusionThe findings suggest the need for urban retrofit rooted in a sound understanding of users’ needs and experiences, and walkability as a sub-system of the urban environment. Recommendations include higher interdisciplinary collaboration at the policy and practice level, reviewed delivery processes, and better-quality data.     

Did you see the unicycling clown? Inattentional blindness while walking and talking on a cell phone

We investigated the effects of divided attention during walking. Individuals were classified based on whether they were walking while talking on a cell phone, listening to an MP3 player, walking without any electronics or walking in a pair. In the first study, we found that cell phone users walked more slowly, changed directions more frequently, and were less likely to acknowledge other people than individuals in the other conditions. In the second study, we found that cell phone users were less likely to notice an unusual activity along their walking route (a unicycling clown). Cell phone usage may cause inattentional blindness even during a simple activity that should require few cognitive resources. Copyright © 2009 John Wiley & Sons, Ltd.     

An emerging postural response: is control of the hip possible in the newly walking child?

Previous researchers have proposed that because of their slow muscle-response latencies, 1- to 2-year-old children are unable to control hip-dominant postural responses when responding to balance threats (G. McCollum & T. Leen, 1989). To test that proposition, the authors exposed 41 children to backward support-surface translations and recorded muscle activations and movement kinematics. Children between 10 months and 10 years of age stood on a platform that was unexpectedly moved. Passive hip-dominant responses were observed among the least experienced walkers. In contrast, older children produced an active response, signified by higher levels of abdominal and quadriceps muscle activity and accompanied by larger hip flexor torques. Greater success in withstanding large magnitudes of perturbations were associated with actively generated hip responses.     

Becoming a person: How long-distance walking can lead to personal growth – A cultural and health-related approach

Long-distance walking is an activity that has been practiced across cultures and ages. More recently, it has been associated with notions of mental health, and it has been suggested that long-distance walking may have psychotherapeutic effects. There is still, however, a lack of clarity regarding several central questions, including what long-distance walking is, and why it may be beneficial to mental health. In this article, we provide an overview of understandings and cultural expressions of the long-distance walk, and we provide a new definition, reaching across these various understandings and expressions. Next, we discuss the different explanations given regarding the therapeutic aspects of the long-distance walk, and suggest a new approach, leaning on an existential framework. Finally, we discuss the implications that the knowledge on long-distance walking has for notions of therapeutic interventions more generally.