Back Strength Predicts Walking Improvement in Obese, Older Adults With Chronic Low Back Pain

PubMed Central

Vincent, Heather K.; Vincent, Kevin R.; Seay, Amanda N.; Conrad, Bryan P.; Hurley, Robert W.; George, Steven Z.

2014-01-01

Objective To compare the effects of 4 months of isolated lumbar resistance exercise and total body resistance exercise on walking performance in obese, older adults with chronic low back pain. A secondary analysis examined whether responsiveness to training modulated walking improvement. Design Randomized, controlled trial. Setting Research laboratory affiliated with tertiary care facility. Methods and Intervention Participants (N = 49; 60–85 years) were randomized into a 4-month resistance exercise intervention (TOTRX), lumbar extensor exercise intervention (LEXT), or a control group (CON). Main Outcome Measurements Walking performance, maximal low back strength and leg strength, and average resting and low back pain severity score (from an 11-point numerical pain rating scale; NRSpain) were collected at baseline and month 4. Results The TOTRX and LEXT improved lumbar extensor strength relative to CON and the TOTRX (P < .05). NRSpain scores at month 4 were lowest in the TOTRX group compared with the LEXT and CON groups, respectively (2.0 ± 1.7 points vs 3.7 ± 2.6 points and 4.6 ± 2.4 points; P < .006). A total of 53% and 67% of participants in the TOTRX and LEXT groups were responders who made lumbar extensor strength gains that achieved ≥20% greater than baseline values. Although the TOTRX demonstrated the greatest improvement in walking endurance among the intervention groups, this did not reach significance (10.1 ± 12.2% improvement in TOTRX vs 7.4 ± 30.0% LEXT and −1.7 ± 17.4% CON; P = .11). Gait speed increased most in the TOTRX (9.0 ± 13.5%) compared with the LEXT and CON groups (P < .05). The change in lumbar extensor strength explained 10.6% of the variance of the regression model for the change in walking endurance (P = .024). Conclusions The use of LEXT and TOTRX produced similar modest improvements in patients’ walking endurance. Lumbar extensor strength gain compared with leg strength gain is a moderate but important contributor to walking endurance in obese older adults with chronic low back pain. Responders to resistance exercise programs (event those with only lumbar extension exercise) who make at least a 20% improvement in strength can expect better improvement in walking endurance than those who do not achieve this strength improvement. PMID:24211698

Anomalous diffusion analysis of the lifting events in the event-chain Monte Carlo for the classical XY models

NASA Astrophysics Data System (ADS)

Kimura, Kenji; Higuchi, Saburo

2017-11-01

We introduce a novel random walk model that emerges in the event-chain Monte Carlo (ECMC) of spin systems. In the ECMC, the lifting variable specifying the spin to be updated changes its value to one of its interacting neighbor spins. This movement can be regarded as a random walk in a random environment with a feedback. We investigate this random walk numerically in the case of the classical XY model in 1, 2, and 3 dimensions to find that it is superdiffusive near the critical point of the underlying spin system. It is suggested that the performance improvement of the ECMC is related to this anomalous behavior.

Development of a Subject-Specific Foot-Ground Contact Model for Walking.

PubMed

Jackson, Jennifer N; Hass, Chris J; Fregly, Benjamin J

2016-09-01

Computational walking simulations could facilitate the development of improved treatments for clinical conditions affecting walking ability. Since an effective treatment is likely to change a patient's foot-ground contact pattern and timing, such simulations should ideally utilize deformable foot-ground contact models tailored to the patient's foot anatomy and footwear. However, no study has reported a deformable modeling approach that can reproduce all six ground reaction quantities (expressed as three reaction force components, two center of pressure (CoP) coordinates, and a free reaction moment) for an individual subject during walking. This study proposes such an approach for use in predictive optimizations of walking. To minimize complexity, we modeled each foot as two rigid segments-a hindfoot (HF) segment and a forefoot (FF) segment-connected by a pin joint representing the toes flexion-extension axis. Ground reaction forces (GRFs) and moments acting on each segment were generated by a grid of linear springs with nonlinear damping and Coulomb friction spread across the bottom of each segment. The stiffness and damping of each spring and common friction parameter values for all springs were calibrated for both feet simultaneously via a novel three-stage optimization process that used motion capture and ground reaction data collected from a single walking trial. The sequential three-stage process involved matching (1) the vertical force component, (2) all three force components, and finally (3) all six ground reaction quantities. The calibrated model was tested using four additional walking trials excluded from calibration. With only small changes in input kinematics, the calibrated model reproduced all six ground reaction quantities closely (root mean square (RMS) errors less than 13 N for all three forces, 25 mm for anterior-posterior (AP) CoP, 8 mm for medial-lateral (ML) CoP, and 2 N·m for the free moment) for both feet in all walking trials. The largest errors in AP CoP occurred at the beginning and end of stance phase when the vertical ground reaction force (vGRF) was small. Subject-specific deformable foot-ground contact models created using this approach should enable changes in foot-ground contact pattern to be predicted accurately by gait optimization studies, which may lead to improvements in personalized rehabilitation medicine.

Development of a Subject-Specific Foot-Ground Contact Model for Walking

PubMed Central

Jackson, Jennifer N.; Hass, Chris J.; Fregly, Benjamin J.

2016-01-01

Computational walking simulations could facilitate the development of improved treatments for clinical conditions affecting walking ability. Since an effective treatment is likely to change a patient's foot-ground contact pattern and timing, such simulations should ideally utilize deformable foot-ground contact models tailored to the patient's foot anatomy and footwear. However, no study has reported a deformable modeling approach that can reproduce all six ground reaction quantities (expressed as three reaction force components, two center of pressure (CoP) coordinates, and a free reaction moment) for an individual subject during walking. This study proposes such an approach for use in predictive optimizations of walking. To minimize complexity, we modeled each foot as two rigid segments—a hindfoot (HF) segment and a forefoot (FF) segment—connected by a pin joint representing the toes flexion–extension axis. Ground reaction forces (GRFs) and moments acting on each segment were generated by a grid of linear springs with nonlinear damping and Coulomb friction spread across the bottom of each segment. The stiffness and damping of each spring and common friction parameter values for all springs were calibrated for both feet simultaneously via a novel three-stage optimization process that used motion capture and ground reaction data collected from a single walking trial. The sequential three-stage process involved matching (1) the vertical force component, (2) all three force components, and finally (3) all six ground reaction quantities. The calibrated model was tested using four additional walking trials excluded from calibration. With only small changes in input kinematics, the calibrated model reproduced all six ground reaction quantities closely (root mean square (RMS) errors less than 13 N for all three forces, 25 mm for anterior–posterior (AP) CoP, 8 mm for medial–lateral (ML) CoP, and 2 N·m for the free moment) for both feet in all walking trials. The largest errors in AP CoP occurred at the beginning and end of stance phase when the vertical ground reaction force (vGRF) was small. Subject-specific deformable foot-ground contact models created using this approach should enable changes in foot-ground contact pattern to be predicted accurately by gait optimization studies, which may lead to improvements in personalized rehabilitation medicine. PMID:27379886

Can environmental improvement change the population distribution of walking?

PubMed

Panter, Jenna; Ogilvie, David

2017-06-01

Few studies have explored the impact of environmental change on walking using controlled comparisons. Even fewer have examined whose behaviour changes and how. In a natural experimental study of new walking and cycling infrastructure, we explored changes in walking, identified groups who changed in similar ways and assessed whether exposure to the infrastructure was associated with trajectories of walking. 1257 adults completed annual surveys assessing walking, sociodemographic and health characteristics and use of the infrastructure (2010-2012). Residential proximity to the new routes was assessed objectively. We used latent growth curve models to assess change in total walking, walking for recreation and for transport, used simple descriptive analysis and latent class analysis (LCA) to identify groups who changed in similar ways and examined factors associated with group membership using multinomial regression. LCA identified five trajectories, characterised by consistently low levels; consistently high levels; decreases; short-lived increases; and sustained increases. Those with lower levels of education and lower incomes were more likely to show both short-lived and sustained increases in walking for transport. However, those with lower levels of education were less likely to take up walking. Proximity to the intervention was associated with both uptake of and short-lived increases in walking for transport. Environmental improvement encouraged the less active to take up walking for transport, as well as encouraging those who were already active to walk more. Further research should disentangle the role of socioeconomic characteristics in determining use of new environments and changes in walking. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Atomic clocks and the continuous-time random-walk

NASA Astrophysics Data System (ADS)

Formichella, Valerio; Camparo, James; Tavella, Patrizia

2017-11-01

Atomic clocks play a fundamental role in many fields, most notably they generate Universal Coordinated Time and are at the heart of all global navigation satellite systems. Notwithstanding their excellent timekeeping performance, their output frequency does vary: it can display deterministic frequency drift; diverse continuous noise processes result in nonstationary clock noise (e.g., random-walk frequency noise, modelled as a Wiener process), and the clock frequency may display sudden changes (i.e., "jumps"). Typically, the clock's frequency instability is evaluated by the Allan or Hadamard variances, whose functional forms can identify the different operative noise processes. Here, we show that the Allan and Hadamard variances of a particular continuous-time random-walk, the compound Poisson process, have the same functional form as for a Wiener process with drift. The compound Poisson process, introduced as a model for observed frequency jumps, is an alternative to the Wiener process for modelling random walk frequency noise. This alternate model fits well the behavior of the rubidium clocks flying on GPS Block-IIR satellites. Further, starting from jump statistics, the model can be improved by considering a more general form of continuous-time random-walk, and this could bring new insights into the physics of atomic clocks.

Elastic coupling of limb joints enables faster bipedal walking

PubMed Central

Dean, J.C.; Kuo, A.D.

2008-01-01

The passive dynamics of bipedal limbs alone are sufficient to produce a walking motion, without need for control. Humans augment these dynamics with muscles, actively coordinated to produce stable and economical walking. Present robots using passive dynamics walk much slower, perhaps because they lack elastic muscles that couple the joints. Elastic properties are well known to enhance running gaits, but their effect on walking has yet to be explored. Here we use a computational model of dynamic walking to show that elastic joint coupling can help to coordinate faster walking. In walking powered by trailing leg push-off, the model's speed is normally limited by a swing leg that moves too slowly to avoid stumbling. A uni-articular spring about the knee allows faster but uneconomical walking. A combination of uni-articular hip and knee springs can speed the legs for improved speed and economy, but not without the swing foot scuffing the ground. Bi-articular springs coupling the hips and knees can yield high economy and good ground clearance similar to humans. An important parameter is the knee-to-hip moment arm that greatly affects the existence and stability of gaits, and when selected appropriately can allow for a wide range of speeds. Elastic joint coupling may contribute to the economy and stability of human gait. PMID:18957360

The effect of objectively measured crime on walking in minority adults.

PubMed

McDonald, Noreen C

2008-01-01

Evaluate the relationship between neighborhood crime and the amount of daily walking by minority adults. This was a cross-sectional study of minority adult walking behavior and crime. Setting. Oakland, California was chosen as the study area because of the substantial spatial variation in levels of criminal activity combined with detailed information on walking trips. The study was restricted to minority adults who responded to the 2000 Bay Area Travel Survey and lived in Oakland, California (n = 359). Data on leisure and utilitarian walking were collected through the 2000 Bay Area Travel Survey and combined with crime data from the Oakland Police Department. A negative binomial model was used to test if violent, property, or quality of life crimes had significant associations with daily minutes walked, controlling for individual and neighborhood covariates. The model showed a significant negative association between violent crime and minutes walked per day (b = -.07; p = .016). Neither property nor quality of life crimes were correlated with amount of walking. Reductions in violent crime may increase opportunities for minority residents in urban areas to participate in physical activity such as walking, thereby providing another reason to pursue anticrime measures. Urban designers' efforts to increase physical activity by improving neighborhood walkability may consider violent crime prevention in their designs.

Prediction of clothing thermal insulation and moisture vapour resistance of the clothed body walking in wind.

PubMed

Qian, Xiaoming; Fan, Jintu

2006-11-01

Clothing thermal insulation and moisture vapour resistance are the two most important parameters in thermal environmental engineering, functional clothing design and end use of clothing ensembles. In this study, clothing thermal insulation and moisture vapour resistance of various types of clothing ensembles were measured using the walking-able sweating manikin, Walter, under various environmental conditions and walking speeds. Based on an extensive experimental investigation and an improved understanding of the effects of body activities and environmental conditions, a simple but effective direct regression model has been established, for predicting the clothing thermal insulation and moisture vapour resistance under wind and walking motion, from those when the manikin was standing in still air. The model has been validated by using experimental data reported in the previous literature. It has shown that the new models have advantages and provide very accurate prediction.

Understanding Walking Behavior among University Students Using Theory of Planned Behavior

PubMed Central

Sun, Guibo; Acheampong, Ransford A.; Lin, Hui; Pun, Vivian C.

2015-01-01

Walking has been shown to improve physical and mental well-being, yet insufficient walking among university students has been increasingly reported. This study aimed to understand walking behavior of university students using theory of planned behavior (TPB). We recruited 169 undergraduate students by university mass email of the Chinese University of Hong Kong, and first administered a salient belief elicitation survey, which was used to design the TPB questionnaire, to a subset of the study sample. Secondly, all participants completed the TPB questionnaire and walking-oriented diary in a two-day period in December 2012. We mapped the walking behavior data obtained from the diary using geographic information system, and examined the extent to which TPB constructs explained walking intentions and walking behavior using Structural equation model (SEM). We found perceived behavioral control to be the key determinant of walking intention. Shaped by participants’ perceived behavioral control, attitude toward walking and subjective norms, and behavioral intention, in turn had a moderate explanatory effect on their walking behavior. In summary, our findings suggest that walking behavior among university students can be understood within the TPB framework, and could inform walking promotion interventions on the university campuses. PMID:26516895

The e-MSWS-12: improving the multiple sclerosis walking scale using item response theory.

PubMed

Engelhard, Matthew M; Schmidt, Karen M; Engel, Casey E; Brenton, J Nicholas; Patek, Stephen D; Goldman, Myla D

2016-12-01

The Multiple Sclerosis Walking Scale (MSWS-12) is the predominant patient-reported measure of multiple sclerosis (MS) -elated walking ability, yet it had not been analyzed using item response theory (IRT), the emerging standard for patient-reported outcome (PRO) validation. This study aims to reduce MSWS-12 measurement error and facilitate computerized adaptive testing by creating an IRT model of the MSWS-12 and distributing it online. MSWS-12 responses from 284 subjects with MS were collected by mail and used to fit and compare several IRT models. Following model selection and assessment, subpopulations based on age and sex were tested for differential item functioning (DIF). Model comparison favored a one-dimensional graded response model (GRM). This model met fit criteria and explained 87 % of response variance. The performance of each MSWS-12 item was characterized using category response curves (CRCs) and item information. IRT-based MSWS-12 scores correlated with traditional MSWS-12 scores (r = 0.99) and timed 25-foot walk (T25FW) speed (r =  -0.70). Item 2 showed DIF based on age (χ 2  = 19.02, df = 5, p < 0.01), and Item 11 showed DIF based on sex (χ 2  = 13.76, df = 5, p = 0.02). MSWS-12 measurement error depends on walking ability, but could be lowered by improving or replacing items with low information or DIF. The e-MSWS-12 includes IRT-based scoring, error checking, and an estimated T25FW derived from MSWS-12 responses. It is available at https://ms-irt.shinyapps.io/e-MSWS-12 .

Exercise training for intermittent claudication.

PubMed

McDermott, Mary M

2017-11-01

The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD). This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium. Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance. Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as the 6-minute walk test. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Walking Performance: Correlation between Energy Cost of Walking and Walking Participation. New Statistical Approach Concerning Outcome Measurement

PubMed Central

Franceschini, Marco; Rampello, Anais; Agosti, Maurizio; Massucci, Maurizio; Bovolenta, Federica; Sale, Patrizio

2013-01-01

Walking ability, though important for quality of life and participation in social and economic activities, can be adversely affected by neurological disorders, such as Spinal Cord Injury, Stroke, Multiple Sclerosis or Traumatic Brain Injury. The aim of this study is to evaluate if the energy cost of walking (CW), in a mixed group of chronic patients with neurological diseases almost 6 months after discharge from rehabilitation wards, can predict the walking performance and any walking restriction on community activities, as indicated by Walking Handicap Scale categories (WHS). One hundred and seven subjects were included in the study, 31 suffering from Stroke, 26 from Spinal Cord Injury and 50 from Multiple Sclerosis. The multivariable binary logistical regression analysis has produced a statistical model with good characteristics of fit and good predictability. This model generated a cut-off value of.40, which enabled us to classify correctly the cases with a percentage of 85.0%. Our research reveal that, in our subjects, CW is the only predictor of the walking performance of in the community, to be compared with the score of WHS. We have been also identifying a cut-off value of CW cost, which makes a distinction between those who can walk in the community and those who cannot do it. In particular, these values could be used to predict the ability to walk in the community when discharged from the rehabilitation units, and to adjust the rehabilitative treatment to improve the performance. PMID:23468871

Research the Gait Characteristics of Human Walking Based on a Robot Model and Experiment

NASA Astrophysics Data System (ADS)

He, H. J.; Zhang, D. N.; Yin, Z. W.; Shi, J. H.

2017-02-01

In order to research the gait characteristics of human walking in different walking ways, a robot model with a single degree of freedom is put up in this paper. The system control models of the robot are established through Matlab/Simulink toolbox. The gait characteristics of straight, uphill, turning, up the stairs, down the stairs up and down areanalyzed by the system control models. To verify the correctness of the theoretical analysis, an experiment was carried out. The comparison between theoretical results and experimental results shows that theoretical results are better agreement with the experimental ones. Analyze the reasons leading to amplitude error and phase error and give the improved methods. The robot model and experimental ways can provide foundation to further research the various gait characteristics of the exoskeleton robot.

Stimulation of the mesencephalic locomotor region for gait recovery after stroke.

PubMed

Fluri, Felix; Malzahn, Uwe; Homola, György A; Schuhmann, Michael K; Kleinschnitz, Christoph; Volkmann, Jens

2017-11-01

One-third of all stroke survivors are unable to walk, even after intensive physiotherapy. Thus, other concepts to restore walking are needed. Because electrical stimulation of the mesencephalic locomotor region (MLR) is known to elicit gait movements, this area might be a promising target for restorative neurostimulation in stroke patients with gait disability. The present study aims to delineate the effect of high-frequency stimulation of the MLR (MLR-HFS) on gait impairment in a rodent stroke model. Male Wistar rats underwent photothrombotic stroke of the right sensorimotor cortex and chronic implantation of a stimulating electrode into the right MLR. Gait was assessed using clinical scoring of the beam-walking test and video-kinematic analysis (CatWalk) at baseline and on days 3 and 4 after experimental stroke with and without MLR-HFS. Kinematic analysis revealed significant changes in several dynamic and static gait parameters resulting in overall reduced gait velocity. All rats exhibited major coordination deficits during the beam-walking challenge and were unable to cross the beam. Simultaneous to the onset of MLR-HFS, a significantly higher walking speed and improvements in several dynamic gait parameters were detected by the CatWalk system. Rats regained the ability to cross the beam unassisted, showing a reduced number of paw slips and misses. MLR-HFS can improve disordered locomotor function in a rodent stroke model. It may act by shielding brainstem and spinal locomotor centers from abnormal cortical input after stroke, thus allowing for compensatory and independent action of these circuits. Ann Neurol 2017;82:828-840. © 2017 American Neurological Association.

Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents.

PubMed

Carlson, Jordan A; Saelens, Brian E; Kerr, Jacqueline; Schipperijn, Jasper; Conway, Terry L; Frank, Lawrence D; Chapman, Jim E; Glanz, Karen; Cain, Kelli L; Sallis, James F

2015-03-01

To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth. Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups. Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking. Increasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Relationship Between Objectively Measured Walking and Risk of Pedestrian–Motor Vehicle Collision

PubMed Central

Quistberg, D. Alex; Howard, Eric J.; Hurvitz, Philip M.; Moudon, Anne V.; Ebel, Beth E.; Rivara, Frederick P.; Saelens, Brian E.

2017-01-01

Abstract Safe urban walking environments may improve health by encouraging physical activity, but the relationship between an individual's location and walking pattern and the risk of pedestrian–motor vehicle collision is unknown. We examined associations between individuals’ walking bouts and walking risk, measured as mean exposure to the risk of pedestrian-vehicle collision. Walking bouts were ascertained through integrated accelerometry and global positioning system data and from individual travel-diary data obtained from adults in the Travel Assessment and Community Study (King County, Washington) in 2008–2009. Walking patterns were superimposed onto maps of the historical probabilities of pedestrian-vehicle collisions for intersections and midblock segments within Seattle, Washington. Mean risk of pedestrian-vehicle collision in specific walking locations was assessed according to walking exposure (duration, distance, and intensity) and participant demographic characteristics in linear mixed models. Participants typically walked in areas with low pedestrian collision risk when walking for recreation, walking at a faster pace, or taking longer-duration walks. Mean daily walking duration and distance were not associated with collision risk. Males walked in areas with higher collision risk compared with females, while vehicle owners, residents of single-family homes, and parents of young children walked in areas with lower collision risk. These findings may suggest that pedestrians moderate collision risk by using lower-risk routes. PMID:28338921

What's keeping people after stroke from walking outdoors to become physically active? A qualitative study, using an integrated biomedical and behavioral theory of functioning and disability.

PubMed

Outermans, Jacqueline; Pool, Jan; van de Port, Ingrid; Bakers, Japie; Wittink, Harriet

2016-08-15

In general people after stroke do not meet the recommendations for physical activity to conduct a healthy lifestyle. Programs to stimulate walking activity to increase physical activity are based on the available insights into barriers and facilitators to physical activity after stroke. However, these programs are not entirely successful. The purpose of this study was to comprehensively explore perceived barriers and facilitators to outdoor walking using a model of integrated biomedical and behavioral theory, the Physical Activity for people with a Disability model (PAD). Included were community dwelling respondents after stroke, classified ≥ 3 at the Functional Ambulation Categories (FAC), purposively sampled regarding the use of healthcare. The data was collected triangulating in a multi-methods approach, i.e. semi-structured, structured and focus-group interviews. A primarily deductive thematic content analysis using the PAD-model in a framework-analysis' approach was conducted after verbatim transcription. 36 respondents (FAC 3-5) participated in 16 semi-structured interviews, eight structured interviews and two focus-group interviews. The data from the interviews covered all domains of the PAD model. Intention, ability and opportunity determined outdoor walking activity. Personal factors determined the intention to walk outdoors, e.g. negative social influence, resulting from restrictive caregivers in the social environment, low self-efficacy influenced by physical environment, and also negative attitude towards physical activity. Walking ability was influenced by loss of balance and reduced walking distance and by impairments of motor control, cognition and aerobic capacity as well as fatigue. Opportunities arising from household responsibilities and lively social constructs facilitated outdoor walking. To stimulate outdoor walking activity, it seems important to influence the intention by addressing social influence, self-efficacy and attitude towards physical activity in the development of efficient interventions. At the same time, improvement of walking ability and creation of opportunity should be considered.

Examining the Impact of the Walking School Bus With an Agent-Based Model

PubMed Central

Diez-Roux, Ana; Evenson, Kelly R.; Colabianchi, Natalie

2014-01-01

We used an agent-based model to examine the impact of the walking school bus (WSB) on children’s active travel to school. We identified a synergistic effect of the WSB with other intervention components such as an educational campaign designed to improve attitudes toward active travel to school. Results suggest that to maximize active travel to school, children should arrive on time at “bus stops” to allow faster WSB walking speeds. We also illustrate how an agent-based model can be used to identify the location of routes maximizing the effects of the WSB on active travel. Agent-based models can be used to examine plausible effects of the WSB on active travel to school under various conditions and to identify ways of implementing the WSB that maximize its effectiveness. PMID:24832410

Impact of Exercise to Improve Gait Efficiency on Activity and Participation in Older Adults With Mobility Limitations: A Randomized Controlled Trial

PubMed Central

Perera, Subashan; Brach, Jennifer S.; Wert, David; Studenski, Stephanie A.

2011-01-01

Background Definitive evidence that exercise interventions that improve gait also reduce disability is lacking. A task-oriented, motor sequence learning exercise intervention has been shown to reduce the energy cost of walking and improve gait speed, but whether the intervention also improves activity and participation has not been demonstrated. Objective The objective of this study was to compare the impact of a task-oriented, motor sequence learning exercise (TO) intervention and the impact of an impairment-oriented, multicomponent exercise (IO) intervention on activity and participation outcomes in older adults with mobility limitations. The mediating effects of a change in the energy cost of walking on changes in activity and participation also were determined. Design This study was a single-blind, randomized controlled trial. Setting The study was conducted in an ambulatory clinical research training center. Participants The study participants were 47 older adults (mean age=77.2 years, SD=5.5) with slow and variable gait. Intervention The intervention was a 12-week, physical therapist–guided program of TO or IO. Measurements Measures of activity (gait speed over an instrumented walkway; daily physical activity measured with an accelerometer; confidence in walking determined with the Gait Efficacy Scale; and physical function determined with the total, basic lower-extremity, and advanced lower-extremity components of the Late-Life Function and Disability Instrument [Late-Life FDI]) and participation (disability limitation dimension and instrumental role [home and community task performance] domain components of the Late-Life FDI) were recorded before and after the intervention. The energy cost of walking was determined from the rate of oxygen consumption during self-paced treadmill walking at the physiological steady state standardized by walking speed. An adjusted comparison of activity and participation outcomes in the treatment arms was made by use of an analysis of covariance model, with baseline and change in energy cost of walking added to the model to test for mediation. Tests were used to determine the significance of the mediating effects. Results Activity improved in TO but not in IO for confidence in walking (Gait Efficacy Scale; mean adjusted difference=9.8 [SD=3.5]) and physical function (Late-Life FDI basic lower-extremity component; mean adjusted difference=3.5 [SD=1.7]). Improvements in TO were marginally greater than those in IO for gait speed, physical activity, and total physical function. Participation improved marginally more in TO than in IO for disability limitations and instrumental role. Limitations The older adults were randomized to the intervention group, but differences in baseline measures had to be accounted for in the analyses. Conclusions A TO intervention that improved gait also led to improvements in some activity and participation outcomes in older adults with mobility limitations. PMID:22003158

Spontaneous Velocity Effect of Musical Expression on Self-Paced Walking.

PubMed

Buhmann, Jeska; Desmet, Frank; Moens, Bart; Van Dyck, Edith; Leman, Marc

2016-01-01

The expressive features of music can influence the velocity of walking. So far, studies used instructed (and intended) synchronization. But is this velocity effect still present with non-instructed (spontaneous) synchronization? To figure that out, participants were instructed to walk in their own comfort tempo on an indoor track, first in silence and then with tempo-matched music. We compared velocities of silence and music conditions. The results show that some music has an activating influence, increasing velocity and motivation, while other music has a relaxing influence, decreasing velocity and motivation. The influence of musical expression on the velocity of self-paced walking can be predicted with a regression model using only three sonic features explaining 56% of the variance. Phase-coherence between footfall and beat did not contribute to the velocity effect, due to its implied fixed pacing. The findings suggest that the velocity effect depends on vigor entrainment that influences both stride length and pacing. Our findings are relevant for preventing injuries, for gait improvement in walking rehabilitation, and for improving performance in sports activities.

Spontaneous Velocity Effect of Musical Expression on Self-Paced Walking

PubMed Central

Buhmann, Jeska; Desmet, Frank; Moens, Bart; Van Dyck, Edith; Leman, Marc

2016-01-01

The expressive features of music can influence the velocity of walking. So far, studies used instructed (and intended) synchronization. But is this velocity effect still present with non-instructed (spontaneous) synchronization? To figure that out, participants were instructed to walk in their own comfort tempo on an indoor track, first in silence and then with tempo-matched music. We compared velocities of silence and music conditions. The results show that some music has an activating influence, increasing velocity and motivation, while other music has a relaxing influence, decreasing velocity and motivation. The influence of musical expression on the velocity of self-paced walking can be predicted with a regression model using only three sonic features explaining 56% of the variance. Phase-coherence between footfall and beat did not contribute to the velocity effect, due to its implied fixed pacing. The findings suggest that the velocity effect depends on vigor entrainment that influences both stride length and pacing. Our findings are relevant for preventing injuries, for gait improvement in walking rehabilitation, and for improving performance in sports activities. PMID:27167064

Intensive walking exercise for lower extremity peripheral arterial disease: A systematic review and meta-analysis.

PubMed

Lyu, Xiafei; Li, Sheyu; Peng, Shifeng; Cai, Huimin; Liu, Guanjian; Ran, Xingwu

2016-05-01

Supervised treadmill exercise is the recommended therapy for peripheral arterial disease (PAD) patients with intermittent claudication (IC). However, most PAD patients do not exhibit typical symptoms of IC. The aim of the present study was to explore the efficacy and safety of intensive walking exercise in PAD patients with and without IC. The PubMed, Embase and Cochrane Library databases were systematically searched. Randomized controlled trials comparing the effects of intensive walking exercise with usual care in patients with PAD were included for systematic review and meta-analysis. Eighteen trials with 1200 patients were eligible for the present analysis. Compared with usual care, intensive walking exercise significantly improved the maximal walking distance (MWD), pain-free walking distance, and the 6-min walking distance in patients with PAD (P < 0.00001 for all). Subgroup analyses indicated that a lesser improvement in MWD was observed in the subgroup with more diabetes patients, and that the subgroup with better baseline walking ability exhibited greater improvement in walking performance. In addition, similar improvements in walking performance were observed for exercise programs of different durations and modalities. No significant difference was found in adverse events between the intensive walking and usual care groups (relative risk 0.84; 95% confidence interval 0.51, 1.39; P = 0.50). Regardless of exercise length and modality, regularly intensive walking exercise improves walking ability in PAD patients more than usual care. The presence of diabetes may attenuate the improvements in walking performance in patients with PAD following exercise. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Associations between cognitive and gait performance during single- and dual-task walking in people with Parkinson disease.

PubMed

Stegemöller, Elizabeth L; Wilson, Jonathan P; Hazamy, Audrey; Shelley, Mack C; Okun, Michael S; Altmann, Lori J P; Hass, Chris J

2014-06-01

Cognitive impairments in Parkinson disease (PD) manifest as deficits in speed of processing, working memory, and executive function and attention abilities. The gait impairment in PD is well documented to include reduced speed, shortened step lengths, and increased step-to-step variability. However, there is a paucity of research examining the relationship between overground walking and cognitive performance in people with PD. This study sought to examine the relationship between both the mean and variability of gait spatiotemporal parameters and cognitive performance across a broad range of cognitive domains. A cross-sectional design was used. Thirty-five participants with no dementia and diagnosed with idiopathic PD completed a battery of 12 cognitive tests that yielded 3 orthogonal factors: processing speed, working memory, and executive function and attention. Participants completed 10 trials of overground walking (single-task walking) and 5 trials of overground walking while counting backward by 3's (dual-task walking). All gait measures were impaired by the dual task. Cognitive processing speed correlated with stride length and walking speed. Executive function correlated with step width variability. There were no significant associations with working memory. Regression models relating speed of processing to gait spatiotemporal variables revealed that including dual-task costs in the model significantly improved the fit of the model. Participants with PD were tested only in the on-medication state. Different characteristics of gait are related to distinct types of cognitive processing, which may be differentially affected by dual-task walking due to the pathology of PD. © 2014 American Physical Therapy Association.

Body weight-supported treadmill training vs. overground walking training for persons with chronic stroke: a pilot randomized controlled trial.

PubMed

Combs-Miller, Stephanie A; Kalpathi Parameswaran, Anu; Colburn, Dawn; Ertel, Tara; Harmeyer, Amanda; Tucker, Lindsay; Schmid, Arlene A

2014-09-01

To compare the effects of body weight-supported treadmill training and overground walking training when matched for task and dose (duration/frequency/intensity) on improving walking function, activity, and participation after stroke. Single-blind, pilot randomized controlled trial with three-month follow-up. University and community settings. A convenience sample of participants (N = 20) at least six months post-stroke and able to walk independently were recruited. Thirty-minute walking interventions (body weight-supported treadmill training or overground walking training) were administered five times a week for two weeks. Intensity was monitored with the Borg Rating of Perceived Exertion Scale at five-minute increments to maintain a moderate training intensity. Walking speed (comfortable/fast 10-meter walk), walking endurance (6-minute walk), spatiotemporal symmetry, and the ICF Measure of Participation and ACTivity were assessed before, immediately after, and three months following the intervention. The overground walking training group demonstrated significantly greater improvements in comfortable walking speed compared with the body weight-supported treadmill training group immediately (change of 0.11 m/s vs. 0.06 m/s, respectively; p = 0.047) and three months (change of 0.14 m/s vs. 0.08 m/s, respectively; p = 0.029) after training. Only the overground walking training group significantly improved comfortable walking speed (p = 0.001), aspects of gait symmetry (p = 0.032), and activity (p = 0.003) immediately after training. Gains were maintained at the three-month follow-up (p < 0.05) for all measures except activity. Improvements in participation were not demonstrated. Overgound walking training was more beneficial than body weight-supported treadmill training at improving self-selected walking speed for the participants in this study. © The Author(s) 2014.

Does public transport use prevent declines in walking speed among older adults living in England? A prospective cohort study

PubMed Central

Rouxel, Patrick; Webb, Elizabeth; Chandola, Tarani

2017-01-01

Objectives Although there is some evidence that public transport use confers public health benefits, the evidence is limited by cross-sectional study designs and health-related confounding factors. This study examines the effect of public transport use on changes in walking speed among older adults living in England, comparing frequent users of public transport to their peers who did not use public transport because of structural barriers (poor public transport infrastructure) or through choice. Design Prospective cohort study. Setting England, UK. Participants Older adults aged ≥60 years eligible for the walking speed test. 6246 individuals at wave 2 (2004–2005); 5909 individuals at wave 3 (2006–2007); 7321 individuals at wave 4 (2008–2009); 7535 individuals at wave 5 (2010–2011) and 7664 individuals at wave 6 (2012–2013) of the English Longitudinal Study of Ageing. Main outcome measure The walking speed was estimated from the time taken to walk 2.4 m. Fixed effects models and growth curve models were used to examine the associations between public transport use and walking speed. Results Older adults who did not use public transport through choice or because of structural reasons had slower walking speeds (−0.02 m/s (95% CI −0.03 to –0.003) and −0.02 m/s (95% CI −0.03 to –0.01), respectively) and took an extra 0.07 s to walk 2.4 m compared with their peers who used public transport frequently. The age-related trajectories of decline in walking speed were slower for frequent users of public transport compared with non-users. Conclusions Frequent use of public transport may prevent age-related decline in physical capability by promoting physical activity and lower limb muscle strength among older adults. The association between public transport use and slower decline in walking speed among older adults is unlikely to be confounded by health-related selection factors. Improving access to good quality public transport could improve the health of older adults. PMID:28963309

Accounting for the daily locations visited in the study of the built environment correlates of recreational walking (the RECORD Cohort Study).

PubMed

Perchoux, Camille; Kestens, Yan; Brondeel, Ruben; Chaix, Basile

2015-12-01

Understanding how built environment characteristics influence recreational walking is of the utmost importance to develop population-level strategies to increase levels of physical activity in a sustainable manner. This study analyzes the residential and non-residential environmental correlates of recreational walking, using precisely geocoded activity space data. The point-based locations regularly visited by 4365 participants of the RECORD Cohort Study (Residential Environment and CORonary heart Disease) were collected between 2011 and 2013 in the Paris region using the VERITAS software (Visualization and Evaluation of Regular Individual Travel destinations and Activity Spaces). Zero-inflated negative binomial regressions were used to investigate associations between both residential and non-residential environmental exposure and overall self-reported recreational walking over 7 days. Density of destinations, presence of a lake or waterway, and neighborhood education were associated with an increase in the odds of reporting any recreational walking time. Only the density of destinations was associated with an increase in time spent walking for recreational purpose. Considering the recreational locations visited (i.e., sports and cultural destinations) in addition to the residential neighborhood in the calculation of exposure improved the model fit and increased the environment-walking associations, compared to a model accounting only for the residential space (Akaike Information Criterion equal to 52797 compared to 52815). Creating an environment supportive to walking around recreational locations may particularly stimulate recreational walking among people willing to use these facilities. Copyright © 2015 Elsevier Inc. All rights reserved.

The Relationship Between Objectively Measured Walking and Risk of Pedestrian-Motor Vehicle Collision.

PubMed

Quistberg, D Alex; Howard, Eric J; Hurvitz, Philip M; Moudon, Anne V; Ebel, Beth E; Rivara, Frederick P; Saelens, Brian E

2017-05-01

Safe urban walking environments may improve health by encouraging physical activity, but the relationship between an individual's location and walking pattern and the risk of pedestrian-motor vehicle collision is unknown. We examined associations between individuals' walking bouts and walking risk, measured as mean exposure to the risk of pedestrian-vehicle collision. Walking bouts were ascertained through integrated accelerometry and global positioning system data and from individual travel-diary data obtained from adults in the Travel Assessment and Community Study (King County, Washington) in 2008-2009. Walking patterns were superimposed onto maps of the historical probabilities of pedestrian-vehicle collisions for intersections and midblock segments within Seattle, Washington. Mean risk of pedestrian-vehicle collision in specific walking locations was assessed according to walking exposure (duration, distance, and intensity) and participant demographic characteristics in linear mixed models. Participants typically walked in areas with low pedestrian collision risk when walking for recreation, walking at a faster pace, or taking longer-duration walks. Mean daily walking duration and distance were not associated with collision risk. Males walked in areas with higher collision risk compared with females, while vehicle owners, residents of single-family homes, and parents of young children walked in areas with lower collision risk. These findings may suggest that pedestrians moderate collision risk by using lower-risk routes. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Random walks of colloidal probes in viscoelastic materials

NASA Astrophysics Data System (ADS)

Khan, Manas; Mason, Thomas G.

2014-04-01

To overcome limitations of using a single fixed time step in random walk simulations, such as those that rely on the classic Wiener approach, we have developed an algorithm for exploring random walks based on random temporal steps that are uniformly distributed in logarithmic time. This improvement enables us to generate random-walk trajectories of probe particles that span a highly extended dynamic range in time, thereby facilitating the exploration of probe motion in soft viscoelastic materials. By combining this faster approach with a Maxwell-Voigt model (MVM) of linear viscoelasticity, based on a slowly diffusing harmonically bound Brownian particle, we rapidly create trajectories of spherical probes in soft viscoelastic materials over more than 12 orders of magnitude in time. Appropriate windowing of these trajectories over different time intervals demonstrates that random walk for the MVM is neither self-similar nor self-affine, even if the viscoelastic material is isotropic. We extend this approach to spatially anisotropic viscoelastic materials, using binning to calculate the anisotropic mean square displacements and creep compliances along different orthogonal directions. The elimination of a fixed time step in simulations of random processes, including random walks, opens up interesting possibilities for modeling dynamics and response over a highly extended temporal dynamic range.

Effect of motion inputs on the wear prediction of artificial hip joints

PubMed Central

Liu, Feng; Fisher, John; Jin, Zhongmin

2013-01-01

Hip joint simulators have been largely used to assess the wear performance of joint implants. Due to the complexity of joint movement, the motion mechanism adopted in simulators varies. The motion condition is particularly important for ultra-high molecular weight polyethylene (UHMWPE) since polyethylene wear can be substantially increased by the bearing cross-shear motion. Computational wear modelling has been improved recently for the conventional UHMWPE used in total hip joint replacements. A new polyethylene wear law is an explicit function of the contact area of the bearing and the sliding distance, and the effect of multidirectional motion on wear has been quantified by a factor, cross-shear ratio. In this study, the full simulated walking cycle condition based on a walking measurement and two simplified motions, including the ISO standard motion and a simplified ProSim hip simulator motion, were considered as the inputs for wear modelling based on the improved wear model. Both the full simulation and simplified motions generated the comparable multidirectional motion required to reproduce the physiological wear of the bearing in vivo. The predicted volumetric wear of the ProSim simulator motion and the ISO motion conditions for the walking cycle were 13% and 4% lower, respectively, than that of the measured walking condition. The maximum linear wear depths were almost the same, and the areas of the wear depth distribution were 13% and 7% lower for the ProSim simulator and the ISO condition, respectively, compared with that of the measured walking cycle motion condition. PMID:25540472

Technology-Based Programs to Promote Walking Fluency or Improve Foot-Ground Contact during Walking: Two Case Studies of Adults with Multiple Disabilities

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; La Martire, Maria L.; Oliva, Doretta; Groeneweg, Jop

2012-01-01

These two case studies assessed technology-based programs for promoting walking fluency and improving foot-ground contact during walking with a man and a woman with multiple disabilities, respectively. The man showed breaks during walking and the woman presented with toe walking. The technology used in the studies included a microprocessor with…

Random-walk mobility analysis of Lisbon's plans for the post-1755 reconstruction

NASA Astrophysics Data System (ADS)

de Sampayo, Mafalda Teixeira; Sousa-Rodrigues, David

2016-11-01

The different options for the reconstruction of the city of Lisbon in the aftermath of the 1755 earthquake are studied with an agent-based model based on randomwalks. This method gives a comparative quantitative measure of mobility of the circulation spaces within the city. The plans proposed for the city of Lisbon signified a departure from the medieval mobility city model. The intricacy of the old city circulation spaces is greatly reduced in the new plans and the mobility between different areas is substantially improved. The simulation results of the random-walk model show that those plans keeping the main force lines of the old city presented less improvement in terms ofmobility. The plans that had greater design freedom were, by contrast, easier to navigate. Lisbon's reconstruction followed a plan that included a shift in the traditional notions of mobility. This affected the daily lives of its citizens by potentiating an easy access to the waterfront, simplifying orientation and navigability. Using the random-walk model it is shown how to quantitatively measure the potential that synthetic plans have in terms of the permeability and navigability of different city public spaces.

Sources of Variability in Physical Activity Among Inactive People with Multiple Sclerosis.

PubMed

Uszynski, Marcin K; Herring, Matthew P; Casey, Blathin; Hayes, Sara; Gallagher, Stephen; Motl, Robert W; Coote, Susan

2018-04-01

Evidence supports that physical activity (PA) improves symptoms of multiple sclerosis (MS). Although application of principles from Social Cognitive Theory (SCT) may facilitate positive changes in PA behaviour among people with multiple sclerosis (pwMS), the constructs often explain limited variance in PA. This study investigated the extent to which MS symptoms, including fatigue, depression, and walking limitations combined with the SCT constructs, explained more variance in PA than SCT constructs alone among pwMS. Baseline data, including objectively assessed PA, exercise self-efficacy, goal setting, outcome expectations, 6-min walk test, fatigue and depression, from 65 participants of the Step It Up randomized controlled trial completed in Ireland (2016), were included. Multiple regression models quantified variance explained in PA and independent associations of (1) SCT constructs, (2) symptoms and (3) SCT constructs and symptoms. Model 1 included exercise self-efficacy, exercise goal setting and multidimensional outcomes expectations for exercise and explained ~14% of the variance in PA (R 2 =0.144, p < 0.05). Model 2 included walking limitations, fatigue and depression and explained 20% of the variance in PA (R 2 =0.196, p < 0.01). Model 3 combined models 1 and 2 and explained variance increased to ~29% (R 2 =0.288; p<0.01). In Model 3, exercise self-efficacy (β=0.30, p < 0.05), walking limitations (β=0.32, p < 0.01), fatigue (β = -0.41, p < 0.01) and depression (β = 0.34, p < 0.05) were significantly and independently associated with PA. Findings suggest that relevant MS symptoms improved by PA, including fatigue, depression and walking limitations, and SCT constructs together explained more variance in PA than SCT constructs alone, providing support for targeting both SCT constructs and these symptoms in the multifactorial promotion of PA among pwMS.

Faster search by lackadaisical quantum walk

NASA Astrophysics Data System (ADS)

Wong, Thomas G.

2018-03-01

In the typical model, a discrete-time coined quantum walk searching the 2D grid for a marked vertex achieves a success probability of O(1/log N) in O(√{N log N}) steps, which with amplitude amplification yields an overall runtime of O(√{N} log N). We show that making the quantum walk lackadaisical or lazy by adding a self-loop of weight 4 / N to each vertex speeds up the search, causing the success probability to reach a constant near 1 in O(√{N log N}) steps, thus yielding an O(√{log N}) improvement over the typical, loopless algorithm. This improved runtime matches the best known quantum algorithms for this search problem. Our results are based on numerical simulations since the algorithm is not an instance of the abstract search algorithm.

Treadmill training improves overground walking economy in Parkinson's disease: a randomized, controlled pilot study.

PubMed

Fernández-Del-Olmo, Miguel Angel; Sanchez, Jose Andres; Bello, Olalla; Lopez-Alonso, Virginia; Márquez, Gonzalo; Morenilla, Luis; Castro, Xabier; Giraldez, Manolo; Santos-García, Diego

2014-01-01

Gait disturbances are one of the principal and most incapacitating symptoms of Parkinson's disease (PD). In addition, walking economy is impaired in PD patients and could contribute to excess fatigue in this population. An important number of studies have shown that treadmill training can improve kinematic parameters in PD patients. However, the effects of treadmill and overground walking on the walking economy remain unknown. The goal of this study was to explore the walking economy changes in response to a treadmill and an overground training program, as well as the differences in the walking economy during treadmill and overground walking. Twenty-two mild PD patients were randomly assigned to a treadmill or overground training group. The training program consisted of 5 weeks (3 sessions/week). We evaluated the energy expenditure of overground walking, before and after each of the training programs. The energy expenditure of treadmill walking (before the program) was also evaluated. The treadmill, but not the overground training program, lead to an improvement in the walking economy (the rate of oxygen consumed per distance during overground walking at a preferred speed) in PD patients. In addition, walking on a treadmill required more energy expenditure compared with overground walking at the same speed. This study provides evidence that in mild PD patients, treadmill training is more beneficial compared with that of walking overground, leading to a greater improvement in the walking economy. This finding is of clinical importance for the therapeutic administration of exercise in PD.

The effect of rhythmic-cued motor imagery on walking, fatigue and quality of life in people with multiple sclerosis: A randomised controlled trial.

PubMed

Seebacher, Barbara; Kuisma, Raija; Glynn, Angela; Berger, Thomas

2017-02-01

Motor imagery and rhythmic auditory stimulation are physiotherapy strategies for walking rehabilitation. To investigate the effect of motor imagery combined with rhythmic cueing on walking, fatigue and quality of life (QoL) in people with multiple sclerosis (MS). Individuals with MS and Expanded Disability Status Scale scores of 1.5-4.5 were randomised into one of three groups: 17 minutes of motor imagery, six times per week, for 4 weeks, with music (A) or metronome cues (B), both with verbal cueing, and (C) controls. Primary outcomes were walking speed (Timed 25-Foot Walk) and distance (6-Minute Walk Test). Secondary outcomes were walking perception (Multiple Sclerosis Walking Scale-12), fatigue (Modified Fatigue Impact Scale) and QoL (Short Form-36 Health Survey, Multiple Sclerosis Impact Scale-29, Euroquol-5D-3L Questionnaire). Of the 112 participants randomised, 101 completed the study. Compared to controls, both interventions significantly improved walking speed, distance and perception. Significant improvements in cognitive but not psychosocial fatigue were seen in the intervention groups, and physical fatigue improved only in the music-based group. Both interventions improved QoL; however, music-cued motor imagery was superior at improving health-related QoL. Rhythmic-cued motor imagery improves walking, fatigue and QoL in people with MS, with music-cued motor imagery being more effective.

Factors Influencing the Efficacy of Aerobic Exercise for Improving Fitness and Walking Capacity After Stroke: A Meta-Analysis With Meta-Regression.

PubMed

Boyne, Pierce; Welge, Jeffrey; Kissela, Brett; Dunning, Kari

2017-03-01

To assess the influence of dosing parameters and patient characteristics on the efficacy of aerobic exercise (AEX) poststroke. A systematic review was conducted using PubMed, MEDLINE, Cumulative Index of Nursing and Allied Health Literature, Physiotherapy Evidence Database, and Academic Search Complete. Studies were selected that compared an AEX group with a nonaerobic control group among ambulatory persons with stroke. Extracted outcome data included peak oxygen consumption (V˙o 2 peak) during exercise testing, walking speed, and walking endurance (6-min walk test). Independent variables of interest were AEX mode (seated or walking), AEX intensity (moderate or vigorous), AEX volume (total hours), stroke chronicity, and baseline outcome scores. Significant between-study heterogeneity was confirmed for all outcomes. Pooled AEX effect size estimates (AEX group change minus control group change) from random effects models were V˙o 2 peak, 2.2mL⋅kg -1 ⋅min -1 (95% confidence interval [CI], 1.3-3.1mL⋅kg -1 ⋅min -1 ); walking speed, .06m/s (95% CI, .01-.11m/s); and 6-minute walk test distance, 29m (95% CI, 15-42m). In meta-regression, larger V˙o 2 peak effect sizes were significantly associated with higher AEX intensity and higher baseline V˙o 2 peak. Larger effect sizes for walking speed and the 6-minute walk test were significantly associated with a walking AEX mode. In contrast, seated AEX did not have a significant effect on walking outcomes. AEX significantly improves aerobic capacity poststroke, but may need to be task specific to affect walking speed and endurance. Higher AEX intensity is associated with better outcomes. Future randomized studies are needed to confirm these results. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of a Flexibility and Relaxation Programme, Walking, and Nordic Walking on Parkinson's Disease

PubMed Central

Reuter, I.; Mehnert, S.; Leone, P.; Kaps, M.; Oechsner, M.; Engelhardt, M.

2011-01-01

Symptoms of Parkinson's disease (PD) progress despite optimized medical treatment. The present study investigated the effects of a flexibility and relaxation programme, walking, and Nordic walking (NW) on walking speed, stride length, stride length variability, Parkinson-specific disability (UPDRS), and health-related quality of life (PDQ 39). 90 PD patients were randomly allocated to the 3 treatment groups. Patients participated in a 6-month study with 3 exercise sessions per week, each lasting 70 min. Assessment after completion of the training showed that pain was reduced in all groups, and balance and health-related quality of life were improved. Furthermore, walking, and Nordic walking improved stride length, gait variability, maximal walking speed, exercise capacity at submaximal level, and PD disease-specific disability on the UPDRS in addition. Nordic walking was superior to the flexibility and relaxation programme and walking in improving postural stability, stride length, gait pattern and gait variability. No significant injuries occurred during the training. All patients of the Nordic walking group continued Nordic walking after completing the study. PMID:21603199

Sole vibration improves locomotion through the recovery of joint movements in a mouse cast model

PubMed Central

Sakasaki, Juntaro; Kasae, Syota; Nishimura, Keisuke; Shin, Min-Chul; Yoshimura, Megumu

2017-01-01

We investigated the effects of a vibratory stimulus on the plantar surface of the hind limb for motor, sensory, and locomotive function using a mouse cast model. The right knee joint of C57BL/6 male mice (7 weeks, 20 g, n = 31) was flexed with aluminum splint and tape for 6 weeks. These mice were randomly divided into 2 groups (control group, n = 11 and vibration group, n = 12). The mice in the vibration group received vibration on the sole of the ankle for 15 minutes per day, 5 days per week. After the knee joint cast was removed, we measured the range of motion (ROM) of both knee and ankle joints and the sensory threshold of the sole. Further, both walking and swimming movements were analyzed with a digital video. The sole vibration did not affect the passive ROM of the knee joint and sensory threshold after cast removal. However, it increased the ankle dorsiflexion range and improved free walking, swimming, and active movement of the knee joint. In conclusion, we show that the vibration recovered both walking and swimming movements, which resulted from improvements in both the passive ankle dorsiflexion and active knee movement. PMID:29040289

IRWRLDA: improved random walk with restart for lncRNA-disease association prediction.

PubMed

Chen, Xing; You, Zhu-Hong; Yan, Gui-Ying; Gong, Dun-Wei

2016-09-06

In recent years, accumulating evidences have shown that the dysregulations of lncRNAs are associated with a wide range of human diseases. It is necessary and feasible to analyze known lncRNA-disease associations, predict potential lncRNA-disease associations, and provide the most possible lncRNA-disease pairs for experimental validation. Considering the limitations of traditional Random Walk with Restart (RWR), the model of Improved Random Walk with Restart for LncRNA-Disease Association prediction (IRWRLDA) was developed to predict novel lncRNA-disease associations by integrating known lncRNA-disease associations, disease semantic similarity, and various lncRNA similarity measures. The novelty of IRWRLDA lies in the incorporation of lncRNA expression similarity and disease semantic similarity to set the initial probability vector of the RWR. Therefore, IRWRLDA could be applied to diseases without any known related lncRNAs. IRWRLDA significantly improved previous classical models with reliable AUCs of 0.7242 and 0.7872 in two known lncRNA-disease association datasets downloaded from the lncRNADisease database, respectively. Further case studies of colon cancer and leukemia were implemented for IRWRLDA and 60% of lncRNAs in the top 10 prediction lists have been confirmed by recent experimental reports.

Research on Walking Wheel Slippage Control of Live Inspection Robot

NASA Astrophysics Data System (ADS)

Yan, Yu; Liu, Xiaqing; Guo, Hao; Li, Jinliang; Liu, Lanlan

2017-07-01

To solve the problem of walking wheel slippage of a live inspection robot during walking or climbing, this paper analyzes the climbing capacity of the robot with a statics method, designs a pressing wheel mechanism, and presents a method of indirectly identifying walking wheel slippage by reading speed of the pressing wheel due to the fact that the linear speed of the pressing wheel and the walking wheel at the contract point is the same; and finds that the slippage state can not be controlled through accurate mathematical models after identifying the slippage state, whereas slippage can be controlled with fuzzy control. The experiment results indicate that due to design of the pressing wheel mechanism, friction force of the walking wheel is increased, and the climbing capability of the robot is improved. Within the range of climbing capability of the robot, gradient is the key factor that has influence on slippage of robot, and slippage can be effectively eliminated through the fuzzy control method proposed in this paper.

Stabilization of a three-dimensional limit cycle walking model through step-to-step ankle control.

PubMed

Kim, Myunghee; Collins, Steven H

2013-06-01

Unilateral, below-knee amputation is associated with an increased risk of falls, which may be partially related to a loss of active ankle control. If ankle control can contribute significantly to maintaining balance, even in the presence of active foot placement, this might provide an opportunity to improve balance using robotic ankle-foot prostheses. We investigated ankle- and hip-based walking stabilization methods in a three-dimensional model of human gait that included ankle plantarflexion, ankle inversion-eversion, hip flexion-extension, and hip ad/abduction. We generated discrete feedback control laws (linear quadratic regulators) that altered nominal actuation parameters once per step. We used ankle push-off, lateral ankle stiffness and damping, fore-aft foot placement, lateral foot placement, or all of these as control inputs. We modeled environmental disturbances as random, bounded, unexpected changes in floor height, and defined balance performance as the maximum allowable disturbance value for which the model walked 500 steps without falling. Nominal walking motions were unstable, but were stabilized by all of the step-to-step control laws we tested. Surprisingly, step-by-step modulation of ankle push-off alone led to better balance performance (3.2% leg length) than lateral foot placement (1.2% leg length) for these control laws. These results suggest that appropriate control of robotic ankle-foot prosthesis push-off could make balancing during walking easier for individuals with amputation.

The hour-to-hour influence of weather conditions on walking and cycling among Dutch older adults.

PubMed

Prins, Richard G; van Lenthe, F J

2015-09-01

physical activity (PA) is an important factor to promote healthy ageing. However, older adults are not physically active enough. Socio-ecological models suggest that weather conditions are determinants of PA and may bias relations between other environmental factors and PA. This may especially be the case for the most vulnerable and inactive older persons. Understanding the role of weather conditions is based on daily or seasonal variation in weather, but it can be improved by using hour-to-hour measured weather conditions. to study the hour-to-hour relationships between weather factors and objectively measured walking and cycling in a sample of Dutch older adults. baseline data (2013) of a sub-sample of older adults (3,248 observations clustered in 43 adults) participating in The Neighborhood Walking in Rotterdam Older ADultS (NEW.ROADS) trial were used. Participants wore a GPS logger for 7 consecutive days. Hour-to-hour weather data (temperature, wind speed, rain and sun time) for the city of Rotterdam were retrieved from the Royal Netherlands Meteorological Institute. Multilevel linear regression models were fitted with minutes walked and minutes cycled as dependent variables and the weather variables as independent variables. the time older adults walked increased with higher temperature, higher wind speed and the absence of rain. The time cycled increased with higher temperature. this study improves the evidence of weather factors as a determinant for walking and cycling in older adults. Studies on the relation between environmental factors and PA should consider adjustment for weather factors. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An anterior ankle-foot orthosis improves walking economy in Charcot-Marie-Tooth type 1A patients.

PubMed

Menotti, Federica; Laudani, Luca; Damiani, Antonello; Mignogna, Teresa; Macaluso, Andrea

2014-10-01

Ankle-foot orthoses are commonly prescribed in Charcot-Marie-Tooth type 1A disease to improve quality of walking and reduce the risk of falling due to the foot drop. This study aimed at assessing the effect of an anterior ankle-foot orthosis on walking economy in a group of Charcot-Marie-Tooth type 1A patients. Within-group comparisons. 7 Charcot-Marie-Tooth type 1A patients (four women and three men; 37 ± 11 years; age range = 22-53 years) were asked to walk on a circuit at their self-selected speeds ('slow', 'comfortable' and 'fast') in two walking conditions: (1) with shoes only and (2) with Taloelast(®) anterior elastic ankle-foot orthoses. Speed of walking and metabolic cost of walking energy cost per unit of distance were assessed at the three self-selected speeds of walking for both walking conditions. Speed of walking at the three self-selected speeds did not differ between shoes only and anterior elastic ankle-foot orthoses, whereas walking energy cost per unit of distance at comfortable speed was lower in patients using anterior elastic ankle-foot orthoses with respect to shoes only (2.39 ± 0.22 vs 2.70 ± 0.19 J kg(-1) m(-1); P < 0.05). In Charcot-Marie-Tooth type 1A patients, the use of anterior elastic ankle-foot orthoses improved walking economy by reducing the energy cost of walking per unit of distance, thus reflecting a lower level of metabolic effort and improved mechanical efficiency in comparison with shoes only. From a practical perspective, Charcot-Marie-Tooth type 1A patients with anterior elastic ankle-foot orthoses can walk for a longer duration with a lower level of physical effort. Improvements in walking economy due to ankle-foot orthoses are likely a consequence of the reduction in steppage gait. © The International Society for Prosthetics and Orthotics 2013.

Pilates and aerobic training improve levels of depression, anxiety and quality of life in overweight and obese individuals.

PubMed

Vancini, Rodrigo Luiz; Rayes, Angeles Bonal Rosell; Lira, Claudio Andre Barbosa de; Sarro, Karine Jacon; Andrade, Marilia Santos

2017-12-01

To compare the effects of Pilates and walking on quality of life, depression, and anxiety levels. Sixty-three overweight/obese participants were randomly divided into: control (n = 20), walking (n = 21), and Pilates (n = 22) groups. Pilates and walking groups attended eight weeks of 60-minute exercise sessions three times per week. Quality of life, depression, and state- and trait-anxiety levels were evaluated before and after eight weeks of training. Scores of quality of life, depression, and trait-anxiety improved in the Pilates and walking groups. State-anxiety levels improved only in the walking group. Pilates and walking positively impact quality of life, depression and anxiety. The Pilates method could be used as an alternative to improve mood disorders in overweight/obese individuals.

Stair evacuation simulation based on cellular automata considering evacuees’ walk preferences

NASA Astrophysics Data System (ADS)

Ding, Ning; Zhang, Hui; Chen, Tao; Peter, B. Luh

2015-06-01

As a physical model, the cellular automata (CA) model is widely used in many areas, such as stair evacuation. However, existing CA models do not consider evacuees’ walk preferences nor psychological status, and the structure of the basic model is unapplicable for the stair structure. This paper is to improve the stair evacuation simulation by addressing these issues, and a new cellular automata model is established. Several evacuees’ walk preference and how evacuee’s psychology influences their behaviors are introduced into this model. Evacuees’ speeds will be influenced by these features. To validate this simulation, two fire drills held in two high-rise buildings are video-recorded. It is found that the simulation results are similar to the fire drill results. The structure of this model is simple, and it is easy to further develop and utilize in different buildings with various kinds of occupants. Project supported by the National Basic Research Program of China (Grant No. 2012CB719705) and the National Natural Science Foundation of China (Grant Nos. 91224008, 91024032, and 71373139).

Effects of aquatic walking exercise using a walker in a chronic stroke patient.

PubMed

Matsuda, Tadashi; Akezaki, Yoshiteru

2017-07-01

[Purpose] The aim of this study was to examine the usefulness of aquatic walking exercise using a walker for chronic stroke patients. We also examined the psychological effects on the study subject and the primary caregiver before and after aquatic walking exercise. [Subject and Methods] The subject was a 60-year-old male with bilateral paralysis after a cerebrovascular accident. The Fugl-Meyer Assessment (FMA) total score was 116 on the right and 115 on the left. The intervention combined aquatic and land walking exercise. A U-shaped walker was used for both water and land exercise. Continuous walking distance was the measure used to evaluate land walking ability. The psychological effects on the study subject and the primary caregiver were examined with the questionnaire. [Results] In aquatic walking, the mean time to walk 5 m showed an increase from the intervention after two months. After the aquatic walking and land walking combination, continuous walking distance also showed a prolonged trend. In the survey given to the main caregivers, improvements were observed. [Conclusion] Aquatic walking practice using a walker improved motivation in a chronic stroke patient, leading to improved walking ability, with a positive psychological influence on the participant and family caregiver.

Effects of aquatic walking exercise using a walker in a chronic stroke patient

PubMed Central

Matsuda, Tadashi; Akezaki, Yoshiteru

2017-01-01

[Purpose] The aim of this study was to examine the usefulness of aquatic walking exercise using a walker for chronic stroke patients. We also examined the psychological effects on the study subject and the primary caregiver before and after aquatic walking exercise. [Subject and Methods] The subject was a 60-year-old male with bilateral paralysis after a cerebrovascular accident. The Fugl-Meyer Assessment (FMA) total score was 116 on the right and 115 on the left. The intervention combined aquatic and land walking exercise. A U-shaped walker was used for both water and land exercise. Continuous walking distance was the measure used to evaluate land walking ability. The psychological effects on the study subject and the primary caregiver were examined with the questionnaire. [Results] In aquatic walking, the mean time to walk 5 m showed an increase from the intervention after two months. After the aquatic walking and land walking combination, continuous walking distance also showed a prolonged trend. In the survey given to the main caregivers, improvements were observed. [Conclusion] Aquatic walking practice using a walker improved motivation in a chronic stroke patient, leading to improved walking ability, with a positive psychological influence on the participant and family caregiver. PMID:28744062

Using Wearable Sensors and Machine Learning Models to Separate Functional Upper Extremity Use From Walking-Associated Arm Movements.

PubMed

McLeod, Adam; Bochniewicz, Elaine M; Lum, Peter S; Holley, Rahsaan J; Emmer, Geoff; Dromerick, Alexander W

2016-02-01

To improve measurement of upper extremity (UE) use in the community by evaluating the feasibility of using body-worn sensor data and machine learning models to distinguish productive prehensile and bimanual UE activity use from extraneous movements associated with walking. Comparison of machine learning classification models with criterion standard of manually scored videos of performance in UE prosthesis users. Rehabilitation hospital training apartment. Convenience sample of UE prosthesis users (n=5) and controls (n=13) similar in age and hand dominance (N=18). Participants were filmed executing a series of functional activities; a trained observer annotated each frame to indicate either UE movement directed at functional activity or walking. Synchronized data from an inertial sensor attached to the dominant wrist were similarly classified as indicating either a functional use or walking. These data were used to train 3 classification models to predict the functional versus walking state given the associated sensor information. Models were trained over 4 trials: on UE amputees and controls and both within subject and across subject. Model performance was also examined with and without preprocessing (centering) in the across-subject trials. Percent correct classification. With the exception of the amputee/across-subject trial, at least 1 model classified >95% of test data correctly for all trial types. The top performer in the amputee/across-subject trial classified 85% of test examples correctly. We have demonstrated that computationally lightweight classification models can use inertial data collected from wrist-worn sensors to reliably distinguish prosthetic UE movements during functional use from walking-associated movement. This approach has promise in objectively measuring real-world UE use of prosthetic limbs and may be helpful in clinical trials and in measuring response to treatment of other UE pathologies. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The contribution of area-level walkability to geographic variation in physical activity: a spatial analysis of 95,837 participants from the 45 and Up Study living in Sydney, Australia.

PubMed

Mayne, Darren J; Morgan, Geoffrey G; Jalaludin, Bin B; Bauman, Adrian E

2017-10-03

Individual-level studies support a positive relation between walkable built environments and participation in moderate-intensity walking. However, the utility of this evidence for population-level planning is less clear as it is derived at much finer spatial scales than those used for regional programming. The aims of this study were to: evaluate if individual-level relations between walkability and walking to improve health manifest at population-level spatial scales; assess the specificity of area-level walkability for walking relative to other moderate and vigorous physical activity (MVPA); describe geographic variation in walking and other MVPA; and quantify the contribution of walkability to this variation. Data on sufficient walking, sufficient MVPA, and high MVPA to improve health were analyzed for 95,837 Sydney respondents to the baseline survey of the 45 and Up Study between January 2006 and April 2010. We used conditional autoregressive models to create smoothed MVPA "disease maps" and assess relations between sufficient MVPA to improve health and area-level walkability adjusted for individual-level demographic, socioeconomic, and health factors, and area-level relative socioeconomic disadvantage. Within-cohort prevalence of meeting recommendations for sufficient walking, sufficient MVPA, and high MVPA were 31.7 (95% CI 31.4-32.0), 69.4 (95% CI 69.1-69.7), and 56.1 (95% CI 55.8-56.4) percent. Prevalence of sufficient walking was increased by 1.20 (95% CrI 1.12-1.29) and 1.07 (95% CrI 1.01-1.13) for high and medium-high versus low walkability postal areas, and for sufficient MVPA by 1.05 (95% CrI 1.01-1.08) for high versus low walkability postal areas. Walkability was not related to high MVPA. Postal area walkability explained 65.8 and 47.4 percent of residual geographic variation in sufficient walking and sufficient MVPA not attributable to individual-level factors. Walkability is associated with area-level prevalence and geographic variation in sufficient walking and sufficient MVPA to improve health in Sydney, Australia. Our study supports the use of walkability indexes at multiple spatial scales for informing population-level action to increase physical activity and the utility of spatial analysis for walkability research and planning.

Aerobic treadmill plus Bobath walking training improves walking in subacute stroke: a randomized controlled trial.

PubMed

Eich, H-J; Mach, H; Werner, C; Hesse, S

2004-09-01

To evaluate the immediate and long-term effects of aerobic treadmill plus Bobath walking training in subacute stroke survivors compared with Bobath walking training alone. Randomized controlled trial. Rehabilitation unit. Fifty patients, first-time supratentorial stroke, stroke interval less than six weeks, Barthel Index (0-100) from 50 to 80, able to walk a minimum distance of 12 m with either intermittent help or stand-by while walking, cardiovascular stable, minimum 50 W in the bicycle ergometry, randomly allocated to two groups, A and B. Group A 30 min of treadmill training, harness secured and minimally supported according to patients' needs, and 30 min of physiotherapy, every workday for six weeks, speed and inclination of the treadmill were adjusted to achieve a heart rate of HR: (Hrmax-HRrest)*0.6+HRrest; in group B 60 min of daily physiotherapy for six weeks. Primary outcome variables were the absolute improvement of walking velocity (m/s) and capacity (m), secondary were gross motor function including walking ability (score out of 13) and walking quality (score out of 41), blindly assessed before and after the intervention, and at follow-up three months later. Patients tolerated the aerobic training well with no side-effects, significantly greater improvement of walking velocity and capacity both at study end (p =0.001 versus p =0.002) and at follow-up (p <0.001 versus p <0.001) in the experimental group. Between weeks 0 and 6, the experimental group improved walking speed and capacity by a mean of.31 m/s and 91 m, the control group by a mean of 0.16 m/s and 56 m. Between weeks 0 and 18, the experimental group improved walking speed and capacity by a mean of 0.36 m/s and 111 m, the control group by a mean of 0.15 m/s and 57 m. Gross motor function and walking quality did not differ at any time. Aerobic treadmill plus Bobath walking training in moderately affected stroke patients was better than Bobath walking training alone with respect to the improvement of walking velocity and capacity. The treatment approach is recommended in patients meeting the inclusion criteria. A multicentre trial should follow to strengthen the evidence.

Moving-window dynamic optimization: design of stimulation profiles for walking.

PubMed

Dosen, Strahinja; Popović, Dejan B

2009-05-01

The overall goal of the research is to improve control for electrical stimulation-based assistance of walking in hemiplegic individuals. We present the simulation for generating offline input (sensors)-output (intensity of muscle stimulation) representation of walking that serves in synthesizing a rule-base for control of electrical stimulation for restoration of walking. The simulation uses new algorithm termed moving-window dynamic optimization (MWDO). The optimization criterion was to minimize the sum of the squares of tracking errors from desired trajectories with the penalty function on the total muscle efforts. The MWDO was developed in the MATLAB environment and tested using target trajectories characteristic for slow-to-normal walking recorded in healthy individual and a model with the parameters characterizing the potential hemiplegic user. The outputs of the simulation are piecewise constant intensities of electrical stimulation and trajectories generated when the calculated stimulation is applied to the model. We demonstrated the importance of this simulation by showing the outputs for healthy and hemiplegic individuals, using the same target trajectories. Results of the simulation show that the MWDO is an efficient tool for analyzing achievable trajectories and for determining the stimulation profiles that need to be delivered for good tracking.

Daily intermittent hypoxia enhances walking after chronic spinal cord injury

PubMed Central

Hayes, Heather B.; Jayaraman, Arun; Herrmann, Megan; Mitchell, Gordon S.; Rymer, William Z.

2014-01-01

Objectives: To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve walking speed and endurance in persons with chronic incomplete spinal cord injury (iSCI). Methods: Nineteen subjects completed the randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio2] = 0.09) or daily normoxia (dSHAM, Fio2 = 0.21) at 60-second normoxic intervals on 5 consecutive days; dAIH was given alone or combined with 30 minutes of overground walking 1 hour later. Walking speed and endurance were quantified using 10-Meter and 6-Minute Walk Tests. The trial is registered at ClinicalTrials.gov (NCT01272349). Results: dAIH improved walking speed and endurance. Ten-Meter Walk time improved with dAIH vs dSHAM after 1 day (mean difference [MD] 3.8 seconds, 95% confidence interval [CI] 1.1–6.5 seconds, p = 0.006) and 2 weeks (MD 3.8 seconds, 95% CI 0.9–6.7 seconds, p = 0.010). Six-Minute Walk distance increased with combined dAIH + walking vs dSHAM + walking after 5 days (MD 94.4 m, 95% CI 17.5–171.3 m, p = 0.017) and 1-week follow-up (MD 97.0 m, 95% CI 20.1–173.9 m, p = 0.014). dAIH + walking increased walking distance more than dAIH after 1 day (MD 67.7 m, 95% CI 1.3–134.1 m, p = 0.046), 5 days (MD 107.0 m, 95% CI 40.6–173.4 m, p = 0.002), and 1-week follow-up (MD 136.0 m, 95% CI 65.3–206.6 m, p < 0.001). Conclusions: dAIH ± walking improved walking speed and distance in persons with chronic iSCI. The impact of dAIH is enhanced by combination with walking, demonstrating that combinatorial therapies may promote greater functional benefits in persons with iSCI. Classification of evidence: This study provides Class I evidence that transient hypoxia (through measured breathing treatments), along with overground walking training, improves walking speed and endurance after iSCI. PMID:24285617

Walking Ahead: The Headed Social Force Model.

PubMed

Farina, Francesco; Fontanelli, Daniele; Garulli, Andrea; Giannitrapani, Antonio; Prattichizzo, Domenico

2017-01-01

Human motion models are finding an increasing number of novel applications in many different fields, such as building design, computer graphics and robot motion planning. The Social Force Model is one of the most popular alternatives to describe the motion of pedestrians. By resorting to a physical analogy, individuals are assimilated to point-wise particles subject to social forces which drive their dynamics. Such a model implicitly assumes that humans move isotropically. On the contrary, empirical evidence shows that people do have a preferred direction of motion, walking forward most of the time. Lateral motions are observed only in specific circumstances, such as when navigating in overcrowded environments or avoiding unexpected obstacles. In this paper, the Headed Social Force Model is introduced in order to improve the realism of the trajectories generated by the classical Social Force Model. The key feature of the proposed approach is the inclusion of the pedestrians' heading into the dynamic model used to describe the motion of each individual. The force and torque representing the model inputs are computed as suitable functions of the force terms resulting from the traditional Social Force Model. Moreover, a new force contribution is introduced in order to model the behavior of people walking together as a single group. The proposed model features high versatility, being able to reproduce both the unicycle-like trajectories typical of people moving in open spaces and the point-wise motion patterns occurring in high density scenarios. Extensive numerical simulations show an increased regularity of the resulting trajectories and confirm a general improvement of the model realism.

Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

NASA Astrophysics Data System (ADS)

Huang, Yan; Wang, Qi-Ning; Gao, Yue; Xie, Guang-Ming

2012-10-01

Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait. This paper presents a passive dynamic walking model with segmented feet, which makes the bipedal walking gait more close to natural human-like gait. The proposed model extends the simplest walking model with the addition of flat feet and torsional spring based compliance on ankle joints and toe joints, to achieve stable walking on a slope driven by gravity. The push-off phase includes foot rotations around the toe joint and around the toe tip, which shows a great resemblance to human normal walking. This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

Impact of a stance phase microprocessor-controlled knee prosthesis on level walking in lower functioning individuals with a transfemoral amputation.

PubMed

Eberly, Valerie J; Mulroy, Sara J; Gronley, JoAnne K; Perry, Jacquelin; Yule, William J; Burnfield, Judith M

2014-12-01

For individuals with transfemoral amputation, walking with a prosthesis presents challenges to stability and increases the demand on the hip of the prosthetic limb. Increasing age or comorbidities magnify these challenges. Computerized prosthetic knee joints improve stability and efficiency of gait, but are seldom prescribed for less physically capable walkers who may benefit from them. To compare level walking function while wearing a microprocessor-controlled knee (C-Leg Compact) prosthesis to a traditionally prescribed non-microprocessor-controlled knee prosthesis for Medicare Functional Classification Level K-2 walkers. Crossover. Stride characteristics, kinematics, kinetics, and electromyographic activity were recorded in 10 participants while walking with non-microprocessor-controlled knee and Compact prostheses. Walking with the Compact produced significant increase in velocity, cadence, stride length, single-limb support, and heel-rise timing compared to walking with the non-microprocessor-controlled knee prosthesis. Hip and thigh extension during late stance improved bilaterally. Ankle dorsiflexion, knee extension, and hip flexion moments of the prosthetic limb were significantly improved. Improvements in walking function and stability on the prosthetic limb were demonstrated by the K-2 level walkers when using the C-Leg Compact prosthesis. Understanding the impact of new prosthetic designs on gait mechanics is essential to improve prescription guidelines for deconditioned or older persons with transfemoral amputation. Prosthetic designs that improve stability for safety and walking function have the potential to improve community participation and quality of life. © The International Society for Prosthetics and Orthotics 2013.

Patient-Centered Appointment Scheduling Using Agent-Based Simulation

PubMed Central

Turkcan, Ayten; Toscos, Tammy; Doebbeling, Brad N.

2014-01-01

Enhanced access and continuity are key components of patient-centered care. Existing studies show that several interventions such as providing same day appointments, walk-in services, after-hours care, and group appointments, have been used to redesign the healthcare systems for improved access to primary care. However, an intervention focusing on a single component of care delivery (i.e. improving access to acute care) might have a negative impact other components of the system (i.e. reduced continuity of care for chronic patients). Therefore, primary care clinics should consider implementing multiple interventions tailored for their patient population needs. We collected rapid ethnography and observations to better understand clinic workflow and key constraints. We then developed an agent-based simulation model that includes all access modalities (appointments, walk-ins, and after-hours access), incorporate resources and key constraints and determine the best appointment scheduling method that improves access and continuity of care. This paper demonstrates the value of simulation models to test a variety of alternative strategies to improve access to care through scheduling. PMID:25954423

Nordic Walking Can Be Incorporated in the Exercise Prescription to Increase Aerobic Capacity, Strength, and Quality of Life for Elderly: A Systematic Review and Meta-Analysis.

PubMed

Bullo, Valentina; Gobbo, Stefano; Vendramin, Barbara; Duregon, Federica; Cugusi, Lucia; Di Blasio, Andrea; Bocalini, Danilo Sales; Zaccaria, Marco; Bergamin, Marco; Ermolao, Andrea

2018-04-01

The aim of this systematic review and meta-analysis was to summarize and analyze the effects of Nordic Walking on physical fitness, body composition, and quality of life in the elderly. Keyword "Nordic Walking" associated with "elderly" AND/OR "aging" AND/OR "old subjects" AND/OR "aged" AND/OR "older adults" were used in the online database MEDLINE, Embase, PubMed, Scopus, PsycINFO, and SPORTDiscus. Only studies written in English language and published in peer-reviewed journals were considered. A meta-analysis was performed and effect sizes calculated. Fifteen studies were identified; age of participants ranged from 60 to 92 years old. Comparing with a sedentary group, effect sizes showed that Nordic Walking was able to improve dynamic balance (0.30), functional balance (0.62), muscle strength of upper (0.66) and lower limbs (0.43), aerobic capacity (0.92), cardiovascular outcomes (0.23), body composition (0.30), and lipid profile (0.67). It seemed that Nordic Walking had a negative effect on static balance (-0.72). Comparing with a walking (alone) training, effect sizes showed that Nordic Walking improved the dynamic balance (0.30), flexibility of the lower body (0.47), and quality of life (0.53). Walking training was more effective in improving aerobic capacity (-0.21). Comparing Nordic Walking with resistance training, effect sizes showed that Nordic Walking improved dynamic balance (0.33), muscle strength of the lower body (0.39), aerobic capacity (0.75), flexibility of the upper body (0.41), and the quality of life (0.93). Nordic Walking can be considered as a safe and accessible form of aerobic exercise for the elderly population, able to improve cardiovascular outcomes, muscle strength, balance ability, and quality of life.

Environmental perceptions and objective walking trail audits inform a community-based participatory research walking intervention

PubMed Central

2012-01-01

Background Given the documented physical activity disparities that exist among low-income minority communities and the increased focused on socio-ecological approaches to address physical inactivity, efforts aimed at understanding the built environment to support physical activity are needed. This community-based participatory research (CBPR) project investigates walking trails perceptions in a high minority southern community and objectively examines walking trails. The primary aim is to explore if perceived and objective audit variables predict meeting recommendations for walking and physical activity, MET/minutes/week of physical activity, and frequency of trail use. Methods A proportional sampling plan was used to survey community residents in this cross-sectional study. Previously validated instruments were pilot tested and appropriately adapted and included the short version of the validated International Physical Activity Questionnaire, trail use, and perceptions of walking trails. Walking trails were assessed using the valid and reliable Path Environmental Audit Tool which assesses four content areas including: design features, amenities, maintenance, and pedestrian safety from traffic. Analyses included Chi-square, one-way ANOVA's, multiple linear regression, and multiple logistic models. Results Numerous (n = 21) high quality walking trails were available. Across trails, there were very few indicators of incivilities and safety features rated relatively high. Among the 372 respondents, trail use significantly predicted meeting recommendations for walking and physical activity, and MET/minutes/week. While controlling for other variables, significant predictors of trail use included proximity to trails, as well as perceptions of walking trail safety, trail amenities, and neighborhood pedestrian safety. Furthermore, while controlling for education, gender, and income; for every one time per week increase in using walking trails, the odds for meeting walking recommendations increased 1.27 times, and the odds for meeting PA recommendation increased 3.54 times. Perceived and objective audit variables did not predict meeting physical activity recommendations. Conclusions To improve physical activity levels, intervention efforts are needed to maximize the use of existing trails, as well as improve residents' perceptions related to incivilities, safety, conditions of trail, and amenities of the walking trails. This study provides important insights for informing development of the CBPR walking intervention and informing local recreational and environmental policies in this southern community. PMID:22289653

Acute effects on cognitive performance following bouts of standing and light-intensity physical activity in a simulated workplace environment.

PubMed

Mullane, Sarah L; Buman, Matthew P; Zeigler, Zachary S; Crespo, Noe C; Gaesser, Glenn A

2017-05-01

To compare acute cognitive effects following bouts of standing (STAND), cycling (CYCLE) and walking (WALK) to a sit-only (SIT) condition. Randomized cross-over full-factorial study. Nine overweight (BMI=29±3kg/m 2 ) adults (30±15years; 7 females, 2 males) completed four conditions (SIT, STAND, WALK and CYCLE) across a 6h period with a 7days washout period between conditions. SIT consisted of uninterrupted sitting. Experimental conditions included intermittent bouts of standing (STAND), cycling (CYCLE) and walking (WALK). A cognitive performance battery (Cogstate) was completed twice in a seated position following bouts of standing and light-intensity physical activity. Mixed-effects models compared between-condition differences in standardized score (z-score), accuracy (%), and speed (log10ms). Cognitive performance z-score and accuracy measures were higher during STAND, CYCLE and WALK (P<0.05) conditions compared to the SIT condition. CYCLE was better than other experimental conditions. Compared to uninterrupted sitting, short bouts of standing or light-intensity cycling and walking may improve acute cognitive performance. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Nordic walking in fibromyalgia: a means of promoting fitness that is easy for busy clinicians to recommend

PubMed Central

2011-01-01

A total of 67 women with fibromyalgia were recruited to an exercise study and were randomized to moderate-to-high-intensity Nordic walking (age 48 ± 7.8 years) or to a control group engaging in supervised low-intensity walking (age 50 ± 7.6 years). A total of 58 patients completed. Significantly greater improvement in the 6-minute walk test was found in the Nordic walking group (P = 0.009), compared with the low-intensity walking group. A significantly larger decrease in exercise heart rate (P = 0.020) and significantly improved scores on the Fibromyalgia Impact Questionnaire Physical function (P = 0.027) were found in the Nordic walking group as compared with the low-intensity walking group. No between-group difference was found for the Fibromyalgia Impact Questionnaire total or pain scores. The authors conclude that moderate-to-high intensity aerobic exercise by means of Nordic walking twice a week for 15 weeks was found to be a feasible mode of exercise, resulting in improved functional capacity and a decreased level of activity limitations. PMID:21345243

Relation between aerobic capacity and walking ability in older adults with a lower-limb amputation.

PubMed

Wezenberg, Daphne; van der Woude, Lucas H; Faber, Willemijn X; de Haan, Arnold; Houdijk, Han

2013-09-01

To determine the relative aerobic load, walking speed, and walking economy of older adults with a lower-limb prosthesis, and to predict the effect of an increased aerobic capacity on their walking ability. Cross-sectional. Human motion laboratory at a rehabilitation center. Convenience sample of older adults (n=36) who underwent lower-limb amputation because of vascular deficiency or trauma and able-bodied controls (n=21). Not applicable. Peak aerobic capacity and oxygen consumption while walking were determined. The relative aerobic load and walking economy were assessed as a function of walking speed, and a data-based model was constructed to predict the effect of an increased aerobic capacity on walking ability. People with a vascular amputation walked at a substantially higher (45.2%) relative aerobic load than people with an amputation because of trauma. The preferred walking speed in both groups of amputees was slower than that of able-bodied controls and below their most economical walking speed. We predicted that a 10% increase in peak aerobic capacity could potentially result in a reduction in the relative aerobic load of 9.1%, an increase in walking speed of 17.3% and 13.9%, and an improvement in the walking economy of 6.8% and 2.9%, for people after a vascular or traumatic amputation, respectively. Current findings corroborate the notion that, especially in people with a vascular amputation, the peak aerobic capacity is an important determinant for walking ability. The data provide quantitative predictions on the effect of aerobic training; however, future research is needed to experimentally confirm these predictions. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Effect of "Xingnao Kaiqiao Zhenfa" (Acupuncture Technique for Restoring Consciousness) Combined with Rehabilitation Training on Nerve Repair and Expression of Growth-associated Protein-43 of Peri-ischemic Cortex in Ischemic Stroke Rats].

PubMed

Xu, Lei; Yan, Xing-Zhou; Li, Zhen-Yu; Cao, Xiao-Fang; Wang, Min

2017-06-25

To observe the effect of "Xingnao Kaiqiao Zhenfa" (acupuncture technique for restoring consciousness) combined with enriched rehabilitation training on motor function and expression of growth-associated protein-43 (GAP-43) of peri-ischemic cortex in ischemic stroke rats, so as to investigate its mechanism underlying improvement of ischemic stroke. SD rats were randomly divided into sham operation, model, rehabilitation and comprehensive rehabilitation groups, which were further divided into 3 time-points:7, 14 and 21 d ( n =6 in each). Cerebral ischemia(CI) model was established by occlusion of the middle cerebral artery with heat-coagulation. The rehabilitation group was treated by enriched rehabilitation training, once a day. The comprehensive rehabilitation group was treated by acupuncture combined with enriched rehabilitation training. Acupuncture was applied to bilateral "Neiguan"(PC 6) and "Shuigou"(GV 26) for 30 min, once a day. The neurological function score, balance-beam walking test and rotating-rod walking test were evaluated at the end of the corresponding treatment time. The expression of GAP-43 in peri-ischemic cortex was detected by immunohistochemistry. In comparison with the sham operation group, the scores of neurological function, beam walking test and rotating-rod walking test were significantly higher in the model group ( P <0.01). There were no significant changes in the scores of balance-beam walking and rotating-rod walking tests in the rehabilitation group compared with the model group on day 7 ( P >0.05). Compared with the model group at the other time points, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the rehabilitation and comprehensive rehabilitation groups ( P <0.05). Compared with the rehabilitation group, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the comprehensive rehabilitation group ( P <0.05). In comparison with the sham operation group, the number of GAP-43 positive cells of peri-ischemic cortex was significantly higher in the model group ( P <0.01). Compared with the model group, the numbers of GAP-43 positive cells of peri-ischemic cortex were significantly increased in the rehabilitation and comprehensive rehabilitation groups ( P <0.01). The number of GAP-43 positive cells of peri-ischemic cortex in the comprehensive rehabilitation group was significantly higher than that in the rehabilitation group ( P <0.01). "Xingnao Kaiqiao Zhenfa" combined with enriched rehabilitation training can promote the recovery of nerve function in ischemic stroke rats, which may be associated with its effect in up-regulating the expression of GAP-43 in the peri-ischemic cortex.

Kinematic and EMG Responses to Pelvis and Leg Assistance Force during Treadmill Walking in Children with Cerebral Palsy

PubMed Central

Kim, Janis; Arora, Pooja; Zhang, Yunhui

2016-01-01

Treadmill training has been used for improving locomotor function in children with cerebral palsy (CP), but the functional gains are relatively small, suggesting a need to improve current paradigms. The understanding of the kinematic and EMG responses to forces applied to the body of subjects during treadmill walking is crucial for improving current paradigms. The objective of this study was to determine the kinematics and EMG responses to the pelvis and/or leg assistance force. Ten children with spastic CP were recruited to participate in this study. A controlled assistance force was applied to the pelvis and/or legs during stance and swing phase of gait through a custom designed robotic system during walking. Muscle activities and spatial-temporal gait parameters were measured at different loading conditions during walking. In addition, the spatial-temporal gait parameters during overground walking before and after treadmill training were also collected. Applying pelvis assistance improved step height and applying leg assistance improved step length during walking, but applying leg assistance also reduced muscle activation of ankle flexor during the swing phase of gait. In addition, step length and self-selected walking speed significantly improved after one session of treadmill training with combined pelvis and leg assistance. PMID:27651955

A random walk model for evaluating clinical trials involving serial observations.

PubMed

Hopper, J L; Young, G P

1988-05-01

For clinical trials where the variable of interest is ordered and categorical (for example, disease severity, symptom scale), and where measurements are taken at intervals, it might be possible to achieve a greater discrimination between the efficacy of treatments by modelling each patient's progress as a stochastic process. The random walk is a simple, easily interpreted model that can be fitted by maximum likelihood using a maximization routine with inference based on standard likelihood theory. In general the model can allow for randomly censored data, incorporates measured prognostic factors, and inference is conditional on the (possibly non-random) allocation of patients. Tests of fit and of model assumptions are proposed, and application to two therapeutic trials of gastroenterological disorders are presented. The model gave measures of the rate of, and variability in, improvement for patients under different treatments. A small simulation study suggested that the model is more powerful than considering the difference between initial and final scores, even when applied to data generated by a mechanism other than the random walk model assumed in the analysis. It thus provides a useful additional statistical method for evaluating clinical trials.

Nordic walking versus walking without poles for rehabilitation with cardiovascular disease: Randomized controlled trial.

PubMed

Girold, Sébastien; Rousseau, Jérome; Le Gal, Magalie; Coudeyre, Emmanuel; Le Henaff, Jacqueline

2017-07-01

With Nordic walking, or walking with poles, one can travel a greater distance and at a higher rate than with walking without poles, but whether the activity is beneficial for patients with cardiovascular disease is unknown. This randomized controlled trial was undertaken to determine whether Nordic walking was more effective than walking without poles on walk distance to support rehabilitation training for patients with acute coronary syndrome (ACS) and peripheral arterial occlusive disease (PAOD). Patients were recruited in a private specialized rehabilitation centre for cardiovascular diseases. The entire protocol, including patient recruitment, took place over 2 months, from September to October 2013. We divided patients into 2 groups: Nordic Walking Group (NWG, n=21) and Walking Group without poles (WG, n=21). All patients followed the same program over 4 weeks, except for the walk performed with or without poles. The main outcome was walk distance on the 6-min walk test. Secondary outcomes were maximum heart rate during exercise and walk distance and power output on a treadmill stress test. We included 42 patients (35 men; mean age 57.2±11 years and BMI 26.5±4.5kg/m 2 ). At the end of the training period, both groups showed improved walk distance on the 6-min walk test and treatment stress test as well as power on the treadmill stress test (P<0.05). The NWG showed significantly greater walk distance than the WG (P<0.05). Both ACS and PAOD groups showed improvement, but improvement was significant for only PAOD patients. After a 4-week training period, Nordic walking training appeared more efficient than training without poles for increasing walk distance on the 6-min walk test for patients with ACS and PAOD. Copyright © 2017. Published by Elsevier Masson SAS.

A Three Month Home Exercise Programme Augmented with Nordic Poles for Patients with Intermittent Claudication Enhances Quality of Life and Continues to Improve Walking Distance and Compliance After One Year.

PubMed

Oakley, C; Spafford, C; Beard, J D

2017-05-01

The objective of this study was to collect 1 year follow-up information on walking distance, speed, compliance, and cost in patients with intermittent claudication who took part in a previously reported 12 week randomised clinical trial of a home exercise programme augmented with Nordic pole walking versus controls who walked normally. A second objective was to look at quality of life and ankle brachial pressure indices (ABPIs) after a 12 week augmented home exercise programme. Thirty-two of the 38 patients who completed the original trial were followed-up after 6 and 12 months. Frequency, duration, speed, and distance of walking were recorded using diaries and pedometers. A new observational cohort of 29 patients was recruited to the same augmented home exercise programme. ABPIs, walking improvement, and quality of life questionnaire were recorded at baseline and 12 weeks (end of the programme). Both groups in the follow-up study continued to improve their walking distance and speed over the following year. Compliance was excellent: 98% of the augmented group were still walking with poles at both 6 and 12 months, while 74% of the control group were still walking at the same point. The augmented group increased their mean walking distance to 17.5 km by 12 months, with a mean speed of 4.2 km/hour. The control group only increased their mean walking distance from 4.2 km to 5.6 km, and speed to 3.3 km/hour. Repeated ANOVA showed the results to be highly significant (p = .002). The 21/29 patients who completed the observational study showed a statistically significant increase in resting ABPIs from baseline (mean ± SD 0.75 ± 0.12) to week 12 (mean ± SD 0.85 ± 0.12) (t = (20) -8.89, p = .000 [two-tailed]). All their walking improvement and quality of life parameters improved significantly (p = .002 or less in the six categories) over the same period and their mean health scores improved by 79%. Following a 12 week augmented home exercise programme, most patients with intermittent claudication continued to significantly improve their walking distance and walking speed at 1 year compared with normal walking. Quality of life and ABPIs improved significantly after only 12 weeks and it is postulated that the improvement in ABPI was due to collateral development. These results justify the belief that an augmented home exercise programme will be as clinically effective as existing supervised exercise programmes, with the added benefits of lower cost and better compliance. Funding for a multicentre trial comparing an augmented home exercise programme with existing supervised exercise programme is now urgently required. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Effects of walking speed and age on the muscle forces of unimpaired gait subjects

NASA Astrophysics Data System (ADS)

Fliger, Carlos G.; Crespo, Marcos J.; Braidot, Ariel A.; Ravera, Emiliano P.

2016-04-01

Clinical gait analysis provides great contributions to the understanding of gait disorders and also provides a mean for a more comprehensive treatment plan. However, direct measures of muscle forces are difficult to obtain in clinical settings because it generally requires invasive techniques. Techniques of musculoskeletal modeling have been used for several decades to improve the benefits of clinical gait analysis, but many of the previous studies were focused on analyzing separately the muscle forces distribution of children or adult subjects with only one condition of walking speed. For these reason, the present study aims to enhance the current literature by describing the age and speed gait effects on muscle forces during walking. We used a musculoskeletal model with 23 degrees of freedom and 92 musculotendon actuators to represent 76 muscles in the lower extremities and torso. The computed muscle control algorithm was used to estimate the muscle forces from the kinematics and to adjust the model obtained in the residual reduction algorithm. We find that hamstrings has an important peak in the mid-stance phase in the adult group but this peak disappears in the children group with the same walking speed condition. Furthermore, the rectus femoris presents an increase in the muscle force during the pre- and mid-swing in concordance with the increment in the walking speed of subjects. This behavior could be associated with the role that the rectus femoris has in the acceleration of the knee joint. Finally, we show that the soleus is the muscle that perform the major force throughout the gait cycle regardless of age and walking speed.

DNA bipedal motor walking dynamics: an experimental and theoretical study of the dependency on step size

PubMed Central

Khara, Dinesh C; Berger, Yaron; Ouldridge, Thomas E

2018-01-01

Abstract We present a detailed coarse-grained computer simulation and single molecule fluorescence study of the walking dynamics and mechanism of a DNA bipedal motor striding on a DNA origami. In particular, we study the dependency of the walking efficiency and stepping kinetics on step size. The simulations accurately capture and explain three different experimental observations. These include a description of the maximum possible step size, a decrease in the walking efficiency over short distances and a dependency of the efficiency on the walking direction with respect to the origami track. The former two observations were not expected and are non-trivial. Based on this study, we suggest three design modifications to improve future DNA walkers. Our study demonstrates the ability of the oxDNA model to resolve the dynamics of complex DNA machines, and its usefulness as an engineering tool for the design of DNA machines that operate in the three spatial dimensions. PMID:29294083

Evaluation of group and self-directed formats of the Arthritis Foundation's Walk With Ease Program.

PubMed

Callahan, Leigh F; Shreffler, Jack H; Altpeter, Mary; Schoster, Britta; Hootman, Jennifer; Houenou, Laura O; Martin, Kathryn R; Schwartz, Todd A

2011-08-01

To evaluate the effects of a revised 6-week walking program for adults with arthritis, Walk With Ease (WWE), delivered in 2 formats, instructor-led group or self-directed. In an observational pre-post study design, 462 individuals with self-reported arthritis selected either a group format (n = 192) or a self-directed (n = 270) format. Performance and self-reported outcomes were assessed at baseline and at 6 weeks. Self-reported outcomes were assessed at 1 year. Adjusted mean outcome values for group and self-directed participants were determined using regression models, adjusting for covariates. At 6 weeks, significant adjusted mean improvements (P < 0.05) were seen for nearly all self-report and performance measures in both formats. Modest to moderate effect sizes (ES) were seen for disability (ES 0.16-0.23), pain, fatigue, and stiffness (ES 0.21-0.40), and helplessness (ES 0.24-0.28). The Arthritis Self-Efficacy (ASE) pain and symptom scales had modest improvements (ES 0.09-0.21). The performance measures of strength (ES 0.29-0.35), balance (ES 0.12-0.36), and walking pace (ES 0.12-0.32) all showed modest to moderate improvements. No adverse events were reported for either format. At 1 year, both formats showed modest improvement in ASE pain, but there were 5 outcomes where self-directed participants showed significant improvement, while the group participants did not. The revised WWE program decreases disability and improves arthritis symptoms, self-efficacy, and perceived control, balance, strength, and walking pace in individuals with arthritis, regardless of whether they are taking a group class or doing the program as self-directed walkers. At 1 year, some benefits are maintained, particularly among the self-directed. This is a safe, easy, and inexpensive program to promote community-based physical activity. Copyright © 2011 by the American College of Rheumatology.

Imputational Modeling of Spatial Context and Social Environmental Predictors of Walking in an Underserved Community: The PATH Trial

PubMed Central

Ellerbe, Caitlyn; Lawson, Andrew B.; Alia, Kassandra A.; Meyers, Duncan C.; Coulon, Sandra M.; Lawman, Hannah G.

2013-01-01

Background This study examined imputational modeling effects of spatial proximity and social factors of walking in African American adults. Purpose Models were compared that examined relationships between household proximity to a walking trail and social factors in determining walking status. Methods Participants (N=133; 66% female; mean age=55 yrs) were recruited to a police-supported walking and social marketing intervention. Bayesian modeling was used to identify predictors of walking at 12 months. Results Sensitivity analysis using different imputation approaches, and spatial contextual effects, were compared. All the imputation methods showed social life and income were significant predictors of walking, however, the complete data approach was the best model indicating Age (1.04, 95% OR: 1.00, 1.08), Social Life (0.83, 95% OR: 0.69, 0.98) and Income > $10,000 (0.10, 95% OR: 0.01, 0.97) were all predictors of walking. Conclusions The complete data approach was the best model of predictors of walking in African Americans. PMID:23481250

Imputational modeling of spatial context and social environmental predictors of walking in an underserved community: the PATH trial.

PubMed

Wilson, Dawn K; Ellerbe, Caitlyn; Lawson, Andrew B; Alia, Kassandra A; Meyers, Duncan C; Coulon, Sandra M; Lawman, Hannah G

2013-03-01

This study examined imputational modeling effects of spatial proximity and social factors of walking in African American adults. Models were compared that examined relationships between household proximity to a walking trail and social factors in determining walking status. Participants (N=133; 66% female; mean age=55 years) were recruited to a police-supported walking and social marketing intervention. Bayesian modeling was used to identify predictors of walking at 12 months. Sensitivity analysis using different imputation approaches, and spatial contextual effects, were compared. All the imputation methods showed social life and income were significant predictors of walking, however, the complete data approach was the best model indicating Age (1.04, 95% OR: 1.00, 1.08), Social Life (0.83, 95% OR: 0.69, 0.98) and Income <$10,000 (0.10, 95% OR: 0.01, 0.97) were all predictors of walking. The complete data approach was the best model of predictors of walking in African Americans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of Systematic Increases in Treadmill Walking Speed on Gait Kinematics After Stroke

PubMed Central

Tyrell, Christine M.; Roos, Margaret A.; Rudolph, Katherine S.

2011-01-01

Background Fast treadmill training improves walking speed to a greater extent than training at a self-selected speed after stroke. It is unclear whether fast treadmill walking facilitates a more normal gait pattern after stroke, as has been suggested for treadmill training at self-selected speeds. Given the massed stepping practice that occurs during treadmill training, it is important for therapists to understand how the treadmill speed selected influences the gait pattern that is practiced on the treadmill. Objective The purpose of this study was to characterize the effect of systematic increases in treadmill speed on common gait deviations observed after stroke. Design A repeated-measures design was used. Methods Twenty patients with stroke walked on a treadmill at their self-selected walking speed, their fastest speed, and 2 speeds in between. Using a motion capture system, spatiotemporal gait parameters and kinematic gait compensations were measured. Results Significant improvements in paretic- and nonparetic-limb step length and in single- and double-limb support were found. Asymmetry of these measures improved only for step length. Significant improvements in paretic hip extension, trailing limb position, and knee flexion during swing also were found as speed increased. No increases in circumduction or hip hiking were found with increasing speed. Limitations Caution should be used when generalizing these results to survivors of a stroke with a self-selected walking speed of less than 0.4 m/s. This study did not address changes with speed during overground walking. Conclusions Faster treadmill walking facilitates a more normal walking pattern after stroke, without concomitant increases in common gait compensations, such as circumduction. The improvements in gait deviations were observed with small increases in walking speed. PMID:21252308

Randomized Controlled Trial of a Home-Based Action Observation Intervention to Improve Walking in Parkinson Disease.

PubMed

Jaywant, Abhishek; Ellis, Terry D; Roy, Serge; Lin, Cheng-Chieh; Neargarder, Sandy; Cronin-Golomb, Alice

2016-05-01

To examine the feasibility and efficacy of a home-based gait observation intervention for improving walking in Parkinson disease (PD). Participants were randomly assigned to an intervention or control condition. A baseline walking assessment, a training period at home, and a posttraining assessment were conducted. The laboratory and participants' home and community environments. Nondemented individuals with PD (N=23) experiencing walking difficulty. In the gait observation (intervention) condition, participants viewed videos of healthy and parkinsonian gait. In the landscape observation (control) condition, participants viewed videos of moving water. These tasks were completed daily for 8 days. Spatiotemporal walking variables were assessed using accelerometers in the laboratory (baseline and posttraining assessments) and continuously at home during the training period. Variables included daily activity, walking speed, stride length, stride frequency, leg swing time, and gait asymmetry. Questionnaires including the 39-item Parkinson Disease Questionnaire (PDQ-39) were administered to determine self-reported change in walking, as well as feasibility. At posttraining assessment, only the gait observation group reported significantly improved mobility (PDQ-39). No improvements were seen in accelerometer-derived walking data. Participants found the at-home training tasks and accelerometer feasible to use. Participants found procedures feasible and reported improved mobility, suggesting that observational training holds promise in the rehabilitation of walking in PD. Observational training alone, however, may not be sufficient to enhance walking in PD. A more challenging and adaptive task, and the use of explicit perceptual learning and practice of actions, may be required to effect change. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Effects of curved-walking training on curved-walking performance and freezing of gait in individuals with Parkinson's disease: A randomized controlled trial.

PubMed

Cheng, Fang-Yu; Yang, Yea-Ru; Wu, Yih-Ru; Cheng, Shih-Jung; Wang, Ray-Yau

2017-10-01

The purpose of this study was to investigate the effects of curved-walking training (CWT) on curved-walking performance and freezing of gait (FOG) in people with Parkinson's disease (PD). Twenty-four PD subjects were recruited and randomly assigned to the CWT group or control exercise (CE) group and received 12 sessions of either CWT with a turning-based treadmill or general exercise training for 30 min followed by 10 min of over-ground walking in each session for 4-6 weeks. The primary outcomes included curved-walking performance and FOG. All measurements were assessed at baseline, after training, and at 1-month follow-up. Our results showed significant improvements in curved-walking performance (speed, p = 0.007; cadence, p = 0.003; step length, p < 0.001) and FOG, measured by a FOG questionnaire (p = 0.004). The secondary outcomes including straight-walking performance (speed, cadence and step length, p < 0.001), timed up and go test (p = 0.014), functional gait assessment (p < 0.001), Unified Parkinson's disease Rating Scale III (p = 0.001), and quality of life (p < 0.001) were also improved in the experimental group. We further noted that the improvements were maintained for at least one month after training (p < 0.05). A 12-session CWT program can improve curved-walking ability, FOG, and other measures of functional walking performance in individuals with PD. Most of the improvements were sustained for at least one month after training. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Spatial Agent-Based Model for the Simulation of Adults’ Daily Walking Within a City

PubMed Central

Yang, Yong; Roux, Ana V. Diez; Auchincloss, Amy H.; Rodriguez, Daniel A.; Brown, Daniel G.

2012-01-01

Environmental effects on walking behavior have received attention in recent years because of the potential for policy interventions to increase population levels of walking. Most epidemiologic studies describe associations of walking behavior with environmental features. These analyses ignore the dynamic processes that shape walking behaviors. A spatial agent-based model (ABM) was developed to simulate peoples’ walking behaviors within a city. Each individual was assigned properties such as age, SES, walking ability, attitude toward walking and a home location. Individuals perform different activities on a regular basis such as traveling for work, for shopping, and for recreation. Whether an individual walks and the amount she or he walks is a function distance to different activities and her or his walking ability and attitude toward walking. An individual’s attitude toward walking evolves over time as a function of past experiences, walking of others along the walking route, limits on distances walked per day, and attitudes toward walking of the other individuals within her/his social network. The model was calibrated and used to examine the contributions of land use and safety to socioeconomic differences in walking. With further refinement and validation, ABMs may help to better understand the determinants of walking and identify the most promising interventions to increase walking. PMID:21335269

Gait Evaluation of Overground Walking and Treadmill Walking Using Compass-Type Walking Model

NASA Astrophysics Data System (ADS)

Nagata, Yousuke; Yamamoto, Masayoshi; Funabiki, Shigeyuki

A treadmill is a useful apparatus for the gait training and evaluation. However, many differences are reported between treadmill and overground walking. Experimental comparisons of the muscle activity of the leg and the heart rate have been carried out. However, the dynamic comparison has not been performed. The dynamic evaluation of the overground walking and the treadmill walking using a compass-type walking model (CTWM) which is a simple bipedal walking model, then their comparison is discussed. It is confirmed that the walking simulation using the CTWM can simulate the difference of that walk, it is clarified that there are the differences of the kick impulse on the ground and the turning impulse of the foot to the variation of the belt speed and then differences are the main factor of two walking.

Effects of Nordic walking training on exercise capacity and fitness in men participating in early, short-term inpatient cardiac rehabilitation after an acute coronary syndrome--a controlled trial.

PubMed

Kocur, Piotr; Deskur-Smielecka, Ewa; Wilk, Malgorzata; Dylewicz, Piotr

2009-11-01

To investigate the effects of Nordic Walking training supplemental to a standard, early rehabilitation programme on exercise capacity and physical fitness in men after an acute coronary syndrome. A controlled trial. Cardiac rehabilitation service of a provincial hospital. Eighty men 2-3 weeks after an acute coronary syndrome, with good exercise tolerance. Three-week, inpatient cardiac rehabilitation programme (control group) supplemented with Nordic Walking (Nordic Walking group), or with traditional walking training (walking training group). Exercise capacity was assessed as peak energy cost (in metabolic equivalents) in symptom-limited treadmill exercise test, and physical fitness with the Fullerton Functional Fitness Test. Exercise capacity after the rehabilitation programme was higher in the Nordic Walking group than in the control group (10.8 +/- 1.8 versus 9.2 +/- 2.2 metabolic equivalents, P =0.025). The improvement in exercise capacity in the Nordic Walking group was higher than in the control group (1.8 +/- 1.5 versus 0.7 +/- 1.4 metabolic equivalents, P =0.002). In contrast to the control group, the results of all components of the Fullerton test improved in the Nordic Walking and walking training groups. After the programme, lower body endurance, and dynamic balance were significantly better in the Nordic Walking group in comparison with the walking training and control groups, and upper body endurance was significantly better in the Nordic Walking and walking training groups than in the control group. Nordic Walking may improve exercise capacity, lower body endurance and coordination of movements in patients with good exercise tolerance participating in early, short-term rehabilitation after an acute coronary syndrome.

Using wireless technology in clinical practice: does feedback of daily walking activity improve walking outcomes of individuals receiving rehabilitation post-stroke? Study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Regaining independent ambulation is the top priority for individuals recovering from stroke. Thus, physical rehabilitation post-stroke should focus on improving walking function and endurance. However, the amount of walking completed by individuals with stroke attending rehabilitation is far below that required for independent community ambulation. There has been increased interest in accelerometer-based monitoring of walking post-stroke. Walking monitoring could be integrated within the goal-setting process for those with ambulation goals in rehabilitation. The feedback from these devices can be downloaded to a computer to produce reports. The purpose of this study is to determine the effect of accelerometer-based feedback of daily walking activity during rehabilitation on the frequency and duration of walking post-stroke. Methods Participants will be randomly assigned to one of two groups: feedback or no feedback. Participants will wear accelerometers daily during in- and out-patient rehabilitation and, for participants in the feedback group, the participants’ treating physiotherapist will receive regular reports of walking activity. The primary outcome measures are the amount of daily walking completed, as measured using the accelerometers, and spatio-temporal characteristics of walking (e.g. walking speed). We will also examine goal attainment, satisfaction with progress towards goals, stroke self-efficacy, and community-integration. Discussion Increased walking activity during rehabilitation is expected to improve walking function and community re-integration following discharge. In addition, a focus on altering walking behaviour within the rehabilitation setting may lead to altered behaviour and increased activity patterns after discharge. Trial registration ClinicalTrials.gov NCT01521234 PMID:23865593

Optimization of prosthetic foot stiffness to reduce metabolic cost and intact knee loading during below-knee amputee walking: a theoretical study.

PubMed

Fey, Nicholas P; Klute, Glenn K; Neptune, Richard R

2012-11-01

Unilateral below-knee amputees develop abnormal gait characteristics that include bilateral asymmetries and an elevated metabolic cost relative to non-amputees. In addition, long-term prosthesis use has been linked to an increased prevalence of joint pain and osteoarthritis in the intact leg knee. To improve amputee mobility, prosthetic feet that utilize elastic energy storage and return (ESAR) have been designed, which perform important biomechanical functions such as providing body support and forward propulsion. However, the prescription of appropriate design characteristics (e.g., stiffness) is not well-defined since its influence on foot function and important in vivo biomechanical quantities such as metabolic cost and joint loading remain unclear. The design of feet that improve these quantities could provide considerable advancements in amputee care. Therefore, the purpose of this study was to couple design optimization with dynamic simulations of amputee walking to identify the optimal foot stiffness that minimizes metabolic cost and intact knee joint loading. A musculoskeletal model and distributed stiffness ESAR prosthetic foot model were developed to generate muscle-actuated forward dynamics simulations of amputee walking. Dynamic optimization was used to solve for the optimal muscle excitation patterns and foot stiffness profile that produced simulations that tracked experimental amputee walking data while minimizing metabolic cost and intact leg internal knee contact forces. Muscle and foot function were evaluated by calculating their contributions to the important walking subtasks of body support, forward propulsion and leg swing. The analyses showed that altering a nominal prosthetic foot stiffness distribution by stiffening the toe and mid-foot while making the ankle and heel less stiff improved ESAR foot performance by offloading the intact knee during early to mid-stance of the intact leg and reducing metabolic cost. The optimal design also provided moderate braking and body support during the first half of residual leg stance, while increasing the prosthesis contributions to forward propulsion and body support during the second half of residual leg stance. Future work will be directed at experimentally validating these results, which have important implications for future designs of prosthetic feet that could significantly improve amputee care.

The Use of Classroom Walk-Through Observations as a Strategy to Improve Teaching and Learning: An Administrative Perspective

ERIC Educational Resources Information Center

Weller, Mark J.

2010-01-01

The purpose of this study was to identify the possible use of structured classroom walk-through observations as a strategy to improve teaching and learning. A wide variety of programs and initiatives have recently been implemented across the country to improve student achievement. One such initiative is classroom walk-through observations.…

Effects of intensive therapy using gait trainer or floor walking exercises early after stroke.

PubMed

Peurala, Sinikka H; Airaksinen, Olavi; Huuskonen, Pirjo; Jäkälä, Pekka; Juhakoski, Mika; Sandell, Kaisa; Tarkka, Ina M; Sivenius, Juhani

2009-02-01

To analyse the effects of gait therapy for patients after acute stroke in a randomized controlled trial. Fifty-six patients with a mean of 8 days post-stroke participated in: (i) gait trainer exercise; (ii) walking training over ground; or (iii) conventional treatment. Patients in the gait trainer exercise and walking groups practiced gait for 15 sessions over 3 weeks and received additional physiotherapy. Functional Ambulatory Category and several secondary outcome measures assessing gait and mobility were administered before and after rehabilitation and at 6-month follow-up. Patients also evaluated their own effort. Walking ability improved more with intensive walk training compared with conventional treatment; median Functional Ambulatory Category was zero in all patients at the start of the study, but it was 3 in both walk-training groups and 0.5 in the conventional treatment group at the end of the therapy. Median Functional Ambulatory Category was 4 in both walk-training groups and 2.5 in conventional treatment group at 6-month follow-up. Mean accomplished walking distance was not different between the gait trainer exercise and over ground walking groups. Borg scale indicated more effort in over ground walking. Secondary outcomes also indicated improvements. Exercise therapy with walking training improved gait function irrespective of the method used, but the time and effort required to achieve the results favour the gait trainer exercise. Early intensive gait training resulted in better walking ability than did conventional treatment.

Community-based walking exercise for peripheral artery disease: An exploratory pilot study

PubMed Central

Mays, Ryan J; Hiatt, William R; Casserly, Ivan P; Rogers, R Kevin; Main, Deborah S; Kohrt, Wendy M; Ho, P Michael; Regensteiner, Judith G

2016-01-01

Supervised walking exercise is an effective treatment to improve walking ability of patients with peripheral artery disease (PAD), but few exercise programs in community settings have been effective. The aim of this study was to determine the efficacy of a community-based walking exercise program with training, monitoring, and coaching (TMC) components to improve exercise performance and patient-reported outcomes in PAD patients. This was a randomized, controlled trial including PAD patients who previously received peripheral endovascular therapy or presented with stable claudication. Patients randomized (n=25) to the intervention group received a comprehensive community-based walking exercise program with elements of TMC over 14 weeks. Patients in the control group did not receive treatment beyond standard advice to walk. The primary outcome in the intent-to-treat (ITT) analyses was peak walking time (PWT) on a graded treadmill. Secondary outcomes included claudication onset time (COT) and patient-reported outcomes assessed via the Walking Impairment Questionnaire (WIQ). Intervention group patients (n=10) did not significantly improve PWT when compared with the control group patients (n=10) (mean±standard error: +2.1±0.7 vs. 0.0±0.7 min, p=0.052). Changes in COT and WIQ scores were greater for intervention patients compared with control patients (COT: +1.6±0.8 vs. −0.6±0.7 min, p=0.045; WIQ: +18.3±4.2 vs. −4.6±4.2%, p=0.001). This pilot using a walking program with TMC and an ITT analyses did not improve the primary outcome in PAD patients. Other walking performance and patient self-reported outcomes were improved following exercise in community settings. Further study is needed to determine whether this intervention improves outcomes in a trial employing a larger sample size. PMID:25755148

Let's Walk Outdoors! Self-Paced Walking Outdoors Improves Future Intention to Exercise in Women With Obesity.

PubMed

Krinski, Kleverton; Machado, Daniel G S; Lirani, Luciana S; DaSilva, Sergio G; Costa, Eduardo C; Hardcastle, Sarah J; Elsangedy, Hassan M

2017-04-01

In order to examine whether environmental settings influence psychological and physiological responses of women with obesity during self-paced walking, 38 women performed two exercise sessions (treadmill and outdoors) for 30 min, where oxygen uptake, heart rate, ratings of perceived exertion, affect, attentional focus, enjoyment, and future intentions to walk were analyzed. Physiological responses were similar during both sessions. However, during outdoor exercise, participants displayed higher externally focused attention, positive affect, and lower ratings of perceived exertion, followed by greater enjoyment and future intention to participate in outdoor walking. The more externally focused attention predicted greater future intentions to participate in walking. Therefore, women with obesity self-selected an appropriate exercise intensity to improve fitness and health in both environmental settings. Also, self-paced outdoor walking presented improved psychological responses. Health care professionals should consider promoting outdoor forms of exercise to maximize psychological benefits and promote long-term adherence to a physically active lifestyle.

Identifying Stride-To-Stride Control Strategies in Human Treadmill Walking

PubMed Central

Dingwell, Jonathan B.; Cusumano, Joseph P.

2015-01-01

Variability is ubiquitous in human movement, arising from internal and external noise, inherent biological redundancy, and from the neurophysiological control actions that help regulate movement fluctuations. Increased walking variability can lead to increased energetic cost and/or increased fall risk. Conversely, biological noise may be beneficial, even necessary, to enhance motor performance. Indeed, encouraging more variability actually facilitates greater improvements in some forms of locomotor rehabilitation. Thus, it is critical to identify the fundamental principles humans use to regulate stride-to-stride fluctuations in walking. This study sought to determine how humans regulate stride-to-stride fluctuations in stepping movements during treadmill walking. We developed computational models based on pre-defined goal functions to compare if subjects, from each stride to the next, tried to maintain the same speed as the treadmill, or instead stay in the same position on the treadmill. Both strategies predicted average behaviors empirically indistinguishable from each other and from that of humans. These strategies, however, predicted very different stride-to-stride fluctuation dynamics. Comparisons to experimental data showed that human stepping movements were generally well-predicted by the speed-control model, but not by the position-control model. Human subjects also exhibited no indications they corrected deviations in absolute position only intermittently: i.e., closer to the boundaries of the treadmill. Thus, humans clearly do not adopt a control strategy whose primary goal is to maintain some constant absolute position on the treadmill. Instead, humans appear to regulate their stepping movements in a way most consistent with a strategy whose primary goal is to try to maintain the same speed as the treadmill at each consecutive stride. These findings have important implications both for understanding how biological systems regulate walking in general and for being able to harness these mechanisms to develop more effective rehabilitation interventions to improve locomotor performance. PMID:25910253

A randomised control trial of walking to ameliorate brain injury fatigue: a NIDRR TBI model system centre-based study.

PubMed

Kolakowsky-Hayner, Stephanie A; Bellon, Kimberly; Toda, Ketra; Bushnik, Tamara; Wright, Jerry; Isaac, Linda; Englander, Jeffrey

2017-10-01

Fatigue is one of the most commonly reported sequelae after traumatic brain injury (TBI). This study evaluated the impact of a graduated physical activity programme on fatigue after TBI. Using a prospective randomised single-blind crossover design, 123 individuals with TBI, over the age of 18, were enrolled. Interventions included a home-based walking programme utilising a pedometer to track daily number of steps at increasing increments accompanied by tapered coaching calls over a 12-week period. Nutritional counselling with the same schedule of coaching calls served as the control condition. Main outcome measures included: the Global Fatigue Index (GFI), the Barrow Neurological Institute (BNI) Fatigue Scale Overall Severity Index Score, and the Multidimensional Fatigue Inventory (MFI). Step counts improved over time regardless of group assignment. The walking intervention led to a decrease in GFI, BNI Total, and MFI General scores. Participants reported less fatigue at the end of the active part of the intervention (24 weeks) and after a wash out period (36 weeks) as measured by the BNI Overall. The study suggests that walking can be used as an efficient and cost-effective tool to improve fatigue in persons who have sustained a TBI.

Effects of Acupuncture on Gait of Patients with Multiple Sclerosis.

PubMed

Criado, Maria Begoña; Santos, Maria João; Machado, Jorge; Gonçalves, Arminda Manuela; Greten, Henry Johannes

2017-11-01

Multiple sclerosis is considered a complex and heterogeneous disease. Approximately 85% of patients with multiple sclerosis indicate impaired gait as one of the major limitations in their daily life. Acupuncture studies found a reduction of spasticity and improvement of fatigue and imbalance in patients with multiple sclerosis, but there is a lack of studies regarding gait. We designed a study of acupuncture treatment, according to the Heidelberg model of Traditional Chinese Medicine (TCM), to investigate if acupuncture can be a useful therapeutic strategy in patients with gait impairment in multiple sclerosis of relapsing-remitting type. The sample consisted of 20 individuals with diagnosis of multiple sclerosis of relapsing-remitting type. Gait impairment was evaluated by the 25-foot walk test. The results showed differences in time to walk 25 feet following true acupuncture. In contrast, there was no difference in time to walk 25 feet following sham acupuncture. When using true acupuncture, 95% of cases showed an improvement in 25-foot walk test, compared with 45% when sham acupuncture was done. Our study protocol provides evidence that acupuncture treatment can be an attractive option for patients with multiple sclerosis, with gait impairment.

Intra-Articular Knee Contact Force Estimation During Walking Using Force-Reaction Elements and Subject-Specific Joint Model.

PubMed

Jung, Yihwan; Phan, Cong-Bo; Koo, Seungbum

2016-02-01

Joint contact forces measured with instrumented knee implants have not only revealed general patterns of joint loading but also showed individual variations that could be due to differences in anatomy and joint kinematics. Musculoskeletal human models for dynamic simulation have been utilized to understand body kinetics including joint moments, muscle tension, and knee contact forces. The objectives of this study were to develop a knee contact model which can predict knee contact forces using an inverse dynamics-based optimization solver and to investigate the effect of joint constraints on knee contact force prediction. A knee contact model was developed to include 32 reaction force elements on the surface of a tibial insert of a total knee replacement (TKR), which was embedded in a full-body musculoskeletal model. Various external measurements including motion data and external force data during walking trials of a subject with an instrumented knee implant were provided from the Sixth Grand Challenge Competition to Predict in vivo Knee Loads. Knee contact forces in the medial and lateral portions of the instrumented knee implant were also provided for the same walking trials. A knee contact model with a hinge joint and normal alignment could predict knee contact forces with root mean square errors (RMSEs) of 165 N and 288 N for the medial and lateral portions of the knee, respectively, and coefficients of determination (R2) of 0.70 and -0.63. When the degrees-of-freedom (DOF) of the knee and locations of leg markers were adjusted to account for the valgus lower-limb alignment of the subject, RMSE values improved to 144 N and 179 N, and R2 values improved to 0.77 and 0.37, respectively. The proposed knee contact model with subject-specific joint model could predict in vivo knee contact forces with reasonable accuracy. This model may contribute to the development and improvement of knee arthroplasty.

Effect of uphill and downhill walking on walking performance in geriatric patients using a wheeled walker.

PubMed

Lindemann, Ulrich; Schwenk, Michael; Schmitt, Syn; Weyrich, Michael; Schlicht, Wolfgang; Becker, Clemens

2017-08-01

Wheeled walkers are recommended to improve walking performance in older persons and to encourage and assist participation in daily life. Nevertheless, using a wheeled walker can cause serious problems in the natural environment. This study aimed to compare uphill and downhill walking with walking level in geriatric patients using a wheeled walker. Furthermore, we investigated the effect of using a wheeled walker with respect to dual tasking when walking level. A total of 20 geriatric patients (median age 84.5 years) walked 10 m at their habitual pace along a level surface, uphill and downhill, with and without a standard wheeled walker. Gait speed, stride length and cadence were assessed by wearable sensors and the walk ratio was calculated. When using a wheeled walker while walking level the walk ratio improved (0.58 m/[steps/min] versus 0.57 m/[steps/min], p = 0.023) but gait speed decreased (1.07 m/s versus 1.12 m/s, p = 0.020) when compared to not using a wheeled walker. With respect to the walk ratio, uphill and downhill walking with a wheeled walker decreased walking performance when compared to level walking (0.54 m/[steps/min] versus 0.58 m/[steps/min], p = 0.023 and 0.55 m/[steps/min] versus 0.58 m/[steps/min], p = 0.001, respectively). At the same time, gait speed decreased (0.079 m/s versus 1.07 m/s, p < 0.0001) or was unaffected. The use of a wheeled walker improved the quality of level walking but the performance of uphill and downhill walking was worse compared to walking level when using a wheeled walker.

Over ground walking and body weight supported walking improve mobility equally in cerebral palsy: a randomised controlled trial.

PubMed

Swe, Ni Ni; Sendhilnnathan, Sunitha; van Den Berg, Maayken; Barr, Christopher

2015-11-01

To assess partial body weight supported treadmill training versus over ground training for walking ability in children with mild to moderate cerebral palsy. Randomised controlled trial. A Special Needs school in Singapore. Thirty children with cerebral palsy, aged 6-18, with a Gross Motor Function Classification System score of II-III. Two times 30 minute sessions of walking training per week for 8 weeks, progressed as tolerated, either over ground (control) or using partial body weight supported treadmill training (intervention). The 10 metre walk test, and the 6 minute walk test. Secondary measures were sub-sections D and E on the Gross Motor Function Measure. Outcomes were assessed at baseline, and after 4 and 8 weeks of training. There was no effect of group allocation on any outcome measure, while time was a significant factor for all outcomes. Walking speed improved significantly more in the intervention group by week 4 (0.109 (0.067)m/s vs 0.048 (0.071)m/s, P=0.024) however by week 8 the change from baseline was similar (intervention 0.0160 (0.069)m/s vs control 0.173 (0.109)m/s, P=0.697). All gains made by week 4 were significantly improved on by week 8 for the 10 metre walk test, 6 minute walk test, and the gross motor function measure. Partial body weight supported treadmill training is no more effective than over ground walking at improving aspects of walking and function in children with mild to moderate cerebral palsy. Gains seen in 4 weeks can be furthered by 8 weeks. © The Author(s) 2015.

Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces.

PubMed

Gerus, Pauline; Sartori, Massimo; Besier, Thor F; Fregly, Benjamin J; Delp, Scott L; Banks, Scott A; Pandy, Marcus G; D'Lima, Darryl D; Lloyd, David G

2013-11-15

Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. © 2013 Published by Elsevier Ltd.

Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

PubMed Central

Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

2013-01-01

Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

Identification of pre-impact conditions of a cyclist involved in a vehicle-bicycle accident using an optimized MADYMO reconstruction combined with motion capture.

PubMed

Sun, Jie; Li, Zhengdong; Pan, Shaoyou; Feng, Hao; Shao, Yu; Liu, Ningguo; Huang, Ping; Zou, Donghua; Chen, Yijiu

2018-05-01

The aim of the present study was to develop an improved method, using MADYMO multi-body simulation software combined with an optimization method and three-dimensional (3D) motion capture, for identifying the pre-impact conditions of a cyclist (walking or cycling) involved in a vehicle-bicycle accident. First, a 3D motion capture system was used to analyze coupled motions of a volunteer while walking and cycling. The motion capture results were used to define the posture of the human model during walking and cycling simulations. Then, cyclist, bicycle and vehicle models were developed. Pre-impact parameters of the models were treated as unknown design variables. Finally, a multi-objective genetic algorithm, the nondominated sorting genetic algorithm II, was used to find optimal solutions. The objective functions of the walk parameter were significantly lower than cycle parameter; thus, the cyclist was more likely to have been walking with the bicycle than riding the bicycle. In the most closely matched result found, all observed contact points matched and the injury parameters correlated well with the real injuries sustained by the cyclist. Based on the real accident reconstruction, the present study indicates that MADYMO multi-body simulation software, combined with an optimization method and 3D motion capture, can be used to identify the pre-impact conditions of a cyclist involved in a vehicle-bicycle accident. Copyright © 2018. Published by Elsevier Ltd.

Determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis undergoing lung transplant evaluation.

PubMed

Porteous, Mary K; Rivera-Lebron, Belinda N; Kreider, Maryl; Lee, James; Kawut, Steven M

2016-03-01

Little is known about the physiologic determinants of 6-minute walk distance in idiopathic pulmonary fibrosis. We investigated the demographic, pulmonary function, echocardiographic, and hemodynamic determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis evaluated for lung transplantation. We performed a cross-sectional analysis of 130 patients with idiopathic pulmonary fibrosis who completed a lung transplantation evaluation at the Hospital of the University of Pennsylvania between 2005 and 2010. Multivariable linear regression analysis was used to generate an explanatory model for 6-minute walk distance. After adjustment for age, sex, race, height, and weight, the presence of right ventricular dilation was associated with a decrease of 50.9 m (95% confidence interval [CI], 8.4-93.3) in 6-minute walk distance ([Formula: see text]). For each 200-mL reduction in forced vital capacity, the walk distance decreased by 15.0 m (95% CI, 9.0-21.1; [Formula: see text]). For every increase of 1 Wood unit in pulmonary vascular resistance, the walk distance decreased by 17.3 m (95% CI, 5.1-29.5; [Formula: see text]). Six-minute walk distance in idiopathic pulmonary fibrosis depends in part on circulatory impairment and the degree of restrictive lung disease. Future trials that target right ventricular morphology, pulmonary vascular resistance, and forced vital capacity may potentially improve exercise capacity in patients with idiopathic pulmonary fibrosis.

Virtual Reality Training with Cognitive Load Improves Walking Function in Chronic Stroke Patients.

PubMed

Cho, Ki Hun; Kim, Min Kyu; Lee, Hwang-Jae; Lee, Wan Hee

2015-08-01

Virtual reality training is considered as an effective intervention method of stroke patients, and the virtual reality system for therapeutic rehabilitation has emphasized the cognitive factors to improve walking function. The purpose of current study was to investigate the effect of virtual reality training with cognitive load (VRTCL) on walking function of chronic stroke. Chronic stroke patients were randomly assigned to the VRTCL group (11 patients, including 5 men; mean age, 60.0 years; post-stroke duration, 273.9 days) or control group (11 patients, including 2 men; mean age, 58.6 years; post-stroke duration, 263.9 days). All subjects participated in the standard rehabilitation program that consisted of physical and occupational therapies. In addition, VRTCL group participated in the VRTCL for 4 weeks (30 min per day and five times a week), while those in the control group participated in virtual reality treadmill training. Walking function under single (walking alone) and dual task (walking with cognitive tasks) conditions was assessed using an electrical walkway system. After the 4-week intervention, under both single and dual task conditions, significant improvement on walking function was observed in VRTCL and control groups (P < 0.05). In addition, in the dual task condition, greater improvement on walking function was observed in the VRTCL group, compared with the control group (P < 0.05). These findings demonstrated the efficacy of VRTCL on the walking function under the dual task condition. Therefore, we suggest that VRTCL may be an effective method for the achievement of independent walking in chronic stroke patients.

Nordic Walking Practice Might Improve Plantar Pressure Distribution

ERIC Educational Resources Information Center

Perez-Soriano, Pedro; Llana-Belloch, Salvador; Martinez-Nova, Alfonso; Morey-Klapsing, G.; Encarnacion-Martinez, Alberto

2011-01-01

Nordic walking (NW), characterized by the use of two walking poles, is becoming increasingly popular (Morgulec-Adamowicz, Marszalek, & Jagustyn, 2011). We studied walking pressure patterns of 20 experienced and 30 beginner Nordic walkers. Plantar pressures from nine foot zones were measured during trials performed at two walking speeds (preferred…

Cost-effectiveness of investing in sidewalks as a means of increasing physical activity: a RESIDE modelling study

PubMed Central

Veerman, J Lennert; Zapata-Diomedi, Belen; Gunn, Lucy; McCormack, Gavin R; Cobiac, Linda J; Mantilla Herrera, Ana Maria; Giles-Corti, Billie; Shiell, Alan

2016-01-01

Background Studies consistently find that supportive neighbourhood built environments increase physical activity by encouraging walking and cycling. However, evidence on the cost-effectiveness of investing in built environment interventions as a means of promoting physical activity is lacking. In this study, we assess the cost-effectiveness of increasing sidewalk availability as one means of encouraging walking. Methods Using data from the RESIDE study in Perth, Australia, we modelled the cost impact and change in health-adjusted life years (HALYs) of installing additional sidewalks in established neighbourhoods. Estimates of the relationship between sidewalk availability and walking were taken from a previous study. Multistate life table models were used to estimate HALYs associated with changes in walking frequency and duration. Sensitivity analyses were used to explore the impact of variations in population density, discount rates, sidewalk costs and the inclusion of unrelated healthcare costs in added life years. Results Installing and maintaining an additional 10 km of sidewalk in an average neighbourhood with 19 000 adult residents was estimated to cost A$4.2 million over 30 years and gain 24 HALYs over the lifetime of an average neighbourhood adult resident population. The incremental cost-effectiveness ratio was A$176 000/HALY. However, sensitivity results indicated that increasing population densities improves cost-effectiveness. Conclusions In low-density cities such as in Australia, installing sidewalks in established neighbourhoods as a single intervention is unlikely to cost-effectively improve health. Sidewalks must be considered alongside other complementary elements of walkability, such as density, land use mix and street connectivity. Population density is particularly important because at higher densities, more residents are exposed and this improves the cost-effectiveness. Health gain is one of many benefits of enhancing neighbourhood walkability and future studies might consider a more comprehensive assessment of its social value (eg, social cohesion, safety and air quality). PMID:27650762

Seeing the Errors You Feel Enhances Locomotor Performance but Not Learning.

PubMed

Roemmich, Ryan T; Long, Andrew W; Bastian, Amy J

2016-10-24

In human motor learning, it is thought that the more information we have about our errors, the faster we learn. Here, we show that additional error information can lead to improved motor performance without any concomitant improvement in learning. We studied split-belt treadmill walking that drives people to learn a new gait pattern using sensory prediction errors detected by proprioceptive feedback. When we also provided visual error feedback, participants acquired the new walking pattern far more rapidly and showed accelerated restoration of the normal walking pattern during washout. However, when the visual error feedback was removed during either learning or washout, errors reappeared with performance immediately returning to the level expected based on proprioceptive learning alone. These findings support a model with two mechanisms: a dual-rate adaptation process that learns invariantly from sensory prediction error detected by proprioception and a visual-feedback-dependent process that monitors learning and corrects residual errors but shows no learning itself. We show that our voluntary correction model accurately predicted behavior in multiple situations where visual feedback was used to change acquisition of new walking patterns while the underlying learning was unaffected. The computational and behavioral framework proposed here suggests that parallel learning and error correction systems allow us to rapidly satisfy task demands without necessarily committing to learning, as the relative permanence of learning may be inappropriate or inefficient when facing environments that are liable to change. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simulating intrafraction prostate motion with a random walk model.

PubMed

Pommer, Tobias; Oh, Jung Hun; Munck Af Rosenschöld, Per; Deasy, Joseph O

2017-01-01

Prostate motion during radiation therapy (ie, intrafraction motion) can cause unwanted loss of radiation dose to the prostate and increased dose to the surrounding organs at risk. A compact but general statistical description of this motion could be useful for simulation of radiation therapy delivery or margin calculations. We investigated whether prostate motion could be modeled with a random walk model. Prostate motion recorded during 548 radiation therapy fractions in 17 patients was analyzed and used for input in a random walk prostate motion model. The recorded motion was categorized on the basis of whether any transient excursions (ie, rapid prostate motion in the anterior and superior direction followed by a return) occurred in the trace and transient motion. This was separately modeled as a large step in the anterior/superior direction followed by a returning large step. Random walk simulations were conducted with and without added artificial transient motion using either motion data from all observed traces or only traces without transient excursions as model input, respectively. A general estimate of motion was derived with reasonable agreement between simulated and observed traces, especially during the first 5 minutes of the excursion-free simulations. Simulated and observed diffusion coefficients agreed within 0.03, 0.2 and 0.3 mm 2 /min in the left/right, superior/inferior, and anterior/posterior directions, respectively. A rapid increase in variance at the start of observed traces was difficult to reproduce and seemed to represent the patient's need to adjust before treatment. This could be estimated somewhat using artificial transient motion. Random walk modeling is feasible and recreated the characteristics of the observed prostate motion. Introducing artificial transient motion did not improve the overall agreement, although the first 30 seconds of the traces were better reproduced. The model provides a simple estimate of prostate motion during delivery of radiation therapy.

Does walking improve disability status, function, or quality of life in adults with chronic low back pain? A systematic review.

PubMed

Lawford, Belinda J; Walters, Julie; Ferrar, Katia

2016-06-01

To establish the effectiveness of walking alone and walking compared to other non-pharmacological management methods to improve disability, quality of life, or function in adults with chronic low back pain. A systematic search of the following databases was undertaken: Medline, Embase, CINAHL, Scopus, Pedro, SportDiscus, Cochrane Central Register of Controlled Trials. The following keywords were used: 'back pain' or 'low back pain' or 'chronic low back pain' and 'walk*' or 'ambulation' or 'treadmill*' or 'pedometer*' or 'acceleromet*' or 'recreational' and 'disability' or 'quality of life' or 'function*'. Primary research studies with an intervention focus that investigated walking as the primary intervention compared to no intervention or any other non-pharmacological method in adults with chronic low back pain (duration >3 months). Seven randomised controlled trials involving 869 participants were included in the review. There was no evidence that walking was more effective than other management methods such as usual care, specific strength exercises, medical exercise therapy, or supervised exercise classes. One study found over-ground walking to be superior to treadmill walking, and another found internet-mediated walking to be more beneficial than non-internet-mediated walking in the short term. There is low quality evidence to suggest that walking is as effective as other non-pharmacological management methods at improving disability, function, and quality of life in adults with chronic low back pain. © The Author(s) 2015.

The physiological cost index of walking with a powered knee-ankle-foot orthosis in subjects with poliomyelitis: A pilot study.

PubMed

Arazpour, Mokhtar; Ahmadi Bani, Monireh; Samadian, Mohammad; Mousavi, Mohammad E; Hutchins, Stephen W; Bahramizadeh, Mahmood; Curran, Sarah; Mardani, Mohammad A

2016-08-01

A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee-ankle-foot orthosis with drop lock knee joints. Quasi experimental study. Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee-ankle-foot orthosis. Walking with the powered knee-ankle-foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee-ankle-foot orthosis. Using a powered knee-ankle-foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. This powered knee-ankle-foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee-ankle-foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted. © The International Society for Prosthetics and Orthotics 2015.

HAL® exoskeleton training improves walking parameters and normalizes cortical excitability in primary somatosensory cortex in spinal cord injury patients.

PubMed

Sczesny-Kaiser, Matthias; Höffken, Oliver; Aach, Mirko; Cruciger, Oliver; Grasmücke, Dennis; Meindl, Renate; Schildhauer, Thomas A; Schwenkreis, Peter; Tegenthoff, Martin

2015-08-20

Reorganization in the sensorimotor cortex accompanied by increased excitability and enlarged body representations is a consequence of spinal cord injury (SCI). Robotic-assisted bodyweight supported treadmill training (BWSTT) was hypothesized to induce reorganization and improve walking function. To assess whether BWSTT with hybrid assistive limb® (HAL®) exoskeleton affects cortical excitability in the primary somatosensory cortex (S1) in SCI patients, as measured by paired-pulse somatosensory evoked potentials (ppSEP) stimulated above the level of injury. Eleven SCI patients took part in HAL® assisted BWSTT for 3 months. PpSEP were conducted before and after this training period, where the amplitude ratios (SEP amplitude following double pulses - SEP amplitude following single pulses) were assessed and compared to eleven healthy control subjects. To assess improvement in walking function, we used the 10-m walk test, timed-up-and-go test, the 6-min walk test, and the lower extremity motor score. PpSEPs were significantly increased in SCI patients as compared to controls at baseline. Following training, ppSEPs were increased from baseline and no longer significantly differed from controls. Walking parameters also showed significant improvements, yet there was no significant correlation between ppSEP measures and walking parameters. The findings suggest that robotic-assisted BWSTT with HAL® in SCI patients is capable of inducing cortical plasticity following highly repetitive, active locomotive use of paretic legs. While there was no significant correlation of excitability with walking parameters, brain areas other than S1 might reflect improvement of walking functions. EEG and neuroimaging studies may provide further information about supraspinal plastic processes and foci in SCI rehabilitation.

Active Travel Behavior in a Border Region of Texas and New Mexico: Motivators, Deterrents, and Characteristics.

PubMed

Sener, Ipek N; Lee, Richard J

2017-08-01

Active travel has been linked with improved transportation and health outcomes, such as reduced traffic congestion and air pollution, improved mobility, accessibility, and equity, and increased physical and mental health. The purpose of this study was to better understand active travel characteristics, motivators, and deterrents in the El Paso, TX, region. A multimodal transportation survey brought together elements of transportation and health, with a focus on attitudinal characteristics. The analysis consisted of an initial descriptive analysis, spatial analysis, and multivariate binary and ordered-response models of walking and bicycling behavior. The motivators and deterrents of active travel differed for walkers, bicyclists, and noncyclists interested in bicycling. The link between active travel and life satisfaction was moderated by age, with a negative association for older travelers. This effect was stronger for bicycling than it was for walking. Based on the findings, several interventions to encourage walking and bicycling were suggested. These included infrastructure and built environment enhancements, workplace programs, and interventions targeting specific subpopulations.

Does walking speed mediate the association between visual impairment and self-report of mobility disability? The Salisbury Eye Evaluation Study.

PubMed

Swenor, Bonnielin K; Bandeen-Roche, Karen; Muñoz, Beatriz; West, Sheila K

2014-08-01

To determine whether performance speeds mediate the association between visual impairment and self-reported mobility disability over an 8-year period. Longitudinal analysis. Salisbury, Maryland. Salisbury Eye Evaluation Study participants aged 65 and older (N=2,520). Visual impairment was defined as best-corrected visual acuity worse than 20/40 in the better-seeing eye or visual field less than 20°. Self-reported mobility disability on three tasks was assessed: walking up stairs, walking down stairs, and walking 150 feet. Performance speed on three similar tasks was measured: walking up steps (steps/s), walking down steps (steps/s), and walking 4 m (m/s). For each year of observation, the odds of reporting mobility disability was significantly greater for participants who were visually impaired (VI) than for those who were not (NVI) (odds ratio (OR) difficulty walking up steps=1.58, 95% confidence interval (CI)=1.32-1.89; OR difficulty walking down steps=1.90, 95% CI=1.59-2.28; OR difficulty walking 150 feet=2.11, 95% CI=1.77-2.51). Once performance speed on a similar mobility task was included in the models, VI participants were no longer more likely to report mobility disability than those who were NVI (OR difficulty walking up steps=0.84, 95% CI=0.65-1.11; OR difficulty walking down steps=0.96, 95% CI=0.74-1.24; OR difficulty walking 150 feet=1.22, 95% CI=0.98-1.50). Slower performance speed in VI individuals largely accounted for the difference in the odds of reporting mobility disability, suggesting that VI older adults walk slower and are therefore more likely to report mobility disability than those who are NVI. Improving mobility performance in older adults with visual impairment may minimize the perception of mobility disability. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING.

PubMed

Highsmith, M Jason; Klenow, Tyler D; Kahle, Jason T; Wernke, Matthew M; Carey, Stephanie L; Miro, Rebecca M; Lura, Derek J

2016-09-01

Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs ( n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds.

Mechanical work and energy consumption in children with cerebral palsy after single-event multilevel surgery.

PubMed

Marconi, Valeria; Hachez, Hélèn; Renders, Anne; Docquier, Pierre-Louis; Detrembleur, Chrisitine

2014-09-01

Multilevel surgery is commonly performed to improve walking in children with cerebral palsy (CP). Classical gait analysis (kinetics, kinematics) demonstrated positive outcomes after this intervention, however it doesn't give global indication about gait's features. The assessment of energy cost and mechanical work of locomotion can provide an overall description of walking functionality. Therefore, we propose to describe the effects of multilevel surgery in children with CP, considering energetics, mechanical work, kinetic and kinematic of walking. We measured external, internal, total work, energy cost, recovery, efficiency, kinetic and kinematic of walking in 10 children with CP (4 girls, 6 boys; 13 years ± 2) before and 1 year after multilevel surgery. Kinetic and kinematic results are partially comparable to previous findings, energy cost of walking is significantly reduced (p < 0.05); external, internal, total work, recovery, efficiency are not significantly different (p = 0.129; p = 0.147; p = 0.795; p = 0.119; p = 0.21). The improvement of the walking's energy consumption is not accompanied by a corresponding improvement of mechanical work. Therefore it is conceivable that the improvement of walking economy depend on a reduced effort of the muscle to maintain the posture, rather then to an improvement of the mechanism of energy recovery typical of human locomotion. Copyright © 2014 Elsevier B.V. All rights reserved.

Learning to Walk, Walking to Learn: Reconsidering the Walkthrough as an Improvement Strategy

ERIC Educational Resources Information Center

Lemons, Richard W.; Helsing, Deborah

2009-01-01

School leaders desperate for strategies that will improve student learning have often opted to embrace strategies that they have observed being used successfully in other districts. Sometimes, this works; sometimes, it does not. This article presents two vignettes about districts that made similar decisions to implement learning walks. The…

A randomized trial of functional electrical stimulation for walking in incomplete spinal cord injury: Effects on walking competency

PubMed Central

Kapadia, Naaz; Masani, Kei; Catharine Craven, B.; Giangregorio, Lora M.; Hitzig, Sander L.; Richards, Kieva; Popovic, Milos R.

2014-01-01

Background Multi-channel surface functional electrical stimulation (FES) for walking has been used to improve voluntary walking and balance in individuals with spinal cord injury (SCI). Objective To investigate short- and long-term benefits of 16 weeks of thrice-weekly FES-assisted walking program, while ambulating on a body weight support treadmill and harness system, versus a non-FES exercise program, on improvements in gait and balance in individuals with chronic incomplete traumatic SCI, in a randomized controlled trial design. Methods Individuals with traumatic and chronic (≥18 months) motor incomplete SCI (level C2 to T12, American Spinal Cord Injury Association Impairment Scale C or D) were recruited from an outpatient SCI rehabilitation hospital, and randomized to FES-assisted walking therapy (intervention group) or aerobic and resistance training program (control group). Outcomes were assessed at baseline, and after 4, 6, and 12 months. Gait, balance, spasticity, and functional measures were collected. Results Spinal cord independence measure (SCIM) mobility sub-score improved over time in the intervention group compared with the control group (baseline/12 months: 17.27/21.33 vs. 19.09/17.36, respectively). On all other outcome measures the intervention and control groups had similar improvements. Irrespective of group allocation walking speed, endurance, and balance during ambulation all improved upon completion of therapy, and majority of participants retained these gains at long-term follow-ups. Conclusions Task-oriented training improves walking ability in individuals with incomplete SCI, even in the chronic stage. Further randomized controlled trials, involving a large number of participants are needed, to verify if FES-assisted treadmill training is superior to aerobic and strength training. PMID:25229735

A systematic review: efficacy of botulinum toxin in walking and quality of life in post-stroke lower limb spasticity.

PubMed

Gupta, Anupam Datta; Chu, Wing Hong; Howell, Stuart; Chakraborty, Subhojit; Koblar, Simon; Visvanathan, Renuka; Cameron, Ian; Wilson, David

2018-01-05

Improved walking is one of the highest priorities in people living with stroke. Post-stroke lower limb spasticity (PSLLS) impedes walking and quality of life (QOL). The understanding of the evidence of improved walking and QOL following botulinum toxin (BoNTA) injection is not clear. We performed a systematic review of the randomized control trials (RCT) to evaluate the effectiveness of BoNTA injection on walking and QOL in PSLLS. We searched PubMed, Web of Science, Embase, CINAHL, ProQuest Thesis and Dissertation checks, Google Scholar, WHO International Clinical Trial Registry Platform, ClinicalTrials.gov , Cochrane, and ANZ and EU Clinical Trials Register for RCTs looking at improvement in walking and QOL following injection of BoNTA in PSLLS. The original search was carried out prior to 16 September 2015. We conducted an additional verifying search on CINHAL, EMBASE, and MEDLINE (via PubMed) from 16 September 2015 to 6 June 2017 using the same clauses as the previous search. Methodological quality of the individual studies was critically appraised using Joanna Briggs Institute's instrument. Only placebo-controlled RCTs looking at improvement in walking and QOL were included in the review. Of 2026 records, we found 107 full-text records. Amongst them, we found five RCTs qualifying our criteria. No new trials were found from the verifying search. Two independent reviewers assessed methodological validity prior to inclusion in the review using Joanna Briggs Institute's appraisal instrument. Two studies reported significant improvement in gait velocity (p = 0.020) and < 0.05, respectively. One study showed significant improvement in 2-min-walking distance (p < 0.05). QOL was recorded in one study without any significant improvement. Meta-analysis of reviewed studies could not be performed because of different methods of assessing walking ability, small sample size with large confidence interval and issues such as lack of power calculations in some studies. Findings from our systematic and detailed study identify the need for a well-designed RCT to adequately investigate the issues highlighted. This review could not conclude there was sufficient evidence to support or refute improvement on walking or QOL following BoNTA injection. Reasons for this are discussed, and methods for future RCTs are developed.

The efficacy of functional gait training in children and young adults with cerebral palsy: a systematic review and meta-analysis.

PubMed

Booth, Adam T C; Buizer, Annemieke I; Meyns, Pieter; Oude Lansink, Irene L B; Steenbrink, Frans; van der Krogt, Marjolein M

2018-03-07

The aim of this systematic review was to investigate the effects of functional gait training on walking ability in children and young adults with cerebral palsy (CP). The review was conducted using standardized methodology, searching four electronic databases (PubMed, Embase, CINAHL, Web of Science) for relevant literature published between January 1980 and January 2017. Included studies involved training with a focus on actively practising the task of walking as an intervention while reporting outcome measures relating to walking ability. Forty-one studies were identified, with 11 randomized controlled trials included. There is strong evidence that functional gait training results in clinically important benefits for children and young adults with CP, with a therapeutic goal of improved walking speed. Functional gait training was found to have a moderate positive effect on walking speed over standard physical therapy (effect size 0.79, p=0.04). Further, there is weaker yet relatively consistent evidence that functional gait training can also benefit walking endurance and gait-related gross motor function. There is promising evidence that functional gait training is a safe, feasible, and effective intervention to target improved walking ability in children and young adults with CP. The addition of virtual reality and biofeedback can increase patient engagement and magnify effects. Functional gait training is a safe, feasible, and effective intervention to improve walking ability. Functional gait training shows larger positive effects on walking speed than standard physical therapy. Walking endurance and gait-related gross motor function can also benefit from functional gait training. Addition of virtual reality and biofeedback shows promise to increase engagement and improve outcomes. © 2018 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.

Robustness of the non-Markovian Alzheimer walk under stochastic perturbation

NASA Astrophysics Data System (ADS)

Cressoni, J. C.; da Silva, L. R.; Viswanathan, G. M.; da Silva, M. A. A.

2012-12-01

The elephant walk model originally proposed by Schütz and Trimper to investigate non-Markovian processes led to the investigation of a series of other random-walk models. Of these, the best known is the Alzheimer walk model, because it was the first model shown to have amnestically induced persistence —i.e. superdiffusion caused by loss of memory. Here we study the robustness of the Alzheimer walk by adding a memoryless stochastic perturbation. Surprisingly, the solution of the perturbed model can be formally reduced to the solutions of the unperturbed model. Specifically, we give an exact solution of the perturbed model by finding a surjective mapping to the unperturbed model.

Impact of a Pilot Videogame-Based Physical Activity Program on Walking Speed in Adults with Schizophrenia.

PubMed

Leutwyler, H; Hubbard, E; Cooper, B A; Dowling, G

2017-11-10

The purpose of this report is to describe the impact of a videogame-based physical activity program using the Kinect for Xbox 360 game system (Microsoft, Redmond, WA) on walking speed in adults with schizophrenia. In this randomized controlled trial, 28 participants played either an active videogame for 30 min (intervention group) or played a sedentary videogame for 30 min (control group), once a week for 6 weeks. Walking speed was measured objectively with the Short Physical Performance Battery at enrollment and at the end of the 6-week program. The intervention group (n = 13) showed an average improvement in walking speed of 0.08 m/s and the control group (n = 15) showed an average improvement in walking speed of 0.03 m/s. Although the change in walking speed was not statistically significant, the intervention group had between a small and substantial clinically meaningful change. The results suggest a videogame based physical activity program provides clinically meaningful improvement in walking speed, an important indicator of health status.

Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial.

PubMed

Hollands, Kristen L; Pelton, Trudy A; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M; Wing, Alan M; Tyson, Sarah F; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M

2015-01-01

Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services. Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments. Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Clinicaltrials.gov NCT01600391.

Essential energy space random walk via energy space metadynamics method to accelerate molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Li, Hongzhi; Min, Donghong; Liu, Yusong; Yang, Wei

2007-09-01

To overcome the possible pseudoergodicity problem, molecular dynamic simulation can be accelerated via the realization of an energy space random walk. To achieve this, a biased free energy function (BFEF) needs to be priori obtained. Although the quality of BFEF is essential for sampling efficiency, its generation is usually tedious and nontrivial. In this work, we present an energy space metadynamics algorithm to efficiently and robustly obtain BFEFs. Moreover, in order to deal with the associated diffusion sampling problem caused by the random walk in the total energy space, the idea in the original umbrella sampling method is generalized to be the random walk in the essential energy space, which only includes the energy terms determining the conformation of a region of interest. This essential energy space generalization allows the realization of efficient localized enhanced sampling and also offers the possibility of further sampling efficiency improvement when high frequency energy terms irrelevant to the target events are free of activation. The energy space metadynamics method and its generalization in the essential energy space for the molecular dynamics acceleration are demonstrated in the simulation of a pentanelike system, the blocked alanine dipeptide model, and the leucine model.

Modeling spatial segregation and travel cost influences on utilitarian walking: Towards policy intervention

PubMed Central

Yang, Yong; Auchincloss, Amy H.; Rodriguez, Daniel A.; Brown, Daniel G.; Riolo, Rick; Diez-Roux, Ana V.

2015-01-01

We develop an agent-based model of utilitarian walking and use the model to explore spatial and socioeconomic factors affecting adult utilitarian walking and how travel costs as well as various educational interventions aimed at changing attitudes can alter the prevalence of walking and income differentials in walking. The model is validated against US national data. We contrast realistic and extreme parameter values in our model and test effects of changing these parameters across various segregation and pricing scenarios while allowing for interactions between travel choice and place and for behavioral feedbacks. Results suggest that in addition to income differences in the perceived cost of time, the concentration of mixed land use (differential density of residences and businesses) are important determinants of income differences in walking (high income walk less), whereas safety from crime and income segregation on their own do not have large influences on income differences in walking. We also show the difficulty in altering walking behaviors for higher income groups who are insensitive to price and how adding to the cost of driving could increase the income differential in walking particularly in the context of segregation by income and land use. We show that strategies to decrease positive attitudes towards driving can interact synergistically with shifting cost structures to favor walking in increasing the percent of walking trips. Agent-based models, with their ability to capture dynamic processes and incorporate empirical data, are powerful tools to explore the influence on health behavior from multiple factors and test policy interventions. PMID:25733776

The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates.

PubMed

Seethapathi, Nidhi; Srinivasan, Manoj

2015-09-01

Humans do not generally walk at constant speed, except perhaps on a treadmill. Normal walking involves starting, stopping and changing speeds, in addition to roughly steady locomotion. Here, we measure the metabolic energy cost of walking when changing speed. Subjects (healthy adults) walked with oscillating speeds on a constant-speed treadmill, alternating between walking slower and faster than the treadmill belt, moving back and forth in the laboratory frame. The metabolic rate for oscillating-speed walking was significantly higher than that for constant-speed walking (6-20% cost increase for ±0.13-0.27 m s(-1) speed fluctuations). The metabolic rate increase was correlated with two models: a model based on kinetic energy fluctuations and an inverted pendulum walking model, optimized for oscillating-speed constraints. The cost of changing speeds may have behavioural implications: we predicted that the energy-optimal walking speed is lower for shorter distances. We measured preferred human walking speeds for different walking distances and found people preferred lower walking speeds for shorter distances as predicted. Further, analysing published daily walking-bout distributions, we estimate that the cost of changing speeds is 4-8% of daily walking energy budget. © 2015 The Author(s).

The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates

PubMed Central

Seethapathi, Nidhi; Srinivasan, Manoj

2015-01-01

Humans do not generally walk at constant speed, except perhaps on a treadmill. Normal walking involves starting, stopping and changing speeds, in addition to roughly steady locomotion. Here, we measure the metabolic energy cost of walking when changing speed. Subjects (healthy adults) walked with oscillating speeds on a constant-speed treadmill, alternating between walking slower and faster than the treadmill belt, moving back and forth in the laboratory frame. The metabolic rate for oscillating-speed walking was significantly higher than that for constant-speed walking (6–20% cost increase for ±0.13–0.27 m s−1 speed fluctuations). The metabolic rate increase was correlated with two models: a model based on kinetic energy fluctuations and an inverted pendulum walking model, optimized for oscillating-speed constraints. The cost of changing speeds may have behavioural implications: we predicted that the energy-optimal walking speed is lower for shorter distances. We measured preferred human walking speeds for different walking distances and found people preferred lower walking speeds for shorter distances as predicted. Further, analysing published daily walking-bout distributions, we estimate that the cost of changing speeds is 4–8% of daily walking energy budget. PMID:26382072

[Walking assist robot and its clinical application].

PubMed

Kakou, Hiroaki; Shitama, Hideo; Kimura, Yoshiko; Nakamoto, Yoko; Furuta, Nami; Honda, Kanae; Wada, Futoshi; Hachisuka, Kenji

2009-06-01

The walking assist robot was developed to improve gait disturbance in patients with severe disabilities. The robot had a trunk supporter, power generator and operating arms which held patient's lower extremities and simulated walking, a control unit, biofeedback system, and a treadmill. We applied the robot-aided gait training to three patients with severe gait disturbance induced by stroke, axonal Guillan-Barré syndrome or spinal cord injury, and the walking assist robot turned out to be effective in improving the gait disturbance.

Decreased energy cost and improved gait pattern using a new orthosis in persons with long-term stroke.

PubMed

Thijssen, Dick H; Paulus, Rebecca; van Uden, Caro J; Kooloos, Jan G; Hopman, Maria T

2007-02-01

To measure energy cost and gait analysis in persons with stroke with and without a newly developed orthosis. Immediate and long-term (3wk) intervention (before-after trial). University medical center. Volunteer sample of 27 persons with long-term (range, 0.6-19y) hemiparetic stroke. Three-week familiarization to the new walking aid. Energy cost (per distance walked), preferred walking speed (PWS), and step length. Energy cost was examined in all subjects while walking on a treadmill at 3 different velocities (PWS, PWS+30%, PWS-30%) during 3 different situations (without orthosis, with orthosis, after 3-wk orthosis familiarization). Spatiotemporal aspects of the gait pattern were examined using a 6-m instrumented walkway system. Using the orthosis immediately decreased energy cost in persons with stroke during walking at the PWS (P<.001) and significantly increased walking speed (P<.005) and step length (P<.001). After 3 weeks of familiarization to the orthosis, energy cost at the PWS and at PWS+30% showed further improvement in energy cost (P<.05). The newly developed orthosis immediately decreases energy cost and improves walking speed and step length in persons with long-term stroke. After only 3 weeks of orthosis familiarization, energy cost shows additional improvement.

Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis†

PubMed Central

Savin, Douglas N.; Morton, Susanne M.; Whitall, Jill

2013-01-01

Objectives Determine whether adaptation to a swing phase perturbation during gait transferred from treadmill to overground walking, the rate of overground deadaptation, and whether overground aftereffects improved step length asymmetry in persons with hemiparetic stroke and gait asymmetry. Methods Ten participants with stroke and hemiparesis and 10 controls walked overground on an instrumented gait mat, adapted gait to a swing phase perturbation on a treadmill, then walked overground on the gait mat again. Outcome measures, primary: overground step length symmetry, rates of treadmill step length symmetry adaptation and overground step length symmetry deadaptation; secondary: overground gait velocity, stride length, and stride cycle duration. Results Step length symmetry aftereffects generalized to overground walking and adapted at a similar rate on the treadmill in both groups. Aftereffects decayed at a slower rate overground in participants with stroke and temporarily improved overground step length asymmetry. Both groups’ overground gait velocity increased post adaptation due to increased stride length and decreased stride duration. Conclusions Stroke and hemiparesis do not impair generalization of step length symmetry changes from adapted treadmill to overground walking, but prolong overground aftereffects. Significance Motor adaptation during treadmill walking may be an effective treatment for improving overground gait asymmetries post-stroke. PMID:24286858

Exoskeleton Training May Improve Level of Physical Activity After Spinal Cord Injury: A Case Series.

PubMed

Gorgey, Ashraf S; Wade, Rodney; Sumrell, Ryan; Villadelgado, Lynette; Khalil, Refka E; Lavis, Timothy

2017-01-01

Objectives: To determine whether the use of a powered exoskeleton can improve parameters of physical activity as determined by walking time, stand up time, and number of steps in persons with spinal cord injury (SCI). Methods: Three men with complete (1 C5 AIS A and 2 T4 AIS A) and one man with incomplete (C5 AIS D) SCI participated in a clinical rehabilitation program. In the training program, the participants walked once weekly using a powered exoskeleton (Ekso) for approximately 1 hour over the course of 10 to 15 weeks. Walking time, stand up time, ratio of walking to stand up time, and number of steps were determined. Oxygen uptake (L/min), energy expenditure, and body composition were measured in one participant after training. Results: Over the course of 10 to 15 weeks, the maximum walking time increased from 12 to 57 minutes and the number of steps increased from 59 to 2,284 steps. At the end of the training, the 4 participants were able to exercise for 26 to 59 minutes. For one participant, oxygen uptake increased from 0.27 L/min during rest to 0.55 L/min during walking. Maximum walking speed was 0.24 m/s, and delta energy expenditure increased by 1.4 kcal/min during walking. Body composition showed a modest decrease in absolute fat mass in one participant. Conclusion: Exoskeleton training may improve parameters of physical activity after SCI by increasing the number of steps and walking time. Other benefits may include increasing energy expenditure and improving the profile of body composition.

Walking adaptability therapy after stroke: study protocol for a randomized controlled trial.

PubMed

Timmermans, Celine; Roerdink, Melvyn; van Ooijen, Marielle W; Meskers, Carel G; Janssen, Thomas W; Beek, Peter J

2016-08-26

Walking in everyday life requires the ability to adapt walking to the environment. This adaptability is often impaired after stroke, and this might contribute to the increased fall risk after stroke. To improve safe community ambulation, walking adaptability training might be beneficial after stroke. This study is designed to compare the effects of two interventions for improving walking speed and walking adaptability: treadmill-based C-Mill therapy (therapy with augmented reality) and the overground FALLS program (a conventional therapy program). We hypothesize that C-Mill therapy will result in better outcomes than the FALLS program, owing to its expected greater amount of walking practice. This is a single-center parallel group randomized controlled trial with pre-intervention, post-intervention, retention, and follow-up tests. Forty persons after stroke (≥3 months) with deficits in walking or balance will be included. Participants will be randomly allocated to either C-Mill therapy or the overground FALLS program for 5 weeks. Both interventions will incorporate practice of walking adaptability and will be matched in terms of frequency, duration, and therapist attention. Walking speed, as determined by the 10 Meter Walking Test, will be the primary outcome measure. Secondary outcome measures will pertain to walking adaptability (10 Meter Walking Test with context or cognitive dual-task and Interactive Walkway assessments). Furthermore, commonly used clinical measures to determine walking ability (Timed Up-and-Go test), walking independence (Functional Ambulation Category), balance (Berg Balance Scale), and balance confidence (Activities-specific Balance Confidence scale) will be used, as well as a complementary set of walking-related assessments. The amount of walking practice (the number of steps taken per session) will be registered using the treadmill's inbuilt step counter (C-Mill therapy) and video recordings (FALLS program). This process measure will be compared between the two interventions. This study will assess the effects of treadmill-based C-Mill therapy compared with the overground FALLS program and thereby the relative importance of the amount of walking practice as a key aspect of effective intervention programs directed at improving walking speed and walking adaptability after stroke. Netherlands Trial Register NTR4030 . Registered on 11 June 2013, amendment filed on 17 June 2016.

Comparison of the Effect of Lateral and Backward Walking Training on Walking Function in Patients with Poststroke Hemiplegia: A Pilot Randomized Controlled Trial.

PubMed

Kim, Chang-Yong; Lee, Jung-Sun; Kim, Hyeong-Dong

2017-02-01

The purposes of the present study were to compare the effects of backward and lateral walking training and to identify whether additional backward or lateral walking training would be more effective in increasing the walking function of poststroke patients. Fifty-one subjects with hemiplegic stroke were randomly allocated to 3 groups, each containing 17 subjects: the control group, the backward walking training group, and the lateral walking training group. The walking abilities of each group were assessed using a 10-m walk test and the GAITRite system for spatiotemporal gait. The results show that there were significantly greater posttest increases in gait velocity (F = -12.09, P = 0.02) and stride length (F = -11.50, P = 0.02), decreases in the values of the 10-m walk test (F = -7.10, P = 0.03) (P < 0.05) and double-limb support period (F = 40.15, P = 0.000), and improvements in gait asymmetry (F = 13.88, P = 0.002) (P < 0.01) in subjects in the lateral walking training group compared with those in the other 2 groups. These findings demonstrate that asymmetric gait patterns in poststroke patients could be improved by receiving additional lateral walking training therapy rather than backward walking training. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) understand the potential benefits of backward walking (BW) and lateral walking (LW) training on improving muscle strength and gait; (2) appreciate the potential value of backward and lateral walking gait training in the treatment of hemiplegic stroke patients; and (3) appropriately incorporate backward and lateral walking gait training into the treatment plan of hemiplegic stroke patients. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Theorising and testing environmental pathways to behaviour change: natural experimental study of the perception and use of new infrastructure to promote walking and cycling in local communities

PubMed Central

Panter, Jenna; Ogilvie, David

2015-01-01

Objective Some studies have assessed the effectiveness of environmental interventions to promote physical activity, but few have examined how such interventions work. We investigated the environmental mechanisms linking an infrastructural intervention with behaviour change. Design Natural experimental study. Setting Three UK municipalities (Southampton, Cardiff and Kenilworth). Participants Adults living within 5 km of new walking and cycling infrastructure. Intervention Construction or improvement of walking and cycling routes. Exposure to the intervention was defined in terms of residential proximity. Outcome measures Questionnaires at baseline and 2-year follow-up assessed perceptions of the supportiveness of the environment, use of the new infrastructure, and walking and cycling behaviours. Analysis proceeded via factor analysis of perceptions of the physical environment (step 1) and regression analysis to identify plausible pathways involving physical and social environmental mediators and refine the intervention theory (step 2) to a final path analysis to test the model (step 3). Results Participants who lived near and used the new routes reported improvements in their perceptions of provision and safety. However, path analysis (step 3, n=967) showed that the effects of the intervention on changes in time spent walking and cycling were largely (90%) explained by a simple causal pathway involving use of the new routes, and other pathways involving changes in environmental cognitions explained only a small proportion of the effect. Conclusions Physical improvement of the environment itself was the key to the effectiveness of the intervention, and seeking to change people's perceptions may be of limited value. Studies of how interventions lead to population behaviour change should complement those concerned with estimating their effects in supporting valid causal inference. PMID:26338837

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease.

PubMed

Crowther, Robert G; Leicht, Anthony S; Spinks, Warwick L; Sangla, Kunwarjit; Quigley, Frank; Golledge, Jonathan

2012-01-01

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal-Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.

Walking economy during cued versus non-cued treadmill walking in persons with Parkinson's disease.

PubMed

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2013-01-01

Gait impairment is common in Parkinson's disease (PD) and may result in greater energy expenditure, poorer walking economy, and fatigue during activities of daily living. Auditory cueing is an effective technique to improve gait; but the effects on energy expenditure are unknown. To determine whether energy expenditure differs in individuals with PD compared with healthy controls and if auditory cueing improves walking economy in PD. Twenty participants (10 PD and 10 controls) came to the laboratory for three sessions. Participants performed two, 6-minute bouts of treadmill walking at two speeds (1.12 m·sec-1 and 0.67 m·sec-1). One session used cueing and the other without cueing. A metabolic cart measured energy expenditure and walking economy was calculated (energy expenditure/power). PD had worse walking economy and higher energy expenditure than control participants during cued and non-cued walking at the 0.67 m·sec-1 speed and during non-cued walking at the 1.12 m·sec-1. With auditory cueing, energy expenditure and walking economy worsened in both participant groups. People with PD use more energy and have worse walking economy than adults without PD. Walking economy declines further with auditory cuing in persons with PD.

Covering Ground: Movement Patterns and Random Walk Behavior in Aquilonastra anomala Sea Stars.

PubMed

Lohmann, Amanda C; Evangelista, Dennis; Waldrop, Lindsay D; Mah, Christopher L; Hedrick, Tyson L

2016-10-01

The paths animals take while moving through their environments affect their likelihood of encountering food and other resources; thus, models of foraging behavior abound. To collect movement data appropriate for comparison with these models, we used time-lapse photography to track movements of a small, hardy, and easy-to-obtain organism, Aquilonastra anomala sea stars. We recorded the sea stars in a tank over many hours, with and without a food cue. With food present, they covered less distance, as predicted by theory; this strategy would allow them to remain near food. We then compared the paths of the sea stars to three common models of animal movement: Brownian motion, Lévy walks, and correlated random walks; we found that the sea stars' movements most closely resembled a correlated random walk. Additionally, we compared the search performance of models of Brownian motion, a Lévy walk, and a correlated random walk to that of a model based on the sea stars' movements. We found that the behavior of the modeled sea star walk was similar to that of the modeled correlated random walk and the Brownian motion model, but that the sea star walk was slightly more likely than the other walks to find targets at intermediate distances. While organisms are unlikely to follow an idealized random walk in all details, our data suggest that comparing the effectiveness of an organism's paths to those from theory can give insight into the organism's actual movement strategy. Finally, automated optical tracking of invertebrates proved feasible, and A. anomala was revealed to be a tractable, 2D-movement study system.

Foot trajectory approximation using the pendulum model of walking.

PubMed

Fang, Juan; Vuckovic, Aleksandra; Galen, Sujay; Conway, Bernard A; Hunt, Kenneth J

2014-01-01

Generating a natural foot trajectory is an important objective in robotic systems for rehabilitation of walking. Human walking has pendular properties, so the pendulum model of walking has been used in bipedal robots which produce rhythmic gait patterns. Whether natural foot trajectories can be produced by the pendulum model needs to be addressed as a first step towards applying the pendulum concept in gait orthosis design. This study investigated circle approximation of the foot trajectories, with focus on the geometry of the pendulum model of walking. Three able-bodied subjects walked overground at various speeds, and foot trajectories relative to the hip were analysed. Four circle approximation approaches were developed, and best-fit circle algorithms were derived to fit the trajectories of the ankle, heel and toe. The study confirmed that the ankle and heel trajectories during stance and the toe trajectory in both the stance and the swing phases during walking at various speeds could be well modelled by a rigid pendulum. All the pendulum models were centred around the hip with pendular lengths approximately equal to the segment distances from the hip. This observation provides a new approach for using the pendulum model of walking in gait orthosis design.

"Step by Step". A feasibility study of a lunchtime walking intervention designed to increase walking, improve mental well-being and work performance in sedentary employees: Rationale and study design.

PubMed

Thøgersen-Ntoumani, Cecilie; Loughren, Elizabeth A; Duda, Joan L; Fox, Kenneth R; Kinnafick, Florence-Emilie

2010-09-27

Following an extensive recruitment campaign, a 16-week lunchtime intervention to increase walking was implemented with insufficiently physically active University employees to examine programme feasibility and the effects of the programme in increasing walking behaviour, and in improving well-being and work performance. A feasibility study in which participants were randomised to an immediate treatment or a delayed treatment control (to start at 10 weeks) group. For the first ten weeks of the intervention, participants took part in three facilitator-led group walks per week each of thirty minutes duration and were challenged to accumulate another sixty minutes of walking during the weekends. In the second phase of the intervention, the organised group walks ceased to be offered and participants were encouraged to self-organise their walks. Motivational principles were employed using contemporary motivational theory. Outcome measures (including self-reported walking, step counts, cardiovascular fitness, general and work-related well-being and work performance) were assessed at baseline, at the end of the 16-week intervention and (for some) four months after the end of the intervention. Process and outcome assessments were also taken throughout, and following, the intervention. The results of the intervention will determine the feasibility of implementing a lunchtime walking programme to increase walking behaviour, well-being and performance in sedentary employees. If successful, there is scope to implement definitive trials across a range of worksites with the aim of improving both employee and organisational health. Current Controlled Trials ISRCTN81504663.

Changes in cardiopulmonary function in normal adults after the Rockport 1 mile walking test: a preliminary study.

PubMed

Kim, Kyoung; Lee, Hye-Young; Lee, Do-Youn; Nam, Chan-Woo

2015-08-01

[Purpose] The purpose of this study was to investigate the changes of cardiopulmonary function in normal adults after the Rockport 1 mile walking test. [Subjects and Methods] University students (13 males and 27 females) participated in this study. Before and after the Rockport 1 mile walking test, pulmonary function, respiratory pressure, and maximal oxygen uptake were measured. [Results] Significant improvements in forced vital capacity and maximal inspiratory pressure were observed after the Rockport 1 mile walking test in males, and significant improvements in forced vital capacity, forced expiratory volume at 1 s, maximal inspiratory pressure, and maximal expiratory pressure were observed after the Rockport 1 mile walking test in females. However, the maximal oxygen uptake was not significantly different. [Conclusion] Our findings indicate that the Rockport 1 mile walking test changes cardiopulmonary function in males and females, and that it may improve cardiopulmonary function in middle-aged and older adults and provide basic data on cardiopulmonary endurance.

Changes in cardiopulmonary function in normal adults after the Rockport 1 mile walking test: a preliminary study

PubMed Central

Kim, Kyoung; Lee, Hye-Young; Lee, Do-Youn; Nam, Chan-Woo

2015-01-01

[Purpose] The purpose of this study was to investigate the changes of cardiopulmonary function in normal adults after the Rockport 1 mile walking test. [Subjects and Methods] University students (13 males and 27 females) participated in this study. Before and after the Rockport 1 mile walking test, pulmonary function, respiratory pressure, and maximal oxygen uptake were measured. [Results] Significant improvements in forced vital capacity and maximal inspiratory pressure were observed after the Rockport 1 mile walking test in males, and significant improvements in forced vital capacity, forced expiratory volume at 1 s, maximal inspiratory pressure, and maximal expiratory pressure were observed after the Rockport 1 mile walking test in females. However, the maximal oxygen uptake was not significantly different. [Conclusion] Our findings indicate that the Rockport 1 mile walking test changes cardiopulmonary function in males and females, and that it may improve cardiopulmonary function in middle-aged and older adults and provide basic data on cardiopulmonary endurance. PMID:26356048

Trunk motion visual feedback during walking improves dynamic balance in older adults: Assessor blinded randomized controlled trial.

PubMed

Anson, Eric; Ma, Lei; Meetam, Tippawan; Thompson, Elizabeth; Rathore, Roshita; Dean, Victoria; Jeka, John

2018-05-01

Virtual reality and augmented feedback have become more prevalent as training methods to improve balance. Few reports exist on the benefits of providing trunk motion visual feedback (VFB) during treadmill walking, and most of those reports only describe within session changes. To determine whether trunk motion VFB treadmill walking would improve over-ground balance for older adults with self-reported balance problems. 40 adults (75.8 years (SD 6.5)) with self-reported balance difficulties or a history of falling were randomized to a control or experimental group. Everyone walked on a treadmill at a comfortable speed 3×/week for 4 weeks in 2 min bouts separated by a seated rest. The control group was instructed to look at a stationary bulls-eye target while the experimental group also saw a moving cursor superimposed on the stationary bulls-eye that represented VFB of their walking trunk motion. The experimental group was instructed to keep the cursor in the center of the bulls-eye. Somatosensory (monofilaments and joint position testing) and vestibular function (canal specific clinical head impulses) was evaluated prior to intervention. Balance and mobility were tested before and after the intervention using Berg Balance Test, BESTest, mini-BESTest, and Six Minute Walk. There were no significant differences between groups before the intervention. The experimental group significantly improved on the BESTest (p = 0.031) and the mini-BEST (p = 0.019). The control group did not improve significantly on any measure. Individuals with more profound sensory impairments had a larger improvement on dynamic balance subtests of the BESTest. Older adults with self-reported balance problems improve their dynamic balance after training using trunk motion VFB treadmill walking. Individuals with worse sensory function may benefit more from trunk motion VFB during walking than individuals with intact sensory function. Copyright © 2018 Elsevier B.V. All rights reserved.

[Added value of family practitioners' supervision of junior doctors in a walk-in clinic].

PubMed

Perdrix, J; Gubser, R; Gilgien, W; Bischoff, T

2011-05-18

The pending workforce crisis in family medicine has triggered various initiatives. This article describes the PMU-FLON walk-in clinic, a project of the Institute of General Medicine University of Lausanne. The working conditions in this clinic are close to that of a family practice. Doctors in training are supervised by family doctors who work part-time in the clinic. The objective is to improve training in the various fields of family medicine, from technical skills (improving optimal use of diagnostic tools), to integrating patients' requests in a more global patient-centered approach. This new educational model allows doctors in training to benefit from the specific approaches of different trainers. It will contribute to promoting quality family medicine in the future.

Effect of Granulocyte-Macrophage Colony-Stimulating Factor With or Without Supervised Exercise on Walking Performance in Patients With Peripheral Artery Disease

PubMed Central

Ferrucci, Luigi; Tian, Lu; Guralnik, Jack M.; Lloyd-Jones, Donald; Kibbe, Melina R.; Polonsky, Tamar S.; Domanchuk, Kathryn; Stein, James H.; Zhao, Lihui; Taylor, Doris; Skelly, Christopher; Pearce, William; Perlman, Harris; McCarthy, Walter; Li, Lingyu; Gao, Ying; Sufit, Robert; Bloomfield, Christina L.; Criqui, Michael H.

2017-01-01

Importance Benefits of granulocyte-macrophage colony-stimulating factor (GM-CSF) for improving walking ability in people with lower extremity peripheral artery disease (PAD) are unclear. Walking exercise may augment the effects of GM-CSF in PAD, since exercise-induced ischemia enhances progenitor cell release and may promote progenitor cell homing to ischemic calf muscle. Objectives To determine whether GM-CSF combined with supervised treadmill exercise improves 6-minute walk distance, compared with exercise alone and compared with GM-CSF alone; to determine whether GM-CSF alone improves 6-minute walk more than placebo and whether exercise improves 6-minute walk more than an attention control intervention. Design, Setting, and Participants Randomized clinical trial with 2 × 2 factorial design. Participants were identified from the Chicago metropolitan area and randomized between January 6, 2012, and December 22, 2016, to 1 of 4 groups: supervised exercise + GM-CSF (exercise + GM-CSF) (n = 53), supervised exercise + placebo (exercise alone) (n = 53), attention control  + GM-CSF (GM-CSF alone) (n = 53), attention control + placebo (n = 51). The final follow-up visit was on August 15, 2017. Interventions Supervised exercise consisted of treadmill exercise 3 times weekly for 6 months. The attention control consisted of weekly educational lectures by clinicians for 6 months. GM-CSF (250 μg/m2/d) or placebo were administered subcutaneously (double-blinded) 3 times/wk for the first 2 weeks of the intervention. Main Outcomes and Measures The primary outcome was change in 6-minute walk distance at 12-week follow-up (minimum clinically important difference, 20 m). P values were adjusted based on the Hochberg step-up method. Results Of 827 persons evaluated, 210 participants with PAD were randomized (mean age, 67.0 [SD, 8.6] years; 141 [67%] black, 82 [39%] women). One hundred ninety-five (93%) completed 12-week follow-up. At 12-week follow-up, exercise + GM-CSF did not significantly improve 6-minute walk distance more than exercise alone (mean difference, −6.3 m [95% CI, −30.2 to +17.6]; P = .61) or more than GM-CSF alone (mean difference, +28.7 m [95% CI, +5.1 to +52.3]; Hochberg-adjusted P = .052). GM-CSF alone did not improve 6-minute walk more than attention control + placebo (mean difference, −1.4 m [95% CI, −25.2 to +22.4]; P = .91). Exercise alone improved 6-minute walk compared with attention control + placebo (mean difference, +33.6 m [95% CI, +9.4 to +57.7]; Hochberg-adjusted P = .02). Conclusions and Relevance Among patients with PAD, supervised treadmill exercise significantly improved 6-minute walk distance compared with attention control + placebo, whereas GM-CSF did not significantly improve walking performance, either when used alone or when combined with supervised treadmill exercise. These results confirm the benefits of exercise but do not support using GM-CSF to treat walking impairment in patients with PAD. Trial Registration clinicaltrials.gov Identifier: NCT01408901 PMID:29141087

A systematic review to evaluate the effectiveness of carnitine supplementation in improving walking performance among individuals with intermittent claudication.

PubMed

Delaney, Christopher L; Spark, J Ian; Thomas, Jolene; Wong, Yew Toh; Chan, Lok Tsung; Miller, Michelle D

2013-07-01

To evaluate the evidence for the use of carnitine supplementation in improving walking performance among individuals with intermittent claudication. Systematic review. An electronic search of the literature was performed using MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials and The Cochrane Library from inception through to November 2012. Search terms included peripheral arterial disease, intermittent claudication and carnitine. Reference lists of review articles and primary studies were also examined. Full reports of published experimental studies including randomized controlled trials and pre-test/post-test trials were selected for inclusion. A quality assessment was undertaken according to the Jadad scale. A total of 40 articles were retrieved, of which 23 did not meet the inclusion criteria. The 17 included articles reported on a total of 18 experimental studies of carnitine supplementation (5 pre-test/post-test; 8 parallel RCT; 5 cross-over RCT) for improving walking performance in adults with intermittent claudication. For pre-test/post-test studies, 300-2000 mg propionyl-L-carnitine (PLC) was administered orally or intravenously for a maximum of 90 days (7-42 participants) with statistically significant improvements of between 74 m and 157 m in pain free walking distance and between 71 m and 135 m in maximal walking distance across 3 out of 5 studies. Similarly, PLC (600 mg-3000 mg) was administered orally in 7 out of 8 parallel RCTs (22-485 participants), the longest duration being 12 months. All but one of the smallest trials demonstrated statistically significant improvements in walking performance between 31 and 54 m greater than placebo for pain free walking distance and between 9 and 86 m greater than placebo for maximal walking distance. A double-blind parallel RCT of cilostazol plus 2000 mg oral L-carnitine or placebo for 180 days (145 participants) did not demonstrate any significant improvement in walking performance. Of 5 cross-over RCTs (8-20 participants), 4 demonstrated significant improvements in walking performance following administration of 300-6000 mg L-carnitine or PLC. Compared to placebo, pain free walking distance and maximal walking distance improved by 23-132 m and 104 m respectively following carnitine intervention. Most trials demonstrated a small or modest improvement in walking performance with administration of PLC or L-carnitine. These findings were largely independent of level or quality of evidence, while there was some evidence that intravenous administration was more effective than oral administration and those with severe claudication may achieve greater benefits than those with moderate claudication. Routine carnitine supplementation in the form of PLC may therefore be a useful adjunct therapy for management of intermittent claudication. Further research is warranted to determine the optimal form, duration, dose and safety of carnitine supplementation across the spectrum of peripheral arterial disease severity and its effect with concurrent supervised exercise programs and best medical therapy. These studies should be supplemented with cost effectiveness studies to ensure that the return on the investment is acceptable. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Treadmill exercise rehabilitation improves ambulatory function and cardiovascular fitness in patients with chronic stroke: a randomized, controlled trial.

PubMed

Macko, Richard F; Ivey, Frederick M; Forrester, Larry W; Hanley, Daniel; Sorkin, John D; Katzel, Leslie I; Silver, Kenneth H; Goldberg, Andrew P

2005-10-01

Physical inactivity propagates disability after stroke through physical deconditioning and learned nonuse. We investigated whether treadmill aerobic training (T-AEX) is more effective than conventional rehabilitation to improve ambulatory function and cardiovascular fitness in patients with chronic stroke. Sixty-one adults with chronic hemiparetic gait after ischemic stroke (>6 months) were randomized to 6 months (3x/week) progressive T-AEX or a reference rehabilitation program of stretching plus low-intensity walking (R-CONTROL). Peak exercise capacity (Vo2 peak), o2 consumption during submaximal effort walking (economy of gait), timed walks, Walking Impairment Questionnaire (WIQ), and Rivermead Mobility Index (RMI) were measured before and after 3 and 6 months of training. Twenty-five patients completed T-AEX and 20 completed R-CONTROL. Only T-AEX increased cardiovascular fitness (17% versus 3%, delta% T-AEX versus R-CONTROL, P<0.005). Group-by-time analyses revealed T-AEX improved ambulatory performance on 6-minute walks (30% versus 11%, P<0.02) and mobility function indexed by WIQ distance scores (56% versus 12%, P<0.05). In the T-AEX group, increasing training velocity predicted improved Vo2 peak (r=0.43, P<0.05), but not walking function. In contrast, increasing training session duration predicted improved 6-minute walk (r=0.41, P<0.05), but not fitness gains. T-AEX improves both functional mobility and cardiovascular fitness in patients with chronic stroke and is more effective than reference rehabilitation common to conventional care. Specific characteristics of training may determine the nature of exercise-mediated adaptations.

Deterministic diffusion in flower-shaped billiards.

PubMed

Harayama, Takahisa; Klages, Rainer; Gaspard, Pierre

2002-08-01

We propose a flower-shaped billiard in order to study the irregular parameter dependence of chaotic normal diffusion. Our model is an open system consisting of periodically distributed obstacles in the shape of a flower, and it is strongly chaotic for almost all parameter values. We compute the parameter dependent diffusion coefficient of this model from computer simulations and analyze its functional form using different schemes, all generalizing the simple random walk approximation of Machta and Zwanzig. The improved methods we use are based either on heuristic higher-order corrections to the simple random walk model, on lattice gas simulation methods, or they start from a suitable Green-Kubo formula for diffusion. We show that dynamical correlations, or memory effects, are of crucial importance in reproducing the precise parameter dependence of the diffusion coefficent.

Random walks and diffusion on networks

NASA Astrophysics Data System (ADS)

Masuda, Naoki; Porter, Mason A.; Lambiotte, Renaud

2017-11-01

Random walks are ubiquitous in the sciences, and they are interesting from both theoretical and practical perspectives. They are one of the most fundamental types of stochastic processes; can be used to model numerous phenomena, including diffusion, interactions, and opinions among humans and animals; and can be used to extract information about important entities or dense groups of entities in a network. Random walks have been studied for many decades on both regular lattices and (especially in the last couple of decades) on networks with a variety of structures. In the present article, we survey the theory and applications of random walks on networks, restricting ourselves to simple cases of single and non-adaptive random walkers. We distinguish three main types of random walks: discrete-time random walks, node-centric continuous-time random walks, and edge-centric continuous-time random walks. We first briefly survey random walks on a line, and then we consider random walks on various types of networks. We extensively discuss applications of random walks, including ranking of nodes (e.g., PageRank), community detection, respondent-driven sampling, and opinion models such as voter models.

Body weight supported treadmill training versus traditional training in patients dependent on walking assistance after stroke: a randomized controlled trial.

PubMed

Høyer, Ellen; Jahnsen, Reidun; Stanghelle, Johan Kvalvik; Strand, Liv Inger

2012-01-01

Treadmill training with body weight support (TTBWS) for relearning walking ability after brain damage is an approach under current investigation. Efficiency of this method beyond traditional training is lacking evidence, especially in patients needing walking assistance after stroke. The objective of this study was to investigate change in walking and transfer abilities, comparing TTBWS with traditional walking training. A single-blinded, randomized controlled trial was conducted. Sixty patients referred for multi-disciplinary primary rehabilitation were assigned into one of two intervention groups, one received 30 sessions of TTBWS plus traditional training, the other traditional training alone. Daily training was 1 hr. Outcome measures were Functional Ambulation Categories (FAC), Walking, Functional Independence Measure (FIM); shorter transfer and stairs, 10 m and 6-min walk tests. Substantial improvements in walking and transfer were shown within both groups after 5 and 11 weeks of intervention. Overall no statistical significant differences were found between the groups, but 12 of 17 physical measures tended to show improvements in favour of the treadmill approach. Both training strategies provided significant improvements in the tested activities, suggesting that similar outcomes can be obtained in the two modalities by systematic, intensive and goal directed training.

Walking in circles: a modelling approach

PubMed Central

Maus, Horst-Moritz; Seyfarth, Andre

2014-01-01

Blindfolded or disoriented people have the tendency to walk in circles rather than on a straight line even if they wanted to. Here, we use a minimalistic walking model to examine this phenomenon. The bipedal spring-loaded inverted pendulum exhibits asymptotically stable gaits with centre of mass (CoM) dynamics and ground reaction forces similar to human walking in the sagittal plane. We extend this model into three dimensions, and show that stable walking patterns persist if the leg is aligned with respect to the body (here: CoM velocity) instead of a world reference frame. Further, we demonstrate that asymmetric leg configurations, which are common in humans, will typically lead to walking in circles. The diameter of these circles depends strongly on parameter configuration, but is in line with empirical data from human walkers. Simulation results suggest that walking radius and especially direction of rotation are highly dependent on leg configuration and walking velocity, which explains inconsistent veering behaviour in repeated trials in human data. Finally, we discuss the relation between findings in the model and implications for human walking. PMID:25056215

Subject-Specific Modeling of Muscle Force and Knee Contact in Total Knee Arthroplasty

PubMed Central

Navacchia, Alessandro; Rullkoetter, Paul J.; Schütz, Pascal; List, Renate B.; Fitzpatrick, Clare K.; Shelburne, Kevin B.

2017-01-01

Understanding the mechanical loading environment and resulting joint mechanics for activities of daily living in total knee arthroplasty is essential to continuous improvement in implant design. Although survivorship of these devices is good, a substantial number of patients report dissatisfaction with the outcome of their procedure. Knowledge of in vivo kinematics and joint loading will enable improvement in preclinical assessment and refinement of implant geometry. The purpose of this investigation was to describe the mechanics of total knee arthroplasty during a variety of activities of daily living (gait, walking down stairs, and chair rise/sit). Estimates of muscle forces, tibial contact load, location, and pressure distribution was performed through a combination of mobile fluoroscopy data collection, musculoskeletal modeling, and finite element simulation. For the activities evaluated, joint compressive load was greatest during walking down stairs; however, the highest contact pressure occurred during chair rise/sit. The joint contact moment in the frontal plane was mainly varus for gait and walking down stairs, while it was valgus during chair rise/sit. Excursion of the center of pressure on the tibial component was similar during each activity and between the medial and lateral sides. The main determinants of center of pressure location were internal–external rotation, joint load, and tibial insert conformity. PMID:26792665

Exploring the impact of walk–bike infrastructure, safety perception, and built-environment on active transportation mode choice: a random parameter model using New York City commuter data

DOE PAGES

Aziz, H. M. Abdul; Nagle, Nicholas N.; Morton, April M.; ...

2017-02-06

Here, this study finds the effects of traffic safety, walk-bike network facilities, and land use attributes on walk and bicycle mode choice decision in the New York City for home-to-work commute. Applying the flexible econometric structure of random parameter models, we capture the heterogeneity in the decision making process and simulate scenarios considering improvement in walk-bike infrastructure such as sidewalk width and length of bike lane. Our results indicate that increasing sidewalk width, total length of bike lane, and proportion of protected bike lane will increase the likelihood of more people taking active transportation mode This suggests that the localmore » authorities and planning agencies to invest more on building and maintaining the infrastructure for pedestrians. Furthermore, improvement in traffic safety by reducing traffic crashes involving pedestrians and bicyclists will increase the likelihood of taking active transportation modes. Our results also show positive correlation between number of non-motorized trips by the other family members and the likelihood to choose active transportation mode. The findings will help to make smart investment decisions in context of building sustainable transportation systems accounting for active transportation.« less

Exploring the impact of walk–bike infrastructure, safety perception, and built-environment on active transportation mode choice: a random parameter model using New York City commuter data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aziz, H. M. Abdul; Nagle, Nicholas N.; Morton, April M.

Here, this study finds the effects of traffic safety, walk-bike network facilities, and land use attributes on walk and bicycle mode choice decision in the New York City for home-to-work commute. Applying the flexible econometric structure of random parameter models, we capture the heterogeneity in the decision making process and simulate scenarios considering improvement in walk-bike infrastructure such as sidewalk width and length of bike lane. Our results indicate that increasing sidewalk width, total length of bike lane, and proportion of protected bike lane will increase the likelihood of more people taking active transportation mode This suggests that the localmore » authorities and planning agencies to invest more on building and maintaining the infrastructure for pedestrians. Furthermore, improvement in traffic safety by reducing traffic crashes involving pedestrians and bicyclists will increase the likelihood of taking active transportation modes. Our results also show positive correlation between number of non-motorized trips by the other family members and the likelihood to choose active transportation mode. The findings will help to make smart investment decisions in context of building sustainable transportation systems accounting for active transportation.« less

The development of an estimation model for energy expenditure during water walking by acceleration and walking speed.

PubMed

Kaneda, Koichi; Ohgi, Yuji; Tanaka, Chiaki; Burkett, Brendan

2014-01-01

The aim of this study was to develop an estimation equation for energy expenditure during water walking based on the acceleration and walking speed. Cross-validation study. Fifty participants, males (n=29, age: 27-73) and females (n=21, age: 33-70) volunteered for this study. Based on their physical condition water walking was conducted at three self-selected walking speeds from a range of: 20, 25, 30, 35 and 40 m/min. Energy expenditure during each trial was calculated. During water walking, an accelerometer was attached to the occipital region and recorded three-dimensional accelerations at 100 Hz. A stopwatch was used for timing the participant's walking speed. The estimation model for energy expenditure included three components; (i) resting metabolic rate, (ii) internal energy expenditure for moving participants' body, and (iii) external energy expenditure due to water drag force. When comparing the measured and estimated energy expenditure with the acceleration data being the third component of the estimation model, high correlation coefficients were found in both male (r=0.73) and female (r=0.77) groups. When walking speeds were applied to the third component of the model, higher correlation coefficients were found (r=0.82 in male and r=0.88 in female). Good agreements of the developed estimation model were found in both methods, regardless of gender. This study developed a valid estimation model for energy expenditure during water walking by using head acceleration and walking speed. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Dalfampridine Effects Beyond Walking Speed in Multiple Sclerosis

PubMed Central

Fjeldstad, Cecilie; Suárez, Gustavo; Klingler, Michael; Henney, Herbert R.; Rabinowicz, Adrian L.

2015-01-01

Background: Dalfampridine extended release (ER) improves walking in people with multiple sclerosis (MS), as demonstrated by walking speed improvement. This exploratory study evaluated treatment effects of dalfampridine-ER on gait, balance, and walking through treatment withdrawal and reinitiation. Methods: Dalfampridine-ER responders, based on Timed 25-Foot Walk (T25FW) assessment before study entry, were included in this open-label, three-period, single-center study. Period 1: on-drug evaluations performed at screening and 1 week after screening. Period 2: dalfampridine-ER withdrawal and off-drug evaluations (days 5 and 11). Period 3: dalfampridine-ER reinitiation/final on-drug evaluation (day 15). Primary outcome variables: NeuroCom composite scores for gait and balance; balance was evaluated if gait changes were significant. Secondary variables: individual NeuroCom scores, walking speed (T25FW) and distance (2-Minute Walk Test [2MWT]), and balance (Berg Balance Scale [BBS]). Results: All 20 patients completed the study: mean age, 53.1 years; mean MS duration, 11.3 years; mean time taking dalfampridine-ER, 315.3 days. NeuroCom gait composite scores worsened during period 2 relative to period 1 and improved during period 3; the mean ± SD difference in gait composite scores on drug was 4.03 ± 1.51 points (P = .015). Balance composite scores did not change significantly. Improvements were observed for off-drug versus on-drug for T25FW (0.36 ft/sec, P < .001), 2MWT (25.4 ft, P = .006), and BBS (1.7 points, P = .003). Safety profile was consistent with previous studies. Conclusions: Significant improvements in gait, walking speed, distance, and balance were demonstrated by dalfampridine-ER reinitiation after a 10-day withdrawal period. PMID:26664333

Feasibility and Preliminary Efficacy of Visual Cue Training to Improve Adaptability of Walking after Stroke: Multi-Centre, Single-Blind Randomised Control Pilot Trial

PubMed Central

Hollands, Kristen L.; Pelton, Trudy A.; Wimperis, Andrew; Whitham, Diane; Tan, Wei; Jowett, Sue; Sackley, Catherine M.; Wing, Alan M.; Tyson, Sarah F.; Mathias, Jonathan; Hensman, Marianne; van Vliet, Paulette M.

2015-01-01

Objectives Given the importance of vision in the control of walking and evidence indicating varied practice of walking improves mobility outcomes, this study sought to examine the feasibility and preliminary efficacy of varied walking practice in response to visual cues, for the rehabilitation of walking following stroke. Design This 3 arm parallel, multi-centre, assessor blind, randomised control trial was conducted within outpatient neurorehabilitation services Participants Community dwelling stroke survivors with walking speed <0.8m/s, lower limb paresis and no severe visual impairments Intervention Over-ground visual cue training (O-VCT), Treadmill based visual cue training (T-VCT), and Usual care (UC) delivered by physiotherapists twice weekly for 8 weeks. Main outcome measures: Participants were randomised using computer generated random permutated balanced blocks of randomly varying size. Recruitment, retention, adherence, adverse events and mobility and balance were measured before randomisation, post-intervention and at four weeks follow-up. Results Fifty-six participants participated (18 T-VCT, 19 O-VCT, 19 UC). Thirty-four completed treatment and follow-up assessments. Of the participants that completed, adherence was good with 16 treatments provided over (median of) 8.4, 7.5 and 9 weeks for T-VCT, O-VCT and UC respectively. No adverse events were reported. Post-treatment improvements in walking speed, symmetry, balance and functional mobility were seen in all treatment arms. Conclusions Outpatient based treadmill and over-ground walking adaptability practice using visual cues are feasible and may improve mobility and balance. Future studies should continue a carefully phased approach using identified methods to improve retention. Trial Registration Clinicaltrials.gov NCT01600391 PMID:26445137

Footwear effects on walking balance at elevation.

PubMed

Simeonov, Peter; Hsiao, Hongwei; Powers, John; Ammons, Douglas; Amendola, Alfred; Kau, Tsui-Ying; Cantis, Douglas

2008-12-01

The study evaluated the effects of shoe style on workers' instability during walking at elevation. Twenty-four construction workers performed walking tasks on roof planks in a surround-screen virtual reality system, which simulated a residential roof environment. Three common athletic and three work shoe styles were tested on wide, narrow and tilted planks on a simulated roof and on an unrestricted surface at simulated ground. Dependent variables included lateral angular velocities of the trunk and the rear foot, as well as the workers' rated perceptions of instability. The results demonstrated that shoe style significantly affected workers walking instability at elevated work environments. The results highlighted two major shoe-design pathways for improving walking balance at elevation: enhancing rear foot motion control; and improving ankle proprioception. This study also outlined some of the challenges in optimal shoe selection and specific shoe-design needs for improved walking stability during roof work. The study adds to the knowledge in the area of balance control, by emphasising the role of footwear as a critical human-support surface interface during work on narrow surfaces at height. The results can be used for footwear selection and improvements to reduce risk of falls from elevation.

Factors influencing change in walking ability in patients with heart failure undergoing exercise-based cardiac rehabilitation.

PubMed

Sutherland, Natasha; Harrison, Alexander; Doherty, Patrick

2018-05-17

Exercise-based cardiac rehabilitation (CR) is an effective intervention for patients with heart failure (HF), in which one of the main targets is to increase physical capacity. In the HF population this is traditionally assessed using distance covered during a walking test. This study aims to establish the extent to which change in walking ability, in HF patients attending CR, is determined by patient characteristics and service provision. The study utilised routine clinical data from the National Audit of Cardiac Rehabilitation to perform a robust analysis. Change, in metres, between pre- and post-CR six-minute walk tests was calculated. Multivariate linear regression models were used to explore the relationship between patient characteristics, service-level variables, and change in metres walked. Complete and valid data from 633 patients was analysed, and a mean change of 51.30 m was calculated. Female gender (-34.13 m, p = 0.007), being retired (-36.41 m, p = 0.001) and being married/in a relationship (-32.54 m, p = 0.023) were all significant negative predictors of change. There was an additional negative relationship with body mass index (BMI) whereby for every unit increase in BMI, predicted change reduces by 2.48 m (p = 0.006). This study identified significant patient-level characteristics strongly associated with limited improvement in walking ability following CR. Improving physical capacity is a core component of CR, therefore services should aim to account for baseline characteristics identified in this study as part of tailoring the CR intervention around the individual. Pre- and post-CR physical capacity assessments, which constitute minimum standards for CR, are worryingly low and should be given high priority. Copyright © 2017. Published by Elsevier B.V.

Regional models of bicycle and pedestrian travel in Chittenden County, Vermont.

DOT National Transportation Integrated Search

2015-02-01

Encouraging travelers to walk and bicycle in lieu of motorized modes of travel : benefits both the traveler and the community at large. The traveler benefits from : health improvements that have been shown to accompany increases in physical : activit...

The influence of panic on the efficiency of escape

NASA Astrophysics Data System (ADS)

Shen, Jia-Quan; Wang, Xu-Wen; Jiang, Luo-Luo

2018-02-01

Whenever we (such as pedestrians) perceive a high density or imminent danger in a confined space, we tend to be panic, which can lead to severe injuries even in the absence of real dangers. Although it is difficult to measure panics in real conditions, we introduced a simple model to study the collective behaviors in condition of fire with dense smoke. Owing to blocking the sight with dense smoke, pedestrians in this condition have two strategies to escape: random-walking or walking along the wall. When the pedestrians are in moderate panic that mean the two types of behaviors are mixed(random-walking and walking along the wall). Our simulation results show that moderate panic, meaning that two escape strategies are mixed, reduces the escape time. In addition, the results indicate that moderate panic can improve the efficiency of escape, this theory also can be useful in a real escape situation. We hope that our research provides the theoretical understanding of underlying mechanisms of panic escape in the condition of poor sight.

Using built environment characteristics to predict walking for exercise

PubMed Central

Lovasi, Gina S; Moudon, Anne V; Pearson, Amber L; Hurvitz, Philip M; Larson, Eric B; Siscovick, David S; Berke, Ethan M; Lumley, Thomas; Psaty, Bruce M

2008-01-01

Background Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for exercise. Study participants lived in western Washington State and were adult members of a health maintenance organization. The physical activity data used in this study were collected by telephone interview and were selected for their relevance to cardiovascular disease. In order to limit confounding by prior health conditions, the sample was restricted to participants in good self-reported health and without a documented history of cardiovascular disease. Results For 1,608 participants meeting the inclusion criteria, the mean age was 64 years, 90 percent were white, 37 percent had a college degree, and 62 percent of participants reported that they walked for exercise. Single built environment characteristics, such as residential density or connectivity, did not significantly predict walking for exercise. Regression models using multiple built environment characteristics to predict walking were not successful at predicting walking for exercise in an independent population sample. In the validation set, none of the logistic models had a C-statistic confidence interval excluding the null value of 0.5, and none of the linear models explained more than one percent of the variance in time spent walking for exercise. We did not detect significant differences in walking for exercise among census areas or postal codes, which were used as proxies for neighborhoods. Conclusion None of the built environment characteristics significantly predicted walking for exercise, nor did combinations of these characteristics predict walking for exercise when tested using a holdout approach. These results reflect a lack of neighborhood-level variation in walking for exercise for the population studied. PMID:18312660

Use of Accelerometer-Based Feedback of Walking Activity for Appraising Progress With Walking-Related Goals in Inpatient Stroke Rehabilitation: A Randomized Controlled Trial.

PubMed

Mansfield, Avril; Wong, Jennifer S; Bryce, Jessica; Brunton, Karen; Inness, Elizabeth L; Knorr, Svetlana; Jones, Simon; Taati, Babak; McIlroy, William E

2015-10-01

Regaining independent ambulation is important to those with stroke. Increased walking practice during "down time" in rehabilitation could improve walking function for individuals with stroke. To determine the effect of providing physiotherapists with accelerometer-based feedback on patient activity and walking-related goals during inpatient stroke rehabilitation. Participants with stroke wore accelerometers around both ankles every weekday during inpatient rehabilitation. Participants were randomly assigned to receive daily feedback about walking activity via their physiotherapists (n = 29) or to receive no feedback (n = 28). Changes in measures of daily walking (walking time, number of steps, average cadence, longest bout duration, and number of "long" walking bouts) and changes in gait control and function assessed in-laboratory were compared between groups. There was no significant increase in walking time, number of steps, longest bout duration, or number of long walking bouts for the feedback group compared with the control group (P values > .20). However, individuals who received feedback significantly increased cadence of daily walking more than the control group (P = .013). From the in-laboratory gait assessment, individuals who received feedback had a greater increase in walking speed and decrease in step time variability than the control group (P values < .030). Feedback did not increase the amount of walking completed by individuals with stroke. However, there was a significant increase in cadence, indicating that intensity of daily walking was greater for those who received feedback than the control group. Additionally, more intense daily walking activity appeared to translate to greater improvements in walking speed. © The Author(s) 2015.

Exoskeleton Training May Improve Level of Physical Activity After Spinal Cord Injury: A Case Series

PubMed Central

Wade, Rodney; Sumrell, Ryan; Villadelgado, Lynette; Khalil, Refka E.; Lavis, Timothy

2017-01-01

Objectives: To determine whether the use of a powered exoskeleton can improve parameters of physical activity as determined by walking time, stand up time, and number of steps in persons with spinal cord injury (SCI). Methods: Three men with complete (1 C5 AIS A and 2 T4 AIS A) and one man with incomplete (C5 AIS D) SCI participated in a clinical rehabilitation program. In the training program, the participants walked once weekly using a powered exoskeleton (Ekso) for approximately 1 hour over the course of 10 to 15 weeks. Walking time, stand up time, ratio of walking to stand up time, and number of steps were determined. Oxygen uptake (L/min), energy expenditure, and body composition were measured in one participant after training. Results: Over the course of 10 to 15 weeks, the maximum walking time increased from 12 to 57 minutes and the number of steps increased from 59 to 2,284 steps. At the end of the training, the 4 participants were able to exercise for 26 to 59 minutes. For one participant, oxygen uptake increased from 0.27 L/min during rest to 0.55 L/min during walking. Maximum walking speed was 0.24 m/s, and delta energy expenditure increased by 1.4 kcal/min during walking. Body composition showed a modest decrease in absolute fat mass in one participant. Conclusion: Exoskeleton training may improve parameters of physical activity after SCI by increasing the number of steps and walking time. Other benefits may include increasing energy expenditure and improving the profile of body composition. PMID:29339900

Virtual reality-based training improves community ambulation in individuals with stroke: a randomized controlled trial.

PubMed

Yang, Yea-Ru; Tsai, Meng-Pin; Chuang, Tien-Yow; Sung, Wen-Hsu; Wang, Ray-Yau

2008-08-01

This is a single blind randomized controlled trial to examine the effect of virtual reality-based training on the community ambulation in individuals with stroke. Twenty subjects with stroke were assigned randomly to either the control group (n=9) or the experimental group (n=11). Subjects in the control group received the treadmill training. Subjects in the experimental group underwent the virtual reality-based treadmill training. Walking speed, community walking time, walking ability questionnaire (WAQ), and activities-specific balance confidence (ABC) scale were evaluated. Subjects in the experimental group improved significantly in walking speed, community walking time, and WAQ score at posttraining and 1-month follow-up periods. Their ABC score also significantly increased at posttraining but did not maintain at follow-up period. Regarding the between-group comparisons, the experimental group improved significantly more than control group in walking speed (P=0.03) and community walking time (P=0.04) at posttraining period and in WAQ score (P=0.03) at follow-up period. Our results support the perceived benefits of gait training programs that incorporate virtual reality to augment the community ambulation of individuals with stroke.

Discrete-time quantum walk with nitrogen-vacancy centers in diamond coupled to a superconducting flux qubit

NASA Astrophysics Data System (ADS)

Hardal, Ali Ü. C.; Xue, Peng; Shikano, Yutaka; Müstecaplıoğlu, Özgür E.; Sanders, Barry C.

2013-08-01

We propose a quantum-electrodynamics scheme for implementing the discrete-time, coined quantum walk with the walker corresponding to the phase degree of freedom for a quasimagnon field realized in an ensemble of nitrogen-vacancy centers in diamond. The coin is realized as a superconducting flux qubit. Our scheme improves on an existing proposal for implementing quantum walks in cavity quantum electrodynamics by removing the cumbersome requirement of varying drive-pulse durations according to mean quasiparticle number. Our improvement is relevant to all indirect-coin-flip cavity quantum-electrodynamics realizations of quantum walks. Our numerical analysis shows that this scheme can realize a discrete quantum walk under realistic conditions.

A randomized controlled trial to evaluate the feasibility of the Wii Fit for improving walking in older adults with lower limb amputation.

PubMed

Imam, Bita; Miller, William C; Finlayson, Heather; Eng, Janice J; Jarus, Tal

2017-01-01

To assess the feasibility of Wii.n.Walk for improving walking capacity in older adults with lower limb amputation. A parallel, evaluator-blind randomized controlled feasibility trial. Community-living. Individuals who were ⩾50 years old with a unilateral lower limb amputation. Wii.n.Walk consisted of Wii Fit training, 3x/week (40 minute sessions), for 4 weeks. Training started in the clinic in groups of 3 and graduated to unsupervised home training. Control group were trained using cognitive games. Feasibility indicators: trial process (recruitment, retention, participants' perceived benefit from the Wii.n.Walk intervention measured by exit questionnaire), resources (adherence), management (participant processing, blinding), and treatment (adverse event, and Cohen's d effect size and variance). Primary clinical outcome: walking capacity measured using the 2 Minute Walk Test at baseline, end of treatment, and 3-week retention. Of 28 randomized participants, 24 completed the trial (12/arm). Median (range) age was 62.0 (50-78) years. Mean (SD) score for perceived benefit from the Wii.n.Walk intervention was 38.9/45 (6.8). Adherence was 83.4%. The effect sizes for the 2 Minute Walk Test were 0.5 (end of treatment) and 0.6 (3-week retention) based on intention to treat with imputed data; and 0.9 (end of treatment) and 1.2 (3-week retention) based on per protocol analysis. The required sample size for a future larger RCT was deemed to be 72 (36 per arm). The results suggested the feasibility of the Wii.n.Walk with a medium effect size for improving walking capacity. Future larger randomized controlled trials investigating efficacy are warranted.

SPARKy - Spring Ankle with Regenerative Kinetics to Build a New Generation of Transtibial Prostheses

DTIC Science & Technology

2010-07-01

walking on inclines/declines, and ascending/descending stairs We are able to walk continuously over ground and can walk up and down slopes and... stairs . Walking up a slope and ascending stairs needs to be improved, adding extra propulsion. The propulsion walking down stairs needs to be...bodied subjects walking on flat even surfaces, inclines/declines, and ascending/descending stairs – In Process 4. Using able bodied test data, a

Exercise Training and Cognitive Rehabilitation: A Symbiotic Approach for Rehabilitating Walking and Cognitive Functions in Multiple Sclerosis?

PubMed

Motl, Robert W; Sandroff, Brian M; DeLuca, John

2016-07-01

The current review develops a rationale and framework for examining the independent and combined effects of exercise training and cognitive rehabilitation on walking and cognitive functions in persons with multiple sclerosis (MS). To do so, we first review evidence for improvements in walking and cognitive outcomes with exercise training and cognitive rehabilitation in MS. We then review evidence regarding cognitive-motor coupling and possible cross-modality transfer effects of exercise training and cognitive rehabilitation. We lastly present a macro-level framework for considering mechanisms that might explain improvements in walking and cognitive dysfunction with exercise and cognitive rehabilitation individually and combined in MS. We conclude that researchers should consider examining the effects of exercise training and cognitive rehabilitation on walking, cognition, and cognitive-motor interactions in MS and the possible physiological and central mechanisms for improving these functions. © The Author(s) 2015.

The impact of footwear and walking distance on gait stability in diabetic patients with peripheral neuropathy.

PubMed

Najafi, Bijan; Khan, Tahir; Fleischer, Adam; Wrobel, James

2013-01-01

We explored gait differences in patients with diabetes and peripheral neuropathy (DPN) and aged-matched controls over short and long walking distances. The potential benefit of footwear for improving gait in patients with DPN was also explored. Twelve patients with DPN and eight controls walked at their habitual speed over short (7 m) and long (20 m) distances under two conditions: barefoot and regular shoes. A validated system of body-worn sensors was used to extract spatiotemporal gait parameters. Neuropathy severity was quantified using vibratory perception threshold measured at the great toe. Gait deterioration in the DPN group was observed during all of the walking trials. However, the difference between patients with DPN and participants in the control group achieved statistical significance only during long walking distance trials. Shod and barefoot double support times were longer in the DPN group during long walking distances (>20%, P = .03). Gait unsteadiness, defined as coefficient of variation of gait velocity, was also significantly higher in the DPN group when barefoot walking over long distances (83%, P = .008). Furthermore, there was a high correlation between neuropathy severity and gait unsteadiness best demonstrated during the barefoot walking/long walking distance condition (r = 0.77, P < .001). The addition of footwear improved gait steadiness in the DPN group by 46% (P = .02). All differences were independent of age, sex, and body mass index (P > .05). This study suggests that gait alteration in patients with DPN is most pronounced while walking barefoot over longer distances and that footwear may improve gait steadiness in patients with DPN.

A dual-docking microfluidic cell migration assay (D2-Chip) for testing neutrophil chemotaxis and the memory effect.

PubMed

Yang, Ke; Wu, Jiandong; Xu, Guoqing; Xie, Dongxue; Peretz-Soroka, Hagit; Santos, Susy; Alexander, Murray; Zhu, Ling; Zhang, Michael; Liu, Yong; Lin, Francis

2017-04-18

Chemotaxis is a classic mechanism for guiding cell migration and an important topic in both fundamental cell biology and health sciences. Neutrophils are a widely used model to study eukaryotic cell migration and neutrophil chemotaxis itself can lead to protective or harmful immune actions to the body. While much has been learnt from past research about how neutrophils effectively navigate through a chemoattractant gradient, many interesting questions remain unclear. For example, while it is tempting to model neutrophil chemotaxis using the well-established biased random walk theory, the experimental proof was challenged by the cell's highly persistent migrating nature. A special experimental design is required to test the key predictions from the random walk model. Another question that has interested the cell migration community for decades concerns the existence of chemotactic memory and its underlying mechanism. Although chemotactic memory has been suggested in various studies, a clear quantitative experimental demonstration will improve our understanding of the migratory memory effect. Motivated by these questions, we developed a microfluidic cell migration assay (so-called dual-docking chip or D 2 -Chip) that can test both the biased random walk model and the memory effect for neutrophil chemotaxis on a single chip enabled by multi-region gradient generation and dual-region cell alignment. Our results provide experimental support for the biased random walk model and chemotactic memory for neutrophil chemotaxis. Quantitative data analyses provide new insights into neutrophil chemotaxis and memory by making connections to entropic disorder, cell morphology and oscillating migratory response.

Using impairment and cognitions to predict walking in osteoarthritis: A series of n-of-1 studies with an individually tailored, data-driven intervention.

PubMed

O'Brien, Nicola; Philpott-Morgan, Siôn; Dixon, Diane

2016-02-01

First, this study compares the ability of an integrated model of activity and activity limitations, the International Classification of Functioning, Disability and Health (ICF), and the Theory of Planned Behaviour (TPB) to predict walking within individuals with osteoarthritis. Second, the effectiveness of a walking intervention in these individuals is determined. A series of n-of-1 studies with an AB intervention design was used. Diary methods were used to study four community-dwelling individuals with lower-limb osteoarthritis. Data on impairment symptoms (pain, pain on movement, and joint stiffness), cognitions (intention, self-efficacy, and perceived controllability), and walking (step count) were collected twice daily for 12 weeks. At 6 weeks, an individually tailored, data-driven walking intervention using action planning or a control cognition manipulation was delivered. Simulation modelling analysis examined cross-correlations and differences in baseline and intervention phase means. Post-hoc mediation analyses examined theoretical relationships and multiple regression analyses compared theoretical models. Cognitions, intention in particular, were better and more consistent within individual predictors of walking than impairment. The walking intervention did not increase walking in any of the three participants receiving it. The integrated model and the TPB, which recognize a predictive role for cognitions, were significant predictors of walking variance in all participants, whilst the biomedical ICF model was only predictive for one participant. Despite the lack of evidence for an individually tailored walking intervention, predictive data suggest that interventions for people with osteoarthritis that address cognitions are likely to be more effective than those that address impairment only. Further within-individual investigation, including testing mediational relationships, is warranted. What is already known on this subject? N-of-1 methods have been used to study within-individual predictors of walking in healthy and chronic pain populations An integrated biomedical and behavioural model of activity and activity limitations recognizes the roles of impairment and psychology (cognitions) Interventions modifying cognitions can increase physical activity in people with mobility limitations What does this study add? N-of-1 methods are suitable to study within-individual predictors of walking and interventions in osteoarthritis An integrated and a psychological model are better predictors of walking in osteoarthritis than a biomedical model There was no support for an individually tailored, data-driven walking intervention. © 2015 The British Psychological Society.

Gait training strategies to optimize walking ability in people with stroke: A synthesis of the evidence

PubMed Central

Tang, Pei Fang

2011-01-01

Stroke is a leading cause of long-term disability. Impairments resulting from stroke lead to persistent difficulties with walking and subsequently, improved walking ability is one of the highest priorities for people living with a stroke. In addition, walking ability has important health implications in providing protective effects against secondary complications common after a stroke such as heart disease or osteoporosis. This paper systematically reviews common gait training strategies (neurodevelopmental techniques, muscle strengthening, treadmill training, intensive mobility exercises) to improve walking ability. The results (descriptive summaries as well as pooled effect sizes) from randomized controlled trials are presented and implications for optimal gait training strategies are discussed. Novel and emerging gait training strategies are highlighted and research directions proposed to enable the optimal recovery and maintenance of walking ability. PMID:17939776

Effects of superficial heating and insulation on walking speed in people with hereditary and spontaneous spastic paraparesis: A randomised crossover study.

PubMed

Denton, Amanda L; Hough, Alan D; Freeman, Jennifer A; Marsden, Jonathan F

2018-03-01

Cooling of the lower limb in people with Hereditary and Spontaneous Spastic Paraparesis (pwHSSP) has been shown to affect walking speed and neuromuscular impairments. The investigation of practical strategies, which may help to alleviate these problems is important. The potential of superficial heat to improve walking speed has not been explored in pwHSSP. Primary objective was to explore whether the application of superficial heat (hot packs) to lower limbs in pwHSSP improves walking speed. Secondary objective was to explore whether wearing insulation after heating would prolong any benefits. A randomised crossover study design with 21 pwHSSP. On two separate occasions two hot packs and an insulating wrap (Neo-G™) were applied for 30minutes to the lower limbs of pwHSSP. On one occasion the insulating wrap was maintained for a further 30minutes and on the other occasion it was removed. Measures of temperature (skin, room and core), walking speed (10 metre timed walk) and co-ordination (foot tap time) were taken at baseline (T1), after 30 mins (T2) and at one hour (T3). All 21 pwHSSP reported increased lower limb stiffness and decreased walking ability when their legs were cold. After thirty minutes of heating, improvements were seen in walking speed (12.2%, P<0.0001, effect size 0.18) and foot tap time (21.5%, P<0.0001, effect size 0.59). Continuing to wear insulation for a further 30minutes gave no additional benefit; with significant improvements in walking speed maintained at one hour (9.9%, P>0.001) in both conditions. Application of 30minutes superficial heating moderately improved walking speed in pwHSSP with effects maintained at 1hour. The use of hot packs applied to lower limbs should be the focus of further research for the clinical management of pwHSSP who report increased stiffness of limbs in cold weather and do not have sensory deficits. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Can Change in Prolonged Walking Be Inferred From a Short Test of Gait Speed Among Older Adults Who Are Initially Well-Functioning?

PubMed Central

Neogi, Tuhina; King, Wendy C.; LaValley, Michael P.; Kritchevsky, Stephen B.; Nevitt, Michael C.; Harris, Tamara B.; Ferrucci, Luigi; Simonsick, Eleanor M.; Satterfield, Suzanne; Strotmeyer, Elsa S.; Zhang, Yuqing

2014-01-01

Background The ability to walk for short and prolonged periods of time is often measured with separate walking tests. It is unclear whether decline in the 2-minute walk coincides with decline in a shorter 20-m walk among older adults. Objective The aim of this study was to describe patterns of change in the 20-m walk and 2-minute walk over 8 years among a large cohort of older adults. Should change be similar between tests of walking ability, separate retesting of prolonged walking may need to be reconsidered. Design A longitudinal, observational cohort study was conducted. Methods Data were from 1,893 older adults who were well-functioning (≥70 years of age). The 20-m walk and 2-minute walk were repeatedly measured over 8 years to measure change during short and prolonged periods of walking, respectively. Change was examined using a dual group-based trajectory model (dual model), and agreement between walking trajectories was quantified with a weighted kappa statistic. Results Three trajectory groups for the 20-m walk and 2-minute walk were identified. More than 86% of the participants were in similar trajectory groups for both tests from the dual model. There was high chance-corrected agreement (kappa=.84; 95% confidence interval=.82, .86) between the 20-m walk and 2-minute walk trajectory groups. Limitations One-third of the original Health, Aging and Body Composition (Health ABC) study cohort was excluded from analysis due to missing clinic visits, followed by being excluded for health reasons for performing the 2-minute walk, limiting generalizability to healthy older adults. Conclusions Patterns of change in the 2-minute walk are similar to those in the 20-m walk. Thus, separate retesting of the 2-minute walk may need to be reconsidered to gauge change in prolonged walking. PMID:24786943

Effects of a 6-Week Aquatic Treadmill Exercise Program on Cardiorespiratory Fitness and Walking Endurance in Subacute Stroke Patients: A PILOT TRIAL.

PubMed

Han, Eun Young; Im, Sang Hee

2017-03-15

To assess the feasibility and safety of a 6-week course of water walking performed using a motorized aquatic treadmill in individuals with subacute stroke for cardiorespiratory fitness, walking endurance, and activities of daily living. Twenty subacute stroke patents were randomly assigned to aquatic treadmill exercise (ATE) or land-based exercise (LBE). The ATE group (n = 10) performed water-based aerobic exercise on a motorized aquatic treadmill, and the LBE group (n = 10) performed land-based aerobic exercise on a cycle ergometer. Both groups performed aerobic exercise for 30 minutes, 5 times per week for 6 weeks. Primary outcome measures were 6-minute walk test for walking endurance and cardiopulmonary fitness parameters of a symptom-limited exercise tolerance test, and secondary measures were Korean version of the Modified Barthel Index (K-MBI) for activities of daily living. All variables were assessed at baseline and at the end of the intervention. The ATE group showed significant improvements in 6-minute walk test (P = .005), peak oxygen uptake (V·o2peak; P = .005), peak heart rate (P = .007), exercise tolerance test duration (P = .005), and K-MBI (P = .008). The LBE group showed a significant improvement only in K-MBI (P = .012). In addition, improvement in V·o2peak was greater in the ATE than in the LBE group. This preliminary study showed that a 6-week ATE program improved peak aerobic capacity and walking endurance in patients with subacute stroke. The improvement in V·o2peak after an ATE exercise program was greater than that observed after an LBE program. Therefore, ATE effectively improves cardiopulmonary fitness in patients with subacute stroke.

Using an agent-based model to simulate children’s active travel to school

PubMed Central

2013-01-01

Background Despite the multiple advantages of active travel to school, only a small percentage of US children and adolescents walk or bicycle to school. Intervention studies are in a relatively early stage and evidence of their effectiveness over long periods is limited. The purpose of this study was to illustrate the utility of agent-based models in exploring how various policies may influence children’s active travel to school. Methods An agent-based model was developed to simulate children’s school travel behavior within a hypothetical city. The model was used to explore the plausible implications of policies targeting two established barriers to active school travel: long distance to school and traffic safety. The percent of children who walk to school was compared for various scenarios. Results To maximize the percent of children who walk to school the school locations should be evenly distributed over space and children should be assigned to the closest school. In the case of interventions to improve traffic safety, targeting a smaller area around the school with greater intensity may be more effective than targeting a larger area with less intensity. Conclusions Despite the challenges they present, agent based models are a useful complement to other analytical strategies in studying the plausible impact of various policies on active travel to school. PMID:23705953

Using an agent-based model to simulate children's active travel to school.

PubMed

Yang, Yong; Diez-Roux, Ana V

2013-05-26

Despite the multiple advantages of active travel to school, only a small percentage of US children and adolescents walk or bicycle to school. Intervention studies are in a relatively early stage and evidence of their effectiveness over long periods is limited. The purpose of this study was to illustrate the utility of agent-based models in exploring how various policies may influence children's active travel to school. An agent-based model was developed to simulate children's school travel behavior within a hypothetical city. The model was used to explore the plausible implications of policies targeting two established barriers to active school travel: long distance to school and traffic safety. The percent of children who walk to school was compared for various scenarios. To maximize the percent of children who walk to school the school locations should be evenly distributed over space and children should be assigned to the closest school. In the case of interventions to improve traffic safety, targeting a smaller area around the school with greater intensity may be more effective than targeting a larger area with less intensity. Despite the challenges they present, agent based models are a useful complement to other analytical strategies in studying the plausible impact of various policies on active travel to school.

Action observation training of community ambulation for improving walking ability of patients with post-stroke hemiparesis: a randomized controlled pilot trial.

PubMed

Park, Hyun-Ju; Oh, Duck-Won; Choi, Jong-Duk; Kim, Jong-Man; Kim, Suhn-Yeop; Cha, Yong-Jun; Jeon, Su-Jin

2017-08-01

To investigate the effects of action observation training involving community-based ambulation for improving walking ability after stroke. Randomized, controlled pilot study. Inpatient rehabilitation hospital. A total of 25 inpatients with post-stroke hemiparesis were randomly assigned to either the experimental group ( n = 12) or control group ( n = 13). Subjects of the experimental group watched video clips demonstrating four-staged ambulation training with a more complex environment factor for 30 minutes, three times a week for four weeks. Meanwhile, subjects of the control group watched video clips, which showed different landscape pictures. Walking function was evaluated before and after the four-week intervention using a 10-m walk test, community walk test, activities-specific balance confidence scale, and spatiotemporal gait measures. Changes in the values for the 10-m walk test (0.17 ±0.19 m/s vs. 0.05 ±0.08 m/s), community walk test (-151.42 ±123.82 seconds vs. 67.08 ±176.77 seconds), and activities-specific balance confidence (6.25 ±5.61 scores vs. 0.72 ±2.24 scores) and the spatiotemporal parameters (i.e. stride length (19.00 ±11.34 cm vs. 3.16 ±11.20 cm), single support (5.87 ±5.13% vs. 0.25 ±5.95%), and velocity (15.66 ±12.34 cm/s vs. 2.96 ±10.54 cm/s)) indicated a significant improvement in the experimental group compared with the control group. In the experimental group, walking function and ambulation confidence was significantly different between the pre- and post-intervention, whereas the control group showed a significant difference only in the 10-m walk test. Action observation training of community ambulation may be favorably used for improving walking function of patients with post-stroke hemiparesis.

Comparison of training methods to improve walking in persons with chronic spinal cord injury: a randomized clinical trial

PubMed Central

Alexeeva, Natalia; Sames, Carol; Jacobs, Patrick L.; Hobday, Lori; DiStasio, Marcello M.; Mitchell, Sarah A.; Calancie, Blair

2011-01-01

Objective To compare two forms of device-specific training – body-weight-supported (BWS) ambulation on a fixed track (TRK) and BWS ambulation on a treadmill (TM) – to comprehensive physical therapy (PT) for improving walking speed in persons with chronic, motor-incomplete spinal cord injury (SCI). Methods Thirty-five adult subjects with a history of chronic SCI (>1 year; AIS ‘C’ or ‘D’) participated in a 13-week (1 hour/day; 3 days per week) training program. Subjects were randomized into one of the three training groups. Subjects in the two BWS groups trained without the benefit of additional input from a physical therapist or gait expert. For each training session, performance values and heart rate were monitored. Pre- and post-training maximal 10-m walking speed, balance, muscle strength, fitness, and quality of life were assessed in each subject. Results All three training groups showed significant improvement in maximal walking speed, muscle strength, and psychological well-being. A significant improvement in balance was seen for PT and TRK groups but not for subjects in the TM group. In all groups, post-training measures of fitness, functional independence, and perceived health and vitality were unchanged. Conclusions Our results demonstrate that persons with chronic, motor-incomplete SCI can improve walking ability and psychological well-being following a concentrated period of ambulation therapy, regardless of training method. Improvement in walking speed was associated with improved balance and muscle strength. In spite of the fact that we withheld any formal input of a physical therapist or gait expert from subjects in the device-specific training groups, these subjects did just as well as subjects receiving comprehensive PT for improving walking speed and strength. It is likely that further modest benefits would accrue to those subjects receiving a combination of device-specific training with input from a physical therapist or gait expert to guide that training. PMID:21903010

The effect of impedance-controlled robotic gait training on walking ability and quality in individuals with chronic incomplete spinal cord injury: an explorative study.

PubMed

Fleerkotte, Bertine M; Koopman, Bram; Buurke, Jaap H; van Asseldonk, Edwin H F; van der Kooij, Herman; Rietman, Johan S

2014-03-04

There is increasing interest in the use of robotic gait-training devices in walking rehabilitation of incomplete spinal cord injured (iSCI) individuals. These devices provide promising opportunities to increase the intensity of training and reduce physical demands on therapists. Despite these potential benefits, robotic gait-training devices have not yet demonstrated clear advantages over conventional gait-training approaches, in terms of functional outcomes. This might be due to the reduced active participation and step-to-step variability in most robotic gait-training strategies, when compared to manually assisted therapy. Impedance-controlled devices can increase active participation and step-to-step variability. The aim of this study was to assess the effect of impedance-controlled robotic gait training on walking ability and quality in chronic iSCI individuals. A group of 10 individuals with chronic iSCI participated in an explorative clinical trial. Participants trained three times a week for eight weeks using an impedance-controlled robotic gait trainer (LOPES: LOwer extremity Powered ExoSkeleton). Primary outcomes were the 10-meter walking test (10 MWT), the Walking Index for Spinal Cord Injury (WISCI II), the six-meter walking test (6 MWT), the Timed Up and Go test (TUG) and the Lower Extremity Motor Scores (LEMS). Secondary outcomes were spatiotemporal and kinematics measures. All participants were tested before, during, and after training and at 8 weeks follow-up. Participants experienced significant improvements in walking speed (0.06 m/s, p = 0.008), distance (29 m, p = 0.005), TUG (3.4 s, p = 0.012), LEMS (3.4, p = 0.017) and WISCI after eight weeks of training with LOPES. At the eight-week follow-up, participants retained the improvements measured at the end of the training period. Significant improvements were also found in spatiotemporal measures and hip range of motion. Robotic gait training using an impedance-controlled robot is feasible in gait rehabilitation of chronic iSCI individuals. It leads to improvements in walking ability, muscle strength, and quality of walking. Improvements observed at the end of the training period persisted at the eight-week follow-up. Slower walkers benefit the most from the training protocol and achieve the greatest relative improvement in speed and walking distance.

The effect of impedance-controlled robotic gait training on walking ability and quality in individuals with chronic incomplete spinal cord injury: an explorative study

PubMed Central

2014-01-01

Background There is increasing interest in the use of robotic gait-training devices in walking rehabilitation of incomplete spinal cord injured (iSCI) individuals. These devices provide promising opportunities to increase the intensity of training and reduce physical demands on therapists. Despite these potential benefits, robotic gait-training devices have not yet demonstrated clear advantages over conventional gait-training approaches, in terms of functional outcomes. This might be due to the reduced active participation and step-to-step variability in most robotic gait-training strategies, when compared to manually assisted therapy. Impedance-controlled devices can increase active participation and step-to-step variability. The aim of this study was to assess the effect of impedance-controlled robotic gait training on walking ability and quality in chronic iSCI individuals. Methods A group of 10 individuals with chronic iSCI participated in an explorative clinical trial. Participants trained three times a week for eight weeks using an impedance-controlled robotic gait trainer (LOPES: LOwer extremity Powered ExoSkeleton). Primary outcomes were the 10-meter walking test (10MWT), the Walking Index for Spinal Cord Injury (WISCI II), the six-meter walking test (6MWT), the Timed Up and Go test (TUG) and the Lower Extremity Motor Scores (LEMS). Secondary outcomes were spatiotemporal and kinematics measures. All participants were tested before, during, and after training and at 8 weeks follow-up. Results Participants experienced significant improvements in walking speed (0.06 m/s, p = 0.008), distance (29 m, p = 0.005), TUG (3.4 s, p = 0.012), LEMS (3.4, p = 0.017) and WISCI after eight weeks of training with LOPES. At the eight-week follow-up, participants retained the improvements measured at the end of the training period. Significant improvements were also found in spatiotemporal measures and hip range of motion. Conclusion Robotic gait training using an impedance-controlled robot is feasible in gait rehabilitation of chronic iSCI individuals. It leads to improvements in walking ability, muscle strength, and quality of walking. Improvements observed at the end of the training period persisted at the eight-week follow-up. Slower walkers benefit the most from the training protocol and achieve the greatest relative improvement in speed and walking distance. PMID:24594284

A Novel Mobility Device to Improve Walking for a Child With Cerebral Palsy.

PubMed

Fergus, Andrea

2017-10-01

To describe the use and outcomes associated with the Upsee in conjunction with Kinesiotape for a child with cerebral palsy. The Upsee and Kinesiotaping were implemented for 24 weeks with a 31-month-old child with cerebral palsy, Gross Motor Function Classification System level III. She progressed from walking with maximal assistance and extensive gait deviations to walking with supervision with a walker on level surfaces with improved gait. Genu recurvatum, heel strike, scissoring, hip extension, foot placement, step length, and stiff knee in swing improved on the basis of videotaped analyses. The Gross Motor Function Measure-66 improved by 11.4. The Upsee is a clinically feasible approach for gait impairments in children through providing increased opportunities for walking while supporting biomechanical alignment. Upsee effectiveness with and without taping is an area for future study.

Hydrotherapy vs. conventional land-based exercise for improving walking and balance after stroke: a randomized controlled trial.

PubMed

Zhu, Zhizhong; Cui, Liling; Yin, Miaomiao; Yu, Yang; Zhou, Xiaona; Wang, Hongtu; Yan, Hua

2016-06-01

To investigate the effects of hydrotherapy on walking ability and balance in patients with chronic stroke. Single-blind, randomized controlled pilot trial. Outpatient rehabilitation clinic at a tertiary neurological hospital in China. A total of 28 participants with impairments in walking and controlling balance more than six months post-stroke. After baseline evaluations, participants were randomly assigned to a land-based therapy (control group, n = 14) or hydrotherapy (study group, n = 14). Participants underwent individual sessions for four weeks, five days a week, for 45 minutes per session. After four weeks of rehabilitation, all participants were evaluated by a blinded assessor. Functional assessments included the Functional Reach Test, Berg Balance Scale, 2-minute walk test, and Timed Up and Go Test. After four weeks of treatment, the Berg Balance Scale, functional reach test, 2-minute walk test, and the Timed Up and Go Test scores had improved significantly in each group (P < 0.05). The mean improvement of the functional reach test and 2-minute walk test were significantly higher in the aquatic group than in the control group (P < 0.01). The differences in the mean values of the improvements in the Berg Balance Scale and the Timed Up and Go Test were not statistically significant. The results of this study suggest that a relatively short programme (four weeks) of hydrotherapy exercise resulted in a large improvement in a small group (n = 14) of individuals with relatively high balance and walking function following a stroke. © The Author(s) 2015.

Effects of Nordic walking on physical functions and depression in frail people aged 70 years and above.

PubMed

Lee, Han Suk; Park, Jeung Hun

2015-08-01

[Purpose] This study investigated the effects of Nordic walking on physical functions and depression in frail people aged 70 years and above. [Subjects] Twenty frail elderly individuals ≥70 years old were assigned to either a Nordic walking group (n=8) or general exercise group (n=10). [Methods] The duration of intervention was equal in both groups (3 sessions/week for 12 weeks, 60 min/session). Physical function (balance, upper extremity strength, lower extremity strength, weakness) and depression were examined before and after the interventions. [Results] With the exception of upper extremity muscle strength, lower extremity strength, weakness, balance, and depression after Nordic walking demonstrated statistically significant improvement. However, in the general exercise group, only balance demonstrated a statistically significant improvement after the intervention. There were significant differences in the changes in lower extremity muscle strength, weakness and depression between the groups. [Conclusion] In conclusion, Nordic walking was more effective than general exercise. Therefore, we suggest that Nordic walking may be an attractive option for significant functional improvement in frail people over 70 years old.

The impact of an anti-gravity treadmill (AlterG) training on walking capacity and corticospinal tract structure in children with cerebral palsy.

PubMed

Azizi, Sh; Marzbani, H; Raminfard, S; Birgani, P M; Rasooli, A H; Mirbagheri, M M

2017-07-01

We studied the effects of an anti-gravity treadmill (AlterG) training on walking capacity and corticospinal tract structure in children with Cerebral Palsy (CP). AlterG can help CP children walk on the treadmill by reducing their weights up to 80% and maintain their balance during locomotion. AlterG training thus has the potential to improve walking capacity permanently as it can provide systematic and intense locomotor training for sufficiently long period of time and produce brain neuroplasticity. AlterG training was given for 45 minutes, three times a week for two months. The neuroplasticity of corticospinal tract was evaluated using Diffusion Tensor Imaging (DTI). The fractional Anisotropy (FA) feature was extracted to quantify structural changes of the corticospinal tract. Walking capacity was evaluated using popular clinical measurements of gait; i.e., walking speed, mobility and balance. The evaluations were done before and after training. Our results revealed that AlterG training resulted in an increase in average FA value of the corticospinal tract following the training. The outcome measures of clinical assessments of gait presented enhanced walking capacity of the CP subjects. Our findings indicated that the improved walking capacity was concurrent with the enhancement of the corticospinal tract structure. The clinical implication is that AlterG training may be considered as a therapeutic tool for permanent gait improvement in CP children.

Robotically assisted treadmill exercise training for improving peak fitness in chronic motor incomplete spinal cord injury: A randomized controlled trial

PubMed Central

Scott, William; York, Henry; Theyagaraj, Melita; Price-Miller, Naomi; McQuaid, Jean; Eyvazzadeh, Megan; Ivey, Frederick M.; Macko, Richard F.

2016-01-01

Objective To assess the effectiveness of robotically assisted body weight supported treadmill training (RABWSTT) for improving cardiovascular fitness in chronic motor incomplete spinal cord injury (CMISCI). Design Pilot prospective randomized, controlled clinical trial. Setting Outpatient rehabilitation specialty hospital. Participants Eighteen individuals with CMISCI with American Spinal Injury Association (ASIA) level between C4 and L2 and at least one-year post injury. Interventions CMISCI participants were randomized to RABWSTT or a home stretching program (HSP) three times per week for three months. Those in the home stretching group were crossed over to three months of RABWSTT following completion of the initial three month phase. Outcome measures Peak oxygen consumption (peak VO2) was measured during both robotic treadmill walking and arm cycle ergometry: twice at baseline, once at six weeks (mid-training) and twice at three months (post-training). Peak VO2 values were normalized for body mass. Results The RABWSTT group improved peak VO2 by 12.3% during robotic treadmill walking (20.2 ± 7.4 to 22.7 ± 7.5 ml/kg/min, P = 0.018), compared to a non-significant 3.9% within group change observed in HSP controls (P = 0.37). Neither group displayed a significant change in peak VO2 during arm cycle ergometry (RABWSTT, 8.5% (P = 0.25); HSP, 1.76% (P = 0.72)). A repeated measures analysis showed statistically significant differences between treatments for peak VO2 during both robotic treadmill walking (P = 0.002) and arm cycle ergometry (P = 0.001). Conclusion RABWSTT is an effective intervention model for improving peak fitness levels assessed during robotic treadmill walking in persons with CMISCI. PMID:25520035

Quantitative measures of walking and strength provide insight into brain corticospinal tract pathology in multiple sclerosis.

PubMed

Fritz, Nora E; Keller, Jennifer; Calabresi, Peter A; Zackowski, Kathleen M

2017-01-01

At least 85% of individuals with multiple sclerosis report walking dysfunction as their primary complaint. Walking and strength measures are common clinical measures to mark increasing disability or improvement with rehabilitation. Previous studies have shown an association between strength or walking ability and spinal cord MRI measures, and strength measures with brainstem corticospinal tract magnetization transfer ratio. However, the relationship between walking performance and brain corticospinal tract magnetization transfer imaging measures and the contribution of clinical measurements of walking and strength to the underlying integrity of the corticospinal tract has not been explored in multiple sclerosis. The objectives of this study were explore the relationship of quantitative measures of walking and strength to whole-brain corticospinal tract-specific MRI measures and to determine the contribution of quantitative measures of function in addition to basic clinical measures (age, gender, symptom duration and Expanded Disability Status Scale) to structural imaging measures of the corticospinal tract. We hypothesized that quantitative walking and strength measures would be related to brain corticospinal tract-specific measures, and would provide insight into the heterogeneity of brain pathology. Twenty-nine individuals with relapsing-remitting multiple sclerosis (mean(SD) age 48.7 (11.5) years; symptom duration 11.9(8.7); 17 females; median[range] Expanded Disability Status Scale 4.0 [1.0-6.5]) and 29 age and gender-matched healthy controls (age 50.8(11.6) years; 20 females) participated in clinical tests of strength and walking (Timed Up and Go, Timed 25 Foot Walk, Two Minute Walk Test ) as well as 3 T imaging including diffusion tensor imaging and magnetization transfer imaging. Individuals with multiple sclerosis were weaker (p = 0.0024) and walked slower (p = 0.0013) compared to controls. Quantitative measures of walking and strength were significantly related to corticospinal tract fractional anisotropy (r > 0.26; p < 0.04) and magnetization transfer ratio (r > 0.29; p < 0.03) measures. Although the Expanded Disability Status Scale was highly correlated with walking measures, it was not significantly related to either corticospinal tract fractional anisotropy or magnetization transfer ratio (p > 0.05). Walk velocity was a significant contributor to magnetization transfer ratio (p = 0.006) and fractional anisotropy (p = 0.011) in regression modeling that included both quantitative measures of function and basic clinical information. Quantitative measures of strength and walking are associated with brain corticospinal tract pathology. The addition of these quantitative measures to basic clinical information explains more of the variance in corticospinal tract fractional anisotropy and magnetization transfer ratio than the basic clinical information alone. Outcome measurement for multiple sclerosis clinical trials has been notoriously challenging; the use of quantitative measures of strength and walking along with tract-specific imaging methods may improve our ability to monitor disease change over time, with intervention, and provide needed guidelines for developing more effective targeted rehabilitation strategies.

Antipersistent dynamics in kinetic models of wealth exchange

NASA Astrophysics Data System (ADS)

Goswami, Sanchari; Chatterjee, Arnab; Sen, Parongama

2011-11-01

We investigate the detailed dynamics of gains and losses made by agents in some kinetic models of wealth exchange. An earlier work suggested that a walk in an abstract gain-loss space can be conceived for the agents. For models in which agents do not save, or save with uniform saving propensity, the walk has diffusive behavior. For the case in which the saving propensity λ is distributed randomly (0≤λ<1), the resultant walk showed a ballistic nature (except at a particular value of λ*≈0.47). Here we consider several other features of the walk with random λ. While some macroscopic properties of this walk are comparable to a biased random walk, at microscopic level, there are gross differences. The difference turns out to be due to an antipersistent tendency toward making a gain (loss) immediately after making a loss (gain). This correlation is in fact present in kinetic models without saving or with uniform saving as well, such that the corresponding walks are not identical to ordinary random walks. In the distributed saving case, antipersistence occurs with a simultaneous overall bias.

Interactive locomotion: Investigation and modeling of physically-paired humans while walking

PubMed Central

Le Goff, Camille G.; Ijspeert, Auke Jan

2017-01-01

In spite of extensive studies on human walking, less research has been conducted on human walking gait adaptation during interaction with another human. In this paper, we study a particular case of interactive locomotion where two humans carry a rigid object together. Experimental data from two persons walking together, one in front of the other, while carrying a stretcher-like object is presented, and the adaptation of their walking gaits and coordination of the foot-fall patterns are analyzed. It is observed that in more than 70% of the experiments the subjects synchronize their walking gaits; it is shown that these walking gaits can be associated to quadrupedal gaits. Moreover, in order to understand the extent by which the passive dynamics can explain this synchronization behaviour, a simple 2D model, made of two-coupled spring-loaded inverted pendulums, is developed, and a comparison between the experiments and simulations with this model is presented, showing that with this simple model we are able to reproduce some aspects of human walking behaviour when paired with another human. PMID:28877161

Architectures for wrist-worn energy harvesting

NASA Astrophysics Data System (ADS)

Rantz, R.; Halim, M. A.; Xue, T.; Zhang, Q.; Gu, L.; Yang, K.; Roundy, S.

2018-04-01

This paper reports the simulation-based analysis of six dynamical structures with respect to their wrist-worn vibration energy harvesting capability. This work approaches the problem of maximizing energy harvesting potential at the wrist by considering multiple mechanical substructures; rotational and linear motion-based architectures are examined. Mathematical models are developed and experimentally corroborated. An optimization routine is applied to the proposed architectures to maximize average power output and allow for comparison. The addition of a linear spring element to the structures has the potential to improve power output; for example, in the case of rotational structures, a 211% improvement in power output was estimated under real walking excitation. The analysis concludes that a sprung rotational harvester architecture outperforms a sprung linear architecture by 66% when real walking data is used as input to the simulations.

Evaluation of measurements of propulsion used to reflect changes in walking speed in individuals poststroke.

PubMed

Hsiao, HaoYuan; Zabielski, Thomas M; Palmer, Jacqueline A; Higginson, Jill S; Binder-Macleod, Stuart A

2016-12-08

Recent rehabilitation approaches for individuals poststroke have focused on improving walking speed because it is a reliable measurement that is associated with quality of life. Previous studies have demonstrated that propulsion, the force used to propel the body forward, determines walking speed. However, there are several different ways of measuring propulsion and no studies have identified which measurement best reflects differences in walking speed. The primary purposes of this study were to determine for individuals poststroke, which measurement of propulsion (1) is most closely related to their self-selected walking speeds and (2) best reflects changes in walking speed within a session. Participants (N=43) with chronic poststroke hemiparesis walked at their self-selected and maximal walking speeds on a treadmill. Propulsive impulse, peak propulsive force, and mean propulsive value (propulsive impulse divided by duration) were analyzed. In addition, each participant׳s cadence was calculated. Pearson correlation coefficients were used to determine the relationships between different measurements of propulsion versus walking speed as well as changes in propulsion versus changes in walking speed. Stepwise linear regression was used to determine which measurement of propulsion best predicted walking speed and changes in walking speed. The results showed that all 3 measurements of propulsion were correlated to walking speed, with peak propulsive force showed the strongest correlation. Similarly, when participants increased their walking speeds, changes in peak propulsive forces showed the strongest correlation to changes in walking speed. In addition, multiplying each measurement by cadence improved the correlations. The present study suggests that measuring peak propulsive force and cadence may be most appropriate of the variables studied to characterize propulsion in individuals poststroke. Copyright © 2016 Elsevier Ltd. All rights reserved.

Superdiffusion in a non-Markovian random walk model with a Gaussian memory profile

NASA Astrophysics Data System (ADS)

Borges, G. M.; Ferreira, A. S.; da Silva, M. A. A.; Cressoni, J. C.; Viswanathan, G. M.; Mariz, A. M.

2012-09-01

Most superdiffusive Non-Markovian random walk models assume that correlations are maintained at all time scales, e.g., fractional Brownian motion, Lévy walks, the Elephant walk and Alzheimer walk models. In the latter two models the random walker can always "remember" the initial times near t = 0. Assuming jump size distributions with finite variance, the question naturally arises: is superdiffusion possible if the walker is unable to recall the initial times? We give a conclusive answer to this general question, by studying a non-Markovian model in which the walker's memory of the past is weighted by a Gaussian centered at time t/2, at which time the walker had one half the present age, and with a standard deviation σt which grows linearly as the walker ages. For large widths we find that the model behaves similarly to the Elephant model, but for small widths this Gaussian memory profile model behaves like the Alzheimer walk model. We also report that the phenomenon of amnestically induced persistence, known to occur in the Alzheimer walk model, arises in the Gaussian memory profile model. We conclude that memory of the initial times is not a necessary condition for generating (log-periodic) superdiffusion. We show that the phenomenon of amnestically induced persistence extends to the case of a Gaussian memory profile.

Stochastic models for atomic clocks

NASA Technical Reports Server (NTRS)

Barnes, J. A.; Jones, R. H.; Tryon, P. V.; Allan, D. W.

1983-01-01

For the atomic clocks used in the National Bureau of Standards Time Scales, an adequate model is the superposition of white FM, random walk FM, and linear frequency drift for times longer than about one minute. The model was tested on several clocks using maximum likelihood techniques for parameter estimation and the residuals were acceptably random. Conventional diagnostics indicate that additional model elements contribute no significant improvement to the model even at the expense of the added model complexity.

Revealing and Resolving Patient Safety Defects: The Impact of Leadership WalkRounds on Frontline Caregiver Assessments of Patient Safety

PubMed Central

Frankel, Allan; Grillo, Sarah Pratt; Pittman, Mary; Thomas, Eric J; Horowitz, Lisa; Page, Martha; Sexton, Bryan

2008-01-01

Objective To evaluate the impact of rigorous WalkRounds on frontline caregiver assessments of safety climate, and to clarify the steps and implementation of rigorous WalkRounds. Data Sources/Study Setting Primary outcome variables were baseline and post WalkRounds safety climate scores from the Safety Attitudes Questionnaire (SAQ). Secondary outcomes were safety issues elicited through WalkRounds. Study period was August 2002 to April 2005; seven hospitals in Massachusetts agreed to participate; and the project was implemented in all patient care areas. Study Design Prospective study of the impact of rigorously applied WalkRounds on frontline caregivers assessments of safety climate in their patient care area. WalkRounds were conducted weekly and according to the seven-step WalkRounds Guide. The SAQ was administered at baseline and approximately 18 months post-WalkRounds implementation to all caregivers in patient care areas. Results Two of seven hospitals complied with the rigorous WalkRounds approach; hospital A was an academic teaching center and hospital B a community teaching hospital. Of 21 patient care areas, SAQ surveys were received from 62 percent of respondents at baseline and 60 percent post WalkRounds. At baseline, 10 of 21 care areas (48 percent) had safety climate scores below 60 percent, whereas post-WalkRounds three care areas (14 percent) had safety climate scores below 60 percent without improving by 10 points or more. Safety climate scale scores in hospital A were 62 percent at baseline and 77 percent post-WalkRounds (t=2.67, p=.03), and in hospital B were 46 percent at baseline and 56 percent post WalkRounds (t=2.06, p=.06). Main safety issues by category were equipment/facility (A [26 percent] and B [33 percent]) and communication (A [24 percent] and B [18 percent]). Conclusions WalkRounds implementation requires significant organizational will; sustainability requires outstanding project management and leadership engagement. In the patient care areas that rigorously implemented WalkRounds, frontline caregiver assessments of patient safety increased. SAQ results such as safety climate scores facilitate the triage of quality improvement efforts, and provide consensus assessments of frontline caregivers that identify themes for improvement. PMID:18671751

Impact of total hip arthroplasty on pain, walking ability, and cardiovascular fitness.

PubMed

Horstmann, Thomas; Vornholt-Koch, Sandra; Brauner, Torsten; Grau, Stefan; Mündermann, Annegret

2012-12-01

We tested the hypothesis that total hip arthroplasty (THA) patients have less pain and are able to walk longer post-operatively than pre-operatively, and that THA patients before and after have higher heart rates and compromised gas exchange determinants at rest and following exercise compared to healthy subjects with a post-operative improvement. Fifty-two patients completed questionnaires and an incremental walking stress test pre-operatively and 6-months after THA. Twenty-four age-matched control subjects completed the same stress test. Fifty-one patients had less pain 6-months after THA compared to pre-operative levels. Forty-three patients showed an improvement of at least one walking duration category. Patients had compromised cardiovascular fitness compared to the control group with a tendency to improve after THA. Hence, 6-months following THA, deficits exist other than reduced strength as reported in the literature. Prior to THA, the ability to walk longer is compromised by pain and not by poor cardiovascular fitness. Studies on specific rehabilitation programs of varying intensities may demonstrate opportunities to improve the cardiovascular fitness of this population. Copyright © 2012 Orthopaedic Research Society.

Cost-effectiveness of investing in sidewalks as a means of increasing physical activity: a RESIDE modelling study.

PubMed

Veerman, J Lennert; Zapata-Diomedi, Belen; Gunn, Lucy; McCormack, Gavin R; Cobiac, Linda J; Mantilla Herrera, Ana Maria; Giles-Corti, Billie; Shiell, Alan

2016-09-20

Studies consistently find that supportive neighbourhood built environments increase physical activity by encouraging walking and cycling. However, evidence on the cost-effectiveness of investing in built environment interventions as a means of promoting physical activity is lacking. In this study, we assess the cost-effectiveness of increasing sidewalk availability as one means of encouraging walking. Using data from the RESIDE study in Perth, Australia, we modelled the cost impact and change in health-adjusted life years (HALYs) of installing additional sidewalks in established neighbourhoods. Estimates of the relationship between sidewalk availability and walking were taken from a previous study. Multistate life table models were used to estimate HALYs associated with changes in walking frequency and duration. Sensitivity analyses were used to explore the impact of variations in population density, discount rates, sidewalk costs and the inclusion of unrelated healthcare costs in added life years. Installing and maintaining an additional 10 km of sidewalk in an average neighbourhood with 19 000 adult residents was estimated to cost A$4.2 million over 30 years and gain 24 HALYs over the lifetime of an average neighbourhood adult resident population. The incremental cost-effectiveness ratio was A$176 000/HALY. However, sensitivity results indicated that increasing population densities improves cost-effectiveness. In low-density cities such as in Australia, installing sidewalks in established neighbourhoods as a single intervention is unlikely to cost-effectively improve health. Sidewalks must be considered alongside other complementary elements of walkability, such as density, land use mix and street connectivity. Population density is particularly important because at higher densities, more residents are exposed and this improves the cost-effectiveness. Health gain is one of many benefits of enhancing neighbourhood walkability and future studies might consider a more comprehensive assessment of its social value (eg, social cohesion, safety and air quality). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Adaptive gait responses to awareness of an impending slip during treadmill walking.

PubMed

Yang, Feng; Kim, JaeEun; Munoz, Jose

2016-10-01

The awareness of potential slip risk has been shown to cause protective changes to human gait during overground walking. It remains unknown if such adaptations to walking pattern also exist when ambulating on a treadmill. This study sought to determine whether and to what extent individuals, when being aware of a potential slip risk during treadmill walking, could adjust their gait pattern to improve their dynamic stability against backward balance loss in response to the impending slip hazard. Fifty-four healthy young subjects (age: 23.9±4.7years) participated in this study. Subjects' gait pattern was measured under two conditions: walking on a treadmill without (or normal walking) and with (or aware walking) the awareness of the potential slip perturbation. During both walking conditions, subjects' full body kinematics were gathered by using a motion capture system. Spatial gait parameters and the dynamic gait stability against backward balance were compared between the two walking conditions. The results revealed that subjects proactively adopted a "cautious gait" during aware walking compared with the normal walking. The cautious gait, which was achieved by taking a shorter step and a more flatfoot landing, positioned the body center of mass closer to the base of support, improving participants' dynamic stability and increasing their resistance against a possible slip-related fall. The finding from this study could provide insights into the dynamic stability control when individuals anticipate potential slip risk during treadmill walking. Copyright © 2016 Elsevier B.V. All rights reserved.

Kinematic Gait Changes Following Serial Casting and Bracing to Treat Toe Walking in a Child With Autism.

PubMed

Barkocy, Marybeth; Dexter, James; Petranovich, Colleen

2017-07-01

To evaluate the effectiveness of serial casting in a child with autism spectrum disorder (ASD) exhibiting a toe-walking gait pattern with equinus contractures. Although many children with ASD toe walk, little research on physical therapy interventions exists for this population. Serial casting has been validated for use in idiopathic toe walking to increase passive dorsiflexion and improve gait, but not for toe walking in children with ASD. Serial casting followed by ankle-foot orthosis use was implemented to treat a child with ASD who had an obligatory equinus gait pattern. Gait analysis supported improvements in kinematic, spatial, and temporal parameters of gait, and the child maintained a consistent heel-toe gait at 2-year follow-up. STATEMENT OF CONCLUSION AND RECOMMENDATIONS FOR CLINICAL PRACTICE:: Serial casting followed by ankle-foot orthosis use is a viable treatment option for toe walking in children with ASD.

Stilt walking: how do we learn those first steps?

PubMed

Akram, Sakineh B; Frank, James S

2009-09-01

This study examined how young healthy adults learn stilt walking. Ten healthy male university students attended two sessions of testing held on two consecutive days. In each session participants performed three blocks of 10 stilt-walking trials. Angular movements of head and trunk and the spatial and temporal gait parameters were recorded. When walking on stilts young adults improved their gait velocity through modifications of step parameters while maintaining trunk movements close to that observed during normal over-ground walking. Participants improved their performance by increasing their step frequency and step length and reducing the double support percentage of the gait cycle. Stilts are often used for drywall installation, painting over-the-head areas and raising workers above the ground without the burden of erecting scaffolding. This research examines the locomotor adaptation as young healthy adults learn the complex motor task of stilt walking; a task that is frequently used in the construction industry.

Assessment of Walking Stability of Elderly by Means of Nonlinear Time-Series Analysis and Simple Accelerometry

NASA Astrophysics Data System (ADS)

Ohtaki, Yasuaki; Arif, Muhammad; Suzuki, Akihiro; Fujita, Kazuki; Inooka, Hikaru; Nagatomi, Ryoichi; Tsuji, Ichiro

This study presents an assessment of walking stability in elderly people, focusing on local dynamic stability of walking. Its main objectives were to propose a technique to quantify local dynamic stability using nonlinear time-series analyses and a portable instrument, and to investigate their reliability in revealing the efficacy of an exercise training intervention for elderly people for improvement of walking stability. The method measured three-dimensional acceleration of the upper body, and computation of Lyapunov exponents, thereby directly quantifying the local stability of the dynamic system. Straight level walking of young and elderly subjects was investigated in the experimental study. We compared Lyapunov exponents of young and the elderly subjects, and of groups before and after the exercise intervention. Experimental results demonstrated that the exercise intervention improved local dynamic stability of walking. The proposed method was useful in revealing effects and efficacies of the exercise intervention for elderly people.

Dose-Response Outcomes Associated with Different Forms of Locomotor Training in Persons with Chronic Motor-Incomplete Spinal Cord Injury.

PubMed

Sandler, Evan B; Roach, Kathryn E; Field-Fote, Edelle C

2017-05-15

Outcomes of training are thought to be related to the amount of training (training dose). Although various approaches to locomotor training have been used to improve walking function in persons with spinal cord injury (SCI), little is known about the relationship between dose of locomotor training and walking outcomes. This secondary analysis aimed to identify the relationship between training dose and improvement in walking distance and speed associated with locomotor training in participants with chronic motor-incomplete spinal cord injury (MISCI). We compared the dose-response relationships associated with each of four different locomotor training approaches. Participants were randomized to either: treadmill-based training with manual assistance (TM = 17), treadmill-based training with stimulation (TS = 18), overground training with stimulation (OG = 15), and treadmill-based training with locomotor robotic device assistance (LR = 14). Subjects trained 5 days/week for 12 weeks, with a target of 60 training sessions. The distance-dose and time-dose were calculated based on the total distance and total time, respectively, participants engaged in walking over all sessions combined. Primary outcome measures included walking distance (traversed in 2 min) and walking speed (over 10 m). Only OG training showed a good correlation between distance-dose and change in walking distance and speed walked over ground (r = 0.61, p = 0.02; r = 0.62, p = 0.01). None of the treadmill-based training approaches were associated with significant correlations between training dose and improvement of functional walking outcome. The findings suggest that greater distance achieved over the course of OG training is associated with better walking outcomes in the studied population. Further investigation to identify the essential elements that determine outcomes would be valuable for guiding rehabilitation.

Initial Outcomes from a Multicenter Study Utilizing the Indego Powered Exoskeleton in Spinal Cord Injury.

PubMed

Tefertiller, Candy; Hays, Kaitlin; Jones, Janell; Jayaraman, Arun; Hartigan, Clare; Bushnik, Tamara; Forrest, Gail F

2018-01-01

Objective: To assess safety and mobility outcomes utilizing the Indego powered exoskeleton in indoor and outdoor walking conditions with individuals previously diagnosed with a spinal cord injury (SCI). Methods: We conducted a multicenter prospective observational cohort study in outpatient clinics associated with 5 rehabilitation hospitals. A convenience sample of nonambulatory individuals with SCI ( N = 32) completed an 8-week training protocol consisting of walking training 3 times per week utilizing the Indego powered exoskeleton in indoor and outdoor conditions. Participants were also trained in donning/doffing the exoskeleton during each session. Safety measures such as adverse events (AEs) were monitored and reported. Time and independence with donning/doffing the exoskeleton as well as walking outcomes to include the 10-meter walk test (10MWT), 6-minute walk test (6MWT), Timed Up & Go test (TUG), and 600-meter walk test were evaluated from midpoint to final evaluations. Results: All 32 participants completed the training protocol with limited device-related AEs, which resulted in no interruption in training. The majority of participants in this trial were able to don and doff the Indego independently. Final walking speed ranged from 0.19 to 0.55 m/s. Final average indoor and outdoor walking speeds among all participants were 0.37 m/s ( SD = 0.08, 0.09, respectively), after 8 weeks of training. Significant ( p < .05) improvements were noted between midpoint and final gait speeds in both indoor and outdoor conditions. Average walking endurance also improved among participants after training. Conclusion: The Indego was shown to be safe for providing upright mobility to 32 individuals with SCIs who were nonambulatory. Improvements in speed and independence were noted with walking in indoor and outdoor conditions as well as with donning/doffing the exoskeleton.

The features of Gait Exercise Assist Robot: Precise assist control and enriched feedback.

PubMed

Hirano, Satoshi; Saitoh, Eiichi; Tanabe, Shigeo; Tanikawa, Hiroki; Sasaki, Shinya; Kato, Daisuke; Kagaya, Hitoshi; Itoh, Norihide; Konosu, Hitoshi

2017-01-01

In a patient with severe hemiplegia, the risk of the knee giving way is high during the early stage of gait exercise with an ankle-foot orthosis. However, use of a knee-ankle-foot orthosis has many problems such as large amount of assistance and compensatory motions. To resolve these problems, we have engaged in the development of the Gait Exercise Assist Robot (GEAR). To evaluate the improvement efficiency of walk with GEAR in a stroke patient. The subject was a 70-year-old man presented with left thalamus hemorrhage and right hemiplegia. The patient underwent exercise with the GEAR 5 days a week, for 40 minutes per day. We evaluated the Functional Independence Measure score for walk (FIM-walk score) every week. The control group consisted of 15 patients aged 20-75 years with hemiplegia after primary stroke, who had equivalent walking ability with the subject at start. As the primary outcome, we defined improvement efficiency of FIM-walk, which was gain of FIM-walk divided the number of required weeks. Improvement efficiency of FIM-walk of the subject was 1.5, while that of control group was 0.48±3.2 (mean±SD). GEAR is potentially useful for gait exercise in hemiplegic patients.

Robot-assisted gait training in patients with Parkinson disease: a randomized controlled trial.

PubMed

Picelli, Alessandro; Melotti, Camilla; Origano, Francesca; Waldner, Andreas; Fiaschi, Antonio; Santilli, Valter; Smania, Nicola

2012-05-01

. Gait impairment is a common cause of disability in Parkinson disease (PD). Electromechanical devices to assist stepping have been suggested as a potential intervention. . To evaluate whether a rehabilitation program of robot-assisted gait training (RAGT) is more effective than conventional physiotherapy to improve walking. . A total of 41 patients with PD were randomly assigned to 45-minute treatment sessions (12 in all), 3 days a week, for 4 consecutive weeks of either robotic stepper training (RST; n = 21) using the Gait Trainer or physiotherapy (PT; n = 20) with active joint mobilization and a modest amount of conventional gait training. Participants were evaluated before, immediately after, and 1 month after treatment. Primary outcomes were 10-m walking speed and distance walked in 6 minutes. . Baseline measures revealed no statistical differences between groups, but the PT group walked 0.12 m/s slower; 5 patients withdrew. A statistically significant improvement was found in favor of the RST group (walking speed 1.22 ± 0.19 m/s [P = .035]; distance 366.06 ± 78.54 m [P < .001]) compared with the PT group (0.98 ± 0.32 m/s; 280.11 ± 106.61 m). The RAGT mean speed increased by 0.13 m/s, which is probably not clinically important. Improvements were maintained 1 month later. . RAGT may improve aspects of walking ability in patients with PD. Future trials should compare robotic assistive training with treadmill or equal amounts of overground walking practice.

The First Order Correction to the Exit Distribution for Some Random Walks

NASA Astrophysics Data System (ADS)

Kennedy, Tom

2016-07-01

We study three different random walk models on several two-dimensional lattices by Monte Carlo simulations. One is the usual nearest neighbor random walk. Another is the nearest neighbor random walk which is not allowed to backtrack. The final model is the smart kinetic walk. For all three of these models the distribution of the point where the walk exits a simply connected domain D in the plane converges weakly to harmonic measure on partial D as the lattice spacing δ → 0. Let ω (0,\\cdot ;D) be harmonic measure for D, and let ω _δ (0,\\cdot ;D) be the discrete harmonic measure for one of the random walk models. Our definition of the random walk models is unusual in that we average over the orientation of the lattice with respect to the domain. We are interested in the limit of (ω _δ (0,\\cdot ;D)- ω (0,\\cdot ;D))/δ . Our Monte Carlo simulations of the three models lead to the conjecture that this limit equals c_{M,L} ρ _D(z) times Lebesgue measure with respect to arc length along the boundary, where the function ρ _D(z) depends on the domain, but not on the model or lattice, and the constant c_{M,L} depends on the model and on the lattice, but not on the domain. So there is a form of universality for this first order correction. We also give an explicit formula for the conjectured density ρ _D.

Engineering online and in-person social networks to sustain physical activity: application of a conceptual model.

PubMed

Rovniak, Liza S; Sallis, James F; Kraschnewski, Jennifer L; Sciamanna, Christopher N; Kiser, Elizabeth J; Ray, Chester A; Chinchilli, Vernon M; Ding, Ding; Matthews, Stephen A; Bopp, Melissa; George, Daniel R; Hovell, Melbourne F

2013-08-14

High rates of physical inactivity compromise the health status of populations globally. Social networks have been shown to influence physical activity (PA), but little is known about how best to engineer social networks to sustain PA. To improve procedures for building networks that shape PA as a normative behavior, there is a need for more specific hypotheses about how social variables influence PA. There is also a need to integrate concepts from network science with ecological concepts that often guide the design of in-person and electronically-mediated interventions. Therefore, this paper: (1) proposes a conceptual model that integrates principles from network science and ecology across in-person and electronically-mediated intervention modes; and (2) illustrates the application of this model to the design and evaluation of a social network intervention for PA. A conceptual model for engineering social networks was developed based on a scoping literature review of modifiable social influences on PA. The model guided the design of a cluster randomized controlled trial in which 308 sedentary adults were randomly assigned to three groups: WalkLink+: prompted and provided feedback on participants' online and in-person social-network interactions to expand networks for PA, plus provided evidence-based online walking program and weekly walking tips; WalkLink: evidence-based online walking program and weekly tips only; Minimal Treatment Control: weekly tips only. The effects of these treatment conditions were assessed at baseline, post-program, and 6-month follow-up. The primary outcome was accelerometer-measured PA. Secondary outcomes included objectively-measured aerobic fitness, body mass index, waist circumference, blood pressure, and neighborhood walkability; and self-reported measures of the physical environment, social network environment, and social network interactions. The differential effects of the three treatment conditions on primary and secondary outcomes will be analyzed using general linear modeling (GLM), or generalized linear modeling if the assumptions for GLM cannot be met. Results will contribute to greater understanding of how to conceptualize and implement social networks to support long-term PA. Establishing social networks for PA across multiple life settings could contribute to cultural norms that sustain active living. ClinicalTrials.gov NCT01142804.

Treadmill Training or Progressive Strength Training to Improve Walking in People with Multiple Sclerosis? A Randomized Parallel Group Trial.

PubMed

Braendvik, Siri Merete; Koret, Teija; Helbostad, Jorunn L; Lorås, Håvard; Bråthen, Geir; Hovdal, Harald Olav; Aamot, Inger Lise

2016-12-01

The most effective treatment approach to improve walking in people with multiple sclerosis (MS) is not known. The aim of this trial was to assess the efficacy of treadmill training and progressive strength training on walking in people with MS. A single blinded randomized parallel group trial was carried out. Eligible participants were adults with MS with Expanded Disability Status Scale score ≤6. A total of 29 participants were randomized and 28 received the allocated exercise intervention, treadmill (n = 13) or strength training (n = 15). Both groups exercised 30 minutes, three times a week for 8 weeks. Primary outcome was The Functional Ambulation Profile evaluated by the GAITRite walkway. Secondary outcomes were walking work economy and balance control during walking, measured by a small lightweight accelerometer connected to the lower back. Testing was performed at baseline and the subsequent week after completion of training. Two participants were lost to follow-up, and 11 (treadmill) and 15 (strength training) were left for analysis. The treadmill group increased their Functional Ambulation Profile score significantly compared with the strength training group (p = .037). A significant improvement in walking work economy (p = .024) and a reduction of root mean square of vertical acceleration (p = .047) also favoured the treadmill group. The results indicate that task-specific training by treadmill walking is a favourable approach compared with strength training to improve walking in persons with mild and moderate MS. Implications for Physiotherapy practice, this study adds knowledge for the decision of optimal treatment approaches in people with MS. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A soft robotic exosuit improves walking in patients after stroke.

PubMed

Awad, Louis N; Bae, Jaehyun; O'Donnell, Kathleen; De Rossi, Stefano M M; Hendron, Kathryn; Sloot, Lizeth H; Kudzia, Pawel; Allen, Stephen; Holt, Kenneth G; Ellis, Terry D; Walsh, Conor J

2017-07-26

Stroke-induced hemiparetic gait is characteristically slow and metabolically expensive. Passive assistive devices such as ankle-foot orthoses are often prescribed to increase function and independence after stroke; however, walking remains highly impaired despite-and perhaps because of-their use. We sought to determine whether a soft wearable robot (exosuit) designed to supplement the paretic limb's residual ability to generate both forward propulsion and ground clearance could facilitate more normal walking after stroke. Exosuits transmit mechanical power generated by actuators to a wearer through the interaction of garment-like, functional textile anchors and cable-based transmissions. We evaluated the immediate effects of an exosuit actively assisting the paretic limb of individuals in the chronic phase of stroke recovery during treadmill and overground walking. Using controlled, treadmill-based biomechanical investigation, we demonstrate that exosuits can function in synchrony with a wearer's paretic limb to facilitate an immediate 5.33 ± 0.91° increase in the paretic ankle's swing phase dorsiflexion and 11 ± 3% increase in the paretic limb's generation of forward propulsion ( P < 0.05). These improvements in paretic limb function contributed to a 20 ± 4% reduction in forward propulsion interlimb asymmetry and a 10 ± 3% reduction in the energy cost of walking, which is equivalent to a 32 ± 9% reduction in the metabolic burden associated with poststroke walking. Relatively low assistance (~12% of biological torques) delivered with a lightweight and nonrestrictive exosuit was sufficient to facilitate more normal walking in ambulatory individuals after stroke. Future work will focus on understanding how exosuit-induced improvements in walking performance may be leveraged to improve mobility after stroke. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

SIRRACT: An international randomized clinical trial of activity feedback during inpatient stroke rehabilitation enabled by wireless sensing

PubMed Central

Dorsch, Andrew K.; Thomas, Seth; Xu, Xiaoyu; Kaiser, William; Dobkin, Bruce H.

2014-01-01

Background Walking-related disability is the most frequent reason for inpatient stroke rehabilitation. Task-related practice is a critical component for improving patient outcomes. Objective To test the feasibility of providing quantitative feedback about daily walking performance and motivating greater skills practice via remote sensing. Methods In this phase III randomized, single blind clinical trial, patients participated in conventional therapies while wearing wireless sensors (tri-axial accelerometers) at both ankles. Activity-recognition algorithms calculated the speed, distance, and duration of walking bouts. Three times a week, therapists provided either feedback about performance on a 10-meter walk (speed-only) or walking speed feedback plus a review of walking activity recorded by the sensors (augmented). Primary outcomes at discharge included total daily walking time, derived from the sensors, and a timed 15-meter walk. Results Sixteen rehabilitation centers in 11 countries enrolled 135 participants over 15 months. Sensors recorded more than 1800 days of therapy, 37,000 individual walking bouts, and 2.5 million steps. No significant differences were found between the two feedback groups in daily walking time (15.1±13.1min vs. 16.6±14.3min, p=0.54) or 15-meter walking speed (0.93±0.47m/s vs. 0.91±0.53m/s, p=0.96). Remarkably, 30% of participants decreased their total daily walking time over their rehabilitation stay. Conclusions In this first trial of remote monitoring of inpatient stroke rehabilitation, augmented feedback beyond speed alone did not increase the time spent practicing or improve walking outcomes. Remarkably modest time was spent walking. Wireless sensing, however, allowed clinicians to audit skills practice and provided ground truth regarding changes in clinically important, mobility-related activities. PMID:25261154

Effects of Interrupting Children's Sedentary Behaviors With Activity on Metabolic Function: A Randomized Trial.

PubMed

Belcher, Britni R; Berrigan, David; Papachristopoulou, Alexia; Brady, Sheila M; Bernstein, Shanna B; Brychta, Robert J; Hattenbach, Jacob D; Tigner, Ira L; Courville, Amber B; Drinkard, Bart E; Smith, Kevin P; Rosing, Douglas R; Wolters, Pamela L; Chen, Kong Y; Yanovski, Jack A

2015-10-01

Limited data suggest that interrupting sedentary behaviors with activity improves metabolic parameters in adults. We tested whether interrupting sitting with short, moderate-intensity walking bouts improved glucose tolerance in children. Participants underwent two experimental conditions in random order on different days: continuous sitting for 3 hours or sitting interrupted by walking (3 min of moderate-intensity walking every 30 min). Insulin, C-peptide, glucose, and free fatty acids were measured every 30 minutes for 3 hours during an oral glucose tolerance test. Area under the curve (AUC) was calculated from hormone and substrate measurements. Children were given a buffet meal after each condition. The study was conducted at the National Institutes of Health Hatfield Clinical Research Center. Twenty-eight normal-weight 7-11 year olds participated. Patterns of substrate/hormone secretion and AUC, as well as energy intake, were examined by experimental condition. Interrupting sitting resulted in a 32% lower insulin AUC (P < .001), 17% lower C-peptide AUC (P < .001), and 7% lower glucose AUC (P = .018) vs continuous sitting. Mixed model results indicated that insulin (P = .036) and free fatty acid concentrations (P = .009) were significantly lower in the interrupted vs the continuous sitting condition. Lunchtime buffet meal energy intake did not significantly differ between the conditions (975 ± 387 vs 963 ± 309 kcal; P = .85). Interrupting sedentary time with brief moderate-intensity walking improved short-term metabolic function in non-overweight children without increasing subsequent energy intake. These findings suggest that interrupting sedentary behavior may be a promising prevention strategy for reducing cardiometabolic risk in children.

Neighbourhood safety and leisure-time physical activity among Dutch adults: a multilevel perspective.

PubMed

Kramer, Daniëlle; Maas, Jolanda; Wingen, Marleen; Kunst, Anton E

2013-01-28

Several neighbourhood elements have been found to be related to leisure-time walking and cycling. However, the association with neighbourhood safety remains unclear. This study aimed to assess the association of neighbourhood-level safety with leisure-time walking and cycling among Dutch adults. Data were derived from the national health survey (POLS) 2006-2009, with valid data on 20046 respondents residing in 2127 neighbourhoods. Multilevel logistic regression models were used to examine the association between neighbourhood-level safety (general safety and specific safety components: physical disorder, social disorder, crime-related fear, traffic safety) and residents' engagement in outdoor leisure-time walking and cycling for at least 30 minutes per week. An increase in neighbourhood safety (both general safety and each of the safety components) was significantly associated with an increase in leisure-time cycling participation. Associations were strongest for general safety and among older women. In the general population, neighbourhood safety was not significantly associated with leisure-time walking. However, among younger and older adult men and lower educated individuals, an increase in general safety was associated with a decrease in leisure-time walking participation. In the Netherlands, neighbourhood safety appears to be related to leisure-time cycling but not to walking. Leisure-time cycling may best be encouraged by improving different safety components at once, rather than focusing on one safety aspect such as traffic safety. Special attention is needed for older women.

Identification of walking human model using agent-based modelling

NASA Astrophysics Data System (ADS)

Shahabpoor, Erfan; Pavic, Aleksandar; Racic, Vitomir

2018-03-01

The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the research on moving (walking) human models, explicitly identified for vibration serviceability assessment of civil structures, is still sparse. In this study, the results of a comprehensive set of FRF-based modal tests were used, in which, over a hundred test subjects walked in different group sizes and walking patterns on a test structure. An agent-based model was used to simulate discrete traffic-structure interactions. The occupied structure modal parameters found in tests were used to identify the parameters of the walking individual's single-degree-of-freedom (SDOF) mass-spring-damper model using 'reverse engineering' methodology. The analysis of the results suggested that the normal distribution with the average of μ = 2.85Hz and standard deviation of σ = 0.34Hz can describe human SDOF model natural frequency. Similarly, the normal distribution with μ = 0.295 and σ = 0.047 can describe the human model damping ratio. Compared to the previous studies, the agent-based modelling methodology proposed in this paper offers significant flexibility in simulating multi-pedestrian walking traffics, external forces and simulating different mechanisms of human-structure and human-environment interaction at the same time.

Use of Perturbation-Based Gait Training in a Virtual Environment to Address Mediolateral Instability in an Individual With Unilateral Transfemoral Amputation

PubMed Central

Rábago, Christopher A.; Rylander, Jonathan H.; Dingwell, Jonathan B.; Wilken, Jason M.

2016-01-01

Background and Purpose Roughly 50% of individuals with lower limb amputation report a fear of falling and fall at least once a year. Perturbation-based gait training and the use of virtual environments have been shown independently to be effective at improving walking stability in patient populations. An intervention was developed combining the strengths of the 2 paradigms utilizing continuous, walking surface angle oscillations within a virtual environment. This case report describes walking function and mediolateral stability outcomes of an individual with a unilateral transfemoral amputation following a novel perturbation-based gait training intervention in a virtual environment. Case Description The patient was a 43-year-old male veteran who underwent a right transfemoral amputation 7+ years previously as a result of a traumatic blast injury. He used a microprocessor-controlled knee and an energy storage and return foot. Outcomes Following the intervention, multiple measures indicated improved function and stability, including faster self-selected walking speed and reduced functional stepping time, mean step width, and step width variability. These changes were seen during normal level walking and mediolateral visual field or platform perturbations. In addition, benefits were retained at least 5 weeks after the final training session. Discussion The perturbation-based gait training program in the virtual environment resulted in the patient's improved walking function and mediolateral stability. Although the patient had completed intensive rehabilitation following injury and was fully independent, the intervention still induced notable improvements to mediolateral stability. Thus, perturbation-based gait training in challenging simulated environments shows promise for improving walking stability and may be beneficial when integrated into a rehabilitation program. PMID:27277497

Long-term safety and efficacy of dalfampridine for walking impairment in patients with multiple sclerosis: Results of open-label extensions of two Phase 3 clinical trials

PubMed Central

Goodman, Andrew D; Bethoux, Francois; Brown, Theodore R; Schapiro, Randall T; Cohen, Ron; Marinucci, Lawrence N; Henney, Herbert R

2015-01-01

Background: In Phase 3 double-blind trials (MS-F203 and MS-F204), dalfampridine extended release tablets 10 mg twice daily (dalfampridine-ER; prolonged-release fampridine in Europe; fampridine modified or sustained release elsewhere) improved walking speed relative to placebo in patients with multiple sclerosis (MS). Objectives: Evaluation of long-term safety and efficacy of dalfampridine-ER in open-label extensions (MS-F203EXT, MS-F204EXT). Methods: Patients received dalfampridine-ER 10 mg twice daily; and had Timed 25-Foot Walk (T25FW) assessments at 2, 14 and 26 weeks, and then every 6 months. Subjects were categorized as dalfampridine-ER responders or non-responders, based on their treatment response in the double-blind parent trials that assessed T25FW. Results: We had 269 patients enter MS-F203EXT and 154 patients complete it; for a maximum exposure of 5 years. We had 214 patients enter MS-F204EXT and 146 complete it; for a maximum exposure of 3.3 years. No new safety signals emerged and dalfampridine-ER tolerability was consistent with the double-blind phase. Improvements in walking speed were lost after dalfampridine-ER was discontinued in the parent trial, but returned by the 2-week assessment after re-initiation of the drug. Throughout the extensions, mean improvement in walking speed declined, but remained improved, among the double-blind responders as compared with non-responders. Conclusions: The dalfamipridine-ER safety profile was consistent with the parent trials. Although walking speed decreased over time, dalfampridine-ER responders continued to show improved walking speed, which was sustained compared with non-responders. PMID:25583832

Anatomic single-bundle anterior cruciate ligament reconstruction improves walking economy: hamstrings tendon versus patellar tendon grafts.

PubMed

Iliopoulos, Efthymios; Galanis, Nikiforos; Zafeiridis, Andreas; Iosifidis, Michael; Papadopoulos, Pericles; Potoupnis, Michael; Geladas, Nikolaos; Vrabas, Ioannis S; Kirkos, John

2017-10-01

Anterior cruciate ligament (ACL) injury is associated with a pathologic gait pattern and increased energy cost during locomotion. ACL reconstruction could improve the gait pattern. Hamstrings tendon (HAM) and bone-patellar tendon-bone (BPTB) grafts are usually used for reconstruction. The aim of this study was to compare the efficacy of anatomic ACL reconstruction with HAM and BPTB grafts on improving and normalizing the energy cost and physiologic reserves during flat, uphill, and downhill walking. Twenty male subjects with unilateral ACL injuries were randomly assigned to ACL reconstruction with a HAM (n = 10) or BPTB (n = 10) graft. Ten matched controls were also enrolled. All participants performed three 8-min walking tasks at 0, +10, and -10 % gradients before and 9 months after surgery. Energy cost (oxygen consumption, VO 2 ), heart rate (HR), and ventilation (VE) were measured. Lysholm/IKDC scores were recorded. Pre-operatively, VO 2 , HR, and VE were higher in the HAM and BPTB groups than in controls during walking at 0, +10, and -10 % gradients (p < 0.001-0.01). Post-operatively, both HAM and BPTB groups showed reduced VO 2 , HR, and VE during the three walking tasks (p < 0.001-0.01). Although the post-operative VO 2 in both surgical groups reached 90-95 % of the normative (control) value during walking, it remained elevated against the value observed in controls (p < 0.001-0.01). The HAM and BPTB groups showed no differences in post-surgical VO 2 or HR during walking at all three gradients. Anatomic ACL reconstruction with either HAM or BPTB graft resulted in similar short-term improvements in energy cost and nearly normalized locomotion economy and cardiorespiratory reserves during flat, uphill, and downhill walking. The improved locomotion economy is an additional benefit of anatomic ACL reconstruction, irrespective of the type of graft used, that the orthopaedic surgeons should consider. II.

Translation of a Motor Learning Walking Rehabilitation Program Into a Group-Based Exercise Program for Community-Dwelling Older Adults.

PubMed

Brach, Jennifer S; Francois, Sara J; VanSwearingen, Jessie M; Gilmore, Sandra; Perera, Subashan; Studenski, Stephanie A

2016-06-01

Traditional exercise programs for older adults, which focus on aerobic and strength training, have had only modest effects on walking. Recently, a motor learning exercise program was shown to have greater effects on walking compared with a traditional exercise program. Translating this novel motor learning exercise program into a group exercise program would allow it to be offered as an evidence-based, community-based program for older adults. To translate a walking rehabilitation program based on motor learning theory from one-on-one to group delivery (On the Move) and evaluate multiple aspects of implementation in older adults with impaired mobility. The translation process involved multiple iterations, including meetings of experts in the field (Phase I), focus groups (Phase II), and implementation of the newly developed program (Phase III). Phase III was based on a one-group model of intervention development for feasibility, safety, potential effects, and acceptability. Community sites, including 2 independent living facilities, an apartment building, and a community center. Adults 65 years of age or older who could ambulate independently and who were medically stable. Thirty-one adults, mean age 82.3 ± 5.6 years, were eligible to participate. The group exercise program was held twice a week for 12 weeks. Acceptability of the program was determined by retention and adherence rates and a satisfaction survey. Risk was measured by adverse events and questions on perceived challenge and safety. Mobility was assessed pre- and postintervention by gait speed, Figure of 8 Walk Test, and 6-minute walk test. Modifications to the program included adjustments to format/length, music, education, and group interaction. The 12-week program was completed by 24 of 31 entrants (77%). Adherence was high, with participants attending on average 83% of the classes. Safety was excellent, with only 1 subject experiencing a controlled, noninjurious fall. There was preliminary evidence for improved mobility after the intervention: gait speed improved from 0.76 ± 0.21 to 0.81 ± 0.22 m/s, P = .06; Figure of 8 Walk Test from 13.0 ± 3.9 to 12.0 ± 3.9 seconds, P = .07; and 6-minute walk test from 246 ± 75 to 281 ± 67 m, P = .02. The group-based program was safe and acceptable to older adults with impaired mobility and resulted in potentially clinically meaningful improvements in mobility. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

The fiber walk: a model of tip-driven growth with lateral expansion.

PubMed

Bucksch, Alexander; Turk, Greg; Weitz, Joshua S

2014-01-01

Tip-driven growth processes underlie the development of many plants. To date, tip-driven growth processes have been modeled as an elongating path or series of segments, without taking into account lateral expansion during elongation. Instead, models of growth often introduce an explicit thickness by expanding the area around the completed elongated path. Modeling expansion in this way can lead to contradictions in the physical plausibility of the resulting surface and to uncertainty about how the object reached certain regions of space. Here, we introduce fiber walks as a self-avoiding random walk model for tip-driven growth processes that includes lateral expansion. In 2D, the fiber walk takes place on a square lattice and the space occupied by the fiber is modeled as a lateral contraction of the lattice. This contraction influences the possible subsequent steps of the fiber walk. The boundary of the area consumed by the contraction is derived as the dual of the lattice faces adjacent to the fiber. We show that fiber walks generate fibers that have well-defined curvatures, and thus enable the identification of the process underlying the occupancy of physical space. Hence, fiber walks provide a base from which to model both the extension and expansion of physical biological objects with finite thickness.

The Fiber Walk: A Model of Tip-Driven Growth with Lateral Expansion

PubMed Central

Bucksch, Alexander; Turk, Greg; Weitz, Joshua S.

2014-01-01

Tip-driven growth processes underlie the development of many plants. To date, tip-driven growth processes have been modeled as an elongating path or series of segments, without taking into account lateral expansion during elongation. Instead, models of growth often introduce an explicit thickness by expanding the area around the completed elongated path. Modeling expansion in this way can lead to contradictions in the physical plausibility of the resulting surface and to uncertainty about how the object reached certain regions of space. Here, we introduce fiber walks as a self-avoiding random walk model for tip-driven growth processes that includes lateral expansion. In 2D, the fiber walk takes place on a square lattice and the space occupied by the fiber is modeled as a lateral contraction of the lattice. This contraction influences the possible subsequent steps of the fiber walk. The boundary of the area consumed by the contraction is derived as the dual of the lattice faces adjacent to the fiber. We show that fiber walks generate fibers that have well-defined curvatures, and thus enable the identification of the process underlying the occupancy of physical space. Hence, fiber walks provide a base from which to model both the extension and expansion of physical biological objects with finite thickness. PMID:24465607

A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking.

PubMed

Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

2016-06-01

Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking.

Effects of Single Bouts of Walking Exercise and Yoga on Acute Mood Symptoms in People with Multiple Sclerosis

PubMed Central

Ensari, Ipek; Sandroff, Brian M.

2016-01-01

Background: Little is known about the acute or immediate effects of walking exercise and yoga on mood in people with multiple sclerosis (MS). Such an examination is important for identifying an exercise modality for inclusion in exercise-training interventions that yields mood benefits in MS. We examined the effects of single bouts of treadmill walking and yoga compared with a quiet, seated-rest control condition on acute mood symptoms in MS. Methods: Twenty-four participants with MS completed 20 minutes of treadmill walking, yoga, or quiet rest in a randomized, counterbalanced order with 1 week between sessions. Participants completed the Profile of Mood States questionnaire before and immediately after each condition. Total mood disturbance (TMD) and the six subscales of the Profile of Mood States were analyzed using repeated-measures analysis of variance and paired-samples t tests. Results: There was a significant condition × time interaction on TMD scores (ηp2 = 0.13). Walking and yoga conditions yielded comparable reductions in TMD scores. There was a significant condition × time interaction on vigor (ηp2 = 0.23) whereby walking but not yoga yielded an improvement in vigor. There was a significant main effect of time on anger, confusion, depression, and tension (P < .05) but not on fatigue. Conclusions: Walking and yoga yielded similar improvements in overall acute mood symptoms, and walking improved feelings of vigor. These effects should be further investigated in long-term exercise-training studies. PMID:26917992

A kinematic model to assess spinal motion during walking.

PubMed

Konz, Regina J; Fatone, Stefania; Stine, Rebecca L; Ganju, Aruna; Gard, Steven A; Ondra, Stephen L

2006-11-15

A 3-dimensional multi-segment kinematic spine model was developed for noninvasive analysis of spinal motion during walking. Preliminary data from able-bodied ambulators were collected and analyzed using the model. Neither the spine's role during walking nor the effect of surgical spinal stabilization on gait is fully understood. Typically, gait analysis models disregard the spine entirely or regard it as a single rigid structure. Data on regional spinal movements, in conjunction with lower limb data, associated with walking are scarce. KinTrak software (Motion Analysis Corp., Santa Rosa, CA) was used to create a biomechanical model for analysis of 3-dimensional regional spinal movements. Measuring known angles from a mechanical model and comparing them to the calculated angles validated the kinematic model. Spine motion data were collected from 10 able-bodied adults walking at 5 self-selected speeds. These results were compared to data reported in the literature. The uniaxial angles measured on the mechanical model were within 5 degrees of the calculated kinematic model angles, and the coupled angles were within 2 degrees. Regional spine kinematics from able-bodied subjects calculated with this model compared well to data reported by other authors. A multi-segment kinematic spine model has been developed and validated for analysis of spinal motion during walking. By understanding the spine's role during ambulation and the cause-and-effect relationship between spine motion and lower limb motion, preoperative planning may be augmented to restore normal alignment and balance with minimal negative effects on walking.

Brain Network Modularity Predicts Exercise-Related Executive Function Gains in Older Adults

PubMed Central

Baniqued, Pauline L.; Gallen, Courtney L.; Voss, Michelle W.; Burzynska, Agnieszka Z.; Wong, Chelsea N.; Cooke, Gillian E.; Duffy, Kristin; Fanning, Jason; Ehlers, Diane K.; Salerno, Elizabeth A.; Aguiñaga, Susan; McAuley, Edward; Kramer, Arthur F.; D'Esposito, Mark

2018-01-01

Recent work suggests that the brain can be conceptualized as a network comprised of groups of sub-networks or modules. The extent of segregation between modules can be quantified with a modularity metric, where networks with high modularity have dense connections within modules and sparser connections between modules. Previous work has shown that higher modularity predicts greater improvements after cognitive training in patients with traumatic brain injury and in healthy older and young adults. It is not known, however, whether modularity can also predict cognitive gains after a physical exercise intervention. Here, we quantified modularity in older adults (N = 128, mean age = 64.74) who underwent one of the following interventions for 6 months (NCT01472744 on ClinicalTrials.gov): (1) aerobic exercise in the form of brisk walking (Walk), (2) aerobic exercise in the form of brisk walking plus nutritional supplement (Walk+), (3) stretching, strengthening and stability (SSS), or (4) dance instruction. After the intervention, the Walk, Walk+ and SSS groups showed gains in cardiorespiratory fitness (CRF), with larger effects in both walking groups compared to the SSS and Dance groups. The Walk, Walk+ and SSS groups also improved in executive function (EF) as measured by reasoning, working memory, and task-switching tests. In the Walk, Walk+, and SSS groups that improved in EF, higher baseline modularity was positively related to EF gains, even after controlling for age, in-scanner motion and baseline EF. No relationship between modularity and EF gains was observed in the Dance group, which did not show training-related gains in CRF or EF control. These results are consistent with previous studies demonstrating that individuals with a more modular brain network organization are more responsive to cognitive training. These findings suggest that the predictive power of modularity may be generalizable across interventions aimed to enhance aspects of cognition and that, especially in low-performing individuals, global network properties can capture individual differences in neuroplasticity. PMID:29354050

Current education versus peer-education on walking in type 2 diabetic patients based on Health Belief Model: a randomized control trial study.

PubMed

Baghianimoghadam, M H; Hadavandkhani, M; Mohammadi, M; Fallahzade, H; Baghianimoghadam, B

2012-01-01

Diabetes is a disease with several metabolic and organic symptoms. Physical activity plays a key role in controlling type 2 diabetes. Several researches confirm that educational strategies can lead to healthy behaviors and its continuation is effective and can indicate what type of relationship with the client is better. The purpose of this study is comparing the Effect of Current Education and Peer-Education on Walking in Type 2 Diabetic Patients based on Health Belief Model (HBM). This was a clinical trial (RCT) study done on 80 people with type 2 diabetes. Patients were divided into two groups, Current education and Peer education groups. Data were collected using a questionnaire based on the health belief model, a checklist related to patients' practice and recording patients' HbA1c, 2HPP and FBS levels. Results were documented before and three months after intervention. The patients participated in 2 educational classes during three months of intervention, as the follow-up of the intervention. Mean scores for HBM Model variables, i.e. perceived susceptibility, perceived severity, perceived benefit and self-efficacy, were significantly increased in the peer education group compared to current education group after intervention. Also, behavioral walking, rates of HbA1c and FBS and 2HPP levels were improved significantly among the peer education group. Applying walking training program developed for diabetic patients and its implementation by the peers in order to control blood sugar using the health belief model is very useful and effective. During implementation of these control programs, monitoring and follow-up training is recommended.

Movement patterns of Tenebrio beetles demonstrate empirically that correlated-random-walks have similitude with a Lévy walk.

PubMed

Reynolds, Andy M; Leprêtre, Lisa; Bohan, David A

2013-11-07

Correlated random walks are the dominant conceptual framework for modelling and interpreting organism movement patterns. Recent years have witnessed a stream of high profile publications reporting that many organisms perform Lévy walks; movement patterns that seemingly stand apart from the correlated random walk paradigm because they are discrete and scale-free rather than continuous and scale-finite. Our new study of the movement patterns of Tenebrio molitor beetles in unchanging, featureless arenas provides the first empirical support for a remarkable and deep theoretical synthesis that unites correlated random walks and Lévy walks. It demonstrates that the two models are complementary rather than competing descriptions of movement pattern data and shows that correlated random walks are a part of the Lévy walk family. It follows from this that vast numbers of Lévy walkers could be hiding in plain sight.

Investigating walking environments in and around assisted living facilities: a facility visit study.

PubMed

Lu, Zhipeng

2010-01-01

This study explores assisted living residents' walking behaviors, locations where residents prefer to walk, and walking environments in and around assisted living facilities. Regular walking is beneficial to older adults' physical and psychological health. Yet frail older residents in assisted living are usually too sedentary to achieve these benefits. The physical environment plays an important role in promoting physical activity. However, there is little research exploring this relationship in assisted living settings. The researcher visited 34 assisted living facilities in a major Texas city. Methods included walk-through observation with the Assisted Living Facility Walking Environment Checklist, and interviews with administrators by open- and close-ended questions. The data from 26 facilities were analyzed using descriptive statistics (for quantitative data) and content analysis (for qualitative data). The results indicate that (a) residents were walking both indoors and outdoors for exercise or other purposes (e.g., going to destinations); (b) assisted living facility planning and design details-such as neighborhood sidewalk conditions, facility site selection, availability of seating, walking path configuration (e.g., looped/nonlooped path), amount of shading along the path, presence of handrails, existence of signage, etc.-may influence residents' walking behaviors; and (c) current assisted living facilities need improvement in all aspects to make their environments more walkable for residents. Findings of the study provide recommendations for assisted living facilities to improve the walkability of environments and to create environmental interventions to promote regular walking among their residents. This study also implies several directions for future research.

On Why Wayne Dennis Found Hopi Infants Retarded in Age at Onset of Walking.

ERIC Educational Resources Information Center

Harriman, Arthur E.; Lukosius, Patricia A.

1982-01-01

In 1940 Dennis found Hopi infants slower in onset of walking, whether or not the cradleboard was used. Present differences in genetic background, health, and nutrition were compared showing that an inadequate diet may have accounted for former walking delays. The present onset of walking may reflect external food program improvements in nutrition.…

A model of cerebrocerebello-spinomuscular interaction in the sagittal control of human walking.

PubMed

Jo, Sungho; Massaquoi, Steve G

2007-03-01

A computationally developed model of human upright balance control (Jo and Massaquoi on Biol cybern 91:188-202, 2004) has been enhanced to describe biped walking in the sagittal plane. The model incorporates (a) non-linear muscle mechanics having activation level -dependent impedance, (b) scheduled cerebrocerebellar interaction for control of center of mass position and trunk pitch angle, (c) rectangular pulse-like feedforward commands from a brainstem/ spinal pattern generator, and (d) segmental reflex modulation of muscular synergies to refine inter-joint coordination. The model can stand when muscles around the ankle are coactivated. When trigger signals activate, the model transitions from standing still to walking at 1.5 m/s. Simulated natural walking displays none of seven pathological gait features. The model can simulate different walking speeds by tuning the amplitude and frequency in spinal pattern generator. The walking is stable against forward and backward pushes of up to 70 and 75 N, respectively, and with sudden changes in trunk mass of up to 18%. The sensitivity of the model to changes in neural parameters and the predicted behavioral results of simulated neural system lesions are examined. The deficit gait simulations may be useful to support the functional and anatomical correspondences of the model. The model demonstrates that basic human-like walking can be achieved by a hierarchical structure of stabilized-long loop feedback and synergy-mediated feedforward controls. In particular, internal models of body dynamics are not required.

Evaluation of the implementation of an intervention to improve the street environment and promote walking for transport in deprived neighbourhoods.

PubMed

Adams, Emma J; Cavill, Nick; Sherar, Lauren B

2017-08-14

Levels of physical activity remain low, particularly in deprived areas. Improving the street environment to promote walking for transport using a community engagement approach is a potential strategy to increase physical activity. An understanding of the implementation of this intervention approach is needed to facilitate further research, replication and scale-up. The aim of this study was to evaluate the implementation of the Fitter for Walking (FFW) intervention in deprived neighbourhoods. FFW was delivered in five regions of England between August 2008 and March 2012 and aimed to use a community engagement approach to improve the street environment to promote walking for transport. Implementation was assessed in relation to reach; dosage; implementation processes and adaptation; and factors influencing implementation. Three data sources were used: focus groups and face-to-face interviews with coordinators; implementation logs; and participation records. Reach: 155 community groups participated in FFW engaging 30,230 local residents. Dosage: A wide variety of environmental improvements were implemented by local authorities (LAs) (42 projects) and by communities (46 projects). Examples of LA-led improvements included removal of encroaching vegetation, new/improved pedestrian signage, new dropped kerbs/kerb improvements and new, repaired or improved footpaths. Examples of community-led improvements included planting bulbs, shrubs or bedding plants, clean-up days and litter pick-ups. In 32 projects, no environmental improvements were implemented. Promotional and awareness-raising activities were undertaken in 81 projects. Examples included led walks, themed walks, development of maps/resources to promote improved routes and community events. Processes and adaptation: The need for a planning phase, a preparatory phase, and a delivery phase with a four step process were identified. Adaptability to local context was important. Factors influencing implementation: Five key themes were identified in relation to the barriers and facilitators of implementing FFW: local knowledge and contacts; intervention delivery; coordinator role; working with LAs and other partners; and working with communities. FFW is one of few reported interventions which have used a community engagement approach to change the street environment to promote walking for transport in deprived neighbourhoods. Delivering these types of interventions is complex and requires considerable resource and time. A set of recommendations and an implementation framework are proposed for future delivery of this and similar types of programme.

Theorising and testing environmental pathways to behaviour change: natural experimental study of the perception and use of new infrastructure to promote walking and cycling in local communities.

PubMed

Panter, Jenna; Ogilvie, David

2015-09-03

Some studies have assessed the effectiveness of environmental interventions to promote physical activity, but few have examined how such interventions work. We investigated the environmental mechanisms linking an infrastructural intervention with behaviour change. Natural experimental study. Three UK municipalities (Southampton, Cardiff and Kenilworth). Adults living within 5 km of new walking and cycling infrastructure. Construction or improvement of walking and cycling routes. Exposure to the intervention was defined in terms of residential proximity. Questionnaires at baseline and 2-year follow-up assessed perceptions of the supportiveness of the environment, use of the new infrastructure, and walking and cycling behaviours. Analysis proceeded via factor analysis of perceptions of the physical environment (step 1) and regression analysis to identify plausible pathways involving physical and social environmental mediators and refine the intervention theory (step 2) to a final path analysis to test the model (step 3). Participants who lived near and used the new routes reported improvements in their perceptions of provision and safety. However, path analysis (step 3, n=967) showed that the effects of the intervention on changes in time spent walking and cycling were largely (90%) explained by a simple causal pathway involving use of the new routes, and other pathways involving changes in environmental cognitions explained only a small proportion of the effect. Physical improvement of the environment itself was the key to the effectiveness of the intervention, and seeking to change people's perceptions may be of limited value. Studies of how interventions lead to population behaviour change should complement those concerned with estimating their effects in supporting valid causal inference. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Early application of tail nerve electrical stimulation-induced walking training promotes locomotor recovery in rats with spinal cord injury.

PubMed

Zhang, S-X; Huang, F; Gates, M; Shen, X; Holmberg, E G

2016-11-01

This is a randomized controlled prospective trial with two parallel groups. The objective of this study was to determine whether early application of tail nerve electrical stimulation (TANES)-induced walking training can improve the locomotor function. This study was conducted in SCS Research Center in Colorado, USA. A contusion injury to spinal cord T10 was produced using the New York University impactor device with a 25 -mm height setting in female, adult Long-Evans rats. Injured rats were randomly divided into two groups (n=12 per group). One group was subjected to TANES-induced walking training 2 weeks post injury, and the other group, as control, received no TANES-induced walking training. Restorations of behavior and conduction were assessed using the Basso, Beattie and Bresnahan open-field rating scale, horizontal ladder rung walking test and electrophysiological test (Hoffmann reflex). Early application of TANES-induced walking training significantly improved the recovery of locomotor function and benefited the restoration of Hoffmann reflex. TANES-induced walking training is a useful method to promote locomotor recovery in rats with spinal cord injury.

The implementation of a community-based aerobic walking program for mild to moderate knee osteoarthritis: A knowledge translation randomized controlled trial: Part II: Clinical outcomes

PubMed Central

2012-01-01

Background Osteoarthritis (OA) is the most common joint disorder in the world, as it is appears to be prevalent among 80% of individuals over the age of 75. Although physical activities such as walking have been scientifically proven to improve physical function and arthritic symptoms, individuals with OA tend to adopt a sedentary lifestyle. There is therefore a need to improve knowledge translation in order to influence individuals to adopt effective self-management interventions, such as an adapted walking program. Methods A single-blind, randomized control trial was conducted. Subjects (n = 222) were randomized to one of three knowledge translation groups: 1) Walking and Behavioural intervention (WB) (18 males, 57 females) which included the supervised community-based aerobic walking program combined with a behavioural intervention and an educational pamphlet on the benefits of walking; 2) Walking intervention (W) (24 males, 57 females) wherein participants only received the supervised community-based aerobic walking program intervention and the educational pamphlet; 3) Self-directed control (C) (32 males, 52 females) wherein participants only received the educational pamphlet. One-way analyses of variance were used to test for differences in quality of life, adherence, confidence, and clinical outcomes among the study groups at each 3 month assessment during the 12-month intervention period and 6-month follow-up period. Results The clinical and quality of life outcomes improved among participants in each of the three comparative groups. However, there were few statistically significant differences observed for quality of life and clinical outcomes at long-term measurements at 12-months end of intervention and at 6- months post intervention (18-month follow-up). Outcome results varied among the three groups. Conclusion The three groups were equivalent when determining the effectiveness of knowledge uptake and improvements in quality of life and other clinical outcomes. OA can be managed through the implementation of a proven effective walking program in existing community-based walking clubs. Trial registration Current Controlled Trials IRSCTNO9193542 PMID:23234575

Clinical impact of exercise in patients with peripheral arterial disease.

PubMed

Novakovic, Marko; Jug, Borut; Lenasi, Helena

2017-08-01

Increasing prevalence, high morbidity and mortality, and decreased health-related quality of life are hallmarks of peripheral arterial disease. About one-third of peripheral arterial disease patients have intermittent claudication with deleterious effects on everyday activities, such as walking. Exercise training improves peripheral arterial disease symptoms and is recommended as first line therapy for peripheral arterial disease. This review examines the effects of exercise training beyond improvements in walking distance, namely on vascular function, parameters of inflammation, activated hemostasis and oxidative stress, and quality of life. Exercise training not only increases walking distance and physiologic parameters in patients with peripheral arterial disease, but also improves the cardiovascular risk profile by helping patients achieve better control of hypertension, hyperglycemia, obesity and dyslipidemia, thus further reducing cardiovascular risk and the prevalence of coexistent atherosclerotic diseases. American guidelines suggest supervised exercise training, performed for a minimum of 30-45 min, at least three times per week, for at least 12 weeks. Walking is the most studied exercise modality and its efficacy in improving cardiovascular parameters in patients with peripheral arterial disease has been extensively proven. As studies have shown that supervised exercise training improves walking performance, cardiovascular parameters and quality of life in patients with peripheral arterial disease, it should be encouraged and more often prescribed.

Improvement of walking distance by defibrotide in patients with intermittent claudication--results of a randomized, placebo-controlled study (the DICLIS study). Defibrotide Intermittent CLaudication Italian Study.

PubMed

Violi, F; Marubini, E; Coccheri, S; Nenci, G G

2000-05-01

Defibrotide is an antithrombotic drug which enhances prostacyclin production and activates fibrinolytic system. The aim of this study was to investigate the improvement of walking distance in patients with intermittent claudication treated with defibrotide. DICLIS was a double blind, placebo-controlled study which included patients with walking distance autonomy at a standardized treadmill test < or =350 > or =100 meters. A total of 310 patients were randomly allocated to placebo (n = 101), defibrotide 800 mg/day (n = 104) or defibrotide 1200 mg/day (n = 105). During a one year follow-up, the Absolute Walking Distance (AWD) was measured six times (0, 30, 60, 90, 180, 360 days). Similar improvement in walking distance was found in the three groups until the 90th day; thereafter placebo group showed no further increase, while AWD continued to increase in the defibrotide groups. Between the 180th and 360th day visits, AWD was significantly higher (P <0.01) in patients given defibrotide than in patients given placebo. No difference in efficacy was observed between the two dosages of defibrotide. No differences in side effects were observed among the three groups. The results of the present trial suggest that long-term administration of defibrotide improves walking distance in patients with intermittent claudication.

Using agent based modeling to assess the effect of increased Bus Rapid Transit system infrastructure on walking for transportation.

PubMed

Lemoine, Pablo D; Cordovez, Juan Manuel; Zambrano, Juan Manuel; Sarmiento, Olga L; Meisel, Jose D; Valdivia, Juan Alejandro; Zarama, Roberto

2016-07-01

The effect of transport infrastructure on walking is of interest to researchers because it provides an opportunity, from the public policy point of view, to increase physical activity (PA). We use an agent based model (ABM) to examine the effect of transport infrastructure on walking. Particular relevance is given to assess the effect of the growth of the Bus Rapid Transit (BRT) system in Bogotá on walking. In the ABM agents are assigned a home, work location, and socioeconomic status (SES) based on which they are assigned income for transportation. Individuals must decide between the available modes of transport (i.e., car, taxi, bus, BRT, and walking) as the means of reaching their destination, based on resources and needed travel time. We calibrated the model based on Bogota's 2011 mobility survey. The ABM results are consistent with previous empirical findings, increasing BRT access does indeed increase the number of minutes that individuals walk for transportation, although this effect also depends on the availability of other transport modes. The model indicates a saturation process: as more BRT lanes are added, the increment in minutes walking becomes smaller, and eventually the walking time decreases. Our findings on the potential contribution of the expansion of the BRT system to walking for transportation suggest that ABMs may prove helpful in designing policies to continue promoting walking. Copyright © 2016 Elsevier Inc. All rights reserved.

A cross-sectional study of frequency and factors associated with dog walking in 9-10 year old children in Liverpool, UK.

PubMed

Westgarth, Carri; Boddy, Lynne M; Stratton, Gareth; German, Alexander J; Gaskell, Rosalind M; Coyne, Karen P; Bundred, Peter; McCune, Sandra; Dawson, Susan

2013-09-10

Owning a pet dog could potentially improve child health through encouraging participation in physical activity, through dog walking. However, evidence to support this is limited and conflicting. In particular, little is known about children's participation in dog walking and factors that may be associated with this. The objective of this study was to describe the participation of children in dog walking, including their own and those belonging to somebody else, and investigate factors associated with regular walking with their own pet dog. Primary school children (n=1021, 9-10 years) from a deprived area of Liverpool were surveyed during a 'fitness fun day' as part of the SportsLinx project. The 'Child Lifestyle and Pets' survey included questions about pet ownership, pet attachment, and dog walking. Multivariable logistic regression models were used to investigate factors associated with walking any dog, or their own dog, several times a day or more, including level of attachment to the dog, dog type, and sociodemographic factors. Overall, 15.4% of children reported walking with any dog (their own or belonging to a friend or family member) ≥ once daily, 14.1% several times a week, 27.6% ≤ once a week, and 42.8% never. Dog owning children (37.1% of the population) more often reported dog walking 'several times a week or more' (OR=12.30, 95% CI=8.10-18.69, P<0.001) compared to those without a dog, but were less likely to report other walking without a dog. The majority (59.3%) of dog owning children indicated that they usually walked their dog, with 34.6% reporting that they walked their dog ≥ once daily. Attachment score was highly associated with the child reporting walking their dog (lower score=higher attachment; OR=0.93, 95% CI=0.89-0.96, P<0.001). There was no evidence that gender, ethnicity, sibling status or deprivation score was associated with dog walking. Children that reported owning Pit Bulls were more likely to report friends walking with their dog than those owning non-Pit bull types (OR=10.01, 95% CI=1.52-65.76, P=0.02, respectively). Promotion of supervised walking of suitable pet dogs may be an opportunity for increasing physical activity in 9-10 year old children. The identification of stronger attachment to dogs regularly walked is similar to findings in adult studies.

A cross-sectional study of frequency and factors associated with dog walking in 9–10 year old children in Liverpool, UK

PubMed Central

2013-01-01

Background Owning a pet dog could potentially improve child health through encouraging participation in physical activity, through dog walking. However, evidence to support this is limited and conflicting. In particular, little is known about children’s participation in dog walking and factors that may be associated with this. The objective of this study was to describe the participation of children in dog walking, including their own and those belonging to somebody else, and investigate factors associated with regular walking with their own pet dog. Methods Primary school children (n=1021, 9–10 years) from a deprived area of Liverpool were surveyed during a ‘fitness fun day’ as part of the SportsLinx project. The ‘Child Lifestyle and Pets’ survey included questions about pet ownership, pet attachment, and dog walking. Multivariable logistic regression models were used to investigate factors associated with walking any dog, or their own dog, several times a day or more, including level of attachment to the dog, dog type, and sociodemographic factors. Results Overall, 15.4% of children reported walking with any dog (their own or belonging to a friend or family member) ≥ once daily, 14.1% several times a week, 27.6% ≤ once a week, and 42.8% never. Dog owning children (37.1% of the population) more often reported dog walking ‘several times a week or more’ (OR=12.30, 95% CI=8.10-18.69, P<0.001) compared to those without a dog, but were less likely to report other walking without a dog. The majority (59.3%) of dog owning children indicated that they usually walked their dog, with 34.6% reporting that they walked their dog ≥ once daily. Attachment score was highly associated with the child reporting walking their dog (lower score=higher attachment; OR=0.93, 95% CI=0.89-0.96, P<0.001). There was no evidence that gender, ethnicity, sibling status or deprivation score was associated with dog walking. Children that reported owning Pit Bulls were more likely to report friends walking with their dog than those owning non-Pit bull types (OR=10.01, 95% CI=1.52-65.76, P=0.02, respectively). Conclusions Promotion of supervised walking of suitable pet dogs may be an opportunity for increasing physical activity in 9–10 year old children. The identification of stronger attachment to dogs regularly walked is similar to findings in adult studies. PMID:24015895

Virtual prototyping of a semi-active transfemoral prosthetic leg.

PubMed

Lui, Zhen Wei; Awad, Mohammed I; Abouhossein, Alireza; Dehghani-Sanij, Abbas A; Messenger, Neil

2015-05-01

This article presents a virtual prototyping study of a semi-active lower limb prosthesis to improve the functionality of an amputee during prosthesis-environment interaction for level ground walking. Articulated ankle-foot prosthesis and a single-axis semi-active prosthetic knee with active and passive operating modes were considered. Data for level ground walking were collected using a photogrammetric method in order to develop a base-line simulation model and with the hip kinematics input to verify the proposed design. The simulated results show that the semi-active lower limb prosthesis is able to move efficiently in passive mode, and the activation time of the knee actuator can be reduced by approximately 50%. Therefore, this semi-active system has the potential to reduce the energy consumption of the actuators required during level ground walking and requires less compensation from the amputee due to lower deviation of the vertical excursion of body centre of mass. © IMechE 2015.

The Bobath Concept in Walking Activity in Chronic Stroke Measured Through the International Classification of Functioning, Disability and Health.

PubMed

Benito García, Miguel; Atín Arratibel, María Ángeles; Terradillos Azpiroz, Maria Estíbaliz

2015-12-01

The aim of this study is to evaluate the effectiveness of a rehabilitation programme based on the Bobath concept in order to improve walking activity in patients with chronic stroke and to show the usefulness of the International Classification of Functioning, Disability and Health (ICF) as a tool for gathering functioning information. This study is a repeated measures study. The setting of this study is an outpatient neurological rehabilitation centre based on a multidisciplinary approach. Twenty-four participants suffering from chronic stroke (>1 year and a half and <5 years post-stroke) and mean age of 65.58 (standard deviation 10.73) were the participants of the study. Multidisciplinary approach based on the Bobath concept principles with three weekly individual physiotherapy sessions of 45 min each over a 6-month period was the intervention for this study. The measures used were Modified Emory Functional Ambulation Profile, 10-m walk test, 6-min walk test, muscle strength testing and subsequent codification of these results into ICF qualifiers. The results of the study showed significant improvement in activities of walking long distances, on different surfaces and around obstacles. There was no significant improvement in the activity of walking short distances or for muscle power functions. A rehabilitation programme based on the Bobath Concept improved walking activities in people with chronic stroke. For this intervention, the use of the ICF qualifiers was sensitive in perceiving post-treatment changes. Copyright © 2014 John Wiley & Sons, Ltd.

Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can reduce energy costs below normal.

PubMed

Joshi, Varun; Srinivasan, Manoj

2015-02-08

Understanding how humans walk on a surface that can move might provide insights into, for instance, whether walking humans prioritize energy use or stability. Here, motivated by the famous human-driven oscillations observed in the London Millennium Bridge, we introduce a minimal mathematical model of a biped, walking on a platform (bridge or treadmill) capable of lateral movement. This biped model consists of a point-mass upper body with legs that can exert force and perform mechanical work on the upper body. Using numerical optimization, we obtain energy-optimal walking motions for this biped, deriving the periodic body and platform motions that minimize a simple metabolic energy cost. When the platform has an externally imposed sinusoidal displacement of appropriate frequency and amplitude, we predict that body motion entrained to platform motion consumes less energy than walking on a fixed surface. When the platform has finite inertia, a mass- spring-damper with similar parameters to the Millennium Bridge, we show that the optimal biped walking motion sustains a large lateral platform oscillation when sufficiently many people walk on the bridge. Here, the biped model reduces walking metabolic cost by storing and recovering energy from the platform, demonstrating energy benefits for two features observed for walking on the Millennium Bridge: crowd synchrony and large lateral oscillations.

Walking on a moving surface: energy-optimal walking motions on a shaky bridge and a shaking treadmill can reduce energy costs below normal

PubMed Central

Joshi, Varun; Srinivasan, Manoj

2015-01-01

Understanding how humans walk on a surface that can move might provide insights into, for instance, whether walking humans prioritize energy use or stability. Here, motivated by the famous human-driven oscillations observed in the London Millennium Bridge, we introduce a minimal mathematical model of a biped, walking on a platform (bridge or treadmill) capable of lateral movement. This biped model consists of a point-mass upper body with legs that can exert force and perform mechanical work on the upper body. Using numerical optimization, we obtain energy-optimal walking motions for this biped, deriving the periodic body and platform motions that minimize a simple metabolic energy cost. When the platform has an externally imposed sinusoidal displacement of appropriate frequency and amplitude, we predict that body motion entrained to platform motion consumes less energy than walking on a fixed surface. When the platform has finite inertia, a mass- spring-damper with similar parameters to the Millennium Bridge, we show that the optimal biped walking motion sustains a large lateral platform oscillation when sufficiently many people walk on the bridge. Here, the biped model reduces walking metabolic cost by storing and recovering energy from the platform, demonstrating energy benefits for two features observed for walking on the Millennium Bridge: crowd synchrony and large lateral oscillations. PMID:25663810

Improved method of step length estimation based on inverted pendulum model.

PubMed

Zhao, Qi; Zhang, Boxue; Wang, Jingjing; Feng, Wenquan; Jia, Wenyan; Sun, Mingui

2017-04-01

Step length estimation is an important issue in areas such as gait analysis, sport training, or pedestrian localization. In this article, we estimate the step length of walking using a waist-worn wearable computer named eButton. Motion sensors within this device are used to record body movement from the trunk instead of extremities. Two signal-processing techniques are applied to our algorithm design. The direction cosine matrix transforms vertical acceleration from the device coordinates to the topocentric coordinates. The empirical mode decomposition is used to remove the zero- and first-order skew effects resulting from an integration process. Our experimental results show that our algorithm performs well in step length estimation. The effectiveness of the direction cosine matrix algorithm is improved from 1.69% to 3.56% while the walking speed increased.

Quantum Ultra-Walks: Walks on a Line with Spatial Disorder

NASA Astrophysics Data System (ADS)

Boettcher, Stefan; Falkner, Stefan

We discuss the model of a heterogeneous discrete-time walk on a line with spatial disorder in the form of a set of ultrametric barriers. Simulations show that such an quantum ultra-walk spreads with a walk exponent dw that ranges from ballistic (dw = 1) to complete confinement (dw = ∞) for increasing separation 1 <= 1 / ɛ < ∞ in barrier heights. We develop a formalism by which the classical random walk as well as the quantum walk can be treated in parallel using a coined walk with internal degrees of freedom. For the random walk, this amounts to a 2nd -order Markov process with a stochastic coin, better know as an (anti-)persistent walk. The exact analysis, based on the real-space renormalization group (RG), reproduces the results of the well-known model of ``ultradiffusion,'' dw = 1 -log2 ɛ for 0 < ɛ <= 1 / 2 . However, while the evaluation of the RG fixed-points proceeds virtually identical, for the corresponding quantum walk with a unitary coin it fails to reproduce the numerical results. A new way to analyze the RG is indicated. Supported by NSF-DMR 1207431.

Towards terrain interaction prediction for bioinspired planetary exploration rovers.

PubMed

Yeomans, Brian; Saaj, Chakravathini M

2014-03-01

Deployment of a small legged vehicle to extend the reach of future planetary exploration missions is an attractive possibility but little is known about the behaviour of a walking rover on deformable planetary terrain. This paper applies ideas from the developing study of granular materials together with a detailed characterization of the sinkage process to propose and validate a combined model of terrain interaction based on an understanding of the physics and micro mechanics at the granular level. Whilst the model reflects the complexity of interactions expected from a walking rover, common themes emerge which enable the model to be streamlined to the extent that a simple mathematical representation is possible without resorting to numerical methods. Bespoke testing and analysis tools are described which reveal some unexpected conclusions and point the way towards intelligent control and foot geometry techniques to improve thrust generation.

Classification Models for Pulmonary Function using Motion Analysis from Phone Sensors.

PubMed

Cheng, Qian; Juen, Joshua; Bellam, Shashi; Fulara, Nicholas; Close, Deanna; Silverstein, Jonathan C; Schatz, Bruce

2016-01-01

Smartphones are ubiquitous, but it is unknown what physiological functions can be monitored at clinical quality. Pulmonary function is a standard measure of health status for cardiopulmonary patients. We have shown phone sensors can accurately measure walking patterns. Here we show that improved classification models can accurately measure pulmonary function, with sole inputs being sensor data from carried phones. Twenty-four cardiopulmonary patients performed six minute walk tests in pulmonary rehabilitation at a regional hospital. They carried smartphones running custom software recording phone motion. For every patient, every ten-second interval was correctly computed. The trained model perfectly computed the GOLD level 1/2/3, which is a standard categorization of pulmonary function as measured by spirometry. These results are encouraging towards field trials with passive monitors always running in the background. We expect patients can simply carry their phones during daily living, while supporting automatic computation ofpulmonary function for health monitoring.

Comparison of forward versus backward walking using body weight supported treadmill training in an individual with a spinal cord injury: a single subject design.

PubMed

Moriello, Gabriele; Pathare, Neeti; Cirone, Cono; Pastore, Danielle; Shears, Dacia; Sulehri, Sahira

2014-01-01

Body weight supported treadmill training (BWSTT) is a task-specific intervention that promotes functional locomotion. There is no research evaluating the effect of backward walking (BW) using BWSTT in individuals with spinal cord injury (SCI). The purpose of this single subject design was to examine the differences between forward walking (FW) and BW training using BWSTT in an individual with quadriparesis. The participant was a 57-year-old male with incomplete C3-C6 SCI. An ABABAB design (A = BW; B = FW; each phase = 3 weeks of biweekly sessions) was utilized. Outcome measures included: gait parameters; a timed 4-meter walk; the 5-repetition sit-to-stand test (STST); tandem stance time; and 6-minute walk test (6MWT). Data was analyzed with split level method of trend estimation. Improvements in gait parameters, on the timed 4-meter walk, 6MWT, tandem balance and aerobic endurance were similar with FW and BW training. The only difference between FW and BW training was that BW training resulted in greater improvements in the STST. The results of this study suggest that in this individual backward walking training was advantageous, resulting in improved ability to perform the 5-repetition STST. It is suspected that these changes can be attributed to the differences in muscle activation and task difficulty between FW and BW.

Walking performance in people with diabetic neuropathy: benefits and threats.

PubMed

Kanade, R V; van Deursen, R W M; Harding, K; Price, P

2006-08-01

Walking is recommended as an adjunct therapy to diet and medication in diabetic patients, with the aim of improving physical fitness, glycaemic control and body weight reduction. Therefore we evaluated walking activity on the basis of capacity, performance and potential risk of plantar injury in the diabetic population before it can be prescribed safely. Twenty-three subjects with diabetic neuropathy (DMPN) were compared with 23 patients with current diabetic foot ulcers, 16 patients with partial foot amputations and 22 patients with trans-tibial amputations. The capacity for walking was measured using a total heart beat index (THBI). Gait velocity and average daily strides were measured to assess the performance of walking, and its impact on weight-bearing was studied using maximum peak pressure. THBI increased (p<0.01) and gait velocity and daily stride count fell (p<0.001 for both) with progression of foot complications. The maximum peak pressures over the affected foot of patients with diabetic foot ulcers (p<0.05) and partial foot amputations (p<0.01) were higher than in the group with DMPN. On the contralateral side, the diabetic foot ulcer group showed higher maximum peak pressure over the total foot (p<0.05), and patients with partial foot amputations (p<0.01) and trans-tibial amputations (p<0.05) showed higher maximum peak pressure over the heel. Walking capacity and performance decrease with progression of foot complications. Although walking is recommended to improve fitness, it cannot be prescribed in isolation, considering the increased risk of plantar injury. For essential walking we therefore recommend the use of protective footwear. Walking exercise should be supplemented by partial or non-weight-bearing exercises to improve physical fitness in diabetic populations.

Partition-based discrete-time quantum walks

NASA Astrophysics Data System (ADS)

Konno, Norio; Portugal, Renato; Sato, Iwao; Segawa, Etsuo

2018-04-01

We introduce a family of discrete-time quantum walks, called two-partition model, based on two equivalence-class partitions of the computational basis, which establish the notion of local dynamics. This family encompasses most versions of unitary discrete-time quantum walks driven by two local operators studied in literature, such as the coined model, Szegedy's model, and the 2-tessellable staggered model. We also analyze the connection of those models with the two-step coined model, which is driven by the square of the evolution operator of the standard discrete-time coined walk. We prove formally that the two-step coined model, an extension of Szegedy model for multigraphs, and the two-tessellable staggered model are unitarily equivalent. Then, selecting one specific model among those families is a matter of taste not generality.

Walking on uneven terrain with a powered ankle prosthesis: A preliminary assessment.

PubMed

Shultz, Amanda H; Lawson, Brian E; Goldfarb, Michael

2015-01-01

A successful walking gait with a powered prosthesis depends heavily on proper timing of power delivery, or push-off. This paper describes a control approach which provides improved walking on uneven terrain relative to previous work intended for use on even (level) terrain. This approach is motivated by an initial healthy subject study which demonstrated less variation in sagittal plane shank angle than sagittal plane ankle angle when walking on uneven terrain relative to even terrain. The latter therefore replaces the former as the control signal used to initiate push-off in the powered prosthesis described herein. The authors demonstrate improvement in consistency for several gait characteristics, relative to healthy, as well as controller characteristics with the new control approach, including a 50% improvement in the consistency of the percentage of stride at which push-off is initiated.

Promoting Safe Walking and Cycling to Improve Public Health: Lessons From The Netherlands and Germany

PubMed Central

Pucher, John; Dijkstra, Lewis

2003-01-01

Objectives. We examined the public health consequences of unsafe and inconvenient walking and bicycling conditions in American cities to suggest improvements based on successful policies in The Netherlands and Germany. Methods. Secondary data from national travel and crash surveys were used to compute fatality trends from 1975 to 2001 and fatality and injury rates for pedestrians and cyclists in The Netherlands, Germany, and the United States in 2000. Results. American pedestrians and cyclists were much more likely to be killed or injured than were Dutch and German pedestrians and cyclists, both on a per-trip and on a per-kilometer basis. Conclusions. A wide range of measures are available to improve the safety of walking and cycling in American cities, both to reduce fatalities and injuries and to encourage walking and cycling. PMID:12948971

The role of parental risk judgements, transport safety attitudes, transport priorities and accident experiences on pupils' walking to school.

PubMed

Mehdizadeh, Milad; Nordfjaern, Trond; Mamdoohi, Amir Reza; Shariat Mohaymany, Afshin

2017-05-01

Walking to school could improve pupils' health condition and might also reduce the use of motorized transport modes, which leads to both traffic congestion and air pollution. The current study aims to examine the role of parental risk judgements (i.e. risk perception and worry), transport safety attitudes, transport priorities and accident experiences on pupils' walking and mode choices on school trips in Iran, a country with poor road safety records. A total of 1078 questionnaires were randomly distributed among pupils at nine public and private schools in January 2014 in Rasht, Iran. Results from valid observations (n=711) showed that parents with high probability assessments of accidents and strong worry regarding pupils' accident risk while walking were less likely to let their children walk to school. Parents with high safety knowledge were also more likely to allow their pupils to walk to school. Parents who prioritized convenience and accessibility in transport had a stronger tendency to choose motorized modes over walking modes. Also, parents who prioritized safety and security in transport were less likely to allow pupils to walk to school. Elasticities results showed that a one percent increase in priorities of convenience and accessibility, priorities of safety and security, car ownership and walking time from home to school reduced walking among pupils by a probability of 0.62, 0.20, 0.86 and 0.57%, respectively. A one percent increase in parental safety knowledge increased the walking probability by around 0.25%. A 1 unit increase in parental probability assessment and worry towards pupils' walking, decreased the probability of choosing walking mode by 0.11 and 0.05, respectively. Policy-makers who aim to promote walking to schools should improve safety and security of the walking facilities and increase parental safety knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adaptive evolutionary walks require neutral intermediates in RNA fitness landscapes.

PubMed

Rendel, Mark D

2011-01-01

In RNA fitness landscapes with interconnected networks of neutral mutations, neutral precursor mutations can play an important role in facilitating the accessibility of epistatic adaptive mutant combinations. I use an exhaustively surveyed fitness landscape model based on short sequence RNA genotypes (and their secondary structure phenotypes) to calculate the minimum rate at which mutants initially appearing as neutral are incorporated into an adaptive evolutionary walk. I show first, that incorporating neutral mutations significantly increases the number of point mutations in a given evolutionary walk when compared to estimates from previous adaptive walk models. Second, that incorporating neutral mutants into such a walk significantly increases the final fitness encountered on that walk - indeed evolutionary walks including neutral steps often reach the global optimum in this model. Third, and perhaps most importantly, evolutionary paths of this kind are often extremely winding in their nature and have the potential to undergo multiple mutations at a given sequence position within a single walk; the potential of these winding paths to mislead phylogenetic reconstruction is briefly considered. Copyright © 2010 Elsevier Inc. All rights reserved.

Gait speed is limited but improves over the course of acute care physical therapy.

PubMed

Braden, Heather J; Hilgenberg, Sean; Bohannon, Richard W; Ko, Man-Soo; Hasson, Scott

2012-01-01

Gait is a common focus of physical therapists' management of patients in acute care settings. Walking speed, the distance a patient covers per unit time, has been advocated as a "sixth vital sign." However, the feasibility of measuring walking speed and the degree to which walking speed is limited or improves over the course of therapy in the acute care setting are unclear. The purpose of this study of patients undergoing physical therapy during acute care hospitalization, therefore, was to determine whether walking speed can be measured in acute care and whether walking speed is limited and changes over the course of therapy. This was an observational cross-sectional study. Participants were 46 hospital inpatients, mean age 75.0 years (SD = 7.8), referred to physical therapy and able to walk at least 20 ft. Information regarding diagnosis, comorbidities, physical assistance, device use, body height, and weight was obtained. Speed was determined during initial and final physical therapy visits while patients walked at their self-selected speed over a marked course in a hospital corridor. Therapists reported that walking speed was clinically feasible, requiring inexpensive, available resources, 4 minutes' additional time, and simple calculations for documentation. Initial walking speed was a mean of 0.33 m/s (SD = 0.21; 95% confidence interval [CI]: 0.27-0.39), whereas final speed was 0.37 m/s (SD = 0.20; 95% CI: 0.31-0.43). The Wilcoxon test showed the increase in walking speed (0.04 m/s) to be significant (P = .005) over a mean therapy period of 2.0 days (SD = 1.4) and total hospitalization period of 5.5 days (SD = 3.6). The effect size and standardized response mean were 0.19 and 0.36, respectively. Minimal detectable change was 0.18 m/s. Walking speed is a feasible measure for patients admitted to an acute care hospital. It shows that patients walk slowly relative to community requirements but that their speed improves even over a short course of therapy.

Associations between resident perceptions of the local residential environment and metabolic syndrome.

PubMed

Baldock, Katherine; Paquet, Catherine; Howard, Natasha; Coffee, Neil; Hugo, Graeme; Taylor, Anne; Adams, Robert; Daniel, Mark

2012-01-01

A substantial body of research has arisen concerning the relationships between objective residential area features, particularly area-level socioeconomic status and cardiometabolic outcomes. Little research has explored residents' perceptions of such features and how these might relate to cardiometabolic outcomes. Perceptions of environments are influenced by individual and societal factors, and may not correspond to objective reality. Understanding relations between environmental perceptions and health is important for the development of environment interventions. This study evaluated associations between perceptions of local built and social environmental attributes and metabolic syndrome, and tested whether walking behaviour mediated these associations. Individual-level data were drawn from a population-based biomedical cohort study of adults in Adelaide, South Australia (North West Adelaide Health Study). Participants' local-area perceptions were analysed in cross-sectional associations with metabolic syndrome using multilevel regression models (n = 1, 324). A nonparametric bootstrapping procedure evaluated whether walking mediated these associations. Metabolic syndrome was negatively associated with greater local land-use mix, positive aesthetics, and greater infrastructure for walking, and was positively associated with greater perceived crime and barriers to walking. Walking partially mediated associations between metabolic syndrome and perceived environmental features. Initiatives targeting residents' perceptions of local areas may enhance the utility of environmental interventions to improve population health.

Associations between Resident Perceptions of the Local Residential Environment and Metabolic Syndrome

PubMed Central

Baldock, Katherine; Paquet, Catherine; Howard, Natasha; Coffee, Neil; Hugo, Graeme; Taylor, Anne; Adams, Robert; Daniel, Mark

2012-01-01

A substantial body of research has arisen concerning the relationships between objective residential area features, particularly area-level socioeconomic status and cardiometabolic outcomes. Little research has explored residents' perceptions of such features and how these might relate to cardiometabolic outcomes. Perceptions of environments are influenced by individual and societal factors, and may not correspond to objective reality. Understanding relations between environmental perceptions and health is important for the development of environment interventions. This study evaluated associations between perceptions of local built and social environmental attributes and metabolic syndrome, and tested whether walking behaviour mediated these associations. Individual-level data were drawn from a population-based biomedical cohort study of adults in Adelaide, South Australia (North West Adelaide Health Study). Participants' local-area perceptions were analysed in cross-sectional associations with metabolic syndrome using multilevel regression models (n = 1, 324). A nonparametric bootstrapping procedure evaluated whether walking mediated these associations. Metabolic syndrome was negatively associated with greater local land-use mix, positive aesthetics, and greater infrastructure for walking, and was positively associated with greater perceived crime and barriers to walking. Walking partially mediated associations between metabolic syndrome and perceived environmental features. Initiatives targeting residents' perceptions of local areas may enhance the utility of environmental interventions to improve population health. PMID:23049574

Muscle Synergies May Improve Optimization Prediction of Knee Contact Forces During Walking

PubMed Central

Walter, Jonathan P.; Kinney, Allison L.; Banks, Scott A.; D'Lima, Darryl D.; Besier, Thor F.; Lloyd, David G.; Fregly, Benjamin J.

2014-01-01

The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking. To generate the predictions, we performed mixed dynamic muscle force optimizations (i.e., inverse skeletal dynamics with forward muscle activation and contraction dynamics) using data collected from a subject implanted with a force-measuring knee replacement. Twelve optimization problems (three cases with four subcases each) that minimized the sum of squares of muscle excitations were formulated to investigate how synergy controls affect knee contact force predictions. The three cases were: (1) Calibrate+Match where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously matched, (2) Precalibrate+Predict where experimental knee contact forces were predicted using precalibrated muscle model parameters values from the first case, and (3) Calibrate+Predict where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously predicted, all while matching inverse dynamic loads at the hip, knee, and ankle. The four subcases used either 44 independent controls or five synergy controls with and without EMG shape tracking. For the Calibrate+Match case, all four subcases closely reproduced the measured medial and lateral knee contact forces (R2 ≥ 0.94, root-mean-square (RMS) error < 66 N), indicating sufficient model fidelity for contact force prediction. For the Precalibrate+Predict and Calibrate+Predict cases, synergy controls yielded better contact force predictions (0.61 < R2 < 0.90, 83 N < RMS error < 161 N) than did independent controls (-0.15 < R2 < 0.79, 124 N < RMS error < 343 N) for corresponding subcases. For independent controls, contact force predictions improved when precalibrated model parameter values or EMG shape tracking was used. For synergy controls, contact force predictions were relatively insensitive to how model parameter values were calibrated, while EMG shape tracking made lateral (but not medial) contact force predictions worse. For the subject and optimization cost function analyzed in this study, use of subject-specific synergy controls improved the accuracy of knee contact force predictions, especially for lateral contact force when EMG shape tracking was omitted, and reduced prediction sensitivity to uncertainties in muscle model parameter values. PMID:24402438

Muscle synergies may improve optimization prediction of knee contact forces during walking.

PubMed

Walter, Jonathan P; Kinney, Allison L; Banks, Scott A; D'Lima, Darryl D; Besier, Thor F; Lloyd, David G; Fregly, Benjamin J

2014-02-01

The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking. To generate the predictions, we performed mixed dynamic muscle force optimizations (i.e., inverse skeletal dynamics with forward muscle activation and contraction dynamics) using data collected from a subject implanted with a force-measuring knee replacement. Twelve optimization problems (three cases with four subcases each) that minimized the sum of squares of muscle excitations were formulated to investigate how synergy controls affect knee contact force predictions. The three cases were: (1) Calibrate+Match where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously matched, (2) Precalibrate+Predict where experimental knee contact forces were predicted using precalibrated muscle model parameters values from the first case, and (3) Calibrate+Predict where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously predicted, all while matching inverse dynamic loads at the hip, knee, and ankle. The four subcases used either 44 independent controls or five synergy controls with and without EMG shape tracking. For the Calibrate+Match case, all four subcases closely reproduced the measured medial and lateral knee contact forces (R2 ≥ 0.94, root-mean-square (RMS) error < 66 N), indicating sufficient model fidelity for contact force prediction. For the Precalibrate+Predict and Calibrate+Predict cases, synergy controls yielded better contact force predictions (0.61 < R2 < 0.90, 83 N < RMS error < 161 N) than did independent controls (-0.15 < R2 < 0.79, 124 N < RMS error < 343 N) for corresponding subcases. For independent controls, contact force predictions improved when precalibrated model parameter values or EMG shape tracking was used. For synergy controls, contact force predictions were relatively insensitive to how model parameter values were calibrated, while EMG shape tracking made lateral (but not medial) contact force predictions worse. For the subject and optimization cost function analyzed in this study, use of subject-specific synergy controls improved the accuracy of knee contact force predictions, especially for lateral contact force when EMG shape tracking was omitted, and reduced prediction sensitivity to uncertainties in muscle model parameter values.

The effects of error augmentation on learning to walk on a narrow balance beam.

PubMed

Domingo, Antoinette; Ferris, Daniel P

2010-10-01

Error augmentation during training has been proposed as a means to facilitate motor learning due to the human nervous system's reliance on performance errors to shape motor commands. We studied the effects of error augmentation on short-term learning of walking on a balance beam to determine whether it had beneficial effects on motor performance. Four groups of able-bodied subjects walked on a treadmill-mounted balance beam (2.5-cm wide) before and after 30 min of training. During training, two groups walked on the beam with a destabilization device that augmented error (Medium and High Destabilization groups). A third group walked on a narrower beam (1.27-cm) to augment error (Narrow). The fourth group practiced walking on the 2.5-cm balance beam (Wide). Subjects in the Wide group had significantly greater improvements after training than the error augmentation groups. The High Destabilization group had significantly less performance gains than the Narrow group in spite of similar failures per minute during training. In a follow-up experiment, a fifth group of subjects (Assisted) practiced with a device that greatly reduced catastrophic errors (i.e., stepping off the beam) but maintained similar pelvic movement variability. Performance gains were significantly greater in the Wide group than the Assisted group, indicating that catastrophic errors were important for short-term learning. We conclude that increasing errors during practice via destabilization and a narrower balance beam did not improve short-term learning of beam walking. In addition, the presence of qualitatively catastrophic errors seems to improve short-term learning of walking balance.

Final Report Phase I Study to Characterize the Market Potential for Non-Motorized Travel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Ho-Ling; Reuscher, Tim; Wilson, Daniel W

The idea of livable communities suggests that people should have the option to utilize non-motorized travel (NMT), specifically walking and bicycling, to conduct their daily tasks. Forecasting personal travel by walk and bike is necessary as part of regional transportation planning, and requires fine detail not only about individual travel, but also on transportation and neighborhood infrastructure. In an attempt to characterize the 'market' potential for NMT, the Office of Planning, Federal Highway Administration (FHWA) funded the Center for Transportation Analysis (CTA) of the Oak Ridge National Laboratory (ORNL) to conduct a study. The objectives of this effort were tomore » identify factors that influence communities to walk and bike and to examine why, or why not, travelers walk and bike in their communities. This study relied on information collected under the 2009 National Household Travel Survey (NHTS) as the major source of data, and was supplemented with data from the American Community Survey (ACS), educational survey, health, employment, and others. Initial statistical screening methods were applied to sort through over 400 potential predictor variables, and examined with various measures (e.g., walk trip per person, walk mileage per person, bike trip per person, bike mileage per person) as the dependent variables. The best geographic level of detail used in the modeling for this study was determined to be the Census block group level for walking and Census tract level for biking. The need for additional supplemental private data (i.e., Walk Scores and Nielsen employment data), and geospatial information that reflects land use and physical environments, became evident after an examination of findings from the initial screening models. To be feasible, in terms of costs and time, the geographic scale of the study region was scaled down to nine selected NHTS add-on regions. These regions were chosen based on various criteria including transit availability, population size, and a mix of geographic locations across the nation. Given the similarities in modeling results from walk trips and walk mileages, additional modeling efforts conducted under the later part of this study were focused on walk trips per person. Bike models were limited only with the stepwise logistic models using Census tracts in the selected regions. Due to NHTS sampling limitations, only about 12% of these tracts have bike trips recorded from NHTS sampled households. The modeling with NHTS bike data proved to be more challenging and time consuming than what was anticipated. Along with the late arrival of Nielsen employment data, the project team had to limit the modeling effort to focus on walking. Therefore, the final modeling and discriminant analysis was conducted only for walking trips.« less

Dog walking: its association with physical activity guideline adherence and its correlates.

PubMed

Hoerster, Katherine D; Mayer, Joni A; Sallis, James F; Pizzi, Nicole; Talley, Sandra; Pichon, Latrice C; Butler, Dalila A

2011-01-01

We examined the prevalence and correlates of dog walking among dog owners, and whether dog walking is associated with meeting the American College of Sports Medicine/American Heart Association physical activity guidelines. In March 2008, we mailed a survey to dog-owning clients from two San Diego County veterinary clinics. Useable data were obtained from 984 respondents, and 75 of these completed retest surveys. We assessed associations between potential correlates and dog walking (i.e., yes/no dog walking for at least 10 min in past week). Test-retest reliability of measures was generally high. Approximately one-third of the sample (31.5%) were not dog walkers. Proportions of dog walkers versus non-dog walkers meeting United States guidelines were 64.3% and 55.0%, respectively. Dog walking was independently associated with meeting guidelines in a multivariate model (odds ratio=1.59, p=0.004). Three variables were independently associated with dog walking in a multivariate model: dog encouragement of dog walking, dog-walking obligation, and dog-walking self-efficacy. Dog walking was associated with meeting physical activity guidelines, making it a viable method for promoting physical activity. Dog-walking obligation and self-efficacy may be important mediators of dog walking and may need to be targeted if interventions are to be successful. Published by Elsevier Inc.

Safe RESIDential Environments? A longitudinal analysis of the influence of crime-related safety on walking.

PubMed

Foster, Sarah; Hooper, Paula; Knuiman, Matthew; Christian, Hayley; Bull, Fiona; Giles-Corti, Billie

2016-02-16

Numerous cross-sectional studies have investigated the premise that the perception of crime will cause residents to constrain their walking; however the findings to date are inconclusive. In contrast, few longitudinal or prospective studies have examined the impact of crime-related safety on residents walking behaviours. This study used longitudinal data to test whether there is a causal relationship between crime-related safety and walking in the local neighbourhood. Participants in the RESIDential Environments Project (RESIDE) in Perth, Australia, completed a questionnaire before moving to their new neighbourhood (n = 1813) and again approximately one (n = 1467), three (n = 1230) and seven years (n = 531) after relocating. Self-report measures included neighbourhood perceptions (modified NEWS items) and walking inside the neighbourhood (min/week). Objective built environmental measures were generated for each participant's 1600 m neighbourhood at each time-point, and the count of crimes reported to police were generated at the suburb-level for the first three time-points only. The impact of crime-related safety on walking was examined in SAS using the Proc Mixed procedure (marginal repeated measures model with unrestricted variance pattern). Initial models controlled for demographics, time and self-selection, and subsequent models progressively adjusted for other built and social environment factors based on a social ecological model. For every increase of one level on a five-point Likert scale in perceived safety from crime, total walking within the local neighbourhood increased by 18.0 min/week (p = 0.000). This relationship attenuated to an increase of 10.5 min/week after accounting for other built and social environment factors, but remained significant (p = 0.008). Further analyses examined transport and recreational walking separately. In the fully adjusted models, each increase in safety from crime was associated with a 7.0 min/week increase in recreational walking (p = 0.009), however findings for transport walking were non-significant. All associations between suburb-level crime and walking were non-significant. This study provides longitudinal evidence of a potential causal relationship between residents' perceptions of safety from crime and recreational walking. Safety perceptions appeared to influence recreational walking, rather than transport-related walking. Given the popularity of recreational walking and the need to increase levels of physical activity, community social and physical environmental interventions that foster residents' feelings of safety are likely to increase recreational walking and produce public health gains.

The effect of light touch on balance control during overground walking in healthy young adults.

PubMed

Oates, A R; Unger, J; Arnold, C M; Fung, J; Lanovaz, J L

2017-12-01

Balance control is essential for safe walking. Adding haptic input through light touch may improve walking balance; however, evidence is limited. This research investigated the effect of added haptic input through light touch in healthy young adults during challenging walking conditions. Sixteen individuals walked normally, in tandem, and on a compliant, low-lying balance beam with and without light touch on a railing. Three-dimensional kinematic data were captured to compute stride velocity (m/s), relative time spent in double support (%DS), a medial-lateral margin of stability (MOS ML ) and its variance (MOS ML CV), as well as a symmetry index (SI) for the MOS ML . Muscle activity was evaluated by integrating electromyography signals for the soleus, tibialis anterior, and gluteus medius muscles bilaterally. Adding haptic input decreased stride velocity, increased the %DS, had no effect on the MOS ML magnitude, decreased the MOS ML CV, had no effect on the SI, and increased activity of most muscles examined during normal walking. During tandem walking, stride velocity and the MOS ML CV decreased, while %DS, MOS ML magnitude, SI, and muscle activity did not change with light touch. When walking on a low-lying, compliant balance beam, light touch had no effect on walking velocity, MOS ML magnitude, or muscle activity; however, the %DS increased and the MOS ML CV and SI decreased when lightly touching a railing while walking on the balance beam. The decreases in the MOS ML CV with light touch across all walking conditions suggest that adding haptic input through light touch on a railing may improve balance control during walking through reduced variability.

To walk or not to walk: insights from a qualitative description study with women suffering from fibromyalgia.

PubMed

Sanz-Baños, Yolanda; Pastor, María-Ángeles; Velasco, Lilian; López-Roig, Sofía; Peñacoba, Cecilia; Lledo, Ana; Rodríguez, Charo

2016-08-01

Walking improves health outcomes in fibromyalgia; however, there is low adherence to this practice. The aim of this research was to explore the beliefs of women suffering from fibromyalgia toward walking, and the meaning that they attribute to the behavior of walking as part of their fibromyalgia treatment. This study is a qualitative description research. Forty-six (46) women suffering from fibromyalgia and associated with local fibromyalgia associations located in four different Spanish cities (Elche, Alicante, Madrid, and Talavera de la Reina) participated in focus group discussions in the summer 2012. Thematic content analysis was performed in transcribed verbatim from interviews. Participants perceived several inhibitors for walking even when they had positive beliefs toward its therapeutic value. Whereas participants believed that walking can generate improvement in their disease and their health in general, they did not feel able to actually do so given their many physical impediments. Furthermore, participants struggled with social isolation and stigma, which was lessened through the conscious support of family. Advice from family doctors was also a very important facilitator to participants. In a health care delivery context that favors person-centered care, and in order to foster adherence to walking-based fibromyalgia treatments, it is recommended that therapeutic walking programs be tailored to each woman' individual circumstances, and developed in close collaboration with them to help them increase control over their health and their condition.

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

DOE PAGES

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton; ...

2016-11-23

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Improvement of walking speed and gait symmetry in older patients after hip arthroplasty: a prospective cohort study.

PubMed

Rapp, Walter; Brauner, Torsten; Weber, Linda; Grau, Stefan; Mündermann, Annegret; Horstmann, Thomas

2015-10-12

Retraining walking in patients after hip or knee arthroplasty is an important component of rehabilitation especially in older persons whose social interactions are influenced by their level of mobility. The objective of this study was to test the effect of an intensive inpatient rehabilitation program on walking speed and gait symmetry in patients after hip arthroplasty (THA) using inertial sensor technology. Twenty-nine patients undergoing a 4-week inpatient rehabilitation program following THA and 30 age-matched healthy subjects participated in this study. Walking speed and gait symmetry parameters were measured using inertial sensor device for standardized walking trials (2*20.3 m in a gym) at their self-selected normal and fast walking speeds on postoperative days 15, 21, and 27 in patients and in a single session in control subjects. Walking speed was measured using timing lights. Gait symmetry was determined using autocorrelation calculation of the cranio-caudal (CC) acceleration signals from an inertial sensor placed at the lower spine. Walking speed and gait symmetry improved from postoperative days 15-27 (speed, female: 3.2 and 4.5 m/s; male: 4.2 and 5.2 m/s; autocorrelation, female: 0.77 and 0.81; male: 0.70 and 0.79; P <0.001 for all). After the 4-week rehabilitation program, walking speed and gait symmetry were still lower than those in control subjects (speed, female 4.5 m/s vs. 5.7 m/s; male: 5.2 m/s vs. 5.3 m/s; autocorrelation, female: 0.81 vs. 0.88; male: 0.79 vs. 0.90; P <0.001 for all). While patients with THA improved their walking capacity during a 4-week inpatient rehabilitation program, subsequent intensive gait training is warranted for achieving normal gait symmetry. Inertial sensor technology may be a useful tool for evaluating the rehabilitation process during the post-inpatient period.

Short-Term Efficacy of a "Sit Less, Walk More" Workplace Intervention on Improving Cardiometabolic Health and Work Productivity in Office Workers.

PubMed

Lin, Yun-Ping; Lin, Chiu-Chu; Chen, Meei-Maan; Lee, Kwo-Chen

2017-03-01

The aim of this study was to test the short-term efficacy of the Sit Less, Walk More (SLWM) workplace intervention. This was a quasi-experimental design. A total of 99 office workers from two workplaces participated in this study. The 12-week intervention included five components: monthly newsletters, motivational tools, pedometer challenge, environmental prompts, and walking route. The comparison group received monthly newsletters only. Generalized estimating equation analyses showed that the intervention group demonstrated significant improvements in weight (P = 0.029), waist circumference (P = 0.038), diastolic blood pressure (P < 0.001), walking (P < 0.001), moderate-intensity physical activity (P = 0.014), and total physical activity (P = 0.003) relative to the comparison group. A significant improvement in lost-productivity was observed in both groups (P = 0.003 to 0.008). The SLWM workplace intervention can improve worker health and lost-productivity.

Lévy walks

NASA Astrophysics Data System (ADS)

Zaburdaev, V.; Denisov, S.; Klafter, J.

2015-04-01

Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

The role of postural control in the association between aerobic capacity and walking capacity in chronic stroke: a cross-sectional analysis.

PubMed

Outermans, Jacqueline C; van de Port, Ingrid; Kwakkel, Gert; Visser-Meily, Johanna M; Wittink, Harriet

2018-03-12

Reports on the association between aerobic capacity and walking capacity in people after stroke show disparate results. To determine (1) if the predictive validity of peak oxygen uptake (VO2peak) for walking capacity post stroke is different from that of maximal oxygen uptake (VO2max) and (2) if postural control, hemiplegic lower extremity muscle strength, age and gender distort the association between aerobic capacity and walking capacity. Cross-sectional study. General community in Utrecht, the Netherlands. Community-dwelling people more than three months after stroke. Measurement of aerobic capacity were performed with cardiopulmonary exercise testing (CPET) and differentiated between the achievement of VO2peak or VO2max. Measurement of walking capacity with the Six Minute Walk Test (6MWT), postural control with the Performance Oriented Mobility Assessment (POMA) and hemiplegic lower extremity muscle strength with the Motricity Index (MI-LE). Fifty-one out of 62 eligible participants, aged 64.7 (±12.5) years were included. Analysis of covariance (ANCOVA) showed a nonsignificant difference between the predictive validities of VO2max (N = 22, β = 0.56; 95%CI 0.12 - 0.97) and VO2peak (N = 29, β = 0.72; 95%CI 0.38 - 0.92). Multiple regression analysis of the pooled sample showed a significant decrease in the β value of VO2peak (21.6%) for the 6MWT when adding the POMA as a covariate in the association model. VO2peak remained significantly related to 6MWT after correcting for the POMA (β = 0.56 (95%CI 0.39 - 0.75)) CONCLUSIONS: The results suggest similar predictive validity of aerobic capacity for walking capacity in participants achieving VO2max compared to those only achieving VO2peak. Postural control confounds the association between aerobic capacity and walking capacity. Aerobic capacity remains a valid predictor of walking capacity. Aerobic capacity is an important factor associated with walking capacity after stroke. However, to understand this relationship, postural control needs to be measured. Both aerobic capacity and postural control may need to be addressed during interventions aiming to improve walking capacity after stroke.

Kinematic and biomimetic assessment of a hydraulic ankle/foot in level ground and camber walking

PubMed Central

Bai, Xuefei; Ewins, David; Crocombe, Andrew D.

2017-01-01

Improved walking comfort has been linked with better bio-mimicking of the prosthetic ankle. This study investigated if a hydraulic ankle/foot can provide enough motion in both the sagittal and frontal planes during level and camber walking and if the hydraulic ankle/foot better mimics the biological ankle moment pattern compared with a fixed ankle/foot device. Five active male unilateral trans-femoral amputees performed level ground walking at normal and fast speeds and 2.5° camber walking in both directions using their own prostheses fitted with an “Echelon” hydraulic ankle/foot and an “Esprit” fixed ankle/foot. Ankle angles and the Trend Symmetry Index of the ankle moments were compared between prostheses and walking conditions. Significant differences between prostheses were found in the stance plantarflexion and dorsiflexion peaks with a greater range of motion being reached with the Echelon foot. The Echelon foot also showed significantly improved bio-mimicry of the ankle resistance moment in all walking conditions, either compared with the intact side of the same subject or with the “normal” mean curve from non-amputees. During camber walking, both types of ankle/foot devices showed similar changes in the frontal plane ankle angles. Results from a questionnaire showed the subjects were more satisfied with Echelon foot. PMID:28704428

Effect of a Combined Walking and Conversation Intervention on Functional Mobility of Nursing Home Residents With Alzheimer Disease

PubMed Central

Tappen, Ruth M.; Roach, Kathryn E.; Applegate, E. Brooks; Stowell, Paula

2007-01-01

Summary Assisted walking and walking combined with conversation were compared to a conversation-only intervention in nursing home residents with Alzheimer disease. Sixty-five subjects randomly assigned to treatment group were tested at baseline and end of treatment. Subjects mean Mini-Mental State Examination score was 10.83; mean age was 87. Treatment was given for 30 minutes three times a week for 16 weeks. Subjects in the assisted walking group declined 20.9% in functional mobility; the conversation group declined 18.8%. The combined walking and conversation treatment group declined only 2.5%. These differences in outcome were significant and appear to have been affected by differences in treatment fidelity. Subjects in the conversation treatment group completed 90% of intended treatment compared with 75% in the combined group and only 57% in the assisted walking group. Failure to treat was due to subject refusal and physical illness. The conversation component of the combined walking and conversation treatment intervention appears to have improved compliance with the intervention, thereby improving treatment outcome. Results indicate that assisted walking with conversation can contribute to maintenance of functional mobility in institutionalized populations with Alzheimer disease. Staff assigned to this task should be prepared to use effective communication strategies to gain acceptance of the intervention. PMID:11186596

Kinematic and biomimetic assessment of a hydraulic ankle/foot in level ground and camber walking.

PubMed

Bai, Xuefei; Ewins, David; Crocombe, Andrew D; Xu, Wei

2017-01-01

Improved walking comfort has been linked with better bio-mimicking of the prosthetic ankle. This study investigated if a hydraulic ankle/foot can provide enough motion in both the sagittal and frontal planes during level and camber walking and if the hydraulic ankle/foot better mimics the biological ankle moment pattern compared with a fixed ankle/foot device. Five active male unilateral trans-femoral amputees performed level ground walking at normal and fast speeds and 2.5° camber walking in both directions using their own prostheses fitted with an "Echelon" hydraulic ankle/foot and an "Esprit" fixed ankle/foot. Ankle angles and the Trend Symmetry Index of the ankle moments were compared between prostheses and walking conditions. Significant differences between prostheses were found in the stance plantarflexion and dorsiflexion peaks with a greater range of motion being reached with the Echelon foot. The Echelon foot also showed significantly improved bio-mimicry of the ankle resistance moment in all walking conditions, either compared with the intact side of the same subject or with the "normal" mean curve from non-amputees. During camber walking, both types of ankle/foot devices showed similar changes in the frontal plane ankle angles. Results from a questionnaire showed the subjects were more satisfied with Echelon foot.

Walking economy during cued versus non-cued self-selected treadmill walking in persons with Parkinson's disease.

PubMed

Gallo, Paul M; McIsaac, Tara L; Garber, Carol Ewing

2014-01-01

Gait impairments related to Parkinson's disease (PD) include variable step length and decreased walking velocity, which may result in poorer walking economy. Auditory cueing is a common method used to improve gait mechanics in PD that has been shown to worsen walking economy at set treadmill walking speeds. It is unknown if auditory cueing has the same effects on walking economy at self-selected treadmill walking speeds. To determine if auditory cueing will affect walking economy at self-selected treadmill walking speeds and at speeds slightly faster and slower than self-selected. Twenty-two participants with moderate PD performed three, 6-minute bouts of treadmill walking at three speeds (self-selected and ± 0.22 m·sec-1). One session used cueing and the other without cueing. Energy expenditure was measured and walking economy was calculated (energy expenditure/power). Poorer walking economy and higher energy expenditure occurred during cued walking at a self-selected and a slightly faster walking speed, but there was no apparent difference at the slightly slower speed. These results suggest that potential gait benefits of auditory cueing may come at an energy cost and poorer walking economy for persons with PD at least at some treadmill walking speeds.

The relationship of area-level sociodemographic characteristics, household composition and individual-level socioeconomic status on walking behavior among adults.

PubMed

Hearst, Mary O; Sirard, John R; Forsyth, Ann; Parker, Emily D; Klein, Elizabeth G; Green, Christine G; Lytle, Leslie A

2013-04-01

Understanding the contextual factors associated with why adults walk is important for those interested in increasing walking as a mode of transportation and leisure. This paper investigates the relationships between neighborhood-level sociodemographic context, individual level sociodemographic characteristics and walking for leisure and transport. Data from two community-based studies of adults (n=550) were used to determine the association between the area-sociodemographic environment (ASDE), calculated from U.S. Census variables, and individual-level SES as potential correlates of walking behavior. Descriptive statistics, mean comparisons and Pearson's correlations coefficients were used to assess bivariate relationships. Generalized estimating equations were used to model the relationship between ASDE, as quartiles, and walking behavior. Adjusted models suggest adults engage in more minutes of walking for transportation and less walking for leisure in the most disadvantaged compared to the least disadvantaged neighborhoods but adding individual level demographics and SES eliminated the significant results. However, when models were stratified for free or reduced cost lunch, of those with children who qualified for free or reduced lunch, those who lived in the wealthiest neighborhoods engaged in 10.7 minutes less of total walking per day compared to those living in the most challenged neighborhoods (p<0.001). Strategies to increase walking for transportation or leisure need to take account of individual level socioeconomic factors in addition to area-level measures.

Effects of Buddhism walking meditation on depression, functional fitness, and endothelium-dependent vasodilation in depressed elderly.

PubMed

Prakhinkit, Susaree; Suppapitiporn, Siriluck; Tanaka, Hirofumi; Suksom, Daroonwan

2014-05-01

The objectives of this study were to determine the effects of the novel Buddhism-based walking meditation (BWM) and the traditional walking exercise (TWE) on depression, functional fitness, and vascular reactivity. This was a randomized exercise intervention study. The study was conducted in a university hospital setting. Forty-five elderly participants aged 60-90 years with mild-to-moderate depressive symptoms were randomly allocated to the sedentary control, TWE, and BWM groups. The BWM program was based on aerobic walking exercise incorporating the Buddhist meditations performed 3 times/week for 12 weeks. Depression score, functional fitness, and endothelium-dependent vasodilation as measured by the flow-mediated dilation (FMD) were the outcome measures used. Muscle strength, flexibility, agility, dynamic balance, and cardiorespiratory endurance increased in both exercise groups (p<0.05). Depression score decreased (p<0.05) only in the BWM group. FMD improved (p<0.05) in both exercise groups. Significant reduction in plasma cholesterol, triglyceride, high-density lipoprotein cholesterol, and C-reactive protein were found in both exercise groups, whereas low-density lipoprotein cholesterol, cortisol, and interleukin-6 concentrations decreased only in the BWM group. Buddhist walking meditation was effective in reducing depression, improving functional fitness and vascular reactivity, and appears to confer greater overall improvements than the traditional walking program.

Neighbourhood safety and leisure-time physical activity among Dutch adults: a multilevel perspective

PubMed Central

2013-01-01

Background Several neighbourhood elements have been found to be related to leisure-time walking and cycling. However, the association with neighbourhood safety remains unclear. This study aimed to assess the association of neighbourhood-level safety with leisure-time walking and cycling among Dutch adults. Methods Data were derived from the national health survey (POLS) 2006–2009, with valid data on 20046 respondents residing in 2127 neighbourhoods. Multilevel logistic regression models were used to examine the association between neighbourhood-level safety (general safety and specific safety components: physical disorder, social disorder, crime-related fear, traffic safety) and residents’ engagement in outdoor leisure-time walking and cycling for at least 30 minutes per week. Results An increase in neighbourhood safety (both general safety and each of the safety components) was significantly associated with an increase in leisure-time cycling participation. Associations were strongest for general safety and among older women. In the general population, neighbourhood safety was not significantly associated with leisure-time walking. However, among younger and older adult men and lower educated individuals, an increase in general safety was associated with a decrease in leisure-time walking participation. Conclusions In the Netherlands, neighbourhood safety appears to be related to leisure-time cycling but not to walking. Leisure-time cycling may best be encouraged by improving different safety components at once, rather than focusing on one safety aspect such as traffic safety. Special attention is needed for older women. PMID:23356476

Thinking Inside the Box: The Health Cube Paradigm for Health and Wellness Program Evaluation and Design

PubMed Central

Harris, Sharon

2013-01-01

Abstract Appropriately constructed health promotions can improve population health. The authors developed a practical model for designing, evaluating, and improving initiatives to provide optimal value. Three independent model dimensions (impact, engagement, and sustainability) and the resultant three-dimensional paradigm were described using hypothetical case studies, including a walking challenge, a health risk assessment survey, and an individual condition management program. The 3-dimensional model is illustrated and the dimensions are defined. Calculation of a 3-dimensional score for program comparisons, refinements, and measurement is explained. Program 1, the walking challenge, had high engagement and impact, but limited sustainability. Program 2, the health risk assessment survey, had high engagement and sustainability but limited impact. Program 3, the on-site condition management program, had measurable impact and sustainability but limited engagement, because of a lack of program capacity. Each initiative, though successful in 2 dimensions, lacked sufficient evolution along the third axis for optimal value. Calculation of a 3-dimensional score is useful for health promotion program development comparison and refinements, and overall measurement of program success. (Population Health Management 2013;16:291–295) PMID:23869538

Different knee joint loading patterns in ACL deficient copers and non-copers during walking.

PubMed

Alkjær, Tine; Henriksen, Marius; Simonsen, Erik B

2011-04-01

Rupture of the anterior cruciate ligament (ACL) causes changes in the walking pattern. ACL deficient subjects classified as copers and non-copers have been observed to adopt different post-injury walking patterns. How these different patterns affect the knee compression and shear forces is unresolved. Thus, the aim of the present study was to investigate how different walking patterns observed between copers, non-copers, and controls affect the knee compression and shear forces during walking. Three-dimensional gait analyses were performed in copers (n = 9), non-copers (n = 10), and control subjects (n =19). The net knee joint moment, knee joint reaction forces, and the sagittal knee joint angle were input parameters to a biomechanical model that assessed the knee compression and shear forces. The results showed that the non-copers walked with significantly reduced knee compression and shear forces than the controls. The overall knee compression force pattern was similar between the copers and controls, although this variable was significantly increased at heel strike in the copers compared to both non-copers and controls. The peak shear force was significantly dependent on the peak knee extensor moment. This covariance was significantly different between groups meaning that at a given knee extensor moment the shear force was significantly reduced in the copers compared to controls. The different knee joint loading patterns observed between non-copers and copers reflected the different walking strategies adopted by these groups, which may have implications for the knee joint stability. The strategy adopted by the copers may resemble an effective way to stabilize the knee joint during walking after an ACL rupture and that the knee kinematics may play a key role for this strategy. It is clinically relevant to investigate if gait retraining would enable non-copers to walk as copers and thereby improve their knee joint stability.

Improving Motor Control in Walking: A Randomized Clinical Trial in Older Adults with Subclinical Walking Difficulty

PubMed Central

Brach, Jennifer S.; Lowry, Kristin; Perera, Subashan; Hornyak, Victoria; Wert, David; Studenski, Stephanie A.; VanSwearingen, Jessie M.

2016-01-01

Objective The objective was to test the proposed mechanism of action of a task-specific motor learning intervention by examining its effect on measures of the motor control of gait. Design Single blinded randomized clinical trial. Setting University research laboratory. Participants Forty older adults 65 years of age and older, with gait speed >1.0 m/s and impaired motor skill (Figure of 8 walk time > 8 secs). Interventions The two interventions included a task-oriented motor learning and a standard exercise program. Both interventions lasted 12 weeks, with twice weekly one hour physical therapist supervised sessions. Main Outcome Measures Two measure of the motor control of gait, gait variability and smoothness of walking, were assessed pre and post intervention by assessors masked to treatment arm. Results Of 40 randomized subjects; 38 completed the trial (mean age 77.1±6.0 years). Motor control group improved more than standard group in double support time variability (0.13 vs. 0.05 m/s; adjusted difference, AD=0.006, p=0.03). Smoothness of walking in the anterior/posterior direction improved more in motor control than standard for all conditions (usual: AD=0.53, p=0.05; narrow: AD=0.56, p=0.01; dual task: AD=0.57, p=0.04). Conclusions Among older adults with subclinical walking difficulty, there is initial evidence that task-oriented motor learning exercise results in gains in the motor control of walking, while standard exercise does not. Task-oriented motor learning exercise is a promising intervention for improving timing and coordination deficits related to mobility difficulties in older adults, and needs to be evaluated in a definitive larger trial. PMID:25448244

Does physiotherapy based on the Bobath concept, in conjunction with a task practice, achieve greater improvement in walking ability in people with stroke compared to physiotherapy focused on structured task practice alone?: a pilot randomized controlled trial.

PubMed

Brock, Kim; Haase, Gerlinde; Rothacher, Gerhard; Cotton, Susan

2011-10-01

To compare the short-term effects of two physiotherapy approaches for improving ability to walk in different environments following stroke: (i) interventions based on the Bobath concept, in conjunction with task practice, compared to (ii) structured task practice alone. Randomized controlled trial. Two rehabilitation centres Participants: Twenty-six participants between four and 20 weeks post-stroke, able to walk with supervision indoors. Both groups received six one-hour physiotherapy sessions over a two-week period. One group received physiotherapy based on the Bobath concept, including one hour of structured task practice. The other group received six hours of structured task practice. The primary outcome was an adapted six-minute walk test, incorporating a step, ramp and uneven surface. Secondary measures were gait velocity and the Berg Balance Scale. Measures were assessed before and after the intervention period. Following the intervention, there was no significant difference in improvement between the two groups for the adapted six-minute walk test (89.9 (standard deviation (SD) 73.1) m Bobath versus 41 (40.7) m task practice, P = 0.07). However, walking velocity showed significantly greater increases in the Bobath group (26.2 (SD 17.2) m/min versus 9.9 (SD = 12.9) m/min, P = 0.01). No significant differences between groups were recorded for the Berg Balance Scale (P = 0.2). This pilot study indicates short-term benefit for using interventions based on the Bobath concept for improving walking velocity in people with stroke. A sample size of 32 participants per group is required for a definitive study.

Mentally walking through doorways causes forgetting: The location updating effect and imagination.

PubMed

Lawrence, Zachary; Peterson, Daniel

2016-01-01

Researchers have documented an intriguing phenomenon whereby simply walking through a doorway causes forgetting (the location updating effect). The Event Horizon Model is the most commonly cited theory to explain these data. Importantly, this model explains the effect without invoking the importance or reliance upon perceptual information (i.e., seeing oneself pass through the doorway). This generates the intriguing hypothesis that the effect may be demonstrated in participants who simply imagine walking through a doorway. Across two experiments, we explicitly test this hypothesis. Participants familiarised themselves with both real (Experiment 1) and virtual (Experiment 2) environments which served as the setting for their mental walk. They were then provided with an image to remember and were instructed to imagine themselves walking through the previously presented space. In both experiments, when the mental walk required participants to pass through a doorway, more forgetting occurred, consistent with the predictions laid out in the Event Horizon Model.

The effects of exercise-based rehabilitation on balance and gait for stroke patients: a systematic review.

PubMed

An, Minjeong; Shaughnessy, Marianne

2011-12-01

This review evaluated the effects of balance and/or gait exercise interventions for stroke survivors and summarized the available evidence on these exercise interventions. A search for studies published between January 2001 and January 2010 was performed using the keywords stroke, walking or balance, and physical activity or exercise. Seventeen randomized clinical trials were identified. The findings suggest that initiating early rehabilitation during acute to subacute stroke recovery can improve balance and walking capacity. The findings also demonstrate that at least 1 hour, three to five times per week, of balance training and 30 minutes, three to five times per week, of gait-oriented exercise are effective to improve balance and walking. This review confirms that balance and walking capacity are improved with specific exercise modalities. A combination of balance, gait, and aerobic exercises would be ideal.

Effects of an Exercise Protocol for Improving Handgrip Strength and Walking Speed on Cognitive Function in Patients with Chronic Stroke.

PubMed

Kim, Jaeeun; Yim, Jongeun

2017-11-13

BACKGROUND Handgrip strength and walking speed predict and influence cognitive function. We aimed to investigate an exercise protocol for improving handgrip strength and walking speed, applied to patients with chronic stroke who had cognitive function disorder. MATERIAL AND METHODS Twenty-nine patients with cognitive function disorder participated in this study, and were randomly divided into one of two groups: exercise group (n=14) and control group (n=15). Both groups underwent conventional physical therapy for 60 minutes per day. Additionally, the exercise group followed an exercise protocol for handgrip using the hand exerciser, power web exerciser, Digi-Flex (15 minutes); and treadmill-based weight loading training on their less-affected leg (15 minutes) using a sandbag for 30 minutes, three times per day, for six weeks. Outcomes, including cognitive function and gait ability, were measured before and after the training. RESULTS The Korean version of Montreal Cognitive Assessment (K-MoCA), Stroop test (both simple and interference), Trail Making-B, Timed Up and Go, and 10-Meter Walk tests (p<0.05) yielded improved results for the exercise group compared with the control group. Importantly, the K-MoCA, Timed Up and Go, and 10-Meter Walk test results were significantly different between the two groups (p<0.05). CONCLUSIONS The exercise protocol for improving handgrip strength and walking speed had positive effects on cognitive function in patients with chronic stroke.

Reliability and minimal detectable difference in multisegment foot kinematics during shod walking and running.

PubMed

Milner, Clare E; Brindle, Richard A

2016-01-01

There has been increased interest recently in measuring kinematics within the foot during gait. While several multisegment foot models have appeared in the literature, the Oxford foot model has been used frequently for both walking and running. Several studies have reported the reliability for the Oxford foot model, but most studies to date have reported reliability for barefoot walking. The purpose of this study was to determine between-day (intra-rater) and within-session (inter-trial) reliability of the modified Oxford foot model during shod walking and running and calculate minimum detectable difference for common variables of interest. Healthy adult male runners participated. Participants ran and walked in the gait laboratory for five trials of each. Three-dimensional gait analysis was conducted and foot and ankle joint angle time series data were calculated. Participants returned for a second gait analysis at least 5 days later. Intraclass correlation coefficients and minimum detectable difference were determined for walking and for running, to indicate both within-session and between-day reliability. Overall, relative variables were more reliable than absolute variables, and within-session reliability was greater than between-day reliability. Between-day intraclass correlation coefficients were comparable to those reported previously for adults walking barefoot. It is an extension in the use of the Oxford foot model to incorporate wearing a shoe while maintaining marker placement directly on the skin for each segment. These reliability data for walking and running will aid in the determination of meaningful differences in studies which use this model during shod gait. Copyright © 2015 Elsevier B.V. All rights reserved.

Musical motor feedback (MMF) in walking hemiparetic stroke patients: randomized trials of gait improvement.

PubMed

Schauer, Michael; Mauritz, Karl-Heinz

2003-11-01

To demonstrate the effect of rhythmical auditory stimulation in a musical context for gait therapy in hemiparetic stroke patients, when the stimulation is played back measure by measure initiated by the patient's heel-strikes (musical motor feedback). Does this type of musical feedback improve walking more than a less specific gait therapy? The randomized controlled trial considered 23 registered stroke patients. Two groups were created by randomization: the control group received 15 sessions of conventional gait therapy and the test group received 15 therapy sessions with musical motor feedback. Inpatient rehabilitation hospital. Median post-stroke interval was 44 days and the patients were able to walk without technical aids with a speed of approximately 0.71 m/s. Gait velocity, step duration, gait symmetry, stride length and foot rollover path length (heel-on-toe-off distance). The test group showed more mean improvement than the control group: stride length increased by 18% versus 0%, symmetry deviation decreased by 58% versus 20%, walking speed increased by 27% versus 4% and rollover path length increased by 28% versus 11%. Musical motor feedback improves the stroke patient's walk in selected parameters more than conventional gait therapy. A fixed memory in the patient's mind about the song and its timing may stimulate the improvement of gait even without the presence of an external pacemaker.

Effects of neuromuscular electrostimulation in patients with heart failure admitted to ward.

PubMed

de Araújo, Carlos José Soares; Gonçalves, Fernanda Souza; Bittencourt, Hugo Souza; dos Santos, Noélia Gonçalves; Mecca Junior, Sérgio Vitor; Neves, Júlio Leal Bandeira; Fernandes, André Maurício Souza; Aras Junior, Roque; dos Reis, Francisco José Farias Borges; Guimarães, Armênio Costa; Rodrigues Junior, Erenaldo de Souza; Carvalho, Vitor Oliveira

2012-11-15

Neuromuscular electrostimulation has become a promising issue in cardiovascular rehabilitation. However there are few articles published in the literature regarding neuromuscular electrostimulation in patients with heart failure during hospital stay. This is a randomized controlled pilot trial that aimed to investigate the effect of neuromuscular electrostimulation in the walked distance by the six-minute walking test in 30 patients admitted to ward for heart failure treatment in a tertiary cardiology hospital. Patients in the intervention group performed a conventional rehabilitation and neuromuscular electrostimulation. Patients underwent 60 minutes of electrostimulation (wave frequency was 20 Hz, pulse duration of 20 us) two times a day for consecutive days until hospital discharge. The walked distance in the six-minute walking test improved 75% in the electrostimulation group (from 379.7 ± 43.5 to 372.9 ± 46.9 meters to controls and from 372.9 ± 62.4 to 500 ± 68 meters to electrostimulation, p<0.001). On the other hand, the walked distance in the control group did not change. The neuromuscular electrostimulation group showed greater improvement in the walked distance in the six-minute walking test in patients admitted to ward for compensation of heart failure.

Short-burst interval treadmill training walking capacity and performance in cerebral palsy: a pilot study.

PubMed

Bjornson, Kristie F; Moreau, Noelle; Bodkin, Amy Winter

2018-04-16

To examine the effect of short-burst interval locomotor treadmill training (SBLTT) on walking capacity and performance in cerebral palsy (CP). Twelve children with spastic diplegic CP (average 8.6 years) across Gross Motor Function Classification System levels II (8) and III (4) were randomized to 20 SBLTT sessions over 4 or 10 weeks. SBLTT consisted of alternating 30 seconds of slow and fast walking for 30 minutes/session. Outcomes included the 10 m walk test, one-minute walk test (1MWT), and timed-up-and go (TUG) (capacity) and StepWatch (performance) collected at baseline, post, and 6 weeks post. Fast speed (+.11, p = .04; +.11 m/s, p = .006), 1MWT (+11.2; +11.7 m, p = .006) and TUG (-1.7; -1.9 seconds, p = .006) improved post SBLTT and 6 weeks, respectively. Walking performance increased: average strides/day (+948; +1712, p < .001) and percent time in high strides rates (+0.4, p = 0.07; +0.2, p = .008). Pilot study suggests SBLTT may improve short-term walking capacity and performance.

An empirical examination of the impacts of decentralized nursing unit design.

PubMed

Pati, Debajyoti; Harvey, Thomas E; Redden, Pamela; Summers, Barbara; Pati, Sipra

2015-01-01

The objective of the study was to examine the impact of decentralization on operational efficiency, staff well-being, and teamwork on three inpatient units. Decentralized unit operations and the corresponding physical design solution were hypothesized to positively affect several concerns-productive use of nursing time, staff stress, walking distances, and teamwork, among others. With a wide adoption of the concept, empirical evidence on the impact of decentralization was warranted. A multimethod, before-and-after, quasi-experimental design was adopted for the study, focusing on five issues, namely, (1) how nurses spend their time, (2) walking distance, (3) acute stress, (4) productivity, and (5) teamwork. Data on all five issues were collected on three older units with centralized operational model (before move). The same set of data, with identical tools and measures, were collected on the same units after move in to new physical units with decentralized operational model. Data were collected during spring and fall of 2011. Documentation, nurse station use, medication room use, and supplies room use showed consistent change across the three units. Walking distance increased (statistically significant) on two of the three units. Self-reported level of collaboration decreased, although assessment of the physical facility for collaboration increased. Decentralized nursing and physical design models potentially result in quality of work improvements associated with documentation, medication, and supplies. However, there are unexpected consequences associated with walking, and staff collaboration and teamwork. The solution to the unexpected consequences may lie in operational interventions and greater emphasis on culture change. © The Author(s) 2015.

Fractional Stability of Trunk Acceleration Dynamics of Daily-Life Walking: Toward a Unified Concept of Gait Stability

PubMed Central

Ihlen, Espen A. F.; van Schooten, Kimberley S.; Bruijn, Sjoerd M.; Pijnappels, Mirjam; van Dieën, Jaap H.

2017-01-01

Over the last decades, various measures have been introduced to assess stability during walking. All of these measures assume that gait stability may be equated with exponential stability, where dynamic stability is quantified by a Floquet multiplier or Lyapunov exponent. These specific constructs of dynamic stability assume that the gait dynamics are time independent and without phase transitions. In this case the temporal change in distance, d(t), between neighboring trajectories in state space is assumed to be an exponential function of time. However, results from walking models and empirical studies show that the assumptions of exponential stability break down in the vicinity of phase transitions that are present in each step cycle. Here we apply a general non-exponential construct of gait stability, called fractional stability, which can define dynamic stability in the presence of phase transitions. Fractional stability employs the fractional indices, α and β, of differential operator which allow modeling of singularities in d(t) that cannot be captured by exponential stability. The fractional stability provided an improved fit of d(t) compared to exponential stability when applied to trunk accelerations during daily-life walking in community-dwelling older adults. Moreover, using multivariate empirical mode decomposition surrogates, we found that the singularities in d(t), which were well modeled by fractional stability, are created by phase-dependent modulation of gait. The new construct of fractional stability may represent a physiologically more valid concept of stability in vicinity of phase transitions and may thus pave the way for a more unified concept of gait stability. PMID:28900400

Accuracy of gastrocnemius muscles forces in walking and running goats predicted by one-element and two-element Hill-type models.

PubMed

Lee, Sabrina S M; Arnold, Allison S; Miara, Maria de Boef; Biewener, Andrew A; Wakeling, James M

2013-09-03

Hill-type models are commonly used to estimate muscle forces during human and animal movement-yet the accuracy of the forces estimated during walking, running, and other tasks remains largely unknown. Further, most Hill-type models assume a single contractile element, despite evidence that faster and slower motor units, which have different activation-deactivation dynamics, may be independently or collectively excited. This study evaluated a novel, two-element Hill-type model with "differential" activation of fast and slow contractile elements. Model performance was assessed using a comprehensive data set (including measures of EMG intensity, fascicle length, and tendon force) collected from the gastrocnemius muscles of goats during locomotor experiments. Muscle forces predicted by the new two-element model were compared to the forces estimated using traditional one-element models and to the forces measured in vivo using tendon buckle transducers. Overall, the two-element model resulted in the best predictions of in vivo gastrocnemius force. The coefficient of determination, r(2), was up to 26.9% higher and the root mean square error, RMSE, was up to 37.4% lower for the two-element model than for the one-element models tested. All models captured salient features of the measured muscle force during walking, trotting, and galloping (r(2)=0.26-0.51), and all exhibited some errors (RMSE=9.63-32.2% of the maximum in vivo force). These comparisons provide important insight into the accuracy of Hill-type models. The results also show that incorporation of fast and slow contractile elements within muscle models can improve estimates of time-varying, whole muscle force during locomotor tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.

Accuracy of gastrocnemius muscles forces in walking and running goats predicted by one-element and two-element Hill-type models

PubMed Central

Lee, Sabrina S.M.; Arnold, Allison S.; Miara, Maria de Boef; Biewener, Andrew A.; Wakeling, James M.

2013-01-01

Hill-type models are commonly used to estimate muscle forces during human and animal movement —yet the accuracy of the forces estimated during walking, running, and other tasks remains largely unknown. Further, most Hill-type models assume a single contractile element, despite evidence that faster and slower motor units, which have different activation-deactivation dynamics, may be independently or collectively excited. This study evaluated a novel, two-element Hill-type model with “differential” activation of fast and slow contractile elements. Model performance was assessed using a comprehensive data set (including measures of EMG intensity, fascicle length, and tendon force) collected from the gastrocnemius muscles of goats during locomotor experiments. Muscle forces predicted by the new two-element model were compared to the forces estimated using traditional one-element models and to the forces measured in vivo using tendon buckle transducers. Overall, the two-element model resulted in the best predictions of in vivo gastrocnemius force. The coefficient of determination, r2, was up to 26.9% higher and the root mean square error, RMSE, was up to 37.4% lower for the two-element model than for the one-element models tested. All models captured salient features of the measured muscle force during walking, trotting, and galloping (r2 = 0.26 to 0.51), and all exhibited some errors (RMSE = 9.63 to 32.2% of the maximum in vivo force). These comparisons provide important insight into the accuracy of Hill-type models. The results also show that incorporation of fast and slow contractile elements within muscle models can improve estimates of time-varying, whole muscle force during locomotor tasks. PMID:23871235

Comparison of the immediate efficacy of the Spinomed® back orthosis and posture training support on walking ability in elderly people with thoracic kyphosis.

PubMed

Namdar, Nategh; Arazpour, Mokhtar; Ahmadi Bani, Monireh

2017-12-21

The effect of spinal orthoses, including the Spinomed ® and posture training support (PTS) in improving balance and reducing falls in older people has been previously evaluated. However, there is little evidence available regarding their effect on the walking ability of older individuals with thoracic hyperkyphosis. This study was therefore designed to compare the immediate effect of the Spinomed ® orthosis and PTS on specific gait parameters in this patient group. A total of 34 older volunteer subjects with thoracic hyperkyphosis participated in this study and were randomly allocated into two groups, to either walk with the Spinomed ® orthosis in situ or the PTS. The elderly mobility scale test (EMS), two-minute walk test (2-MWT), and 10-meter walk test (10-MWT) were used to evaluate their walking performance, the distance walked and their walking speed respectively. There were no significant differences in the mean age, body mass index (BMI), kyphosis angle, EMS, 2-MWT, and 10-MWT between the groups at baseline. All parameters were uniform amongst the two groups. The Spinomed ® orthosis and PTS both had a positive and significant effect on the EMS score, the 2-MWT, and the 10-MWT. No significant difference was detected between two the types of orthoses in terms of the EMS score, the 2-MWT, or the 10-MWT. The Spinomed ® and PTS were both effective in improving all the primary outcome measures, with similar improvements demonstrated by both orthoses. Implications for rehabilitations In this category, one of the approaches to treat the elderly with hyperkyphosis is the use of spinal orthoses such as Spinomed ® orthosis and posture training support (PTS). The results showed that the anti-kyphosis orthosis including Spinomed ® and PTS played effective roles in the elderly with hyperkyphosis to improve their walking function. According to the current study results, there was no significant difference between the efficacies of these orthoses in the mentioned parameters.

Gait parameters associated with responsiveness to treadmill training with body-weight support after stroke: an exploratory study.

PubMed

Mulroy, Sara J; Klassen, Tara; Gronley, JoAnne K; Eberly, Valerie J; Brown, David A; Sullivan, Katherine J

2010-02-01

Task-specific training programs after stroke improve walking function, but it is not clear which biomechanical parameters of gait are most associated with improved walking speed. The purpose of this study was to identify gait parameters associated with improved walking speed after a locomotor training program that included body-weight-supported treadmill training (BWSTT). A prospective, between-subjects design was used. Fifteen people, ranging from approximately 9 months to 5 years after stroke, completed 1 of 3 different 6-week training regimens. These regimens consisted of 12 sessions of BWSTT alternated with 12 sessions of: lower-extremity resistive cycling; lower-extremity progressive, resistive strengthening; or a sham condition of arm ergometry. Gait analysis was conducted before and after the 6-week intervention program. Kinematics, kinetics, and electromyographic (EMG) activity were recorded from the hemiparetic lower extremity while participants walked at a self-selected pace. Changes in gait parameters were compared in participants who showed an increase in self-selected walking speed of greater than 0.08 m/s (high-response group) and in those with less improvement (low-response group). Compared with participants in the low-response group, those in the high-response group displayed greater increases in terminal stance hip extension angle and hip flexion power (product of net joint moment and angular velocity) after the intervention. The intensity of soleus muscle EMG activity during walking also was significantly higher in participants in the high-response group after the intervention. Only sagittal-plane parameters were assessed, and the sample size was small. Task-specific locomotor training alternated with strength training resulted in kinematic, kinetic, and muscle activation adaptations that were strongly associated with improved walking speed. Changes in both hip and ankle biomechanics during late stance were associated with greater increases in gait speed.

Effect of reduced gravity on the preferred walk-run transition speed

NASA Technical Reports Server (NTRS)

Kram, R.; Domingo, A.; Ferris, D. P.

1997-01-01

We investigated the effect of reduced gravity on the human walk-run gait transition speed and interpreted the results using an inverted-pendulum mechanical model. We simulated reduced gravity using an apparatus that applied a nearly constant upward force at the center of mass, and the subjects walked and ran on a motorized treadmill. In the inverted pendulum model for walking, gravity provides the centripetal force needed to keep the pendulum in contact with the ground. The ratio of the centripetal and gravitational forces (mv2/L)/(mg) reduces to the dimensionless Froude number (v2/gL). Applying this model to a walking human, m is body mass, v is forward velocity, L is leg length and g is gravity. In normal gravity, humans and other bipeds with different leg lengths all choose to switch from a walk to a run at different absolute speeds but at approximately the same Froude number (0.5). We found that, at lower levels of gravity, the walk-run transition occurred at progressively slower absolute speeds but at approximately the same Froude number. This supports the hypothesis that the walk-run transition is triggered by the dynamics of an inverted-pendulum system.

Formation mechanism of a basin of attraction for passive dynamic walking induced by intrinsic hyperbolicity

PubMed Central

Aoi, Shinya; Tsuchiya, Kazuo; Kokubu, Hiroshi

2016-01-01

Passive dynamic walking is a useful model for investigating the mechanical functions of the body that produce energy-efficient walking. The basin of attraction is very small and thin, and it has a fractal-like shape; this explains the difficulty in producing stable passive dynamic walking. The underlying mechanism that produces these geometric characteristics was not known. In this paper, we consider this from the viewpoint of dynamical systems theory, and we use the simplest walking model to clarify the mechanism that forms the basin of attraction for passive dynamic walking. We show that the intrinsic saddle-type hyperbolicity of the upright equilibrium point in the governing dynamics plays an important role in the geometrical characteristics of the basin of attraction; this contributes to our understanding of the stability mechanism of bipedal walking. PMID:27436971

Bivariate Gaussian bridges: directional factorization of diffusion in Brownian bridge models.

PubMed

Kranstauber, Bart; Safi, Kamran; Bartumeus, Frederic

2014-01-01

In recent years high resolution animal tracking data has become the standard in movement ecology. The Brownian Bridge Movement Model (BBMM) is a widely adopted approach to describe animal space use from such high resolution tracks. One of the underlying assumptions of the BBMM is isotropic diffusive motion between consecutive locations, i.e. invariant with respect to the direction. Here we propose to relax this often unrealistic assumption by separating the Brownian motion variance into two directional components, one parallel and one orthogonal to the direction of the motion. Our new model, the Bivariate Gaussian bridge (BGB), tracks movement heterogeneity across time. Using the BGB and identifying directed and non-directed movement within a trajectory resulted in more accurate utilisation distributions compared to dynamic Brownian bridges, especially for trajectories with a non-isotropic diffusion, such as directed movement or Lévy like movements. We evaluated our model with simulated trajectories and observed tracks, demonstrating that the improvement of our model scales with the directional correlation of a correlated random walk. We find that many of the animal trajectories do not adhere to the assumptions of the BBMM. The proposed model improves accuracy when describing the space use both in simulated correlated random walks as well as observed animal tracks. Our novel approach is implemented and available within the "move" package for R.

Directional Bias and Pheromone for Discovery and Coverage on Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fink, Glenn A.; Berenhaut, Kenneth S.; Oehmen, Christopher S.

2012-09-11

Natural multi-agent systems often rely on “correlated random walks” (random walks that are biased toward a current heading) to distribute their agents over a space (e.g., for foraging, search, etc.). Our contribution involves creation of a new movement and pheromone model that applies the concept of heading bias in random walks to a multi-agent, digital-ants system designed for cyber-security monitoring. We examine the relative performance effects of both pheromone and heading bias on speed of discovery of a target and search-area coverage in a two-dimensional network layout. We found that heading bias was unexpectedly helpful in reducing search time andmore » that it was more influential than pheromone for improving coverage. We conclude that while pheromone is very important for rapid discovery, heading bias can also greatly improve both performance metrics.« less

Subject-specific modeling of muscle force and knee contact in total knee arthroplasty.

PubMed

Navacchia, Alessandro; Rullkoetter, Paul J; Schütz, Pascal; List, Renate B; Fitzpatrick, Clare K; Shelburne, Kevin B

2016-09-01

Understanding the mechanical loading environment and resulting joint mechanics for activities of daily living in total knee arthroplasty is essential to continuous improvement in implant design. Although survivorship of these devices is good, a substantial number of patients report dissatisfaction with the outcome of their procedure. Knowledge of in vivo kinematics and joint loading will enable improvement in preclinical assessment and refinement of implant geometry. The purpose of this investigation was to describe the mechanics of total knee arthroplasty during a variety of activities of daily living (gait, walking down stairs, and chair rise/sit). Estimates of muscle forces, tibial contact load, location, and pressure distribution was performed through a combination of mobile fluoroscopy data collection, musculoskeletal modeling, and finite element simulation. For the activities evaluated, joint compressive load was greatest during walking down stairs; however, the highest contact pressure occurred during chair rise/sit. The joint contact moment in the frontal plane was mainly varus for gait and walking down stairs, while it was valgus during chair rise/sit. Excursion of the center of pressure on the tibial component was similar during each activity and between the medial and lateral sides. The main determinants of center of pressure location were internal-external rotation, joint load, and tibial insert conformity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1576-1587, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

In vivo measurement of ACL length and relative strain during walking

PubMed Central

Taylor, K A; Cutcliffe, H C; Queen, R M; Utturkar, G M; Spritzer, C E; Garrett, W E; DeFrate, L E

2012-01-01

Although numerous studies have addressed the effects of ACL injury and reconstruction on knee joint motion, there is currently little data available describing in vivo ACL strain during activities of daily living. Data describing in vivo ACL strain during activities such as gait is critical to understanding the biomechanical function of the ligament, and ultimately, to improving the surgical treatment of patients with ACL rupture. Thus, our objective was to characterize the relative strain in the ACL during both the stance and swing phases of normal level walking. Eight normal subjects were recruited for this study. Through a combination of magnetic resonance imaging, biplanar fluoroscopy, and motion capture, we created in vivo models of each subject’s normal walking movements to measure knee flexion, ACL length, and relative ACL strain during gait. Regression analysis demonstrated an inverse relationship between knee flexion and ACL length (R2=0.61, p<0.001). Furthermore, relative strain in the ACL peaked at 13±2% (mean± 95%CI) during mid-stance when the knee was near full extension. Additionally, there was a second local maximum of 10±7% near the end of swing phase, just prior to heel strike. These data are a vital step in further comprehending the normal in vivo biomechanics experienced by the ACL. In the future, this information could prove critical to improving ACL reconstruction and provide useful validation to future computational models investigating ACL function. PMID:23178040

A simplified clinical prediction rule for prognosticating independent walking after spinal cord injury: a prospective study from a Canadian multicenter spinal cord injury registry.

PubMed

Hicks, Katharine E; Zhao, Yichen; Fallah, Nader; Rivers, Carly S; Noonan, Vanessa K; Plashkes, Tova; Wai, Eugene K; Roffey, Darren M; Tsai, Eve C; Paquet, Jerome; Attabib, Najmedden; Marion, Travis; Ahn, Henry; Phan, Philippe

2017-10-01

Traumatic spinal cord injury (SCI) is a debilitating condition with limited treatment options for neurologic or functional recovery. The ability to predict the prognosis of walking post injury with emerging prediction models could aid in rehabilitation strategies and reintegration into the community. To revalidate an existing clinical prediction model for independent ambulation (van Middendorp et al., 2011) using acute and long-term post-injury follow-up data, and to investigatethe accuracy of a simplified model using prospectively collected data from a Canadian multicenter SCI database, the Rick Hansen Spinal Cord Injury Registry (RHSCIR). Prospective cohort study. The analysis cohort consisted of 278 adult individuals with traumatic SCI enrolled in the RHSCIR for whom complete neurologic examination data and Functional Independence Measure (FIM) outcome data were available. The FIM locomotor score was used to assess independent walking ability (defined as modified or complete independence in walk or combined walk and wheelchair modality) at 1-year follow-up for each participant. A logistic regression (LR) model based on age and four neurologic variables was applied to our cohort of 278 RHSCIR participants. Additionally, a simplified LR model was created. The Hosmer-Lemeshow goodness of fit test was used to check if the predictive model is applicable to our data set. The performance of the model was verified by calculating the area under the receiver operating characteristic curve (AUC). The accuracy of the model was tested using a cross-validation technique. This study was supported by a grant from The Ottawa Hospital Academic Medical Organization ($50,000 over 2 years). The RHSCIR is sponsored by the Rick Hansen Institute and is supported by funding from Health Canada, Western Economic Diversification Canada, and the provincial governments of Alberta, British Columbia, Manitoba, and Ontario. ET and JP report receiving grants from the Rick Hansen Institute (approximately $60,000 and $30,000 per year, respectively). DMR reports receiving remuneration for consulting services provided to Palladian Health, LLC and Pacira Pharmaceuticals, Inc ($20,000-$30,000 annually), although neither relationship presents a potential conflict of interest with the submitted work. KEH received a grant for involvement in the present study from the Government of Canada as part of the Canada Summer Jobs Program ($3,000). JP reports receiving an educational grant from Medtronic Canada outside of the submitted work ($75,000 annually). TM reports receiving educational fellowship support from AO Spine, AO Trauma, and Medtronic; however, none of these relationships are financial in nature. All remaining authors have no conflicts of interest to disclose. The fitted prediction model generated 85% overall classification accuracy, 79% sensitivity, and 90% specificity. The prediction model was able to accurately classify independent walking ability (AUC 0.889, 95% confidence interval [CI] 0.846-0.933, p<.001) compared with the existing prediction model, despite the use of a different outcome measure (FIM vs. Spinal Cord Independence Measure) to qualify walking ability. A simplified, three-variable LR model based on age and two neurologic variables had an overall classification accuracy of 84%, with 76% sensitivity and 90% specificity, demonstrating comparable accuracy with its five-variable prediction model counterpart. The AUC was 0.866 (95% CI 0.816-0.916, p<.01), only marginally less than that of the existing prediction model. A simplified predictive model with similar accuracy to a more complex model for predicting independent walking was created, which improves utility in a clinical setting. Such models will allow clinicians to better predict the prognosis of ambulation in individuals who have sustained a traumatic SCI. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Use of the challenge point framework to guide motor learning of stepping reactions for improved balance control in people with stroke: a case series.

PubMed

Pollock, Courtney L; Boyd, Lara A; Hunt, Michael A; Garland, S Jayne

2014-04-01

Stepping reactions are important for walking balance and community-level mobility. Stepping reactions of people with stroke are characterized by slow reaction times, poor coordination of motor responses, and low amplitude of movements, which may contribute to their decreased ability to recover their balance when challenged. An important aspect of rehabilitation of mobility after stroke is optimizing the motor learning associated with retraining effective stepping reactions. The Challenge Point Framework (CPF) is a model that can be used to promote motor learning through manipulation of conditions of practice to modify task difficulty, that is, the interaction of the skill of the learner and the difficulty of the task to be learned. This case series illustrates how the retraining of multidirectional stepping reactions may be informed by the CPF to improve balance function in people with stroke. Four people (53-68 years of age) with chronic stroke (>1 year) and mild to moderate motor recovery received 4 weeks of multidirectional stepping reaction retraining. Important tenets of motor learning were optimized for each person during retraining in accordance with the CPF. Participants demonstrated improved community-level walking balance, as determined with the Community Balance and Mobility Scale. These improvements were evident 1 year later. Aspects of balance-related self-efficacy and movement kinematics also showed improvements during the course of the intervention. The application of CPF motor learning principles in the retraining of stepping reactions to improve community-level walking balance in people with chronic stroke appears to be promising. The CPF provides a plausible theoretical framework for the progression of functional task training in neurorehabilitation.

Three 15-min Bouts of Moderate Postmeal Walking Significantly Improves 24-h Glycemic Control in Older People at Risk for Impaired Glucose Tolerance

PubMed Central

DiPietro, Loretta; Gribok, Andrei; Stevens, Michelle S.; Hamm, Larry F.; Rumpler, William

2013-01-01

OBJECTIVE The purpose of this study was to compare the effectiveness of three 15-min bouts of postmeal walking with 45 min of sustained walking on 24-h glycemic control in older persons at risk for glucose intolerance. RESEARCH DESIGN AND METHODS Inactive older (≥60 years of age) participants (N = 10) were recruited from the community and were nonsmoking, with a BMI <35 kg/m2 and a fasting blood glucose concentration between 105 and 125 mg dL−1. Participants completed three randomly ordered exercise protocols spaced 4 weeks apart. Each protocol comprised a 48-h stay in a whole-room calorimeter, with the first day serving as the control day. On the second day, participants engaged in either 1) postmeal walking for 15 min or 45 min of sustained walking performed at 2) 10:30 a.m. or 3) 4:30 p.m. All walking was on a treadmill at an absolute intensity of 3 METs. Interstitial glucose concentrations were determined over 48 h with a continuous glucose monitor. Substrate utilization was measured continuously by respiratory exchange (VCO2/VO2). RESULTS Both sustained morning walking (127 ± 23 vs. 118 ± 14 mg dL−1) and postmeal walking (129 ± 24 vs. 116 ± 13 mg dL−1) significantly improved 24-h glycemic control relative to the control day (P < 0.05). Moreover, postmeal walking was significantly (P < 0.01) more effective than 45 min of sustained morning or afternoon walking in lowering 3-h postdinner glucose between the control and experimental day. CONCLUSIONS Short, intermittent bouts of postmeal walking appear to be an effective way to control postprandial hyperglycemia in older people. PMID:23761134

History dependent quantum walk on the cycle with an unbalanced coin

NASA Astrophysics Data System (ADS)

Krawec, Walter O.

2015-06-01

Recently, a new model of quantum walk, utilizing recycled coins, was introduced; however little is yet known about its properties. In this paper, we study its behavior on the cycle graph. In particular, we will consider its time averaged distribution and how it is affected by the walk's "memory parameter"-a real parameter, between zero and eight, which affects the walk's coin flip operator. Despite an infinite number of different parameters, our analysis provides evidence that only a few produce non-uniform behavior. Our analysis also shows that the initial state, and cycle size modulo four all affect the behavior of this walk. We also prove an interesting relationship between the recycled coin model and a different memory-based quantum walk recently proposed.

Combined training improves walking mobility in persons with significant disability from multiple sclerosis: a pilot study.

PubMed

Motl, Robert W; Smith, Douglas C; Elliott, Jeannette; Weikert, Madeline; Dlugonski, Deirdre; Sosnoff, Jacob J

2012-03-01

The disabling consequences of multiple sclerosis (MS) emphasize the significance of developing physiologically relevant strategies for rehabilitation of function. This pilot study examined changes in walking function associated with combined exercise training consisting of aerobic, resistance, and balance activities in persons with MS who had recent onset of gait impairment. Thirteen participants with significant disability due to MS (Expanded Disability Status Scale range = 4.0-6.0) completed the Multiple Sclerosis Walking Scale-12, 2 trials of the Timed 25-Foot Walk, the Timed Up & Go, and functional ambulation profile score derived from 4 walking trials on an instrumented walkway (GaitRite) before and after an 8-week training period. The training program was designed by a physical therapist and was performed 3 days per week under the supervision of an exercise specialist. In week 1, the session was 15 minutes in duration (ie, 5 minutes of each mode of exercise), session durations were increased by approximately 5 minutes per week up to a maximum of 60 minutes in week 8 (ie, 20 minutes of each mode of exercise). There were significant improvements in Multiple Sclerosis Walking Scale-12 scores (Mpre = 56.0, Mpost = 46.7, P = 0.03, d = 0.56), Timed 25-Foot Walk (Mpre = 11.7, Mpost = 9.8, P = 0.004, d = 0.90) and Timed Up & Go (Mpre = 16.0, Mpost = 13.0, P = 0.01, d = 0.72) performance, and functional ambulation profile score (Mpre = 72.8, Mpost = 77.6, P = 0.02, d = 0.65). These results suggest that a moderately intense, comprehensive, combined exercise training program represents a rehabilitation strategy that is associated with improved walking mobility in a small sample of persons with MS who have recent onset of gait impairment.

Motor Learning Versus StandardWalking Exercise in Older Adults with Subclinical Gait Dysfunction: A Randomized Clinical Trial

PubMed Central

Brach, Jennifer S.; Van Swearingen, Jessie M.; Perera, Subashan; Wert, David M.; Studenski, Stephanie

2013-01-01

Background Current exercise recommendationsfocus on endurance and strength, but rarely incorporate principles of motor learning. Motor learning exerciseis designed to address neurological aspects of movement. Motor learning exercise has not been evaluated in older adults with subclinical gait dysfunction. Objectives Tocompare motor learning versus standard exercise on measures of mobility and perceived function and disability. Design Single-blind randomized trial. Setting University research center. Participants Olderadults (n=40), mean age 77.1±6.0 years), who had normal walking speed (≥1.0 m/s) and impaired motor skill (Figure of 8 walk time > 8 s). Interventions The motor learning program (ML) incorporated goal-oriented stepping and walking to promote timing and coordination within the phases of the gait cycle. The standard program (S) employed endurance training by treadmill walking.Both included strength training and were offered twice weekly for one hour for 12 weeks. Measurements Primary outcomes included mobility performance (gait efficiency, motor skill in walking, gait speed, and walking endurance)and secondary outcomes included perceived function and disability (Late Life Function and Disability Instrument). Results 38 of 40 participants completed the trial (ML, n=18; S, n=20). ML improved more than Sin gait speed (0.13 vs. 0.05 m/s, p=0.008) and motor skill (−2.2 vs. −0.89 s, p<0.0001). Both groups improved in walking endurance (28.3 and 22.9m, but did not differ significantly p=0.14). Changes in gait efficiency and perceived function and disability were not different between the groups (p>0.10). Conclusion In older adults with subclinical gait dysfunction, motor learning exercise improved some parameters of mobility performance more than standard exercise. PMID:24219189

The effectiveness of body weight-supported gait training and floor walking in patients with chronic stroke.

PubMed

Peurala, Sinikka H; Tarkka, Ina M; Pitkänen, Kauko; Sivenius, Juhani

2005-08-01

To compare body weight-supported exercise on a gait trainer with walking exercise overground. Randomized controlled trial. Rehabilitation hospital. Forty-five ambulatory patients with chronic stroke. Patients were randomized to 3 groups: (1) gait trainer exercise with functional electric stimulation (GTstim), (2) gait trainer exercise without stimulation (GT), and (3) walking overground (WALK). All patients practiced gait for 15 sessions during 3 weeks (each session, 20 min), and they received additional physiotherapy 55 minutes daily. Ten-meter walk test (10MWT), six-minute walk test (6MWT), lower-limb spasticity and muscle force, postural sway tests, Modified Motor Assessment Scale (MMAS), and FIM instrument scores were recorded before, during, and after the rehabilitation and at 6 months follow-up. The mean walking distance using the gait trainer was 6900+/-1200 m in the GTstim group and 6500+/-1700 m in GT group. In the WALK group, the distance was 4800+/-2800 m, which was less than the walking distance obtained in the GTstim group (P=.027). The body-weight support was individually reduced from 30% to 9% of the body weight over the course of the program. In the pooled 45 patients, the 10MWT (P<.001), 6MWT (P<.001), MMAS (P<.001), dynamic balance test time (P<.001), and test trip (P=.005) scores improved; however, no differences were found between the groups. Both the body weight-supported training and walking exercise training programs resulted in faster gait after the intensive rehabilitation program. Patients' motor performance remained improved at the follow-up.

Influence of neuromuscular noise and walking speed on fall risk and dynamic stability in a 3D dynamic walking model.

PubMed

Roos, Paulien E; Dingwell, Jonathan B

2013-06-21

Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-related increases in neuromuscular noise may contribute to the increased fall risk observed at faster walking speeds. Using a 3D dynamic walking model, we systematically varied walking speed without and with physiologically-appropriate neuromuscular noise. We quantified how actual fall risk changed with gait speed, how neuromuscular noise affected speed-related changes in fall risk, and how well orbital and local dynamic stability measures predicted changes in fall risk across speeds. When we included physiologically-appropriate noise to the 'push-off' force in our model, fall risk increased with increasing walking speed. Changes in kinematic variability, orbital, and local dynamic stability did not predict these speed-related changes in fall risk. Thus, the increased neuromuscular variability that results from increased signal-dependent noise that is necessitated by the greater muscular force requirements of faster walking may contribute to the increased fall risk observed at faster walking speeds. The lower fall risk observed at slower speeds supports experimental evidence that slowing down can be an effective strategy to reduce fall risk. This may help explain the slower walking speeds observed in older adults and others. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of Neuromuscular Noise and Walking Speed on Fall Risk and Dynamic Stability in a 3D Dynamic Walking Model

PubMed Central

Roos, Paulien E.; Dingwell, Jonathan B.

2013-01-01

Older adults and those with increased fall risk tend to walk slower. They may do this voluntarily to reduce their fall risk. However, both slower and faster walking speeds can predict increased risk of different types of falls. The mechanisms that contribute to fall risk across speeds are not well known. Faster walking requires greater forward propulsion, generated by larger muscle forces. However, greater muscle activation induces increased signal-dependent neuromuscular noise. These speed-related increases in neuromuscular noise may contribute to the increased fall risk observed at faster walking speeds. Using a 3D dynamic walking model, we systematically varied walking speed without and with physiologically-appropriate neuromuscular noise. We quantified how actual fall risk changed with gait speed, how neuromuscular noise affected speed-related changes in fall risk, and how well orbital and local dynamic stability measures predicted changes in fall risk across speeds. When we included physiologically-appropriate noise to the ‘push-off’ force in our model, fall risk increased with increasing walking speed. Changes in kinematic variability, orbital, and local dynamic stability did not predict these speed-related changes in fall risk. Thus, the increased neuromuscular variability that results from increased signal-dependent noise that is necessitated by the greater muscular force requirements of faster walking may contribute to the increased fall risk observed at faster walking speeds. The lower fall risk observed at slower speeds supports experimental evidence that slowing down can be an effective strategy to reduce fall risk. This may help explain the slower walking speeds observed in older adults and others. PMID:23659911

Does pedometer goal setting improve physical activity among Native elders? Results from a randomized pilot study.

PubMed

Sawchuk, Craig N; Russo, Joan E; Charles, Steve; Goldberg, Jack; Forquera, Ralph; Roy-Byrne, Peter; Buchwald, Dedra

2011-01-01

We examined if step-count goal setting resulted in increases in physical activity and walking compared to only monitoring step counts with pedometers among American Indian/Alaska Native elders. Outcomes included step counts, self-reported physical activity and well-being, and performance on the 6-minute walk test. Although no significant between-group differences were found, within-group analyses indicated that elders significantly improved on the majority of step count, physical activity, health-related quality of life, and 6-minute walk outcomes.

A lower-extremity exoskeleton improves knee extension in children with crouch gait from cerebral palsy.

PubMed

Lerner, Zachary F; Damiano, Diane L; Bulea, Thomas C

2017-08-23

The ability to walk contributes considerably to physical health and overall well-being, particularly in children with motor disability, and is therefore prioritized as a rehabilitation goal. However, half of ambulatory children with cerebral palsy (CP), the most prevalent childhood movement disorder, cease to walk in adulthood. Robotic gait trainers have shown positive outcomes in initial studies, but these clinic-based systems are limited to short-term programs of insufficient length to maintain improved function in a lifelong disability such as CP. Sophisticated wearable exoskeletons are now available, but their utility in treating childhood movement disorders remains unknown. We evaluated an exoskeleton for the treatment of crouch (or flexed-knee) gait, one of the most debilitating pathologies in CP. We show that the exoskeleton reduced crouch in a cohort of ambulatory children with CP during overground walking. The exoskeleton was safe and well tolerated, and all children were able to walk independently with the device. Rather than guiding the lower limbs, the exoskeleton dynamically changed the posture by introducing bursts of knee extension assistance during discrete portions of the walking cycle, a perturbation that resulted in maintained or increased knee extensor muscle activity during exoskeleton use. Six of seven participants exhibited postural improvements equivalent to outcomes reported from invasive orthopedic surgery. We also demonstrate that improvements in crouch increased over the course of our multiweek exploratory trial. Together, these results provide evidence supporting the use of wearable exoskeletons as a treatment strategy to improve walking in children with CP. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Functional Outcome of Neurologic-Controlled HAL-Exoskeletal Neurorehabilitation in Chronic Spinal Cord Injury: A Pilot With One Year Treatment and Variable Treatment Frequency.

PubMed

Jansen, Oliver; Schildhauer, Thomas A; Meindl, Renate C; Tegenthoff, Martin; Schwenkreis, Peter; Sczesny-Kaiser, Matthias; Grasmücke, Dennis; Fisahn, Christian; Aach, Mirko

2017-12-01

Longitudinal prospective study. Whether 1-year HAL-BWSTT of chronic spinal cord injured patients can improve independent ambulated mobility further as a function of training frequency, after an initial 3-month training period. Eight patients with chronic SCI were enrolled. They initially received full standard physical therapy and neurorehabilitation in the acute/subacute posttrauma phase. During this trial, all patients first underwent a daily (5 per week) HAL-BWSTT for 12 weeks. Subsequently, these patients performed a 40-week HAL-BWSTT with a training session frequency of either 1 or 3 to 5 sessions per week. The patients' functional status including HAL-associated treadmill-walking time, -distance, and -speed with additional analysis of gait pattern, and their independent (without wearing the robot suit) functional mobility improvements, were assessed using the 10-Meter-Walk Test (10MWT), Timed-Up-and-Go Test (TUG) and 6-Minute-Walk Test (6MinWT) on admission, at 6 weeks, 12 weeks, and 1 year after enrollment. The data were analyzed separately for the 2 training frequency subgroups after the initial 12-week training period, which was identical in both groups. During the 1-year follow-up, HAL-associated walking parameters and independent functional improvements were maintained in all the patients. This result held irrespective of the training frequency. Long-term 1-year maintenance of HAL-associated treadmill walking parameters and of improved independent walking abilities after initial 12 weeks of daily HAL-BWSTT is possible and depends mainly on the patients' ambulatory status accomplished after initial training period. Subsequent regular weekly training, but not higher frequency training, seems to be sufficient to preserve the improvements accomplished.

Functional Outcome of Neurologic-Controlled HAL-Exoskeletal Neurorehabilitation in Chronic Spinal Cord Injury: A Pilot With One Year Treatment and Variable Treatment Frequency

PubMed Central

Schildhauer, Thomas A.; Meindl, Renate C.; Tegenthoff, Martin; Schwenkreis, Peter; Sczesny-Kaiser, Matthias; Grasmücke, Dennis; Fisahn, Christian; Aach, Mirko

2017-01-01

Study Design: Longitudinal prospective study. Objectives: Whether 1-year HAL-BWSTT of chronic spinal cord injured patients can improve independent ambulated mobility further as a function of training frequency, after an initial 3-month training period. Methods: Eight patients with chronic SCI were enrolled. They initially received full standard physical therapy and neurorehabilitation in the acute/subacute posttrauma phase. During this trial, all patients first underwent a daily (5 per week) HAL-BWSTT for 12 weeks. Subsequently, these patients performed a 40-week HAL-BWSTT with a training session frequency of either 1 or 3 to 5 sessions per week. The patients’ functional status including HAL-associated treadmill-walking time, -distance, and -speed with additional analysis of gait pattern, and their independent (without wearing the robot suit) functional mobility improvements, were assessed using the 10-Meter-Walk Test (10MWT), Timed-Up-and-Go Test (TUG) and 6-Minute-Walk Test (6MinWT) on admission, at 6 weeks, 12 weeks, and 1 year after enrollment. The data were analyzed separately for the 2 training frequency subgroups after the initial 12-week training period, which was identical in both groups. Results: During the 1-year follow-up, HAL-associated walking parameters and independent functional improvements were maintained in all the patients. This result held irrespective of the training frequency. Conclusions: Long-term 1-year maintenance of HAL-associated treadmill walking parameters and of improved independent walking abilities after initial 12 weeks of daily HAL-BWSTT is possible and depends mainly on the patients’ ambulatory status accomplished after initial training period. Subsequent regular weekly training, but not higher frequency training, seems to be sufficient to preserve the improvements accomplished. PMID:29238636

Engineering online and in-person social networks to sustain physical activity: application of a conceptual model

PubMed Central

2013-01-01

Background High rates of physical inactivity compromise the health status of populations globally. Social networks have been shown to influence physical activity (PA), but little is known about how best to engineer social networks to sustain PA. To improve procedures for building networks that shape PA as a normative behavior, there is a need for more specific hypotheses about how social variables influence PA. There is also a need to integrate concepts from network science with ecological concepts that often guide the design of in-person and electronically-mediated interventions. Therefore, this paper: (1) proposes a conceptual model that integrates principles from network science and ecology across in-person and electronically-mediated intervention modes; and (2) illustrates the application of this model to the design and evaluation of a social network intervention for PA. Methods/Design A conceptual model for engineering social networks was developed based on a scoping literature review of modifiable social influences on PA. The model guided the design of a cluster randomized controlled trial in which 308 sedentary adults were randomly assigned to three groups: WalkLink+: prompted and provided feedback on participants’ online and in-person social-network interactions to expand networks for PA, plus provided evidence-based online walking program and weekly walking tips; WalkLink: evidence-based online walking program and weekly tips only; Minimal Treatment Control: weekly tips only. The effects of these treatment conditions were assessed at baseline, post-program, and 6-month follow-up. The primary outcome was accelerometer-measured PA. Secondary outcomes included objectively-measured aerobic fitness, body mass index, waist circumference, blood pressure, and neighborhood walkability; and self-reported measures of the physical environment, social network environment, and social network interactions. The differential effects of the three treatment conditions on primary and secondary outcomes will be analyzed using general linear modeling (GLM), or generalized linear modeling if the assumptions for GLM cannot be met. Discussion Results will contribute to greater understanding of how to conceptualize and implement social networks to support long-term PA. Establishing social networks for PA across multiple life settings could contribute to cultural norms that sustain active living. Trial registration ClinicalTrials.gov NCT01142804 PMID:23945138

Comparing the appropriate geographic region for assessing built environmental correlates with walking trips using different metrics and model approaches

PubMed Central

Tribby, Calvin P.; Miller, Harvey J.; Brown, Barbara B.; Smith, Ken R.; Werner, Carol M.

2017-01-01

There is growing international evidence that supportive built environments encourage active travel such as walking. An unsettled question is the role of geographic regions for analyzing the relationship between the built environment and active travel. This paper examines the geographic region question by assessing walking trip models that use two different regions: walking activity spaces and self-defined neighborhoods. We also use two types of built environment metrics, perceived and audit data, and two types of study design, cross-sectional and longitudinal, to assess these regions. We find that the built environment associations with walking are dependent on the type of metric and the type of model. Audit measures summarized within walking activity spaces better explain walking trips compared to audit measures within self-defined neighborhoods. Perceived measures summarized within self-defined neighborhoods have mixed results. Finally, results differ based on study design. This suggests that results may not be comparable among different regions, metrics and designs; researchers need to consider carefully these choices when assessing active travel correlates. PMID:28237743

The impact of clinical, psychological, behavioral, social, and environmental factors on self-perceived symptom severity in a male cohort with intermittent claudication.

PubMed

Sharath, Sherene E; Kougias, Panos; Pisimisis, George; Barshes, Neal R

2016-05-01

To understand the relationship between self-perceived severity of intermittent claudication and various associated nonclinical factors, we examined how correlates in domains of physical activity (ie, clinical, psychological, behavioral, social, and environmental factors) relate to exertional limb symptoms. A survey was administered to individuals with intermittent claudication during their initial outpatient assessment. The subjects' self-reported exertional limb symptom severity and classic-versus-atypical claudication classification was based on the Walking Impairment Questionnaire (WIQ) and San Diego Claudication Questionnaire (SDCQ), respectively. We evaluated psychosocial and environmental factors, osteoarthritis symptoms, health, behaviors, and beliefs. Logistic and linear regressions identified factors with a strong independent association with total WIQ scores and the SDCQs. A cohort of 102 subjects (99.0% male) was enrolled in the study. The median age was 65 years with a median ankle-brachial index of 0.69. Forty-three subjects (43%) had "typical" claudication per SDCQs. Individuals with atypical claudication were more likely to report higher Aberdeen Clinical Back Pain Questionnaire scores (odds ratio, 1.04; P = .04) and no depressive symptoms (odds ratio, 8.30; P = .03). Exertional limb symptom severity among the entire cohort was significantly associated with increasing osteoarthritis symptoms (P <.001), age (P = .02), a reserved personality (P = .008), and the belief that an exercise regimen would not improve symptoms (P = .005), self-perceived levels of boredom (P = .002), and the belief that exercise (P = .002) was the best way to improve symptoms were associated with decreased symptom severity. When restricted to those with atypical pain, significant factors associated with increasing exertional symptom severity included age greater than 60 years (P = .005), osteoarthritis (P = .02), alcohol use (P = .01), belief that exercise would not improve walking (P = .03), and difficulty walking around the neighborhood (P = .02). When restricted to those with classic claudication, significant factors associated with increasing exertional limb symptom severity included frequent pain or aching in the calves while walking or sitting (P = .03 [walking]; P = .01 [sitting]) and occasional morning joint stiffness (P = .007). Exertional limb symptom severity was also associated with high limitations at home (P = .003) and a belief that exercise would not improve walking (P = .005) among those with classic claudication. Symptom severity and type of pain are associated with a number of nonclinical factors. A multidomain approach, as indicated by the models above, would benefit the continuum of care for intermittent claudication, where management is integrated and coordinated among multiple lines of care. Published by Elsevier Inc.

Quantum Walk Schemes for Universal Quantum Computation

NASA Astrophysics Data System (ADS)

Underwood, Michael S.

Random walks are a powerful tool for the efficient implementation of algorithms in classical computation. Their quantum-mechanical analogues, called quantum walks, hold similar promise. Quantum walks provide a model of quantum computation that has recently been shown to be equivalent in power to the standard circuit model. As in the classical case, quantum walks take place on graphs and can undergo discrete or continuous evolution, though quantum evolution is unitary and therefore deterministic until a measurement is made. This thesis considers the usefulness of continuous-time quantum walks to quantum computation from the perspectives of both their fundamental power under various formulations, and their applicability in practical experiments. In one extant scheme, logical gates are effected by scattering processes. The results of an exhaustive search for single-qubit operations in this model are presented. It is shown that the number of distinct operations increases exponentially with the number of vertices in the scattering graph. A catalogue of all graphs on up to nine vertices that implement single-qubit unitaries at a specific set of momenta is included in an appendix. I develop a novel scheme for universal quantum computation called the discontinuous quantum walk, in which a continuous-time quantum walker takes discrete steps of evolution via perfect quantum state transfer through small 'widget' graphs. The discontinuous quantum-walk scheme requires an exponentially sized graph, as do prior discrete and continuous schemes. To eliminate the inefficient vertex resource requirement, a computation scheme based on multiple discontinuous walkers is presented. In this model, n interacting walkers inhabiting a graph with 2n vertices can implement an arbitrary quantum computation on an input of length n, an exponential savings over previous universal quantum walk schemes. This is the first quantum walk scheme that allows for the application of quantum error correction. The many-particle quantum walk can be viewed as a single quantum walk undergoing perfect state transfer on a larger weighted graph, obtained via equitable partitioning. I extend this formalism to non-simple graphs. Examples of the application of equitable partitioning to the analysis of quantum walks and many-particle quantum systems are discussed.

Walking Outdoors during Seminars Improved Perceived Seminar Quality and Sense of Well-Being among Participants

PubMed Central

Hedin, Björn; Tobiasson, Helena; Toivanen, Susanna

2018-01-01

Low levels of physical activity and sedentary behaviour are a growing health problem globally. Physical inactivity is associated with increased risk of numerous ailments, cardiovascular disease and mortality. Our primary aim was to perform a feasibility study on how to incorporate physical activity among students and teachers in regular teaching activities. The second aim was to investigate how students and teachers perceived the differences between outdoor walking seminars and regular indoor seminars. By transforming an on-campus course into a blended course, we were able to conduct seminars outdoors in nearby nature while walking. These walking seminars were evaluated among 131 students and nine teachers leading the walking seminars. The responses to the student survey and teacher interviews indicate that discussions, sense of well-being and the general quality of the seminar improved, regardless of how physically active participants were the rest of the time. The study shows one way to increase physical activity with small means; in our case, a reorganization of how we prepared for the seminars which allowed for walking discussions. PMID:29425171

Skeletal Muscle Mitochondrial Energetics Are Associated With Maximal Aerobic Capacity and Walking Speed in Older Adults

PubMed Central

2013-01-01

Background. Lower ambulatory performance with aging may be related to a reduced oxidative capacity within skeletal muscle. This study examined the associations between skeletal muscle mitochondrial capacity and efficiency with walking performance in a group of older adults. Methods. Thirty-seven older adults (mean age 78 years; 21 men and 16 women) completed an aerobic capacity (VO2 peak) test and measurement of preferred walking speed over 400 m. Maximal coupled (State 3; St3) mitochondrial respiration was determined by high-resolution respirometry in saponin-permeabilized myofibers obtained from percutanous biopsies of vastus lateralis (n = 22). Maximal phosphorylation capacity (ATPmax) of vastus lateralis was determined in vivo by 31P magnetic resonance spectroscopy (n = 30). Quadriceps contractile volume was determined by magnetic resonance imaging. Mitochondrial efficiency (max ATP production/max O2 consumption) was characterized using ATPmax per St3 respiration (ATPmax/St3). Results. In vitro St3 respiration was significantly correlated with in vivo ATPmax (r 2 = .47, p = .004). Total oxidative capacity of the quadriceps (St3*quadriceps contractile volume) was a determinant of VO2 peak (r 2 = .33, p = .006). ATPmax (r 2 = .158, p = .03) and VO2 peak (r 2 = .475, p < .0001) were correlated with preferred walking speed. Inclusion of both ATPmax/St3 and VO2 peak in a multiple linear regression model improved the prediction of preferred walking speed (r 2 = .647, p < .0001), suggesting that mitochondrial efficiency is an important determinant for preferred walking speed. Conclusions. Lower mitochondrial capacity and efficiency were both associated with slower walking speed within a group of older participants with a wide range of function. In addition to aerobic capacity, lower mitochondrial capacity and efficiency likely play roles in slowing gait speed with age. PMID:23051977

Skeletal muscle mitochondrial energetics are associated with maximal aerobic capacity and walking speed in older adults.

PubMed

Coen, Paul M; Jubrias, Sharon A; Distefano, Giovanna; Amati, Francesca; Mackey, Dawn C; Glynn, Nancy W; Manini, Todd M; Wohlgemuth, Stephanie E; Leeuwenburgh, Christiaan; Cummings, Steven R; Newman, Anne B; Ferrucci, Luigi; Toledo, Frederico G S; Shankland, Eric; Conley, Kevin E; Goodpaster, Bret H

2013-04-01

Lower ambulatory performance with aging may be related to a reduced oxidative capacity within skeletal muscle. This study examined the associations between skeletal muscle mitochondrial capacity and efficiency with walking performance in a group of older adults. Thirty-seven older adults (mean age 78 years; 21 men and 16 women) completed an aerobic capacity (VO2 peak) test and measurement of preferred walking speed over 400 m. Maximal coupled (State 3; St3) mitochondrial respiration was determined by high-resolution respirometry in saponin-permeabilized myofibers obtained from percutanous biopsies of vastus lateralis (n = 22). Maximal phosphorylation capacity (ATPmax) of vastus lateralis was determined in vivo by (31)P magnetic resonance spectroscopy (n = 30). Quadriceps contractile volume was determined by magnetic resonance imaging. Mitochondrial efficiency (max ATP production/max O2 consumption) was characterized using ATPmax per St3 respiration (ATPmax/St3). In vitro St3 respiration was significantly correlated with in vivo ATPmax (r (2) = .47, p = .004). Total oxidative capacity of the quadriceps (St3*quadriceps contractile volume) was a determinant of VO2 peak (r (2) = .33, p = .006). ATPmax (r (2) = .158, p = .03) and VO2 peak (r (2) = .475, p < .0001) were correlated with preferred walking speed. Inclusion of both ATPmax/St3 and VO2 peak in a multiple linear regression model improved the prediction of preferred walking speed (r (2) = .647, p < .0001), suggesting that mitochondrial efficiency is an important determinant for preferred walking speed. Lower mitochondrial capacity and efficiency were both associated with slower walking speed within a group of older participants with a wide range of function. In addition to aerobic capacity, lower mitochondrial capacity and efficiency likely play roles in slowing gait speed with age.

Quantification of gait changes in subjects with visual height intolerance when exposed to heights.

PubMed

Schniepp, Roman; Kugler, Günter; Wuehr, Max; Eckl, Maria; Huppert, Doreen; Huth, Sabrina; Pradhan, Cauchy; Jahn, Klaus; Brandt, Thomas

2014-01-01

Visual height intolerance (vHI) manifests as instability at heights with apprehension of losing balance or falling. We investigated contributions of visual feedback and attention on gait performance of subjects with vHI. Sixteen subjects with vHI walked over a gait mat (GAITRite®) on a 15-m-high balcony and at ground-level. Subjects walked at different speeds (slow, preferred, fast), during changes of the visual input (gaze straight/up/down; eyes open/closed), and while doing a cognitive task. An rmANOVA with the factors "height situation" and "gait condition" was performed. Subjects were also asked to estimate the height of the balcony over ground level. The individual estimates were used for correlations with the gait parameters. Study participants walked slower at heights, with reduced cadence and stride length. The double support phases were increased (all p < 0.01), which correlated with the estimated height of the balcony (R (2) = 0.453, p < 0.05). These changes were still present when walking with upward gaze or closure of the eyes. Under the conditions walking and looking down to the floor of the balcony, during dual-task and fast walking, there were no differences between the gait performance on the balcony and at ground-level. The found gait changes are features of a cautious gait control. Internal, cognitive models with anxiety play an important role for vHI; gait was similarly affected when the visual perception of the depth was prevented. Improvement by dual task at heights may be associated by a reduction of the anxiety level. It is conceivable that mental distraction by dual task or increasing the walking speed might be useful recommendations to reduce the imbalance during locomotion in subjects susceptible to vHI.

Life-space mobility in Parkinson's disease: Associations with motor and non-motor symptoms.

PubMed

Rantakokko, Merja; Iwarsson, Susanne; Slaug, Björn; Nilsson, Maria H

2018-04-10

To describe life-space mobility and explore associations of motor and non-motor symptoms with life-space mobility in people with Parkinson's disease (PD). 164 community-dwelling persons with PD (mean age 71.6 years, 64.6% men) received a postal survey and a subsequent home visit. Motor assessments included perceived walking difficulties (Walk-12G), mobility (Timed Up and Go test), motor symptoms (UPDRS-III) and freezing of gait (item 3, FOG-Qsa). Non-motor symptoms included depressive symptoms (GDS-15), pain, fatigue (NHP-EN) and global cognition (MoCA). Life-space mobility was assessed with the life-space assessment (LSA). Calculations included composite score (range 0-120; higher indicating better life-space mobility), independent life-space (range 0-5), assisted life-space (range 0-5), and maximal life-space (range 0-5). Associations were analyzed with linear regression models, adjusted for age, sex, and PD severity (Hoehn and Yahr). Mean life-space mobility score was 72.3 (SD 28.8). Almost all participants (90 %) reached the highest life-space level (beyond town). Half of these reached this level independently, while one-third were unable to move outside their bedroom without assistive devices or personal help. When adjusted for confounders, depressive symptoms, pain, and perceived walking difficulties was negatively associated with life-space mobility. In the multivariable model, only perceived walking difficulties was associated with life-space mobility. Our findings indicate that perceived walking difficulties should be targeted to maintain or improve life-space mobility in people with PD. Depressive symptoms and pain may also merit consideration. More research is needed to elucidate the role of environmental and personal factors for life-space mobility in PD.

Effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force.

PubMed

Park, Seung Kyu; Yang, Dae Jung; Kang, Yang Hun; Kim, Je Ho; Uhm, Yo Han; Lee, Yong Seon

2015-09-01

[Purpose] The purpose of this study was to investigate the effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force. [Subjects] The subjects of this study were 30 young adult males, who were divided into a Nordic walking group of 15 subjects and a walking group of 15 subjects. [Methods] To analyze the spatiotemporal parameters and ground reaction force during walking in the two groups, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for them between Nordic walking and walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. To determine the pole for Nordic walking, each subject's height was multiplied by 0.68. We then measured the spatiotemporal gait parameters and ground reaction force. [Results] Compared with the walking group, the Nordic walking group showed an increase in cadence, stride length, and step length, and a decrease in stride time, step time, and vertical ground reaction force. [Conclusion] The results of this study indicate that Nordic walking increases the stride and can be considered as helping patients with diseases affecting their gait. This demonstrates that Nordic walking is more effective in improving functional capabilities by promoting effective energy use and reducing the lower limb load, because the weight of the upper and lower limbs is dispersed during Nordic walking.

Model task for the dynamics of an underwater two-legged walker

NASA Technical Reports Server (NTRS)

Beletskiy, V. V.; Golubkov, V. V.; Stepanova, Y. A.

1979-01-01

A model task of two-legged underwater walking was examined. Characteristics of the walking were established. The underwater walking device is a substantial sphere, which moves on dual-member legs. The dynamics of the device were investigated with the calculation of the buoyancy of Archimedes, and the force of hydrodynamic resistance.

Changes in work affect in response to lunchtime walking in previously physically inactive employees: A randomized trial.

PubMed

Thøgersen-Ntoumani, C; Loughren, E A; Kinnafick, F-E; Taylor, I M; Duda, J L; Fox, K R

2015-12-01

Physical activity may regulate affective experiences at work, but controlled studies are needed and there has been a reliance on retrospective accounts of experience. The purpose of the present study was to examine the effect of lunchtime walks on momentary work affect at the individual and group levels. Physically inactive employees (N = 56; M age = 47.68; 92.86% female) from a large university in the UK were randomized to immediate treatment or delayed treatment (DT). The DT participants completed both a control and intervention period. During the intervention period, participants partook in three weekly 30-min lunchtime group-led walks for 10 weeks. They completed twice daily affective reports at work (morning and afternoon) using mobile phones on two randomly chosen days per week. Multilevel modeling was used to analyze the data. Lunchtime walks improved enthusiasm, relaxation, and nervousness at work, although the pattern of results differed depending on whether between-group or within-person analyses were conducted. The intervention was effective in changing some affective states and may have broader implications for public health and workplace performance. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clinical application of carbon fibre reinforced plastic leg orthosis for polio survivors and its advantages and disadvantages.

PubMed

Hachisuka, K; Makino, K; Wada, F; Saeki, S; Yoshimoto, N; Arai, M

2006-08-01

A prospective study was carried out on the clinical application and features of a carbon fibre reinforced plastic leg orthosis (carbon orthosis) for polio survivors. The subjects comprised 9 polio survivors, and 11 carbon knee-ankle-foot orthoses (KAFOs) were prescribed, fabricated, and checked out at the authors' post-polio clinic. Walking was classified based on the functional ambulatory category, and the features of walking with a carbon orthosis were self-evaluated by using a visual analogue scale. The period from modelling a cast to completion was 55 +/- 25 days; the weight of a carbon KAFO was 27.8% lighter than that of the ordinary KAFO; the standard carbon KAFO was 50% more expensive than the ordinary KAFO. The carbon KAFO remained undamaged for at least 2 years. It improved the scores in the functional ambulation categories, but there was no difference between walking with an ordinary and with a carbon KAFO. The self-evaluation of walking with a carbon KAFO revealed that the subjects using a carbon KAFO were satisfied with their carbon KAFO. The carbon KAFO is lightweight, durable, slim and smart, and is positively indicated for polio survivors.

Walking simulator for evaluation of ophthalmic devices

NASA Astrophysics Data System (ADS)

Barabas, James; Woods, Russell L.; Peli, Eli

2005-03-01

Simulating mobility tasks in a virtual environment reduces risk for research subjects, and allows for improved experimental control and measurement. We are currently using a simulated shopping mall environment (where subjects walk on a treadmill in front of a large projected video display) to evaluate a number of ophthalmic devices developed at the Schepens Eye Research Institute for people with vision impairment, particularly visual field defects. We have conducted experiments to study subject's perception of "safe passing distance" when walking towards stationary obstacles. The subject's binary responses about potential collisions are analyzed by fitting a psychometric function, which gives an estimate of the subject's perceived safe passing distance, and the variability of subject responses. The system also enables simulations of visual field defects using head and eye tracking, enabling better understanding of the impact of visual field loss. Technical infrastructure for our simulated walking environment includes a custom eye and head tracking system, a gait feedback system to adjust treadmill speed, and a handheld 3-D pointing device. Images are generated by a graphics workstation, which contains a model with photographs of storefronts from an actual shopping mall, where concurrent validation experiments are being conducted.

[A new procedure for the estimation of physical fitness of patients during clinical rehabilitation using the 6-minute-walk-test].

PubMed

Marek, W; Marek, E; Vogel, P; Mückenhoff, K; Kotschy-Lang, N

2008-11-01

AIMS OF THE INVESTIGATION: The 6-minute-walk-test (6-MW) is an effective tool for measuring physical fitness in elderly patients. The increased walking distance is taken as a parameter for improved physical conditions. Frequently an unaltered walking distance is found after clinical treatment, but heart rate is significantly lower in the second challenge, indicating an improved physical fitness. This positive effect is not recognised when only the walking distance is analysed. An analysis of the 6-MW test was performed on 263 patients before and after 3 - 4 weeks clinical rehabilitation. In a control group of 26 patients 6-MW was repeated after recovery at the beginning and the end of the clinical treatment. Instrumented by a mobile pulse oximeter for recording oxygen saturation and heart rate, patients were instructed to walk as fast as they can do during 6 minutes. Measurements were performed every 30 seconds and printed out. Two new parameters, efficiency (E = S/f (C)), the ratio of distance and mean heart rate, and the theoretical increase in walking distance (S (z) = Delta f (C1)/Delta f (C2) x S (2) - S (1)) were introduced and tested. S (z) = theoretical increase in distance, Delta f (C1) = difference in heart rate at rest and mean heart rate at steady state during the first walk test with distance, S1. Delta f (C2), and S2 are measured during the second walk. Thus, the increase in distance is calculated under the assumption that the second walk test would have been performed by the patient with the same difference in heart rate that he/she achieved in the first walk. The patient groups walked 353 +/- 80 m at 106 +/- 14.3 beats/min in the 1st. 6-MW and 368 +/- 76.9 m at a heart rate of 105 +/- 14.0 beats/min in the final test. The increase of the walking distance was most significant in patients with shorter distances in the 1st 6-MW. A significant increase in the walking distance and in efficiency was found in patients with shorter walking distances or lower heart rates in the final test, using the numerical procedure described above. The patient's performance of the second walk test with an unchanged distance at a lower heart rate reveals an improved physical fitness. This is solely described by an increase by the parameter of efficiency, E. The calculation of the parameter, Sz, theoretical difference in walking distance (i. e., theoretical increase in almost all tests) provides a quantification of the effect of exercise training, even if the patient is not cooperative during the tests. Both parameters have proved to be suitable estimations for the assessment of physical fitness as a beneficial effect of clinical rehabilitation.

An aerobic walking programme versus muscle strengthening programme for chronic low back pain: a randomized controlled trial.

PubMed

Shnayderman, Ilana; Katz-Leurer, Michal

2013-03-01

To assess the effect of aerobic walking training as compared to active training, which includes muscle strengthening, on functional abilities among patients with chronic low back pain. Randomized controlled clinical trial with blind assessors. Outpatient clinic. Fifty-two sedentary patients, aged 18-65 years with chronic low back pain. Patients who were post surgery, post trauma, with cardiovascular problems, and with oncological disease were excluded. Experimental 'walking' group: moderate intense treadmill walking; control 'exercise' group: specific low back exercise; both, twice a week for six weeks. Six-minute walking test, Fear-Avoidance Belief Questionnaire, back and abdomen muscle endurance tests, Oswestry Disability Questionnaire, Low Back Pain Functional Scale (LBPFS). Significant improvements were noted in all outcome measures in both groups with non-significant difference between groups. The mean distance in metres covered during 6 minutes increased by 70.7 (95% confidence interval (CI) 12.3-127.7) in the 'walking' group and by 43.8 (95% CI 19.6-68.0) in the 'exercise' group. The trunk flexor endurance test showed significant improvement in both groups, increasing by 0.6 (95% CI 0.0-1.1) in the 'walking' group and by 1.1 (95% CI 0.3-1.8) in the 'exercise' group. A six-week walk training programme was as effective as six weeks of specific strengthening exercises programme for the low back.

Walking to the Beat of Their Own Drum: How Children and Adults Meet Timing Constraints

PubMed Central

Gill, Simone V.

2015-01-01

Walking requires adapting to meet task constraints. Between 5- and 7-years old, children’s walking approximates adult walking without constraints. To examine how children and adults adapt to meet timing constraints, 57 5- to 7-year olds and 20 adults walked to slow and fast audio metronome paces. Both children and adults modified their walking. However, at the slow pace, children had more trouble matching the metronome compared to adults. The youngest children’s walking patterns deviated most from the slow metronome pace, and practice improved their performance. Five-year olds were the only group that did not display carryover effects to the metronome paces. Findings are discussed in relation to what contributes to the development of adaptation in children. PMID:26011538

Coined quantum walks on weighted graphs

NASA Astrophysics Data System (ADS)

Wong, Thomas G.

2017-11-01

We define a discrete-time, coined quantum walk on weighted graphs that is inspired by Szegedy’s quantum walk. Using this, we prove that many lackadaisical quantum walks, where each vertex has l integer self-loops, can be generalized to a quantum walk where each vertex has a single self-loop of real-valued weight l. We apply this real-valued lackadaisical quantum walk to two problems. First, we analyze it on the line or one-dimensional lattice, showing that it is exactly equivalent to a continuous deformation of the three-state Grover walk with faster ballistic dispersion. Second, we generalize Grover’s algorithm, or search on the complete graph, to have a weighted self-loop at each vertex, yielding an improved success probability when l < 3 + 2\\sqrt{2} ≈ 5.828 .

[The Effects of Urban Forest-walking Program on Health Promotion Behavior, Physical Health, Depression, and Quality of Life: A Randomized Controlled Trial of Office-workers].

PubMed

Bang, Kyung Sook; Lee, In Sook; Kim, Sung Jae; Song, Min Kyung; Park, Se Eun

2016-02-01

This study was performed to determine the physical and psychological effects of an urban forest-walking program for office workers. For many workers, sedentary lifestyles can lead to low levels of physical activity causing various health problems despite an increased interest in health promotion. Fifty four office workers participated in this study. They were assigned to two groups (experimental group and control group) in random order and the experimental group performed 5 weeks of walking exercise based on Information-Motivation-Behavioral skills Model. The data were collected from October to November 2014. SPSS 21.0 was used for the statistical analysis. The results showed that the urban forest walking program had positive effects on the physical activity level (U=65.00, p<.001), health promotion behavior (t=-2.20, p=.033), and quality of life (t=-2.42, p=.020). However, there were no statistical differences in depression, waist size, body mass index, blood pressure, or bone density between the groups. The current findings of the study suggest the forest-walking program may have positive effects on improving physical activity, health promotion behavior, and quality of life. The program can be used as an effective and efficient strategy for physical and psychological health promotion for office workers.

The Animadora Project: Identifying factors related to the promotion of physical activity among Mexican Americans with diabetes

PubMed Central

Ingram, Maia; Ruis, Maricruz; Mayorga, Maria Theresa; Rosales, Cecilia

2015-01-01

Purpose There is a dearth of information about factors related to physical activity among Mexican Americans with diabetes. Self efficacy and social support are associated with physical activity, however little is known about their role within different cultural groups. Design Focus groups were used to identify factors that motivate walking. Setting Two Mexican American communities located in Tucson, Arizona. Subjects Individuals who attended diabetes education. Intervention A community-based provider organized walking groups with people who previously attended diabetes classes. Walkers participated in focus groups exploring themes related to their experience. Measures Self efficacy, social support, and collective efficacy. Grounded theory was used to analyze focus group results using two rounds of analysis; the first identifying references to self efficacy and social support and the second adding collective efficacy as a theoretical basis for walking. Results Among 43 eligible participants, 20 participated in focus groups. Social support was expressed as commitment and companionship. Walkers demonstrated a high level of self efficacy for walking. Development of group identity/social cohesion was also a motivator to walk. Collective efficacy emerged as an applicable theoretical model encompassing these themes and their interrelationship. Conclusion Collective efficacy, or the belief that the group can improve their lives through collective effort, is a viable theoretical construct in the development of physical activity interventions targeting Mexican Americans with diabetes. PMID:19601479

Who walks? Factors associated with walking behavior in disabled older women with and without self-reported walking difficulty.

PubMed

Simonsick, E M; Guralnik, J M; Fried, L P

1999-06-01

To determine how severity of walking difficulty and sociodemographic, psychosocial, and health-related factors influence walking behavior in disabled older women. Cross-sectional analyses of baseline data from the Women's Health and Aging Study (WHAS). An urban community encompassing 12 contiguous zip code areas in the eastern portion of Baltimore City and part of Baltimore County, Maryland. A total of 920 moderately to severely disabled community-resident women, aged 65 years and older, identified from an age-stratified random sample of Medicare beneficiaries. Walking behavior was defined as minutes walked for exercise and total blocks walked per week. Independent variables included self-reported walking difficulty, sociodemographic factors, psychological status (depression, mastery, anxiety, and cognition), and health-related factors (falls and fear of falling, fatigue, vision and balance problems, weight, smoking, and cane use). Walking at least 8 blocks per week was strongly negatively related to severity of walking difficulty. Independent of difficulty level, older age, black race, fatigue, obesity, and cane use were also negatively associated with walking; living alone and high mastery had a positive association with walking. Even among functionally limited women, sociocultural, psychological, and health-related factors were independently associated with walking behavior. Thus, programs aimed at improving walking ability need to address these factors in addition to walking difficulties to maximize participation and compliance.

Experimental estimation of energy absorption during heel strike in human barefoot walking.

PubMed

Baines, Patricia M; Schwab, A L; van Soest, A J

2018-01-01

Metabolic energy expenditure during human gait is poorly understood. Mechanical energy loss during heel strike contributes to this energy expenditure. Previous work has estimated the energy absorption during heel strike as 0.8 J using an effective foot mass model. The aim of our study is to investigate the possibility of determining the energy absorption by more directly estimating the work done by the ground reaction force, the force-integral method. Concurrently another aim is to compare this method of direct determination of work to the method of an effective foot mass model. Participants of our experimental study were asked to walk barefoot at preferred speed. Ground reaction force and lower leg kinematics were collected at high sampling frequency (3000 Hz; 1295 Hz), with tight synchronization. The work done by the ground reaction force is 3.8 J, estimated by integrating this force over the foot-ankle deformation. The effective mass model is improved by dropping the assumption that foot-ankle deformation is maximal at the instant of the impact force peak. On theoretical grounds it is clear that in the presence of substantial damping that peak force and peak deformation do not occur simultaneously. The energy absorption results, due the vertical force only, corresponding to the force-integral method is similar to the results of the improved application of the effective mass model (2.7 J; 2.5 J). However the total work done by the ground reaction force calculated by the force-integral method is significantly higher than that of the vertical component alone. We conclude that direct estimation of the work done by the ground reaction force is possible and preferable over the use of the effective foot mass model. Assuming that energy absorbed is lost, the mechanical energy loss of heel strike is around 3.8 J for preferred walking speeds (≈ 1.3 m/s), which contributes to about 15-20% of the overall metabolic cost of transport.

Cost-effectiveness of active transport for primary school children - Walking School Bus program.

PubMed

Moodie, Marjory; Haby, Michelle; Galvin, Leah; Swinburn, Boyd; Carter, Robert

2009-09-14

To assess from a societal perspective the incremental cost-effectiveness of the Walking School Bus (WSB) program for Australian primary school children as an obesity prevention measure. The intervention was modelled as part of the ACE-Obesity study, which evaluated, using consistent methods, thirteen interventions targeting unhealthy weight gain in Australian children and adolescents. A logic pathway was used to model the effects on body mass index [BMI] and disability-adjusted life years [DALYs] of the Victorian WSB program if applied throughout Australia. Cost offsets and DALY benefits were modelled until the eligible cohort reached 100 years of age or death. The reference year was 2001. Second stage filter criteria ('equity', 'strength of evidence', 'acceptability', feasibility', sustainability' and 'side-effects') were assessed to incorporate additional factors that impact on resource allocation decisions. The modelled intervention reached 7,840 children aged 5 to 7 years and cost $AUD22.8M ($16.6M; $30.9M). This resulted in an incremental saving of 30 DALYs (7:104) and a net cost per DALY saved of $AUD0.76M ($0.23M; $3.32M). The evidence base was judged as 'weak' as there are no data available documenting the increase in the number of children walking due to the intervention. The high costs of the current approach may limit sustainability. Under current modelling assumptions, the WSB program is not an effective or cost-effective measure to reduce childhood obesity. The attribution of some costs to non-obesity objectives (reduced traffic congestion and air pollution etc.) is justified to emphasise the other possible benefits. The program's cost-effectiveness would be improved by more comprehensive implementation within current infrastructure arrangements. The importance of active transport to school suggests that improvements in WSB or its variants need to be developed and fully evaluated.

Cost-effectiveness of active transport for primary school children - Walking School Bus program

PubMed Central

Moodie, Marjory; Haby, Michelle; Galvin, Leah; Swinburn, Boyd; Carter, Robert

2009-01-01

Background To assess from a societal perspective the incremental cost-effectiveness of the Walking School Bus (WSB) program for Australian primary school children as an obesity prevention measure. The intervention was modelled as part of the ACE-Obesity study, which evaluated, using consistent methods, thirteen interventions targeting unhealthy weight gain in Australian children and adolescents. Methods A logic pathway was used to model the effects on body mass index [BMI] and disability-adjusted life years [DALYs] of the Victorian WSB program if applied throughout Australia. Cost offsets and DALY benefits were modelled until the eligible cohort reached 100 years of age or death. The reference year was 2001. Second stage filter criteria ('equity', 'strength of evidence', 'acceptability', feasibility', sustainability' and 'side-effects') were assessed to incorporate additional factors that impact on resource allocation decisions. Results The modelled intervention reached 7,840 children aged 5 to 7 years and cost $AUD22.8M ($16.6M; $30.9M). This resulted in an incremental saving of 30 DALYs (7:104) and a net cost per DALY saved of $AUD0.76M ($0.23M; $3.32M). The evidence base was judged as 'weak' as there are no data available documenting the increase in the number of children walking due to the intervention. The high costs of the current approach may limit sustainability. Conclusion Under current modelling assumptions, the WSB program is not an effective or cost-effective measure to reduce childhood obesity. The attribution of some costs to non-obesity objectives (reduced traffic congestion and air pollution etc.) is justified to emphasise the other possible benefits. The program's cost-effectiveness would be improved by more comprehensive implementation within current infrastructure arrangements. The importance of active transport to school suggests that improvements in WSB or its variants need to be developed and fully evaluated. PMID:19747402

Six-Minute Walk Test Performance in Persons With Multiple Sclerosis While Using Passive or Powered Ankle-Foot Orthoses.

PubMed

Boes, Morgan K; Bollaert, Rachel E; Kesler, Richard M; Learmonth, Yvonne C; Islam, Mazharul; Petrucci, Matthew N; Motl, Robert W; Hsiao-Wecksler, Elizabeth T

2018-03-01

To determine whether a powered ankle-foot orthosis (AFO) that provides dorsiflexor and plantar flexor assistance at the ankle can improve walking endurance of persons with multiple sclerosis (MS). Short-term intervention. University research laboratory. Participants (N=16) with a neurologist-confirmed diagnosis of MS and daily use of a prescribed custom unilateral passive AFO. Three 6-minute walk tests (6MWTs), 1 per footwear condition: shoes (no AFO), prescribed passive AFO, and portable powered AFO (PPAFO). Assistive devices were worn on the impaired limb. Distance walked and metabolic cost of transport were recorded during each 6MWT and compared between footwear conditions. Each participant completed all three 6MWTs within the experimental design. PPAFO use resulted in a shorter 6MWT distance than did a passive AFO or shoe use. No differences were observed in metabolic cost of transport between footwear conditions. The current embodiment of this PPAFO did not improve endurance walking performance during the 6MWT in a sample of participants with gait impairment due to MS. Further research is required to determine whether expanded training or modified design of this powered orthosis can be effective in improving endurance walking performance in persons with gait impairment due to MS. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Improvement in functional capacity after levothyroxine treatment in patients with chronic heart failure and subclinical hypothyroidism].

PubMed

Curotto Grasiosi, Jorge; Peressotti, Bruno; Machado, Rogelio A; Filipini, Eduardo C; Angel, Adriana; Delgado, Jorge; Cortez Quiroga, Gustavo A; Rus Mansilla, Carmen; Martínez Quesada, María del Mar; Degregorio, Alejandro; Cordero, Diego J; Dak, Marcelo; Izurieta, Carlos; Esper, Ricardo J

2013-10-01

To assess whether levothyroxine treatment improves functional capacity in patients with chronic heart failure (New York Heart Association class i-iii) and subclinical hypothyroidism. One hundred and sixty-three outpatients with stable chronic heart failure followed up for at least 6 months were enrolled. A physical examination was performed, and laboratory tests including thyroid hormone levels, Doppler echocardiogram, radionuclide ventriculography, and Holter monitoring were requested. Functional capacity was assessed by of the 6-min walk test. Patients with subclinical hypothyroidism were detected and, after undergoing the s6-min walk test, were given replacement therapy. When they reached normal thyrotropin (TSH) levels, the 6-min walk test was performed again. The distance walked in both tests was recorded, and the difference in meters covered by each patient was analyzed. Prevalence of subclinical hypothyroidism in patients with heart failure was 13%. These patients walked 292±63m while they were hypothyroid and 350±76m when TSH levels returned to normal, a difference of 58±11m (P<.011). Patients with normal baseline TSH levels showed no significant difference between the 2 6-min walk tests. Patients with chronic heart failure and subclinical hypothyroidism significantly improved their physical performance when normal TSH levels were reached. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

Changes in Locomotor Muscle Activity After Treadmill Training in Subjects With Incomplete Spinal Cord Injury

PubMed Central

Gorassini, Monica A.; Norton, Jonathan A.; Nevett-Duchcherer, Jennifer; Roy, Francois D.; Yang, Jaynie F.

2009-01-01

Intensive treadmill training after incomplete spinal cord injury can improve functional walking abilities. To determine the changes in muscle activation patterns that are associated with improvements in walking, we measured the electromyography (EMG) of leg muscles in 17 individuals with incomplete spinal cord injury during similar walking conditions both before and after training. Specific differences were observed between subjects that eventually gained functional improvements in overground walking (responders), compared with subjects where treadmill training was ineffective (nonresponders). Although both groups developed a more regular and less clonic EMG pattern on the treadmill, it was only the tibialis anterior and hamstring muscles in the responders that displayed increases in EMG activation. Likewise, only the responders demonstrated decreases in burst duration and cocontraction of proximal (hamstrings and quadriceps) muscle activity. Surprisingly, the proximal muscle activity in the responders, unlike nonresponders, was three- to fourfold greater than that in uninjured control subjects walking at similar speeds and level of body weight support, suggesting that the ability to modify muscle activation patterns after injury may predict the ability of subjects to further compensate in response to motor training. In summary, increases in the amount and decreases in the duration of EMG activity of specific muscles are associated with functional recovery of walking skills after treadmill training in subjects that are able to modify muscle activity patterns following incomplete spinal cord injury. PMID:19073799

Distributed recurrent neural forward models with synaptic adaptation and CPG-based control for complex behaviors of walking robots

PubMed Central

Dasgupta, Sakyasingha; Goldschmidt, Dennis; Wörgötter, Florentin; Manoonpong, Poramate

2015-01-01

Walking animals, like stick insects, cockroaches or ants, demonstrate a fascinating range of locomotive abilities and complex behaviors. The locomotive behaviors can consist of a variety of walking patterns along with adaptation that allow the animals to deal with changes in environmental conditions, like uneven terrains, gaps, obstacles etc. Biological study has revealed that such complex behaviors are a result of a combination of biomechanics and neural mechanism thus representing the true nature of embodied interactions. While the biomechanics helps maintain flexibility and sustain a variety of movements, the neural mechanisms generate movements while making appropriate predictions crucial for achieving adaptation. Such predictions or planning ahead can be achieved by way of internal models that are grounded in the overall behavior of the animal. Inspired by these findings, we present here, an artificial bio-inspired walking system which effectively combines biomechanics (in terms of the body and leg structures) with the underlying neural mechanisms. The neural mechanisms consist of (1) central pattern generator based control for generating basic rhythmic patterns and coordinated movements, (2) distributed (at each leg) recurrent neural network based adaptive forward models with efference copies as internal models for sensory predictions and instantaneous state estimations, and (3) searching and elevation control for adapting the movement of an individual leg to deal with different environmental conditions. Using simulations we show that this bio-inspired approach with adaptive internal models allows the walking robot to perform complex locomotive behaviors as observed in insects, including walking on undulated terrains, crossing large gaps, leg damage adaptations, as well as climbing over high obstacles. Furthermore, we demonstrate that the newly developed recurrent network based approach to online forward models outperforms the adaptive neuron forward models, which have hitherto been the state of the art, to model a subset of similar walking behaviors in walking robots. PMID:26441629

Brief biomechanical analysis on the walking of spinal cord injury patients with a lower limb exoskeleton robot.

PubMed

Jung, Jun-Young; Park, Hyunsub; Yang, Hyun-Dae; Chae, Mingi

2013-06-01

This paper presents a brief biomechanical analysis on the walking behavior of spinal cord injury (SCI) patients. It is known that SCI patients who have serious injuries to their spines cannot walk, and hence, several walking assistance lower limb exoskeleton robots have been proposed whose assistance abilities are shown to be well customized. However, these robots are not yet fully helpful to all SCI patients for several reasons. To overcome these problems, an exact analysis and evaluation of the restored walking function while the exoskeleton is worn is important. In this work, walking behavior of SCI patients wearing the rehabilitation of brain injuries (ROBIN) lower-limb walking assistant exoskeleton was analyzed in comparison to that of normal unassisted walking. The analysis method and results presented herein can be used by other researchers to improve their robots.

Self-Trapping Self-Repelling Random Walks

NASA Astrophysics Data System (ADS)

Grassberger, Peter

2017-10-01

Although the title seems self-contradictory, it does not contain a misprint. The model we study is a seemingly minor modification of the "true self-avoiding walk" model of Amit, Parisi, and Peliti in two dimensions. The walks in it are self-repelling up to a characteristic time T* (which depends on various parameters), but spontaneously (i.e., without changing any control parameter) become self-trapping after that. For free walks, T* is astronomically large, but on finite lattices the transition is easily observable. In the self-trapped regime, walks are subdiffusive and intermittent, spending longer and longer times in small areas until they escape and move rapidly to a new area. In spite of this, these walks are extremely efficient in covering finite lattices, as measured by average cover times.

Virtual reality and musculoskeletal pain: manipulating sensory cues to improve motor performance during walking.

PubMed

Powell, Wendy; Simmonds, Maureen J

2014-06-01

Musculoskeletal pain (MSP) is the most expensive nonmalignant health problem and the most common reason for activity limitation. Treatment approaches to improve movement without aggravating pain are urgently needed. Virtual reality (VR) can decrease acute pain, as well as influence movement speed. It is not clear whether VR can improve movement speed in individuals with MSP without aggravating pain. This study investigated the extent to which different audio and optic flow cues in a VR environment influenced walking speed in people with and without MSP. A total of 36 subjects participated, 19 with MSP and 17 controls. All walked on a motorized self-paced treadmill interfaced with a three-dimensional virtual walkway. The audio tempo was scaled (75%, 100%, and 125%) from baseline cadence, and optic flow was either absent, or scaled to 50% or 100% of preferred walking speed. Gait speed was measured during each condition, and pain was measured before and after the experiment. Repeated measures analysis of variance showed that audio tempo above baseline cadence significantly increased walking speed in both groups, F(3, 99)=10.41, p<0.001. Walking speed increases of more than 25% occurred in both groups in the 125% audio tempo condition, without any significant increase in pain. There was also a trend toward increased walking speeds with the use of optic flow, but the results in this study did not achieve significance at the p<0.05 level, F(2, 66)=2.01, p=0.14. Further research is needed to establish the generalizability of increasing movement speed across different physical performance tasks in VR.

Effects of 12-week supervised treadmill training on spatio-temporal gait parameters in patients with claudication.

PubMed

Konik, Anita; Kuklewicz, Stanisław; Rosłoniec, Ewelina; Zając, Marcin; Spannbauer, Anna; Nowobilski, Roman; Mika, Piotr

2016-01-01

The purpose of the study was to evaluate selected temporal and spatial gait parameters in patients with intermittent claudication after completion of 12-week supervised treadmill walking training. The study included 36 patients (26 males and 10 females) aged: mean 64 (SD 7.7) with intermittent claudication. All patients were tested on treadmill (Gait Trainer, Biodex). Before the programme and after its completion, the following gait biomechanical parameters were tested: step length (cm), step cycle (cycle/s), leg support time (%), coefficient of step variation (%) as well as pain-free walking time (PFWT) and maximal walking time (MWT) were measured. Training was conducted in accordance with the current TASC II guidelines. After 12 weeks of training, patients showed significant change in gait biomechanics consisting in decreased frequency of step cycle (p < 0.05) and extended step length (p < 0.05). PFWT increased by 96% (p < 0.05). MWT increased by 100% (p < 0.05). After completing the training, patients' gait was more regular, which was expressed via statistically significant decrease of coefficient of variation (p < 0.05) for both legs. No statistically significant relation between the post-training improvement of PFWT and MWT and step length increase and decreased frequency of step cycle was observed (p > 0.05). Twelve-week treadmill walking training programme may lead to significant improvement of temporal and spatial gait parameters in patients with intermittent claudication. Twelve-week treadmill walking training programme may lead to significant improvement of pain-free walking time and maximum walking time in patients with intermittent claudication.

Kinesthetic taping improves walking function in patients with stroke: a pilot cohort study.

PubMed

Boeskov, Birgitte; Carver, Line Tornehøj; von Essen-Leise, Anders; Henriksen, Marius

2014-01-01

Stroke is an important cause of severe disability and impaired motor function. Treatment modalities that improve motor function in patients with stroke are needed. The objective of this study was to investigate the effect of kinesthetic taping of the anterior thigh and knee on maximal walking speed and clinical indices of spasticity in patients with stroke. Thirty-two patients (9 women) receiving rehabilitation after stroke (average, 50 days since stroke) who had impaired walking ability were recruited. Primary outcome was maximal walking speed measured by the 10-meter walk test. Secondary outcomes were number of steps taken during the test and clinical signs of spasticity measured by the Tardieu Scale. Tests were conducted before and immediately after application of kinesthetic tape to the anterior thigh and knee of the paretic lower limb. After application of the tape, the maximal walking speed increased, on average, by 0.08 m/s (95% CI, 0.04 to 0.12; P < .0001). The number of steps taken during the test was significantly decreased by 1.4 steps (95% CI, -2.3 to -0.5; P < .0031). The Tardieu scores were not significantly changed by the tape intervention, although a trend was observed indicating a lesser degree of spasticity. The results of this study indicate that kinesthetic taping of the anterior thigh and knee provides an immediate improvement in walking function in patients with stroke. Such a positive effect on motor function could be a valuable adjunct in physical therapy and rehabilitation of patients with stroke.

Effect of Body Weight-supported Walking on Exercise Capacity and Walking Speed in Patients with Knee Osteoarthritis: A Randomized Controlled Trial

PubMed Central

Someya, Fujiko

2013-01-01

Abstract Objective: To compare the effect of body-weight-supported treadmill training (BWSTT) and full-body-weight treadmill training (FBWTT) on patients with knee osteoarthritis (OA). Methods: Design was Randomized controlled trial. Patients with knee osteoarthritis (n = 30; mean age, 76.0±7.5 y) were randomly assigned to BWSTT or FBWTT group. All patients performed 20 min walking exercise twice a week for 6 weeks under the supervision of the therapist. Main measures were 10-meter walking test (10MWT), functional reach test (FRT), timed get up and go test (TUG), one-leg standing test, 6-minute walking test (6MWT), the parameters set on the treadmill, MOS Short-Form 36-Item Health Survey (SF36), Japanese Knee Osteoarthritis Measure (JKOM). Results: Twenty-five patients (10 men, 15 women; mean age, 76.5 ± 8.0 y) completed the experiment. Exercise capacity, indicated by the heart rate, was similar in both groups. After 3 weeks of BWSTT, the patients performed significantly better in the 10-m and 6-min walking tests. This was not the case with FBWTT even after 6 weeks training. Pain levels assessed were significantly improved after 3 weeks of BWSTT and 6 weeks of FBWTT. There were no significant improvements in either group assessed by the FRT, one-leg standing time test, TUG, or SF -36 questionnaire. Conclusions: BWSTT enhanced exercise capacity in terms of walking speed and pain reduction after 3 weeks; however, there was no significant improvement in patients' functional abilities or quality of life. PMID:25792901

Compliant leg behaviour explains basic dynamics of walking and running

PubMed Central

Geyer, Hartmut; Seyfarth, Andre; Blickhan, Reinhard

2006-01-01

The basic mechanics of human locomotion are associated with vaulting over stiff legs in walking and rebounding on compliant legs in running. However, while rebounding legs well explain the stance dynamics of running, stiff legs cannot reproduce that of walking. With a simple bipedal spring–mass model, we show that not stiff but compliant legs are essential to obtain the basic walking mechanics; incorporating the double support as an essential part of the walking motion, the model reproduces the characteristic stance dynamics that result in the observed small vertical oscillation of the body and the observed out-of-phase changes in forward kinetic and gravitational potential energies. Exploring the parameter space of this model, we further show that it not only combines the basic dynamics of walking and running in one mechanical system, but also reveals these gaits to be just two out of the many solutions to legged locomotion offered by compliant leg behaviour and accessed by energy or speed. PMID:17015312

Autoregressive-moving-average hidden Markov model for vision-based fall prediction-An application for walker robot.

PubMed

Taghvaei, Sajjad; Jahanandish, Mohammad Hasan; Kosuge, Kazuhiro

2017-01-01

Population aging of the societies requires providing the elderly with safe and dependable assistive technologies in daily life activities. Improving the fall detection algorithms can play a major role in achieving this goal. This article proposes a real-time fall prediction algorithm based on the acquired visual data of a user with walking assistive system from a depth sensor. In the lack of a coupled dynamic model of the human and the assistive walker a hybrid "system identification-machine learning" approach is used. An autoregressive-moving-average (ARMA) model is fitted on the time-series walking data to forecast the upcoming states, and a hidden Markov model (HMM) based classifier is built on the top of the ARMA model to predict falling in the upcoming time frames. The performance of the algorithm is evaluated through experiments with four subjects including an experienced physiotherapist while using a walker robot in five different falling scenarios; namely, fall forward, fall down, fall back, fall left, and fall right. The algorithm successfully predicts the fall with a rate of 84.72%.

Walking, running and the evolution of short toes in humans.

PubMed

Rolian, Campbell; Lieberman, Daniel E; Hamill, Joseph; Scott, John W; Werbel, William

2009-03-01

The phalangeal portion of the forefoot is extremely short relative to body mass in humans. This derived pedal proportion is thought to have evolved in the context of committed bipedalism, but the benefits of shorter toes for walking and/or running have not been tested previously. Here, we propose a biomechanical model of toe function in bipedal locomotion that suggests that shorter pedal phalanges improve locomotor performance by decreasing digital flexor force production and mechanical work, which might ultimately reduce the metabolic cost of flexor force production during bipedal locomotion. We tested this model using kinematic, force and plantar pressure data collected from a human sample representing normal variation in toe length (N=25). The effect of toe length on peak digital flexor forces, impulses and work outputs was evaluated during barefoot walking and running using partial correlations and multiple regression analysis, controlling for the effects of body mass, whole-foot and phalangeal contact times and toe-out angle. Our results suggest that there is no significant increase in digital flexor output associated with longer toes in walking. In running, however, multiple regression analyses based on the sample suggest that increasing average relative toe length by as little as 20% doubles peak digital flexor impulses and mechanical work, probably also increasing the metabolic cost of generating these forces. The increased mechanical cost associated with long toes in running suggests that modern human forefoot proportions might have been selected for in the context of the evolution of endurance running.

Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

USGS Publications Warehouse

Langbein, John O.

2012-01-01

Recent studies have documented that global positioning system (GPS) time series of position estimates have temporal correlations which have been modeled as a combination of power-law and white noise processes. When estimating quantities such as a constant rate from GPS time series data, the estimated uncertainties on these quantities are more realistic when using a noise model that includes temporal correlations than simply assuming temporally uncorrelated noise. However, the choice of the specific representation of correlated noise can affect the estimate of uncertainty. For many GPS time series, the background noise can be represented by either: (1) a sum of flicker and random-walk noise or, (2) as a power-law noise model that represents an average of the flicker and random-walk noise. For instance, if the underlying noise model is a combination of flicker and random-walk noise, then incorrectly choosing the power-law model could underestimate the rate uncertainty by a factor of two. Distinguishing between the two alternate noise models is difficult since the flicker component can dominate the assessment of the noise properties because it is spread over a significant portion of the measurable frequency band. But, although not necessarily detectable, the random-walk component can be a major constituent of the estimated rate uncertainty. None the less, it is possible to determine the upper bound on the random-walk noise.

Problems of older persons using a wheeled walker.

PubMed

Lindemann, Ulrich; Schwenk, Michael; Klenk, Jochen; Kessler, Max; Weyrich, Michael; Kurz, Franziska; Becker, Clemens

2016-04-01

Wheeled walkers (WWs) are used to improve mobility and for fall prevention in older persons, but not all users are satisfied with the usability of WWs. Intelligent WWs are being developed to improve the usability. The aim of this study was to support the development of intelligent WWs by investigating possible problems of using a WW. This study investigated 22 geriatric in-patients (median age 82 years) with and without their WW while opening a door against the direction of walking and passing through. Other possible problems when using WWs were identified by interview. Walking through the door was faster without than with using the WW (8.71 versus 12.86 s, p < 0.001), while interference between door and WW was documented in 41 of 44 (93 %) cases. Backward walking performance was better when using a WW with regard to gait speed, step width and walk ratio (all p < 0.002). Most referred problems when using a WW were walking downhill (83 %) and uphill (77 %) and obstacle crossing in general (77 %). Problems with opening a door against the direction of walking and the optimization of downhill and uphill walking as well as obstacle crossing should be regarded when developing an intelligent WW.

Effects of physical guidance on short-term learning of walking on a narrow beam.

PubMed

Domingo, Antoinette; Ferris, Daniel P

2009-11-01

Physical guidance is often used in rehabilitation when teaching patients to re-learn movements. However, the effects of guidance on motor learning of complex skills, such as walking balance, are not clear. We tested four groups of healthy subjects that practiced walking on a narrow (1.27 cm) or wide (2.5 cm) treadmill-mounted balance beam, with or without physical guidance. Assistance was given by springs attached to a hip belt that applied restoring forces towards beam center. Subjects were evaluated while walking unassisted before and after training by calculating the number of times subjects stepped off of the beam per minute of successful walking on the beam (Failures per Minute). Subjects in Unassisted groups had greater performance improvements in walking balance from pre to post compared to subjects in Assisted groups. During training, Unassisted groups had more Failures per Minute than Assisted groups. Performance improvements were smaller in Narrow Beam groups than in Wide Beam groups. The Unassisted-Wide and Assisted-Narrow groups had similar Failures per Minute during training, but the Unassisted-Wide group had much greater performance gains after training. These results suggest that physical assistance can hinder motor learning of walking balance, assistance appears less detrimental for more difficult tasks, and task-specific dynamics are important to learning independent of error experience.

Effect of carbon-composite knee-ankle-foot orthoses on walking efficiency and gait in former polio patients.

PubMed

Brehm, Merel-Anne; Beelen, Anita; Doorenbosch, Caroline A M; Harlaar, Jaap; Nollet, Frans

2007-10-01

To investigate the effects of total-contact fitted carbon-composite knee-ankle-foot orthoses (KAFOs) on energy cost of walking in patients with former polio who normally wear a conventional leather/metal KAFO or plastic/metal KAFO. A prospective uncontrolled study with a multiple baseline and follow-up design. Follow-up measurements continued until 26 weeks after intervention. Twenty adults with polio residuals (mean age 55 years). Each participant received a new carbon-composite KAFO, fitted according to a total-contact principle, which resulted in a rigid, lightweight and well-fitting KAFO. Energy cost of walking, walking speed, biomechanics of gait, physical functioning and patient satisfaction. The energy cost decreased significantly, by 8%, compared with the original KAFO. Furthermore, the incremention energy cost during walking with the carbon-composite KAFO was reduced by 18% towards normative values. An improvement in knee flexion, forward excursion of the centre of pressure, peak ankle moment, and timing of peak ankle power were significantly associated with the decrease in energy cost. Walking speed and physical functioning remained unchanged. In patients with former polio, carbon-composite KAFOs are superior to conventional leather/metal and plastic/metal KAFOs with respect to improving walking efficiency and gait, and are therefore important in reducing overuse and maintaining functional abilities in polio survivors.

Ankle Training With a Robotic Device Improves Hemiparetic Gait After a Stroke

PubMed Central

Forrester, Larry W.; Roy, Anindo; Krebs, Hermano Igo; Macko, Richard F.

2013-01-01

Background Task-oriented therapies such as treadmill exercise can improve gait velocity after stroke, but slow velocities and abnormal gait patterns often persist, suggesting a need for additional strategies to improve walking. Objectives To determine the effects of a 6-week visually guided, impedance controlled, ankle robotics intervention on paretic ankle motor control and gait function in chronic stroke. Methods This was a single-arm pilot study with a convenience sample of 8 stroke survivors with chronic hemiparetic gait, trained and tested in a laboratory. Subjects trained in dorsiflexion–plantarflexion by playing video games with the robot during three 1-hour training sessions weekly, totaling 560 repetitions per session. Assessments included paretic ankle ranges of motion, strength, motor control, and overground gait function. Results Improved paretic ankle motor control was seen as increased target success, along with faster and smoother movements. Walking velocity also increased significantly, whereas durations of paretic single support increased and double support decreased. Conclusions Robotic feedback training improved paretic ankle motor control with improvements in floor walking. Increased walking speeds were comparable with reports from other task-oriented, locomotor training approaches used in stroke, suggesting that a focus on ankle motor control may provide a valuable adjunct to locomotor therapies. PMID:21115945

Improved ambulation and speech production in an adolescent post-traumatic brain injury through a therapeutic intervention to increase postural control.

PubMed

Reinthal, Ann Karas; Mansour, Linda Moeller; Greenwald, Glenna

2004-01-01

This case study examined the effectiveness of a programme designed to improve anticipatory postural control in an adolescent over years 2 and 3 post-traumatic brain injury (TBI). It was hypothesized that her difficulty in walking and talking simultaneously was caused by excessive co-activation of extremity, trunk, and oral musculature during upright activities. The participant was treated weekly by physical and speech therapy. Treatment focussed on improving anticipatory postural control during gross motor activities in conjunction with oral-motor function. Initially, the participant walked using a walker at a speed of 23 cm s(-1). Two years later, she could walk without a device at 53 cm s(-1). Initial laryngoscopic examination showed minimal movement of the velum or pharyngeal walls; full movement was present after treatment. The measure of intelligibility improved from no single word intelligible utterances to 85% intelligible utterances after 2 years. The results suggest that less compensatory rigidification of oral musculature was needed to maintain an upright position against gravity as postural control improved. An adolescent 1-year post-TBI was followed as she underwent additional rehabilitation focussed on improving anticipatory postural control. The functional goal of simultaneously talking while walking was achieved through this intervention.

Walk-in Model for Ill Care in an Urban Academic Pediatric Clinic.

PubMed

Warrick, Stephen; Morehous, John; Samaan, Zeina M; Mansour, Mona; Huentelman, Tracy; Schoettker, Pamela J; Iyer, Srikant

2018-04-01

Since the Institute of Medicine's 2001 charge to reform health care, there has been a focus on the role of the medical home. Access to care in the proper setting and at the proper time is central to health care reform. We aimed to increase the volume of patients receiving care for acute illnesses within the medical home rather than the emergency department or urgent care center from 41% to 60%. We used quality improvement methods to create a separate nonemergency care stream in a large academic primary care clinic serving 19,000 patients (90% Medicaid). The pediatric primary care (PPC) walk-in clinic opened in July 2013 with service 4 hours per day and expanded to an all-day clinic in October 2013. Statistical process control methods were used to measure the change over time in the volume of ill patients and visits seen in the PPC walk-in clinic. Average weekly walk-in nonemergent ill-care visits increased from 61 to 158 after opening the PPC walk-in clinic. The percentage of nonemergent ill-care visits in the medical home increased from 41% to 45%. Visits during regular clinic hours increased from 55% to 60%. Clinic cycle time remained unchanged. Implementation of a walk-in care stream for acute illness within the medical home has allowed us to provide ill care to a higher proportion of patients, although we have not yet achieved our predicted volume. Matching access to demand is key to successfully meeting patient needs. Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Image-based fall detection and classification of a user with a walking support system

NASA Astrophysics Data System (ADS)

Taghvaei, Sajjad; Kosuge, Kazuhiro

2017-10-01

The classification of visual human action is important in the development of systems that interact with humans. This study investigates an image-based classification of the human state while using a walking support system to improve the safety and dependability of these systems.We categorize the possible human behavior while utilizing a walker robot into eight states (i.e., sitting, standing, walking, and five falling types), and propose two different methods, namely, normal distribution and hidden Markov models (HMMs), to detect and recognize these states. The visual feature for the state classification is the centroid position of the upper body, which is extracted from the user's depth images. The first method shows that the centroid position follows a normal distribution while walking, which can be adopted to detect any non-walking state. The second method implements HMMs to detect and recognize these states. We then measure and compare the performance of both methods. The classification results are employed to control the motion of a passive-type walker (called "RT Walker") by activating its brakes in non-walking states. Thus, the system can be used for sit/stand support and fall prevention. The experiments are performed with four subjects, including an experienced physiotherapist. Results show that the algorithm can be adapted to the new user's motion pattern within 40 s, with a fall detection rate of 96.25% and state classification rate of 81.0%. The proposed method can be implemented to other abnormality detection/classification applications that employ depth image-sensing devices.

Ongoing Walking Recovery 2 Years After Locomotor Training in a Child With Severe Incomplete Spinal Cord Injury

PubMed Central

Fox, Emily J.; Tester, Nicole J.; Phadke, Chetan P.; Nair, Preeti M.; Senesac, Claudia R.; Howland, Dena R.

2010-01-01

Background and Purpose The authors previously reported on walking recovery in a nonambulatory child with chronic, severe, incomplete cervical spinal cord injury (SCI) after 76 sessions of locomotor training (LT). Although clinical measures did not predict his recovery, reciprocal patterned leg movements developed, affording recovery of independent walking with a reverse rolling walker. The long-term functional limitations and secondary complications often associated with pediatric-onset SCI necessitate continued follow-up of children with SCI. Therefore, the purpose of this case report is to describe this child's walking function and musculoskeletal growth and development during the 2 years since his participation in an LT program and subsequent walking recovery. Case Description Following LT, the child attended elementary school as a full-time ambulator. He was evaluated 1 month (baseline), 1 year, and 2 years after LT. Examination of walking function included measures of walking independence, gait speed and spatiotemporal parameters, gait kinematics, and daily step activity. Growth and development were assessed by tracking his height, weight, incidence of musculoskeletal complications, and gross motor task performance. Outcomes Over the 2 years, the child continued to ambulate independently with a reverse rolling walker, increasing his fastest gait speed. Spatiotemporal and kinematic features of his walking improved, and daily step activity increased. Height and weight remained on their preinjury trajectory and within age-appropriate norms. The child experienced only minor musculoskeletal complications. Additionally, he gained the ability to use reciprocal patterned leg movements during locomotor tasks such as assisted stair climbing and independent tricycle pedaling. Conclusions Two years after recovery of walking, this child with incomplete SCI had maintained and improved his walking function and experienced age-appropriate growth and development. PMID:20299409

Ongoing walking recovery 2 years after locomotor training in a child with severe incomplete spinal cord injury.

PubMed

Fox, Emily J; Tester, Nicole J; Phadke, Chetan P; Nair, Preeti M; Senesac, Claudia R; Howland, Dena R; Behrman, Andrea L

2010-05-01

The authors previously reported on walking recovery in a nonambulatory child with chronic, severe, incomplete cervical spinal cord injury (SCI) after 76 sessions of locomotor training (LT). Although clinical measures did not predict his recovery, reciprocal patterned leg movements developed, affording recovery of independent walking with a reverse rolling walker. The long-term functional limitations and secondary complications often associated with pediatric-onset SCI necessitate continued follow-up of children with SCI. Therefore, the purpose of this case report is to describe this child's walking function and musculoskeletal growth and development during the 2 years since his participation in an LT program and subsequent walking recovery. Following LT, the child attended elementary school as a full-time ambulator. He was evaluated 1 month (baseline), 1 year, and 2 years after LT. Examination of walking function included measures of walking independence, gait speed and spatiotemporal parameters, gait kinematics, and daily step activity. Growth and development were assessed by tracking his height, weight, incidence of musculoskeletal complications, and gross motor task performance. Over the 2 years, the child continued to ambulate independently with a reverse rolling walker, increasing his fastest gait speed. Spatiotemporal and kinematic features of his walking improved, and daily step activity increased. Height and weight remained on their preinjury trajectory and within age-appropriate norms. The child experienced only minor musculoskeletal complications. Additionally, he gained the ability to use reciprocal patterned leg movements during locomotor tasks such as assisted stair climbing and independent tricycle pedaling. Two years after recovery of walking, this child with incomplete SCI had maintained and improved his walking function and experienced age-appropriate growth and development.

Physiological and psychological responses of young males during spring-time walks in urban parks.

PubMed

Song, Chorong; Ikei, Harumi; Igarashi, Miho; Miwa, Masayuki; Takagaki, Michiko; Miyazaki, Yoshifumi

2014-05-01

It is widely believed that contact with the natural environment can improve physical and mental health. Urban green spaces may provide city residents with these benefits; however, there is a lack of empirical field research on the health benefits of urban parks. This field experiment was performed in May. Seventeen males aged 21.2 ± 1.7 years (mean ± standard deviation) were instructed to walk predetermined 15-minute courses in an urban park and a nearby city area (control). Heart rate and heart rate variability (HRV) were measured to assess physiological responses. The semantic differential (SD) method, Profile of Mood States (POMS), and State-Trait Anxiety Inventory (STAI) were used to measure psychological responses. Heart rate was significantly lower while walking in the urban park than while walking in the city street. Furthermore, the urban park walk led to higher parasympathetic nervous activity and lower sympathetic nervous activity compared with the walk through the city street. Subjective evaluations were generally in accordance with physiological reactions, and significantly higher scores were observed for the 'comfortable', 'natural', and 'relaxed' parameters following the urban park walk. After the urban park walk, the score for the 'vigor' subscale of the POMS was significantly higher, whereas that for negative feelings such as 'tension-anxiety' and 'fatigue' was significantly lower. The score for the anxiety dimension of the STAI was also significantly lower after the urban park walk. Physiological and psychological results from this field experiment provide evidence for the physiological and psychological benefits of urban green spaces. A brief spring-time walk in an urban park shifted sympathetic/parasympathetic balance and improved mood state.

Is body-weight-supported treadmill training or robotic-assisted gait training superior to overground gait training and other forms of physiotherapy in people with spinal cord injury? A systematic review.

PubMed

Mehrholz, J; Harvey, L A; Thomas, S; Elsner, B

2017-08-01

Systematic review about randomised trials comparing different training strategies to improve gait in people with spinal cord injuries (SCI). The aim of this systematic review was to compare the effectiveness of body-weight-supported treadmill training (BWSTT) and robotic-assisted gait training with overground gait training and other forms of physiotherapy in people with traumatic SCI. Systematic review conducted by researchers from Germany and Australia. An extensive search was conducted for randomised controlled trials involving people with traumatic SCI that compared either BWSTT or robotic-assisted gait training with overground gait training and other forms of physiotherapy. The two outcomes of interest were walking speed (m s -1 ) and walking distance (m). BWSTT and robotic-assisted gait training were analysed separately, and data were pooled across trials to derive mean between-group differences using a random-effects model. Thirteen randomised controlled trials involving 586 people were identified. Ten trials involving 462 participants compared BWSTT to overground gait training and other forms of physiotherapy, but only nine trials provided useable data. The pooled mean (95% confidence interval (CI)) between-group differences for walking speed and walking distance were -0.03 m s -1 (-0.10 to 0.04) and -7 m (-45 to 31), respectively, favouring overground gait training. Five trials involving 344 participants compared robotic-assisted gait training to overground gait training and other forms of physiotherapy but only three provided useable data. The pooled mean (95% CI) between-group differences for walking speed and walking distance were -0.04 m s -1 (95% CI -0.21 to 0.13) and -6 m (95% CI -86 to 74), respectively, favouring overground gait training. BWSTT and robotic-assisted gait training do not increase walking speed more than overground gait training and other forms of physiotherapy do, but their effects on walking distance are not clear.

Random walks exhibiting anomalous diffusion: elephants, urns and the limits of normality

NASA Astrophysics Data System (ADS)

Kearney, Michael J.; Martin, Richard J.

2018-01-01

A random walk model is presented which exhibits a transition from standard to anomalous diffusion as a parameter is varied. The model is a variant on the elephant random walk and differs in respect of the treatment of the initial state, which in the present work consists of a given number N of fixed steps. This also links the elephant random walk to other types of history dependent random walk. As well as being amenable to direct analysis, the model is shown to be asymptotically equivalent to a non-linear urn process. This provides fresh insights into the limiting form of the distribution of the walker’s position at large times. Although the distribution is intrinsically non-Gaussian in the anomalous diffusion regime, it gradually reverts to normal form when N is large under quite general conditions.

A simplified analytical random walk model for proton dose calculation

NASA Astrophysics Data System (ADS)

Yao, Weiguang; Merchant, Thomas E.; Farr, Jonathan B.

2016-10-01

We propose an analytical random walk model for proton dose calculation in a laterally homogeneous medium. A formula for the spatial fluence distribution of primary protons is derived. The variance of the spatial distribution is in the form of a distance-squared law of the angular distribution. To improve the accuracy of dose calculation in the Bragg peak region, the energy spectrum of the protons is used. The accuracy is validated against Monte Carlo simulation in water phantoms with either air gaps or a slab of bone inserted. The algorithm accurately reflects the dose dependence on the depth of the bone and can deal with small-field dosimetry. We further applied the algorithm to patients’ cases in the highly heterogeneous head and pelvis sites and used a gamma test to show the reasonable accuracy of the algorithm in these sites. Our algorithm is fast for clinical use.

Clinical Characteristics of Proper Robot-Assisted Gait Training Group in Non-ambulatory Subacute Stroke Patients

PubMed Central

Kim, Soo Jeong; Lee, Hye Jin; Hwang, Seung Won; Pyo, Hannah; Yang, Sung Phil; Lim, Mun-Hee; Park, Gyu Lee

2016-01-01

Objective To identify the clinical characteristics of proper robot-assisted gait training group using exoskeletal locomotor devices in non-ambulatory subacute stroke patients. Methods A total of 38 stroke patients were enrolled in a 4-week robotic training protocol (2 sessions/day, 5 times/week). All subjects were evaluated for their general characteristics, Functional Ambulatory Classification (FAC), Fugl-Meyer Scale (FMS), Berg Balance Scale (BBS), Modified Rankin Scale (MRS), Modified Barthel Index (MBI), and Mini-Mental Status Examination (MMSE) at 0, 2, and 4 weeks. Statistical analysis were performed to determine significant clinical characteristics for improvement of gait function after robot-assisted gait training. Results Paired t-test showed that all functional parameters except MMSE were improved significantly (p<0.05). The duration of disease and baseline BBS score were significantly (p<0.05) correlated with FAC score in multiple regression models. Receiver operating characteristic (ROC) curve showed that a baseline BBS score of '9' was a cutoff value (AUC, 0.966; sensitivity, 91%–100%; specificity, 85%). By repeated-measures ANOVA, the differences in improved walking ability according to time were significant between group of patients who had baseline BBS score of '9' and those who did not have baseline BBS score of '9' Conclusion Our results showed that a baseline BBS score above '9' and a short duration of disease were highly correlated with improved walking ability after robot-assisted gait training. Therefore, baseline BBS and duration of disease should be considered clinically for gaining walking ability in robot-assisted training group. PMID:27152266

The role of passive avian head stabilization in flapping flight

PubMed Central

Pete, Ashley E.; Kress, Daniel; Dimitrov, Marina A.; Lentink, David

2015-01-01

Birds improve vision by stabilizing head position relative to their surroundings, while their body is forced up and down during flapping flight. Stabilization is facilitated by compensatory motion of the sophisticated avian head–neck system. While relative head motion has been studied in stationary and walking birds, little is known about how birds accomplish head stabilization during flapping flight. To unravel this, we approximate the avian neck with a linear mass–spring–damper system for vertical displacements, analogous to proven head stabilization models for walking humans. We corroborate the model's dimensionless natural frequency and damping ratios from high-speed video recordings of whooper swans (Cygnus cygnus) flying over a lake. The data show that flap-induced body oscillations can be passively attenuated through the neck. We find that the passive model robustly attenuates large body oscillations, even in response to head mass and gust perturbations. Our proof of principle shows that bird-inspired drones with flapping wings could record better images with a swan-inspired passive camera suspension. PMID:26311316

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial.

PubMed

Jeon, Hye Joo; Hwang, Byong Yong

2018-02-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients.

Effect of bilateral lower limb strengthening exercise on balance and walking in hemiparetic patients after stroke: a randomized controlled trial

PubMed Central

Jeon, Hye Joo; Hwang, Byong Yong

2018-01-01

[Purpose] To evaluate the effect of bilateral lower limb strengthening designed to improve balance and walking in stroke patients. [Subjects and Methods] Twenty hemiparetic stroke patients were divided into two groups: a unilateral therapy group (UTG) (n=10) and a bilateral therapy group (BTG) (n=10). The UTG completed strength training only in the paretic lower limb. The BTG completed strength training in the paretic and non-paretic lower limbs. Assessment tools included the functional reach test (FRT), the Berg balance scale (BBS), the timed up and go (TUG) test, and a 10-meter walk test (10MWT). [Results] In both groups, the lower limb strengthening exercise for balance and walking significantly improved the FRT, BBS, TUG, and 10MWT scores. Compared with UTG, the BTG attained significantly improved FRT and BBS scores. [Conclusion] Bilateral therapy using this lower limb strengthening exercise effectively promotes balance in hemiparetic stroke patients. PMID:29545693

A training program to improve gait while dual tasking in patients with Parkinson's disease: a pilot study.

PubMed

Yogev-Seligmann, Galit; Giladi, Nir; Brozgol, Marina; Hausdorff, Jeffrey M

2012-01-01

Impairments in the ability to perform another task while walking (ie, dual tasking [DT]) are associated with an increased risk of falling. Here we describe a program we developed specifically to improve DT performance while walking based on motor learning principles and task-specific training. We examined feasibility, potential efficacy, retention, and transfer to the performance of untrained tasks in a pilot study among 7 patients with Parkinson's disease (PD). Seven patients (Hoehn and Yahr stage, 2.1±0.2) were evaluated before, after, and 1 month after 4 weeks of DT training. Gait speed and gait variability were measured during usual walking and during 4 DT conditions. The 4-week program of one-on-one training included walking while performing several distinct cognitive tasks. Gait speed and gait variability during DT significantly improved. Improvements were also seen in the DT conditions that were not specifically trained and were retained 1 month after training. These initial findings support the feasibility of applying a task-specific DT gait training program for patients with PD and suggest that it positively affects DT gait, even in untrained tasks. The present results are also consistent with the possibility that DT gait training enhances divided attention abilities during walking. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Results of a physical therapy program in nursing home residents: A randomized clinical trial].

PubMed

Casilda-López, Jesús; Torres-Sánchez, Irene; Garzón-Moreno, Victor Manuel; Cabrera-Martos, Irene; Valenza, Marie Carmen

2015-01-01

The maintenance of the physical functionality is a key factor in the care of the elderly. Inactive people have a higher risk of death due to diseases associated with inactivity. In addition, the maintenance of optimal levels of physical and mental activity has been suggested as a protective factor against the development and progression of chronic illnesses and disability. The objective of this study is to assess the effectiveness of an 8-week exercise program with elastic bands, on exercise capacity, walking and balance in nursing home residents. A nursing home sample was divided into two groups, intervention group (n=26) and control group (n=25). The intervention group was included in an 8-week physical activity program using elastic bands, twice a week, while the control group was took part in a walking programme. Outcome measurements were descriptive variables (anthropometric characteristics, quality of life, fatigue, fear of movement) and fundamental variables (exercise capacity, walking and balance). A significant improvement in balance and walking speed was observed after the programme. Additionally, exercise capacity improved significantly (P≤.001), and the patients showed an improvement in perceived dyspnea after the physical activity programme in the intervention group. The exercise program was safe and effective in improving dyspnea, exercise capacity, walking, and balance in elderly. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

Effectiveness of functional electrical stimulation on walking speed, functional walking category, and clinically meaningful changes for people with multiple sclerosis.

PubMed

Street, Tamsyn; Taylor, Paul; Swain, Ian

2015-04-01

To determine the effectiveness of functional electrical stimulation (FES) on drop foot in patients with multiple sclerosis (MS), using data from standard clinical practice. Case series with a consecutive sample of FES users collected between 2008 and 2013. Specialist FES center at a district general hospital. Patients with MS who have drop foot (N=187) (117 women, 70 men; mean age, 55y [range, 27-80y]; mean duration since diagnosis, 11.7y [range, 1-56y]). A total of 166 patients were still using FES after 20 weeks, with 153 patients completing the follow-up measures. FES of the common peroneal nerve (178 unilateral, 9 bilateral FES users). Clinically meaningful changes (ie, >.05m/s and >0.1m/s) and functional walking category derived from 10-m walking speed. An increase in walking speed was found to be highly significant (P<.001), both initially where a minimum clinically meaningful change was observed (.07m/s) and after 20 weeks with a substantial clinically meaningful change (.11m/s). After 20 weeks, treatment responders displayed a 27% average improvement in their walking speed. No significant training effect was found. Overall functional walking category was maintained or improved in 95% of treatment responders. FES of the dorsiflexors is a well-accepted intervention that enables clinically meaningful changes in walking speed, leading to a preserved or an increased functional walking category. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Training to walk amid uncertainty with Re-Step: measurements and changes with perturbation training for hemiparesis and cerebral palsy.

PubMed

Bar-Haim, Simona; Harries, Netta; Hutzler, Yeshayahu; Belokopytov, Mark; Dobrov, Igor

2013-09-01

To describe Re-Step™, a novel mechatronic shoe system that measures center of pressure (COP) gait parameters and complexity of COP dispersion while walking, and to demonstrate these measurements in healthy controls and individuals with hemiparesis and cerebral palsy (CP) before and after perturbation training. The Re-Step™ was used to induce programmed chaotic perturbations to the feet while walking for 30 min for 36 sessions over 12-weeks of training in two subjects with hemiparesis and two with CP. Baseline measurements of complexity indices (fractal dimension and approximate entropy) tended to be higher in controls than in those with disabilities, while COP variability, mean and variability of step time and COP dispersion were lower. After training the disabled subjects these measurement values tended toward those of the controls, along with a decrease in step time, 10 m walk time, average step time, percentage of double support and increased Berg balance score. This pilot trial reveals the feasibility and applicability of this unique measurement and perturbation system for evaluating functional disabilities and changes with interventions to improve walking. Implication for Rehabilitation Walking, of individuals with cerebral palsy and hemiparesis following stroke, can be viewed in terms of a rigid motor behavior that prevents adaptation to changing environmental conditions. Re-Step system (a) measures and records linear and non-linear gait parameters during free walking to provide a detailed evaluation of walking disabilities, (b) is an intervention training modality that applies unexpected perturbations during walking. This perturbation intervention may improve gait and motor functions of individuals with hemiparesis and cerebral plasy.

A Spectral Analysis of Discrete-Time Quantum Walks Related to the Birth and Death Chains

NASA Astrophysics Data System (ADS)

Ho, Choon-Lin; Ide, Yusuke; Konno, Norio; Segawa, Etsuo; Takumi, Kentaro

2018-04-01

In this paper, we consider a spectral analysis of discrete time quantum walks on the path. For isospectral coin cases, we show that the time averaged distribution and stationary distributions of the quantum walks are described by the pair of eigenvalues of the coins as well as the eigenvalues and eigenvectors of the corresponding random walks which are usually referred as the birth and death chains. As an example of the results, we derive the time averaged distribution of so-called Szegedy's walk which is related to the Ehrenfest model. It is represented by Krawtchouk polynomials which is the eigenvectors of the model and includes the arcsine law.

Associations of adult physical activity with perceived safety and police-recorded crime: the Multi-ethnic Study of Atherosclerosis

PubMed Central

2012-01-01

Background Due to the inconsistent findings of prior studies, we explored the association of perceived safety and police-recorded crime measures with physical activity. Methods The study included 818 Chicago participants of the Multiethnic Study of Atherosclerosis 45 to 84 years of age. Questionnaire-assessed physical activity included a) transport walking; b) leisure walking; and c) non-walking leisure activities. Perceived safety was assessed through an interviewer-administered questionnaire. Police-recorded crime was assessed through 2-year counts of selected crimes (total and outdoor incivilities, criminal offenses, homicides) per 1000 population. Associations were examined using generalized estimating equation logistic regression models. Results Perceiving a safer neighborhood was positively associated with transport walking and perceiving lower violence was associated with leisure walking. Those in the lowest tertile of total or outdoor incivilities were more likely to report transport walking. Models with both perceived safety and police-recorded measures of crime as independent variables had superior fit for both transport walking and leisure walking outcomes. Neither perceived safety nor police-recorded measures of crime were associated with non-walking leisure activity. Conclusions Perceived and police-recorded measures had independent associations with walking and both should be considered in assessing the impact of neighborhood crime on physical activity. PMID:23245527

Voluntary driven exoskeleton as a new tool for rehabilitation in chronic spinal cord injury: a pilot study.

PubMed

Aach, Mirko; Cruciger, Oliver; Sczesny-Kaiser, Matthias; Höffken, Oliver; Meindl, Renate Ch; Tegenthoff, Martin; Schwenkreis, Peter; Sankai, Yoshiyuki; Schildhauer, Thomas A

2014-12-01

Treadmill training after traumatic spinal cord injury (SCI) has become an established therapy to improve walking capabilities. The hybrid assistive limb (HAL) exoskeleton has been developed to support motor function and is tailored to the patients' voluntary drive. To determine whether locomotor training with the exoskeleton HAL is safe and can increase functional mobility in chronic paraplegic patients after SCI. A single case experimental A-B (pre-post) design study by repeated assessments of the same patients. The subjects performed 90 days (five times per week) of HAL exoskeleton body weight supported treadmill training with variable gait speed and body weight support. Eight patients with chronic SCI classified by the American Spinal Injury Association (ASIA) Impairment Scale (AIS) consisting of ASIA A (zones of partial preservation [ZPP] L3-S1), n=4; ASIA B (with motor ZPP L3-S1), n=1; and ASIA C/D, n=3, who received full rehabilitation in the acute and subacute phases of SCI. Functional measures included treadmill-associated walking distance, speed, and time, with additional analysis of functional improvements using the 10-m walk test (10MWT), timed-up and go test (TUG test), 6-minute walk test (6MWT), and the walking index for SCI II (WISCI II) score. Secondary physiologic measures including the AIS with the lower extremity motor score (LEMS), the spinal spasticity (Ashworth scale), and the lower extremity circumferences. Subjects performed standardized functional testing before and after the 90 days of intervention. Highly significant improvements of HAL-associated walking time, distance, and speed were noticed. Furthermore, significant improvements have been especially shown in the functional abilities without the exoskeleton for over-ground walking obtained in the 6MWT, TUG test, and the 10MWT, including an increase in the WISCI II score of three patients. Muscle strength (LEMS) increased in all patients accompanied by a gain of the lower limb circumferences. A conversion in the AIS was ascertained in one patient (ASIA B to ASIA C). One patient reported a decrease of spinal spasticity. Hybrid assistive limb exoskeleton training results in improved over-ground walking and leads to the assumption of a beneficial effect on ambulatory mobility. However, evaluation in larger clinical trials is required. Copyright © 2014 Elsevier Inc. All rights reserved.

Comprehensive quantitative investigation of arm swing during walking at various speed and surface slope conditions.

PubMed

Hejrati, Babak; Chesebrough, Sam; Bo Foreman, K; Abbott, Jake J; Merryweather, Andrew S

2016-10-01

Previous studies have shown that inclusion of arm swing in gait rehabilitation leads to more effective walking recovery in patients with walking impairments. However, little is known about the correct arm-swing trajectories to be used in gait rehabilitation given the fact that changes in walking conditions affect arm-swing patterns. In this paper we present a comprehensive look at the effects of a variety of conditions on arm-swing patterns during walking. The results describe the effects of surface slope, walking speed, and physical characteristics on arm-swing patterns in healthy individuals. We propose data-driven mathematical models to describe arm-swing trajectories. Thirty individuals (fifteen females and fifteen males) with a wide range of height (1.58-1.91m) and body mass (49-98kg), participated in our study. Based on their self-selected walking speed, each participant performed walking trials with four speeds on five surface slopes while their whole-body kinematics were recorded. Statistical analysis showed that walking speed, surface slope, and height were the major factors influencing arm swing during locomotion. The results demonstrate that data-driven models can successfully describe arm-swing trajectories for normal gait under varying walking conditions. The findings also provide insight into the behavior of the elbow during walking. Copyright © 2016. Published by Elsevier B.V.

Is the 6-minute walk test a reliable substitute for peak oxygen uptake in patients with dilated cardiomyopathy?

PubMed

Zugck, C; Krüger, C; Dürr, S; Gerber, S H; Haunstetter, A; Hornig, K; Kübler, W; Haass, M

2000-04-01

The 6-min walk test may serve as a more simple clinical tool to assess functional capacity in congestive heart failure than determination of peak oxygen uptake by cardiopulmonary exercise testing. The purpose of the study was to prospectively examine whether the distance ambulated during a 6-min walk test (i) correlates with peak oxygen uptake, (ii) allows peak oxygen uptake to be predicted, and (iii) provides prognostic information similar to peak oxygen uptake in patients with dilated cardiomyopathy and left ventricular ejection fraction < or = 35%. In 113 patients (age: 54+/-12 years, NYHA: 2.2+/-0.8) with dilated cardiomyopathy (left ventricular ejection fraction 19+/-7%) a 6-min walk test and cardiopulmonary exercise testing were performed. The 6-min walk test and peak oxygen uptake were closely correlated at the initial visit (r=0.68, n=113), as well as after 263+/-114 (r=0.71, n=28) and 381+/-170 days (r=0.74, n=14). During serial exercise testing the 6-min walk test allowed peak oxygen uptake to be reliably predicted (r=0.76 between calculated and real peak oxygen uptake). After 528+/-234 days, 42 patients were hospitalized due to worsening heart failure and/or died from cardiovascular causes. Compared to clinically stable patients, these 42 patients walked a shorter distance (423+/-104 vs 501+/-95 m, P<0.001) and had a lower peak oxygen uptake (12.7+/-4.0 vs 17.4 + 5.6 ml x min(-1) x kg(-1), P<0.001). By univariate analysis the 6-min walk test outperformed other prognostic parameters such as left ventricular ejection fraction, cardiac index and plasma norepinephrine concentration and conferred a prognostic power similar to peak oxygen uptake. This predictive value could be further improved in a multivariate model, by combining the 6-min walk test with independent variables, such as left ventricular ejection fraction or cardiac index. The 6-min walk test correlated with peak oxygen uptake when tested serially over the course of the disease. Although both tests define two distinct domains of functional capacity, the 6-min walk test provides prognostic information very similar to peak oxygen uptake in congestive heart failure patients with dilated cardiomyopathy.

Improvement of the knee center of rotation during walking after opening wedge high tibial osteotomy.

PubMed

Kim, Kyungsoo; Feng, Jun; Nha, Kyung Wook; Park, Won Man; Kim, Yoon Hyuk

2015-06-01

Accurate measurement of the center of rotation of the knee joint is indispensable for prediction of joint kinematics and kinetics in musculoskeletal models. However, no study has yet identified the knee center of rotations during several daily activities before and after high tibial osteotomy surgery, which is one surgical option for treating knee osteoarthritis. In this study, an estimation method for determining the knee joint center of rotation was developed by applying the optimal common shape technique and symmetrical axis of rotation approach techniques to motion-capture data and validated for typical activities (walking, squatting, climbing up stairs, walking down stairs) of 10 normal subjects. The locations of knee joint center of rotations for injured and contralateral knees of eight subjects with osteoarthritis, both before and after high tibial osteotomy surgery, were then calculated during walking. It was shown that high tibial osteotomy surgery improved the knee joint center of rotation since the center of rotations for the injured knee after high tibial osteotomy surgery were significantly closer to those of the normal healthy population. The difference between the injured and contralateral knees was also generally reduced after surgery, demonstrating increased symmetry. These results indicate that symmetry in both knees can be recovered in many cases after high tibial osteotomy surgery. Moreover, the recovery of center of rotation in the injured knee was prior to that of symmetry. This study has the potential to provide fundamental information that can be applied to understand abnormal kinematics in patients, diagnose knee joint disease, and design a novel implants for knee joint surgeries. © IMechE 2015.

Influence of a Locomotor Training Approach on Walking Speed and Distance in People With Chronic Spinal Cord Injury: A Randomized Clinical Trial

PubMed Central

Roach, Kathryn E.

2011-01-01

Background Impaired walking limits function after spinal cord injury (SCI), but training-related improvements are possible even in people with chronic motor incomplete SCI. Objective The objective of this study was to compare changes in walking speed and distance associated with 4 locomotor training approaches. Design This study was a single-blind, randomized clinical trial. Setting This study was conducted in a rehabilitation research laboratory. Participants Participants were people with minimal walking function due to chronic SCI. Intervention Participants (n=74) trained 5 days per week for 12 weeks with the following approaches: treadmill-based training with manual assistance (TM), treadmill-based training with stimulation (TS), overground training with stimulation (OG), and treadmill-based training with robotic assistance (LR). Measurements Overground walking speed and distance were the primary outcome measures. Results In participants who completed the training (n=64), there were overall effects for speed (effect size index [d]=0.33) and distance (d=0.35). For speed, there were no significant between-group differences; however, distance gains were greatest with OG. Effect sizes for speed and distance were largest with OG (d=0.43 and d=0.40, respectively). Effect sizes for speed were the same for TM and TS (d=0.28); there was no effect for LR. The effect size for distance was greater with TS (d=0.16) than with TM or LR, for which there was no effect. Ten participants who improved with training were retested at least 6 months after training; walking speed at this time was slower than that at the conclusion of training but remained faster than before training. Limitations It is unknown whether the training dosage and the emphasis on training speed were optimal. Robotic training that requires active participation would likely yield different results. Conclusions In people with chronic motor incomplete SCI, walking speed improved with both overground training and treadmill-based training; however, walking distance improved to a greater extent with overground training. PMID:21051593

Entangled spin chain

NASA Astrophysics Data System (ADS)

Salberger, Olof; Korepin, Vladimir

We introduce a new model of interacting spin 1/2. It describes interactions of three nearest neighbors. The Hamiltonian can be expressed in terms of Fredkin gates. The Fredkin gate (also known as the controlled swap gate) is a computational circuit suitable for reversible computing. Our construction generalizes the model presented by Peter Shor and Ramis Movassagh to half-integer spins. Our model can be solved by means of Catalan combinatorics in the form of random walks on the upper half plane of a square lattice (Dyck walks). Each Dyck path can be mapped on a wave function of spins. The ground state is an equally weighted superposition of Dyck walks (instead of Motzkin walks). We can also express it as a matrix product state. We further construct a model of interacting spins 3/2 and greater half-integer spins. The models with higher spins require coloring of Dyck walks. We construct a SU(k) symmetric model (where k is the number of colors). The leading term of the entanglement entropy is then proportional to the square root of the length of the lattice (like in the Shor-Movassagh model). The gap closes as a high power of the length of the lattice [5, 11].

Physical Activity and Functional Limitations in Older Adults: The Influence of Self-Efficacy and Functional Performance

PubMed Central

Mullen, Sean P.; Satariano, William A.; Kealey, Melissa; Prohaska, Thomas R.

2012-01-01

Objectives. Data from the Healthy Aging Network (HAN) study (Prohaska, T., Eisenstein, A., Satariano, W., Hunter, R., Bayles, C., Kurtovich, E., … Ivey, S. [2009]. Walking and the preservation of cognitive function in older populations. The Gerontologist, 49[Suppl. 1], S86–S93; and Satariano, W., Ivey, S., Kurtovich, E., Kealey, M., Hubbard, A., Bayles, C., … Prohaska, T. [2010]. Lower-body function, neighborhoods, and walking in an older population. American Journal of Preventive Medicine, 38, 419–428.) were used to examine the relationships among physical activity, self-efficacy, functional performance, and limitations. Method. Interviews were conducted within homes and senior centers in 4 geographic regions across the United States. Participants were 884 older adults (M age = 74.8; 77% female; 35% minority status) who completed measures of walking behavior, way-finding self-efficacy, walking self-efficacy, functional performance, functional limitations, and demographic characteristics. Results. Path analysis within a covariance modeling framework revealed significant direct effects of walking on self-efficacy constructs, functional performance on functional limitations, and efficacy on limitations. Additionally, significant indirect effects were also found, including walking on limitations via walking self-efficacy and performance and walking self-efficacy on limitations via performance. Furthermore, we found support for invariance of the model across geographical grouping. Discussion. Our findings provide further validation for an efficacy-based model of functional limitations. Walking-related efficacy may help reduce or possibly delay the onset of functional limitations. PMID:22473023

Physical activity and functional limitations in older adults: the influence of self-efficacy and functional performance.

PubMed

Mullen, Sean P; McAuley, Edward; Satariano, William A; Kealey, Melissa; Prohaska, Thomas R

2012-05-01

Data from the Healthy Aging Network (HAN) study (Prohaska, T., Eisenstein, A., Satariano, W., Hunter, R., Bayles, C., Kurtovich, E., … Ivey, S. [2009]. Walking and the preservation of cognitive function in older populations. The Gerontologist, 49[Suppl. 1], S86-S93; and Satariano, W., Ivey, S., Kurtovich, E., Kealey, M., Hubbard, A., Bayles, C., … Prohaska, T. [2010]. Lower-body function, neighborhoods, and walking in an older population. American Journal of Preventive Medicine, 38, 419-428.) were used to examine the relationships among physical activity, self-efficacy, functional performance, and limitations. Interviews were conducted within homes and senior centers in 4 geographic regions across the United States. Participants were 884 older adults (M age = 74.8; 77% female; 35% minority status) who completed measures of walking behavior, way-finding self-efficacy, walking self-efficacy, functional performance, functional limitations, and demographic characteristics. Path analysis within a covariance modeling framework revealed significant direct effects of walking on self-efficacy constructs, functional performance on functional limitations, and efficacy on limitations. Additionally, significant indirect effects were also found, including walking on limitations via walking self-efficacy and performance and walking self-efficacy on limitations via performance. Furthermore, we found support for invariance of the model across geographical grouping. Our findings provide further validation for an efficacy-based model of functional limitations. Walking-related efficacy may help reduce or possibly delay the onset of functional limitations.

From Lévy to Brownian: a computational model based on biological fluctuation.

PubMed

Nurzaman, Surya G; Matsumoto, Yoshio; Nakamura, Yutaka; Shirai, Kazumichi; Koizumi, Satoshi; Ishiguro, Hiroshi

2011-02-03

Theoretical studies predict that Lévy walks maximizes the chance of encountering randomly distributed targets with a low density, but Brownian walks is favorable inside a patch of targets with high density. Recently, experimental data reports that some animals indeed show a Lévy and Brownian walk movement patterns when forage for foods in areas with low and high density. This paper presents a simple, Gaussian-noise utilizing computational model that can realize such behavior. We extend Lévy walks model of one of the simplest creature, Escherichia coli, based on biological fluctuation framework. We build a simulation of a simple, generic animal to observe whether Lévy or Brownian walks will be performed properly depends on the target density, and investigate the emergent behavior in a commonly faced patchy environment where the density alternates. Based on the model, animal behavior of choosing Lévy or Brownian walk movement patterns based on the target density is able to be generated, without changing the essence of the stochastic property in Escherichia coli physiological mechanism as explained by related researches. The emergent behavior and its benefits in a patchy environment are also discussed. The model provides a framework for further investigation on the role of internal noise in realizing adaptive and efficient foraging behavior.

To Walk or Not to Walk?: The Hierarchy of Walking Needs

ERIC Educational Resources Information Center

Alfonzo, Mariela

2005-01-01

The multitude of quality of life problems associated with declining walking rates has impelled researchers from various disciplines to identify factors related to this behavior change. Currently, this body of research is in need of a transdisciplinary, multilevel theoretical model that can help explain how individual, group, regional, and…

Efficacy of gait trainer as an adjunct to traditional physical therapy on walking performance in hemiparetic cerebral palsied children: a randomized controlled trial.

PubMed

Gharib, Nevein Mm; El-Maksoud, Gehan M Abd; Rezk-Allah, Soheir S

2011-10-01

To assess the effects of additional gait trainer assisted walking exercises on walking performance in children with hemiparetic cerebral palsy. A randomized controlled study. Paediatric physical therapy outpatient clinic. Thirty spastic hemiparetic cerebral palsied children of both sexes (10-13 years - 19 girls and 11 boys). Children were randomly assigned into two equal groups; experimental and control groups. Participants in both groups received a traditional physical therapy exercise programme. Those in the experimental group received additional gait trainer based walking exercises which aimed to improve walking performance. Treatment was provided three times per week for three successive months. Children received baseline and post-treatment assessments using Biodex Gait Trainer 2 assessment device to evaluate gait parameters including: average step length, walking speed, time on each foot (% of gait cycle) and ambulation index. Children in the experimental group showed a significant improvement as compared with those in the control group. The ambulation index was 75.53±7.36 (11.93 ± 2.89 change score) for the experimental group and 66.06 ± 5.48 (2.13 ± 4.43 change score) for the control group (t = 3.99 and P = 0.0001). Time of support for the affected side was 42.4 ± 3.37 (7 ± 2.20 change score) for the experimental group and 38.06 ± 4.63 (3.33 ± 6.25 change score) for the control group (t = 2.92 and P = 0.007). Also, there was a significant improvement in step length and walking speed in both groups. Gait trainer combined with traditional physiotherapy increase the chance of improving gait performance in children with spastic hemiparetic cerebral palsy.

A comparison of the health benefits of reduced-exertion high-intensity interval training (REHIT) and moderate-intensity walking in type 2 diabetes patients.

PubMed

Ruffino, José S; Songsorn, Preeyaphorn; Haggett, Malindi; Edmonds, Daniel; Robinson, Anthony M; Thompson, Dylan; Vollaard, Niels B J

2017-02-01

Reduced-exertion high-intensity interval training (REHIT) is a genuinely time-efficient intervention that can improve aerobic capacity and insulin sensitivity in sedentary individuals. The present study compared the effects of REHIT and moderate-intensity walking on health markers in patients with type 2 diabetes (T2D) in a counter-balanced crossover study. Sixteen men with T2D (mean ± SD age: 55 ± 5 years, body mass index: 30.6 ± 2.8 kg·m -2 , maximal aerobic capacity: 27 ± 4 mL·kg -1 ·min -1 ) completed 8 weeks of REHIT (three 10-min low-intensity cycling sessions/week with two "all-out" 10-20-s sprints) and 8 weeks of moderate-intensity walking (five 30-min sessions/week at an intensity corresponding to 40%-55% of heart-rate reserve), with a 2-month wash-out period between interventions. Before and after each intervention, participants underwent an incremental fitness test, an oral glucose tolerance test (OGTT), a whole-body dual-energy X-ray absorptiometry scan, and continuous glucose monitoring. REHIT was associated with a significantly larger increase in maximal aerobic capacity compared with walking (7% vs. 1%; time × intervention interaction effect: p < 0.05). Both REHIT and walking decreased resting mean arterial pressure (-4%; main effect of time: p < 0.05) and plasma fructosamine (-5%; main effect of time: p < 0.05). Neither intervention significantly improved OGTT-derived measures of insulin sensitivity, glycaemic control measured using continuous glucose monitors, blood lipid profile, or body composition. We conclude that REHIT is superior to a 5-fold larger volume of moderate-intensity walking in improving aerobic fitness, but similar to walking REHIT is not an effective intervention for improving insulin sensitivity or glycaemic control in T2D patients in the short term.

Long-Range Correlations in Stride Intervals May Emerge from Non-Chaotic Walking Dynamics

PubMed Central

Ahn, Jooeun; Hogan, Neville

2013-01-01

Stride intervals of normal human walking exhibit long-range temporal correlations. Similar to the fractal-like behaviors observed in brain and heart activity, long-range correlations in walking have commonly been interpreted to result from chaotic dynamics and be a signature of health. Several mathematical models have reproduced this behavior by assuming a dominant role of neural central pattern generators (CPGs) and/or nonlinear biomechanics to evoke chaos. In this study, we show that a simple walking model without a CPG or biomechanics capable of chaos can reproduce long-range correlations. Stride intervals of the model revealed long-range correlations observed in human walking when the model had moderate orbital stability, which enabled the current stride to affect a future stride even after many steps. This provides a clear counterexample to the common hypothesis that a CPG and/or chaotic dynamics is required to explain the long-range correlations in healthy human walking. Instead, our results suggest that the long-range correlation may result from a combination of noise that is ubiquitous in biological systems and orbital stability that is essential in general rhythmic movements. PMID:24086274

Environmental conditions around itineraries to destinations as correlates of walking for transportation among adults: the RECORD cohort study.

PubMed

Karusisi, Noëlla; Thomas, Frédérique; Méline, Julie; Brondeel, Ruben; Chaix, Basile

2014-01-01

Assessing the contextual factors that influence walking for transportation is important to develop more walkable environments and promote physical activity. To advance previous research focused on residential environments and overall walking for transportation, the present study investigates objective environmental factors assessed around the residence, the workplace, the home--work itinerary, and the home--supermarket itinerary, and considered overall walking for transportation but also walking to work and to shops. Data from the RECORD Study involving 7290 participants recruited in 2007-2008, aged 30-79 years, and residing in the Paris metropolitan area were analyzed. Multilevel ordinal regression analyses were conducted to investigate environmental characteristics associated with self-reported overall walking for transportation, walking to work, and walking to shops. High individual education was associated with overall walking for transportation, with walking to work, and walking to shops. Among workers, a high residential neighborhood education was associated with increased overall walking for transportation, while a high workplace neighborhood education was related to an increased time spent walking to work. The residential density of destinations was positively associated with overall walking for transportation, with walking to work, and with walking to shops, while the workplace density of destinations was positively associated with overall walking for transportation among workers. Environmental factors assessed around the itineraries were not associated with walking to work or to the shops. This research improves our understanding of the role of the environments on walking for transportation by accounting for some of the environments visited beyond the residential neighborhood. It shows that workers' walking habits are more influenced by the density of destinations around the workplace than around the residence. These results provide insight for the development of policies and programs to encourage population level active commuting.

Compliance of children with moderate to severe intellectual disability to treadmill walking: a pilot study.

PubMed

Vashdi, E; Hutzler, Y; Roth, D

2008-05-01

Individuals with Intellectual Disability (ID) exhibit reduced levels of compliance to exercise, including treadmill walking. The purpose of this study was to measure the effects of several training conditions on compliance to participation in treadmill walking of children with moderate to severe ID. Criteria for compliance were the averaged number of times participants attempted to discontinue walking during two 5-min exercise sessions of treadmill walking at an intensity of 65-75% of predicted maximal HR. Fifteen children aged 5-11 with moderate to severe ID participated in the study. Training conditions were (a) close supervisor's position, (b) distant supervisor's position, (c) positive reinforcement, and (d) paired modeling. General linear mixed model statistics revealed significant differences in favor of the paired modeling and positive reinforcement compared to the other conditions. Leaning forward was the most frequent type of participants' attempt to stop exercising. Paired modeling and positive reinforcement should be considered within treadmill training programs for children with moderate to severe ID.

A Challenge-Based Approach to Body Weight-Supported Treadmill Training Poststroke: Protocol for a Randomized Controlled Trial.

PubMed

Naidu, Avantika; Brown, David; Roth, Elliot

2018-05-03

Body weight support treadmill training protocols in conjunction with other modalities are commonly used to improve poststroke balance and walking function. However, typical body weight support paradigms tend to use consistently stable balance conditions, often with handrail support and or manual assistance. In this paper, we describe our study protocol, which involved 2 unique body weight support treadmill training paradigms of similar training intensity that integrated dynamic balance challenges to help improve ambulatory function post stroke. The first paradigm emphasized walking without any handrails or manual assistance, that is, hands-free walking, and served as the control group, whereas the second paradigm incorporated practicing 9 essential challenging mobility skills, akin to environmental barriers encountered during community ambulation along with hands-free walking (ie hands-free + challenge walking). We recruited individuals with chronic poststroke hemiparesis and randomized them to either group. Participants trained for 6 weeks on a self-driven, robotic treadmill interface that provided body weight support and a safe gait-training environment. We assessed participants at pre-, mid- and post 6 weeks of intervention-training, with a 6-month follow-up. We hypothesized greater walking improvements in the hands-free + challenge walking group following training because of increased practice opportunity of essential mobility skills along with hands-free walking. We assessed 77 individuals with chronic hemiparesis, and enrolled and randomized 30 individuals poststroke for our study (hands-free group=19 and hands-free + challenge walking group=20) from June 2012 to January 2015. Data collection along with 6-month follow-up continued until January 2016. Our primary outcome measure is change in comfortable walking speed from pre to post intervention for each group. We will also assess feasibility, adherence, postintervention efficacy, and changes in various exploratory secondary outcome measures. Additionally, we will also assess participant responses to a study survey, conducted at the end of training week, to gauge each group's training experiences. Our treadmill training paradigms, and study protocol represent advances in standardized approaches to selecting body weight support levels without the necessity for using handrails or manual assistance, while progressively providing dynamic challenges for improving poststroke ambulatory function during rehabilitation. ClinicalTrials.gov NCT02787759; https://clinicaltrials.gov/ct2/show/NCT02787759 (Archived by Webcite at http://www.webcitation.org/6yJZCrIea). ©Avantika Naidu, David Brown, Elliot Roth. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 03.05.2018.

Walking for Well-Being: Are Group Walks in Certain Types of Natural Environments Better for Well-Being than Group Walks in Urban Environments?

PubMed Central

Marselle, Melissa R.; Irvine, Katherine N.; Warber, Sara L.

2013-01-01

The benefits of walking in natural environments for well-being are increasingly understood. However, less well known are the impacts different types of natural environments have on psychological and emotional well-being. This cross-sectional study investigated whether group walks in specific types of natural environments were associated with greater psychological and emotional well-being compared to group walks in urban environments. Individuals who frequently attended a walking group once a week or more (n = 708) were surveyed on mental well-being (Warwick Edinburgh Mental Well-being Scale), depression (Major Depressive Inventory), perceived stress (Perceived Stress Scale) and emotional well-being (Positive and Negative Affect Schedule). Compared to group walks in urban environments, group walks in farmland were significantly associated with less perceived stress and negative affect, and greater mental well-being. Group walks in green corridors were significantly associated with less perceived stress and negative affect. There were no significant differences between the effect of any environment types on depression or positive affect. Outdoor walking group programs could be endorsed through “green prescriptions” to improve psychological and emotional well-being, as well as physical activity. PMID:24173142

Multilevel lumbar fusion and postoperative physiotherapy rehabilitation in a patient with persistent pain.

PubMed

Pons, Tracey; Shipton, Edward A

2011-04-01

There are no comparative randomised controlled trials of physiotherapy modalities for chronic low back and radicular pain associated with multilevel fusion. Physiotherapy-based rehabilitation to control pain and improve activation levels for persistent pain following multilevel fusion can be challenging. This is a case report of a 68-year-old man who was referred for physiotherapy intervention 10 months after a multilevel spinal fusion for spinal stenosis. He reported high levels of persistent postoperative pain with minimal activity as a consequence of his pain following the surgery. The physiotherapy interventions consisted of three phases of rehabilitation starting with pool exercise that progressed to land-based walking. These were all combined with transcutaneous electrical nerve stimulation (TENS) that was used consistently for up to 8 hours per day. As outcome measures, daily pain levels and walking distances were charted once the pool programme was completed (in the third phase). Phase progression was determined by shuttle test results. The pain level was correlated with the distance walked using linear regression over a 5-day average. Over a 5-day moving average, the pain level reduced and walking distance increased. The chart of recorded pain level and walking distance showed a trend toward decreased pain with the increased distance walked. In a patient undergoing multilevel lumbar fusion, the combined use of TENS and a progressive walking programme (from pool to land) reduced pain and increased walking distance. This improvement was despite poor medication compliance and a reported high level of postsurgical pain.

The effect of a worksite based walking programme on cardiovascular risk in previously sedentary civil servants [NCT00284479].

PubMed

Murphy, Marie H; Murtagh, Elaine M; Boreham, Colin Ag; Hare, Lesley G; Nevill, Alan M

2006-05-22

A significant proportion of Europeans do not meet the recommendations for 30 mins of physical activity 5 times per week. Whether lower frequency, moderate intensity exercise alters cardiovascular disease (CVD) risk has received little attention. This study examined the effects of 45 minutes self-paced walking, 2 d. wk(-1) on aerobic fitness, blood pressure (BP), body composition, lipids and C-Reactive Protein (CRP) in previously sedentary civil servants. 37 subjects (24 women) aged 41.5 +/- 9.3 years were randomly assigned to either two 45 minute walks per week (walking group) or no training (control group). Aerobic fitness, body composition, blood pressure (BP), CRP and lipoprotein variables were measured at baseline and following 8 weeks. Steps counts were measured at baseline and during weeks 4 and 8 of the intervention. Compared to the control group, the walking group showed a significant reduction in systolic BP and maintained body fat levels (P < 0.05). There were no changes other risk factors. Subjects took significantly more steps on the days when prescribed walking was performed (9303 +/- 2665) compared to rest days (5803 +/- 2749; P < 0.001). These findings suggest that walking twice per week for 45 minutes at approximately 62% HRmax, improves activity levels, reduces systolic BP and prevents an increase in body fat in previously sedentary adults. This walking prescription, however, failed to induce significant improvements in other markers of cardiovascular disease risk following eight weeks of training.

Increasing the number of steps walked each day improves physical fitness in Japanese community-dwelling adults.

PubMed

Okamoto, N; Nakatani, T; Okamoto, Y; Iwamoto, J; Saeki, K; Kurumatani, N

2010-04-01

We aimed to investigate the effects of increasing the number of steps each day on physical fitness, and the change in physical fitness according to the angiotensin-converting enzyme (ACE) genotype. A total of 174 participants were randomly assigned to two groups. Subjects in group A were instructed for 24-week trial to increase the number of steps walked each day, while subjects in group B were instructed to engage in brisk walking, at a target heart rate, for 20 min or more a day on two or more days a week. The values of the 3-min shuttle stamina walk test (SSWT) and the 30-s chair-stand test (CS-30) significantly increased, but no differences in increase were found between the groups. A significant relationship was found between the percentage increase in SSWT values and the increase in the number of steps walked by 1 500 steps or more per day over their baseline values. Our results suggest that increasing the number of steps walked daily improves physical fitness. No significant relationships were observed between the change in physical fitness and ACE genotypes. Copyright Georg Thieme Verlag KG Stuttgart . New York.

Opportunities for Promoting Physical Activity in Rural Communities by Understanding the Interests and Values of Community Members.

PubMed

Park, Thomas; Eyler, Amy A; Tabak, Rachel G; Valko, Cheryl; Brownson, Ross C

2017-01-01

Physical activity (PA) has well-established health benefits, but most Americans do not meet national guidelines. In southeastern Missouri, trails have been developed to increase rates of PA. Although this has had success, broad-scale interventions will be needed to improve rates further. In this study, we surveyed residents of southeastern Missouri to identify ways to improve rates of PA. We conducted a telephone survey in 2015 of adults ( n = 524) from eight rural Missouri towns that had walking trails, regarding their activities and interests. Forty percent of respondents reported both walking and meeting PA recommendations, 29% reported walking but not meeting PA recommendations, and the remainder did not walk or did not answer. Respondents who used the trails were significantly more likely to meet PA recommendations (odds ratio = 2.7; 95% confidence interval = 1.7, 4.5). Certain values and interests that may encourage PA or draw people to trails were common. The group that walked but did not meet PA recommendations would be the ideal group to target for intervention, which could focus on their reported values and interests (e.g., personal relationships, being outdoors). Use of walking trails was associated with meeting PA recommendations.

The effect of rhythmic musical training on healthy older adults' gait and cognitive function.

PubMed

Maclean, Linda M; Brown, Laura J E; Astell, Arlene J

2014-08-01

Older adults' gait is disturbed when a demanding secondary cognitive task is added. Gait training has been shown to improve older adults' walking performance, but it is not clear how training affects their cognitive performance. This study examined the impact on gait, in terms of cost or benefit to cognitive performance, of training healthy older adults to walk to a rhythmic musical beat. In a mixed model design, 45 healthy older adults aged more than 65 years (M = 71.7 years) were randomly assigned to 3 groups. One group received a rhythmic musical training and their dual-task (DT) walking and cognitive performances were compared with a group who had music playing in the background but no training, and a third group who heard no music and received no training. Outcomes in single-task (ST) and DT conditions were step-time variability and velocity for gait and correct cognitive responses for the cognitive task. The Musical Training group's step-time variability improved in both the ST (p < .05) and the DT (p < .05) after training, without adversely affecting their cognitive performance. No change was seen in the control groups. Rhythmic musical training can improve gait steadiness in healthy older adults with no negative impact on concurrent cognitive functioning. This could potentially enhance "postural reserve" and reduce fall risk. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The effect of an arm sling used for shoulder support on gait efficiency in hemiplegic patients with stroke using walking aids.

PubMed

Jeong, Yeon-Gyu; Jeong, Yeon-Jae; Koo, Jung-Wan

2017-06-01

The effects of an arm sling on the physiological costs of walking are not known. Even though a previous study reported that an arm sling can improve gait efficiency, its entrance criteria was only hemiparetic patients able to walk without walking aids independently. The aim of this study was to investigate the effect of shoulder support by an arm sling on gait efficiency in hemiplegic stroke patients using walking aids. Randomized crossover design. Rehabilitation department of a university hospital. A total of 57 hemiplegic patients with shoulder subluxation dependent on canes were grouped into single cane (N.=30) and quad cane groups (N.=27) as walking aids. All patients performed a walk with their own walking aid with and without an arm sling in randomized order, on the same day. We measured the energy cost and energy expenditure using a portable gas analyzer and heart rate during a 6-minutes Walk Test and a 10-m Walk Test. We analyzed all outcomes measures with and without an arm sling between the patients who were grouped according to their walking aids using 2-way repeated ANOVA. The energy cost (0.068±0.023 mL/kg/m) and oxygen expenditure (8.609±2.155 mL/kg/minutes) were lower with the arm sling (P<0.05) than without the arm sling (0.074±0.029 mL/kg/m, and 9.109±2.406 mL/kg/minutes, respectively), and the walking endurance (138.942±47.043 m) were longer (P<0.05) with the arm sling among the hemiplegic patients with single cane. Among the hemiplegic patients with a single cane, the walking endurance achieved with an arm sling significantly improved than those achieved without an arm sling, and the energy expenditure and energy cost was significantly lower. The hemiplegic arm support with an arm sling may be beneficial for gait efficiency in hemiplegic patients using a single cane, which lead to decreased oxygen use at a given speed.

The Effect of Chinese Yuanji-Dance on Dynamic Balance and the Associated Attentional Demands in Elderly Adults

PubMed Central

Wu, Wen-Lan; Wei, Ta-Sen; Chen, Shen-Kai; Chang, Jyh-Jong; Guo, Lan-Yuen; Lin, Hwai-Ting

2010-01-01

Walking performance changes with age. This has implications for the problem of falls in older adults. The aim of this study was to investigate the effects of Yuanji-Dance practice on walking balance and the associated attention demand in healthy elderly. Fifteen community-dwelling elderly (comparison group, no regular exercise habit) and fifteen Yuanji- Dance elderly (exercise group, dancing experience: 5.40 ± 1.95 years), aged 60-70 years, were included in this study. The subjects in exercise group participated in a 90-minute Yuanji-Dance practice at least three times per week and the comparison group continued their normal daily physical activity. Walking balance measures (including walking velocity, step length, step width, and percentage of time spent in double limb support, COM velocity and COM-COP inclination angles) and attentional demand tests (button reaction time and accuracy) were conducted under different conditions. Our results showed that stride lengths, walking velocities, peak A/P velocities (AP V) of the COM, medial COM-COP inclination (M angle) angles, reaction time, and accuracy decrease significantly as the dual-task (walking plus hand button pressing tasks) applied for either the comparison or exercise groups. These results demonstrated that walking performance is attenuated in our elderly participants as the cognitive tasks applied. Analysis also identified a significantly faster RT for our exercise group both in standing and walking conditions. This may indicate that physical exercise (Yuanji-Dance) may have facilitating effects on general cognitive and perceptual- motor functions. This implies that Chinese Yuanji-Dance practice for elderly adults may improve their personal safety when walking especially under the condition of multiple task demand. Key points The purpose of this study was to investigate the training effects of a Chinese traditional exercise, Yuanji-Dance, on walking balance and the associated attention demand in the healthy elderly. Walking performance is attenuated in elderly participants as the cognitive tasks applied. A significantly faster reaction time for our exercise group both in standing and walking conditions. Yuanji-Dance exercise training can improve the information processing speed of elderly people and has no influence of the dynamic walking balance. PMID:24149395

5-HT2A receptor antagonists improve motor impairments in the MPTP mouse model of Parkinson's disease.

PubMed

Ferguson, Marcus C; Nayyar, Tultul; Deutch, Ariel Y; Ansah, Twum A

2010-01-01

Clinical observations have suggested that ritanserin, a 5-HT(2A/C) receptor antagonist may reduce motor deficits in persons with Parkinson's Disease (PD). To better understand the potential antiparkinsonian actions of ritanserin, we compared the effects of ritanserin with the selective 5-HT(2A) receptor antagonist M100907 and the selective 5-HT(2C) receptor antagonist SB 206553 on motor impairments in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP-treated mice exhibited decreased performance on the beam-walking apparatus. These motor deficits were reversed by acute treatment with L-3,4-dihydroxyphenylalanine (levodopa). Both the mixed 5-HT(2A/C) antagonist ritanserin and the selective 5-HT(2A) antagonist M100907 improved motor performance on the beam-walking apparatus. In contrast, SB 206553 was ineffective in improving the motor deficits in MPTP-treated mice. These data suggest that 5-HT(2A) receptor antagonists may represent a novel approach to ameliorate motor symptoms of Parkinson's disease. Published by Elsevier Ltd.

5-HT2A receptor antagonists improve motor impairments in the MPTP mouse model of Parkinson's disease

PubMed Central

Ferguson, Marcus C.; Nayyar, Tultul; Deutch, Ariel Y.; Ansah, Twum A.

2010-01-01

Clinical observations have suggested that ritanserin, a 5-HT2A/C receptor antagonist may reduce motor deficits in persons with Parkinson's Disease (PD). To better understand the potential antiparkinsonian actions of ritanserin, we compared the effects of ritanserin with the selective 5-HT2A receptor antagonist M100907 and the selective 5-HT2C receptor antagonist SB 206553 on motor impairments in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP-treated mice exhibited decreased performance on the beam-walking apparatus. These motor deficits were reversed by acute treatment with L-3,4-dihydroxyphenylalanine (levodopa). Both the mixed 5-HT2A/C antagonist ritanserin and the selective 5-HT2A antagonist M100907 improved motor performance on the beam-walking apparatus. In contrast, SB 206553 was ineffective in improving the motor deficits in MPTP-treated mice. These data suggest that 5-HT2A receptor antagonists may represent a novel approach to ameliorate motor symptoms of Parkinson's disease. PMID:20361986

Multimedia Exercise Training Program Improves Distance Walked, Heart Rate Recovery, and Self-efficacy in Cardiac Surgery Patients.

PubMed

Wang, Li-Wei; Ou, Shu-Hua; Tsai, Chien-Sung; Chang, Yue-Cune; Kao, Chi-Wen

2016-01-01

Patient education has been shown to be more effective when delivered using multimedia than written materials. However, the effects of using multimedia to assist patients in cardiac rehabilitation have not been investigated. The purpose of this study is to examine the effect of an inpatient multimedia exercise training program on distance walked in the 6-minute walking test (6MWT), heart rate recovery, and walking self-efficacy of patients who had undergone heart surgery. For this longitudinal quasi-experimental study, 60 consecutive patients were assigned to an experimental (n = 20; inpatient multimedia exercise training program) or control (n = 40; routine care) group. Data were collected at 3 times (before surgery, 1 to 2 days before hospital discharge, and 1 month after hospital discharge) and analyzed with the generalized estimating equation approach. Most subjects were men (66.7%), had a mean age of 61.32 ± 13.4 years and left ventricular ejection fraction of 56.96% ± 13.28%, and underwent coronary artery bypass graft surgery (n = 34, 56.7%). Subjects receiving the exercise training program showed significantly greater improvement than those in the control group in the 6MWT walking distance (P < .001), heart rate recovery (P = .04), and self-efficacy (P = .002) at hospital discharge. Furthermore, the intervention effects on 6MWT distance (P < .001) and self-efficacy (P < .001) were sustained at 1 month after hospital discharge. Our inpatient multimedia exercise training program safely improved distance walked in the 6MWT, heart rate recovery, and self-efficacy at hospital discharge in patients after heart surgery and maintained their improvement in 6MWT and self-efficacy 1 month later.

Does dual task training improve walking performance of older adults with concern of falling?

PubMed

Wollesen, B; Schulz, S; Seydell, L; Delbaere, K

2017-09-11

Older adults with concerns of falling show decrements of gait stability under single (ST) and dual task (DT) conditions. To compare the effects of a DT training integrating task managing strategies for independent living older adults with and without concern about falling (CoF) to a non-training control group on walking performance under ST and DT conditions. Single center parallel group single blind randomized controlled trial with group-based interventions (DT-managing balance training) compared to a control group (Ninety-five independent living older adults; 71.5 ± 5.2 years). A progressive DT training (12 sessions; 60 min each; 12 weeks) including task-managing strategies was compared to a non-training control group. group based intervention for independent living elderly in a gym. ST and DT walking (visual verbal Stroop task) were measured on a treadmill. Gait parameters (step length, step width, and gait line) and cognitive performance while walking were compared with a 2x2x2 Repeated Measures Analyses of Variance. Participants in the intervention group showed an increased step length under ST and DT conditions following the intervention, for both people with and without CoF compared to their respective control groups. Foot rolling movement and cognitive performance while walking however only improved in participants without CoF. The results showed that DT managing training can improve walking performance under ST and DT conditions in people with and without CoF. Additional treatment to directly address CoF, such as cognitive behavioural therapy, should be considered to further improve the cautious gait pattern (as evidenced by reduced foot rolling movements). The study was retrospectively registered in the German Clinical Trials Register (DRKS; Identification number DRKS00012382 , 11.05.2017).

Robotic Resistance Treadmill Training Improves Locomotor Function in Children With Cerebral Palsy: A Randomized Controlled Pilot Study.

PubMed

Wu, Ming; Kim, Janis; Gaebler-Spira, Deborah J; Schmit, Brian D; Arora, Pooja

2017-11-01

To determine whether applying controlled resistance forces to the legs during the swing phase of gait may improve the efficacy of treadmill training as compared with applying controlled assistance forces in children with cerebral palsy (CP). Randomized controlled study. Research unit of a rehabilitation hospital. Children with spastic CP (N=23; mean age, 10.6y; range, 6-14y; Gross Motor Function Classification System levels, I-IV). Participants were randomly assigned to receive controlled assistance (n=11) or resistance (n=12) loads applied to the legs at the ankle. Participants underwent robotic treadmill training 3 times a week for 6 weeks (18 sessions). A controlled swing assistance/resistance load was applied to both legs starting from the toe-off to mid-swing phase of gait during training. Outcome measures consisted of overground walking speed, 6-minute walk distance, and Gross Motor Function Measure scores and were assessed pre and post 6 weeks of training and 8 weeks after the end of training. After 6 weeks of treadmill training in participants from the resistance training group, fast walking speed and 6-minute walk distance significantly improved (18% and 30% increases, respectively), and 6-minute walk distance was still significantly greater than that at baseline (35% increase) 8 weeks after the end of training. In contrast, overground gait speed and 6-minute walk distance had no significant changes after robotic assistance training. The results of the present study indicated that robotic resistance treadmill training is more effective than assistance training in improving locomotor function in children with CP. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Unexpected perturbations training improves balance control and voluntary stepping times in older adults - a double blind randomized control trial.

PubMed

Kurz, Ilan; Gimmon, Yoav; Shapiro, Amir; Debi, Ronen; Snir, Yoram; Melzer, Itshak

2016-03-04

Falls are common among elderly, most of them occur while slipping or tripping during walking. We aimed to explore whether a training program that incorporates unexpected loss of balance during walking able to improve risk factors for falls. In a double-blind randomized controlled trial 53 community dwelling older adults (age 80.1±5.6 years), were recruited and randomly allocated to an intervention group (n = 27) or a control group (n = 26). The intervention group received 24 training sessions over 3 months that included unexpected perturbation of balance exercises during treadmill walking. The control group performed treadmill walking with no perturbations. The primary outcome measures were the voluntary step execution times, traditional postural sway parameters and Stabilogram-Diffusion Analysis. The secondary outcome measures were the fall efficacy Scale (FES), self-reported late life function (LLFDI), and Performance-Oriented Mobility Assessment (POMA). Compared to control, participation in intervention program that includes unexpected loss of balance during walking led to faster Voluntary Step Execution Times under single (p = 0.002; effect size [ES] =0.75) and dual task (p = 0.003; [ES] = 0.89) conditions; intervention group subjects showed improvement in Short-term Effective diffusion coefficients in the mediolateral direction of the Stabilogram-Diffusion Analysis under eyes closed conditions (p = 0.012, [ES] = 0.92). Compared to control there were no significant changes in FES, LLFDI, and POMA. An intervention program that includes unexpected loss of balance during walking can improve voluntary stepping times and balance control, both previously reported as risk factors for falls. This however, did not transferred to a change self-reported function and FES. ClinicalTrials.gov NCT01439451 .

A random-walk/giant-loop model for interphase chromosomes.

PubMed Central

Sachs, R K; van den Engh, G; Trask, B; Yokota, H; Hearst, J E

1995-01-01

Fluorescence in situ hybridization data on distances between defined genomic sequences are used to construct a quantitative model for the overall geometric structure of a human chromosome. We suggest that the large-scale geometry during the G0/G1 part of the cell cycle may consist of flexible chromatin loops, averaging approximately 3 million bp, with a random-walk backbone. A fully explicit, three-parametric polymer model of this random-walk/giant-loop structure can account well for the data. More general models consistent with the data are briefly discussed. PMID:7708711

Walking model with no energy cost.

PubMed

Gomes, Mario; Ruina, Andy

2011-03-01

We have numerically found periodic collisionless motions of a walking model consisting of linked rigid objects. Unlike previous designs, this model can walk on level ground at noninfinitesimal speed with zero energy input. The model avoids collisional losses by using an internal mode of oscillation: swaying of the upper body coupled to the legs by springs. Appropriate synchronized internal oscillations set the foot-strike collision to zero velocity. The concept might be of use for energy-efficient robots and may also help to explain aspects of human and animal locomotion efficiency.

Feasibility and Safety of a Powered Exoskeleton for Assisted Walking for Persons With Multiple Sclerosis: A Single-Group Preliminary Study.

PubMed

Kozlowski, Allan J; Fabian, Michelle; Lad, Dipan; Delgado, Andrew D

2017-07-01

To examine the feasibility, safety, and secondary benefit potential of exoskeleton-assisted walking with one device for persons with multiple sclerosis (MS). Single-group longitudinal preliminary study with 8-week baseline, 8-week intervention, and 4-week follow-up. Outpatient MS clinic, tertiary care hospital. Participants (N=13; age range, 38-62y) were mostly women with Expanded Disability Status Scale scores ranging from 5.5 to 7.0. Exoskeleton-assisted walk training. Primary outcomes were accessibility (enrollment/screen pass), tolerability (completion/dropout), learnability (time to event for standing, walking, and sitting with little or no assistance), acceptability (satisfaction on the device subscale of the Quebec User Evaluation of Satisfaction with Assistive Technology version 2), and safety (event rates standardized to person-time exposure in the powered exoskeleton). Secondary outcomes were walking without the device (timed 25-foot walk test and 6-minute walk test distance), spasticity (Modified Ashworth Scale), and health-related quality of life (Patient-Reported Outcomes Measurement and Information System pain interference and Quality of Life in Neurological Conditions fatigue, sleep disturbance, depression, and positive affect and well-being). The device was accessible to 11 and tolerated by 5 participants. Learnability was moderate, with 5 to 15 sessions required to walk with minimal assistance. Safety was good; the highest adverse event rate was for skin issues at 151 per 1000 hours' exposure. Acceptability ranged from not very satisfied to very satisfied. Participants who walked routinely improved qualitatively on sitting, standing, or walking posture. Two participants improved and 2 worsened on ≥1 quality of life domain. The pattern of spasticity scores may indicate potential benefit. The device appeared feasible and safe for about a third of our sample, for whom routine exoskeleton-assisted walking may offer secondary benefits. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Adults' Daily Walking for Travel and Leisure: Interaction Between Attitude Toward Walking and the Neighborhood Environment.

PubMed

Yang, Yong; Diez-Roux, Ana V

2017-09-01

Studies on how the interaction of psychological and environmental characteristics influences walking are limited, and the results are inconsistent. Our aim is to examine how the attitude toward walking and neighborhood environments interacts to influence walking. Cross-sectional phone and mail survey. Participants randomly sampled from 6 study sites including Los Angeles, Chicago, Baltimore, Minneapolis, Manhattan, and Bronx Counties in New York City, and Forsyth and Davidson Counties in North Carolina. The final sample consisted of 2621 persons from 2011 to 2012. Total minutes of walking for travel or leisure, attitude toward walking, and perceptions of the neighborhood environments were self-reported. Street Smart (SS) Walk Score (a measure of walkability derived from a variety of geographic data) was obtained for each residential location. Linear regression models adjusting for age, gender, race/ethnicity, education, and income. Attitude toward walking was positively associated with walking for both purposes. Walking for travel was significantly associated with SS Walk Score, whereas walking for leisure was not. The SS Walk Score and selected perceived environment characteristics were associated with walking in people with a very positive attitude toward walking but were not associated with walking in people with a less positive attitude. Attitudes toward walking and neighborhood environments interact to affect walking behavior.

An Applied Ecological Framework for Evaluating Infrastructure to Promote Walking and Cycling: The iConnect Study

PubMed Central

Bull, Fiona; Powell, Jane; Cooper, Ashley R.; Brand, Christian; Mutrie, Nanette; Preston, John; Rutter, Harry

2011-01-01

Improving infrastructure for walking and cycling is increasingly recommended as a means to promote physical activity, prevent obesity, and reduce traffic congestion and carbon emissions. However, limited evidence from intervention studies exists to support this approach. Drawing on classic epidemiological methods, psychological and ecological models of behavior change, and the principles of realistic evaluation, we have developed an applied ecological framework by which current theories about the behavioral effects of environmental change may be tested in heterogeneous and complex intervention settings. Our framework guides study design and analysis by specifying the most important data to be collected and relations to be tested to confirm or refute specific hypotheses and thereby refine the underlying theories. PMID:21233429

Using Virtual Reality to Improve Walking Post-Stroke: Translation to Individuals with Diabetes

PubMed Central

Deutsch, Judith E

2011-01-01

Use of virtual reality (VR) technology to improve walking for people post-stroke has been studied for its clinical application since 2004. The hardware and software used to create these systems has varied but has predominantly been constituted by projected environments with users walking on treadmills. Transfer of training from the virtual environment to real-world walking has modest but positive research support. Translation of the research findings to clinical practice has been hampered by commercial availability and costs of the VR systems. Suggestions for how the work for individuals post-stroke might be applied and adapted for individuals with diabetes and other impaired ambulatory conditions include involvement of the target user groups (both practitioners and clients) early in the design and integration of activity and education into the systems. PMID:21527098

Using virtual reality to improve walking post-stroke: translation to individuals with diabetes.

PubMed

Deutsch, Judith E

2011-03-01

Use of virtual reality (VR) technology to improve walking for people post-stroke has been studied for its clinical application since 2004. The hardware and software used to create these systems has varied but has predominantly been constituted by projected environments with users walking on treadmills. Transfer of training from the virtual environment to real-world walking has modest but positive research support. Translation of the research findings to clinical practice has been hampered by commercial availability and costs of the VR systems. Suggestions for how the work for individuals post-stroke might be applied and adapted for individuals with diabetes and other impaired ambulatory conditions include involvement of the target user groups (both practitioners and clients) early in the design and integration of activity and education into the systems. © 2011 Diabetes Technology Society.

Exergame and Balance Training Modulate Prefrontal Brain Activity during Walking and Enhance Executive Function in Older Adults

PubMed Central

Eggenberger, Patrick; Wolf, Martin; Schumann, Martina; de Bruin, Eling D.

2016-01-01

Different types of exercise training have the potential to induce structural and functional brain plasticity in the elderly. Thereby, functional brain adaptations were observed during cognitive tasks in functional magnetic resonance imaging studies that correlated with improved cognitive performance. This study aimed to investigate if exercise training induces functional brain plasticity during challenging treadmill walking and elicits associated changes in cognitive executive functions. Forty-two elderly participants were recruited and randomly assigned to either interactive cognitive-motor video game dancing (DANCE) or balance and stretching training (BALANCE). The 8-week intervention included three sessions of 30 min per week and was completed by 33 participants (mean age 74.9 ± 6.9 years). Prefrontal cortex (PFC) activity during preferred and fast walking speed on a treadmill was assessed applying functional near infrared spectroscopy pre- and post-intervention. Additionally, executive functions comprising shifting, inhibition, and working memory were assessed. The results showed that both interventions significantly reduced left and right hemispheric PFC oxygenation during the acceleration of walking (p < 0.05 or trend, r = 0.25–0.36), while DANCE showed a larger reduction at the end of the 30-s walking task compared to BALANCE in the left PFC [F(1, 31) = 3.54, p = 0.035, r = 0.32]. These exercise training induced modulations in PFC oxygenation correlated with improved executive functions (p < 0.05 or trend, r = 0.31–0.50). The observed reductions in PFC activity may release cognitive resources to focus attention on other processes while walking, which could be relevant to improve mobility and falls prevention in the elderly. This study provides a deeper understanding of the associations between exercise training, brain function during walking, and cognition in older adults. PMID:27148041

Regular walking improves plasma protein concentrations that promote blood hyperviscosity in women 65-74 yr with type 2 diabetes.

PubMed

Simmonds, Michael J; Sabapathy, Surendran; Serre, Kevin R; Haseler, Luke J; Gass, Gregory C; Marshall-Gradisnik, Sonya M; Minahan, Clare L

2016-11-25

The purpose of the present study was to investigate the effects of regular treadmill walking on plasma factors that increase low-shear blood viscosity and red blood cell aggregation in older women with type 2 diabetes. Eighteen women with type 2 diabetes (age: 69±3 yr; body mass index: 30.5±5.0 kg⋅m-2) performed 12-wk of 120 min⋅wk-1 of supervised treadmill walking at an intensity equivalent to the gas-exchange threshold. Peak exercise values, anthropometry and blood indices of diabetic status, markers of inflammation, and plasma fibrinogen were analysed during a 6-wk pre-training 'control' period, and then after 6 and 12-wk of regular walking. Regular walking significantly increased peak oxygen uptake (p = 0.01). Body mass, waist to hip ratio, and glycaemic control did not change. Systolic and diastolic blood pressures decreased by 8.5% (p < 0.01) and 7.2% (p < 0.01) respectively, cholesterol to high-density lipoprotein (HDL) ratio decreased by 9.6% (p = 0.01), and HDL concentration significantly increased (p = 0.01). While 12 wk of regular walking did not significantly alter plasma concentrations of interleukin-6 (IL-6), tumour necrosis factor-α, or C-reactive protein, plasma fibrinogen concentration decreased by 6.9% (p < 0.01) and plasma interleukin-10 (IL-10) concentration increased from 1.15±0.32 to 1.62±0.22 mmol⋅L-1 (p < 0.04). Improved plasma inflammatory profile and decreased plasma fibrinogen concentration is induced by regular walking, independent of glycaemic control. These factors may mediate the improved haemorheology associated with exercise training in metabolic disorders.

Oxygen consumption, oxygen cost, heart rate, and perceived effort during split-belt treadmill walking in young healthy adults.

PubMed

Roper, Jaimie A; Stegemöller, Elizabeth L; Tillman, Mark D; Hass, Chris J

2013-03-01

During split-belt treadmill walking the speed of the treadmill under one limb is faster than the belt under the contralateral limb. This unique intervention has shown evidence of acutely improving gait impairments in individuals with neurologic impairment such as stroke and Parkinson's disease. However, oxygen use, heart rate and perceived effort associated with split-belt treadmill walking are unknown and may limit the utility of this locomotor intervention. To better understand the intensity of this new intervention, this study was undertaken to examine the oxygen consumption, oxygen cost, heart rate, and rating of perceived exertion associated with split-belt treadmill walking in young healthy adults. Fifteen participants completed three sessions of treadmill walking: slow speed with belts tied, fast speed with belts tied, and split-belt walking with one leg walking at the fast speed and one leg walking at the slow speed. Oxygen consumption, heart rate, and rating of perceived exertion were collected during each walking condition and oxygen cost was calculated. Results revealed that oxygen consumption, heart rate, and perceived effort associated with split-belt walking were higher than slow treadmill walking, but only oxygen consumption was significantly lower during both split-belt walking than fast treadmill walking. Oxygen cost associated with slow treadmill walking was significantly higher than fast treadmill walking. These findings have implications for using split-belt treadmill walking as a rehabilitation tool as the cost associated with split-belt treadmill walking may not be higher or potentially more detrimental than that associated with previously used treadmill training rehabilitation strategies.

Walking for Transportation: What do U.S. Adults Think is a Reasonable Distance and Time?

PubMed Central

Watson, Kathleen B; Carlson, Susan A; Humbert-Rico, Tiffany; Carroll, Dianna D.; Fulton, Janet E

2015-01-01

Background Less than one-third of U.S. adults walk for transportation. Public health strategies to increase transportation walking would benefit from knowing what adults think is a reasonable distance to walk. Our purpose was to determine (1) what adults think is a reasonable distance and amount of time to walk and (2) whether there were differences in minutes spent transportation walking by what adults think is reasonable. Methods Analyses used a cross-sectional nationwide adult sample (n=3,653) participating in the 2010 Summer ConsumerStyles mail survey. Results Most adults (>90%) think transportation walking is reasonable. However, less than half (43%) think walking a mile or more or for 20 minutes or more is reasonable. What adults think is reasonable is similar across most demographic subgroups, except for older adults (≥ 65 years) who think shorter distances and times are reasonable. Trend analysis that adjust for demographic characteristics indicates adults who think longer distances and times are reasonable walk more. Conclusions Walking for short distances is acceptable to most U.S. adults. Public health programs designed to encourage longer distance trips may wish to improve supports for transportation walking to make walking longer distances seem easier and more acceptable to most U.S. adults. PMID:25158016

Walking for Transportation: What do U.S. Adults Think is a Reasonable Distance and Time?

PubMed

Watson, Kathleen B; Carlson, Susan A; Humbert-Rico, Tiffany; Carroll, Dianna D; Fulton, Janet E

2015-06-16

Less than one-third of U.S. adults walk for transportation. Public health strategies to increase transportation walking would benefit from knowing what adults think is a reasonable distance to walk. Our purpose was to determine 1) what adults think is a reasonable distance and amount of time to walk and 2) whether there were differences in minutes spent transportation walking by what adults think is reasonable. Analyses used a cross-sectional nationwide adult sample (n = 3653) participating in the 2010 Summer ConsumerStyles mail survey. Most adults (> 90%) think transportation walking is reasonable. However, less than half (43%) think walking a mile or more or for 20 minutes or more is reasonable. What adults think is reasonable is similar across most demographic subgroups, except for older adults (≥ 65 years) who think shorter distances and times are reasonable. Trend analysis that adjust for demographic characteristics indicates adults who think longer distances and times are reasonable walk more. Walking for short distances is acceptable to most U.S. adults. Public health programs designed to encourage longer distance trips may wish to improve supports for transportation walking to make walking longer distances seem easier and more acceptable to most U.S. adults.

Walking performance and muscle strength in the later stage poststroke: a nonlinear relationship.

PubMed

Carvalho, Cristiane; Sunnerhagen, Katharina S; Willén, Carin

2013-05-01

To evaluate the relation between muscle strength in the lower extremities and walking performance (speed and distance) in subjects in the later stage poststroke and to compare this with normative data. A cross-sectional observational study. University hospital department. Subjects poststroke (n=41; 31 men, 10 women) with a mean age of 59±5.8 years and a time from stroke onset of 52±36 months were evaluated. An urban sample (n=144) of 40- to 79-year-olds (69 men, 75 women) formed the healthy reference group. Not applicable. Muscle strength in the lower extremities was measured with an isokinetic dynamometer and combined into a strength index. Values for the 30-meter walk test for self-selected and maximum speed and the 6-minute walk test were measured. A nonlinear regression model was used. The average strength index was 730±309 in the subjects after stroke compared with 1112±362 in the healthy group. A nonlinear relation between walking performance and muscle strength was evident. The model explained 37% of the variance in self-selected speed in the stroke group and 20% in the healthy group, and 63% and 38%, respectively, in the maximum walking speed. For the 6-minute walk test, the model explained 44% of the variance in the stroke group. Subjects in the later stage poststroke were weaker than the healthy reference group, and their weakness was associated with walking performance. At the same strength index, subjects walked at lower speeds and shorter distances after stroke, indicating that there are multiple impairments that affect walking ability. Treatments focused on increasing muscle strength thus continue to hold promise. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Preferred gait and walk-run transition speeds in ostriches measured using GPS-IMU sensors.

PubMed

Daley, Monica A; Channon, Anthony J; Nolan, Grant S; Hall, Jade

2016-10-15

The ostrich (Struthio camelus) is widely appreciated as a fast and agile bipedal athlete, and is a useful comparative bipedal model for human locomotion. Here, we used GPS-IMU sensors to measure naturally selected gait dynamics of ostriches roaming freely over a wide range of speeds in an open field and developed a quantitative method for distinguishing walking and running using accelerometry. We compared freely selected gait-speed distributions with previous laboratory measures of gait dynamics and energetics. We also measured the walk-run and run-walk transition speeds and compared them with those reported for humans. We found that ostriches prefer to walk remarkably slowly, with a narrow walking speed distribution consistent with minimizing cost of transport (CoT) according to a rigid-legged walking model. The dimensionless speeds of the walk-run and run-walk transitions are slower than those observed in humans. Unlike humans, ostriches transition to a run well below the mechanical limit necessitating an aerial phase, as predicted by a compass-gait walking model. When running, ostriches use a broad speed distribution, consistent with previous observations that ostriches are relatively economical runners and have a flat curve for CoT against speed. In contrast, horses exhibit U-shaped curves for CoT against speed, with a narrow speed range within each gait for minimizing CoT. Overall, the gait dynamics of ostriches moving freely over natural terrain are consistent with previous lab-based measures of locomotion. Nonetheless, ostriches, like humans, exhibit a gait-transition hysteresis that is not explained by steady-state locomotor dynamics and energetics. Further study is required to understand the dynamics of gait transitions. © 2016. Published by The Company of Biologists Ltd.

Does visual feedback during walking result in similar improvements in trunk control for young and older healthy adults?

PubMed

Anson, Eric; Rosenberg, Russell; Agada, Peter; Kiemel, Tim; Jeka, John

2013-11-26

Most current applications of visual feedback to improve postural control are limited to a fixed base of support and produce mixed results regarding improved postural control and transfer to functional tasks. Currently there are few options available to provide visual feedback regarding trunk motion while walking. We have developed a low cost platform to provide visual feedback of trunk motion during walking. Here we investigated whether augmented visual position feedback would reduce trunk movement variability in both young and older healthy adults. The subjects who participated were 10 young and 10 older adults. Subjects walked on a treadmill under conditions of visual position feedback and no feedback. The visual feedback consisted of anterior-posterior (AP) and medial-lateral (ML) position of the subject's trunk during treadmill walking. Fourier transforms of the AP and ML trunk kinematics were used to calculate power spectral densities which were integrated as frequency bins "below the gait cycle" and "gait cycle and above" for analysis purposes. Visual feedback reduced movement power at very low frequencies for lumbar and neck translation but not trunk angle in both age groups. At very low frequencies of body movement, older adults had equivalent levels of movement variability with feedback as young adults without feedback. Lower variability was specific to translational (not angular) trunk movement. Visual feedback did not affect any of the measured lower extremity gait pattern characteristics of either group, suggesting that changes were not invoked by a different gait pattern. Reduced translational variability while walking on the treadmill reflects more precise control maintaining a central position on the treadmill. Such feedback may provide an important technique to augment rehabilitation to minimize body translation while walking. Individuals with poor balance during walking may benefit from this type of training to enhance path consistency during over-ground locomotion.

"On" freezing in Parkinson's disease: resistance to visual cue walking devices.

PubMed

Kompoliti, K; Goetz, C G; Leurgans, S; Morrissey, M; Siegel, I M

2000-03-01

To measure "on" freezing during unassisted walking (UW) and test if two devices, a modified inverted stick (MIS) and a visual laser beam stick (LBS) improved walking speed and number of "on" freezing episodes in patients with Parkinson's disease (PD). Multiple visual cues can overcome "off' freezing episodes and can be useful in improving gait function in parkinsonian patients. These devices have not been specifically tested in "on" freezing, which is unresponsive to pharmacologic manipulations. Patients with PD, motor fluctuations and freezing while "on," attempted walking on a 60-ft track with each of three walking conditions in a randomized order: UW, MIS, and LBS. Total time to complete a trial, number of freezes, and the ratio of walking time to the number of freezes were compared using Friedman's test. Twenty-eight patients with PD, mean age 67.81 years (standard deviation [SD] 7.54), mean disease duration 13.04 years (SD 7.49), and mean motor Unified Parkinson's Disease Rating Scale score "on" 32.59 (SD 10.93), participated in the study. There was a statistically significant correlation of time needed to complete a trial and number of freezes for all three conditions (Spearman correlations: UW 0.973, LBS 0.0.930, and MIS 0.842). The median number of freezes, median time to walk in each condition, and median walking time per freeze were not significantly different in pairwise comparisons of the three conditions (Friedman's test). Of the 28 subjects, six showed improvement with the MIS and six with the LBS in at least one outcome measure. Assisting devices, specifically based on visual cues, are not consistently beneficial in overcoming "on" freezing in most patients with PD. Because this is an otherwise untreatable clinical problem and because occasional subjects do respond, cautious trials of such devices under the supervision of a health professional should be conducted to identify those patients who might benefit from their long-term use.

Can Dual Task Walking Improve in Parkinson's Disease After External Focus of Attention Exercise? A Single Blind Randomized Controlled Trial.

PubMed

Beck, Eric N; Intzandt, Brittany N; Almeida, Quincy J

2018-01-01

It may be possible to use attention-based exercise to decrease demands associated with walking in Parkinson's disease (PD), and thus improve dual task walking ability. For example, an external focus of attention (focusing on the effect of an action on the environment) may recruit automatic control processes degenerated in PD, whereas an internal focus (limb movement) may recruit conscious (nonautomatic) control processes. Thus, we aimed to investigate how externally and internally focused exercise influences dual task walking and symptom severity in PD. Forty-seven participants with PD were randomized to either an Externally (n = 24) or Internally (n = 23) focused group and completed 33 one-hour attention-based exercise sessions over 11 weeks. In addition, 16 participants were part of a control group. Before, after, and 8 weeks following the program (pre/post/washout), gait patterns were measured during single and dual task walking (digit-monitoring task, ie, walking while counting numbers announced by an audio-track), and symptom severity (UPDRS-III) was assessed ON and OFF dopamine replacement. Pairwise comparisons (95% confidence intervals [CIs]) and repeated-measures analyses of variance were conducted. Pre to post: Dual task step time decreased in the external group (Δ = 0.02 seconds, CI 0.01-0.04). Dual task step length (Δ = 2.3 cm, CI 0.86-3.75) and velocity (Δ = 4.5 cm/s, CI 0.59-8.48) decreased (became worse) in the internal group. UPDRS-III scores (ON and OFF) decreased (improved) in only the External group. Pre to washout: Dual task step time ( P = .005) and percentage in double support ( P = .014) significantly decreased (improved) in both exercise groups, although only the internal group increased error on the secondary counting task (ie, more errors monitoring numbers). UPDRS-III scores in both exercise groups significantly decreased ( P = .001). Since dual task walking improvements were found immediately, and 8 weeks after the cessation of an externally focused exercise program, we conclude that externally focused exercise may improve on functioning of automatic control networks in PD. Internally focused exercise hindered dual tasking ability. Overall, externally focused exercise led to greater rehabilitation benefits in dual tasking and motor symptoms compared with internally focused exercise.

Immersive Virtual Reality to Improve Walking Abilities in Cerebral Palsy: A Pilot Study.

PubMed

Gagliardi, Chiara; Turconi, Anna Carla; Biffi, Emilia; Maghini, Cristina; Marelli, Alessia; Cesareo, Ambra; Diella, Eleonora; Panzeri, Daniele

2018-04-27

Immersive virtual reality (IVR) offers new possibilities to perform treatments in an ecological and interactive environment with multimodal online feedbacks. Sixteen school-aged children (mean age 11 ± 2.4 years) with Bilateral CP-diplegia, attending mainstream schools were recruited for a pilot study in a pre-post treatment experimental design. The intervention was focused on walking competences and endurance and performed by the Gait Real-time Analysis Interactive Lab (GRAIL), an innovative treadmill platform based on IVR. The participants underwent eighteen therapy sessions in 4 weeks. Functional evaluations, instrumental measures including GAIT analysis and parental questionnaire were utilized to assess the treatment effects. Walking pattern (stride length left and right side, respectively p = 0.001 and 0.003; walking speed p = 0.001), endurance (6MWT, p = 0.026), gross motor abilities (GMFM-88, p = 0.041) and most kinematic and kinetic parameters significantly improved after the intervention. The changes were mainly predicted by age and cognitive abilities. The effect could have been due to the possibility of IVR to foster integration of motor/perceptual competences beyond the training of the walking ability, giving a chance of improvement also to older and already treated children.

Treadmill Training with HAL Exoskeleton-A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy-Preliminary Study.

PubMed

Sczesny-Kaiser, Matthias; Kowalewski, Rebecca; Schildhauer, Thomas A; Aach, Mirko; Jansen, Oliver; Grasmücke, Dennis; Güttsches, Anne-Katrin; Vorgerd, Matthias; Tegenthoff, Martin

2017-01-01

Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb) can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD). Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT), 6-minute walk test, and timed-up-and-go test (TUG). Parameters were assessed pre and post training and 6 weeks later (follow-up). Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up). Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies.

Treadmill Training with HAL Exoskeleton—A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy—Preliminary Study

PubMed Central

Sczesny-Kaiser, Matthias; Kowalewski, Rebecca; Schildhauer, Thomas A.; Aach, Mirko; Jansen, Oliver; Grasmücke, Dennis; Güttsches, Anne-Katrin; Vorgerd, Matthias; Tegenthoff, Martin

2017-01-01

Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb) can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD). Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT), 6-minute walk test, and timed-up-and-go test (TUG). Parameters were assessed pre and post training and 6 weeks later (follow-up). Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up). Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies. PMID:28848377

Chaotic Model for Lévy Walks in Swarming Bacteria

NASA Astrophysics Data System (ADS)

Ariel, Gil; Be'er, Avraham; Reynolds, Andy

2017-06-01

We describe a new mechanism for Lévy walks, explaining the recently observed superdiffusion of swarming bacteria. The model hinges on several key physical properties of bacteria, such as an elongated cell shape, self-propulsion, and a collectively generated regular vortexlike flow. In particular, chaos and Lévy walking are a consequence of group dynamics. The model explains how cells can fine-tune the geometric properties of their trajectories. Experiments confirm the spectrum of these patterns in fluorescently labeled swarming Bacillus subtilis.

Uphill and Downhill Walking in Multiple Sclerosis

PubMed Central

Samaei, Afshin; Hajihasani, Abdolhamid; Fatemi, Elham; Motaharinezhad, Fatemeh

2016-01-01

Background: Various exercise protocols have been recommended for patients with multiple sclerosis (MS). We investigated the effects of uphill and downhill walking exercise on mobility, functional activities, and muscle strength in MS patients. Methods: Thirty-four MS patients were randomly allocated to either the downhill or uphill treadmill walking group for 12 sessions (3 times/wk) of 30 minutes' walking on a 10% negative slope (n = 17) or a 10% positive slope (n = 17), respectively. Measurements were taken before and after the intervention and after 4-week follow-up and included fatigue by Modified Fatigue Impact Scale; mobility by Modified Rivermead Mobility Index; disability by Guy's Neurological Disability Scale; functional activities by 2-Minute Walk Test, Timed 25-Foot Walk test, and Timed Up and Go test; balance indices by Biodex Balance System; and quadriceps and hamstring isometric muscles by torque of left and right knee joints. Analysis of variance with repeated measures was used to investigate the intervention effects on the measurements. Results: After the intervention, significant improvement was found in the downhill group versus the uphill group in terms of fatigue, mobility, and disability indices; functional activities; balance indices; and quadriceps isometric torque (P < .05). The results were stable at 4-week follow-up. Conclusions: Downhill walking on a treadmill may improve muscle performance, functional activity, and balance control in MS patients. These findings support the idea of using eccentric exercise training in MS rehabilitation protocols. PMID:26917996

Impact of an implanted neuroprosthesis on community ambulation in incomplete SCI.

PubMed

Lombardo, Lisa M; Kobetic, Rudolf; Pinault, Gilles; Foglyano, Kevin M; Bailey, Stephanie N; Selkirk, Stephen; Triolo, Ronald J

2018-03-01

Test the effect of a multi-joint control with implanted electrical stimulation on walking after spinal cord injury (SCI). Single subject research design with repeated measures. Hospital-based biomechanics laboratory and user assessment of community use. Female with C6 AIS C SCI 30 years post injury. Lower extremity muscle activation with an implanted pulse generator and gait training. Walking speed, maximum distance, oxygen consumption, upper extremity (UE) forces, kinematics and self-assessment of technology. Short distance walking speed at one-year follow up with or without stimulation was not significantly different from baseline. However, average walking speed was significantly faster (0.22 m/s) with stimulation over longer distances than volitional walking (0.12 m/s). In addition, there was a 413% increase in walking distance from 95 m volitionally to 488 m with stimulation while oxygen consumption and maximum upper extremity forces decreased by 22 and 16%, respectively. Stimulation also produced significant (P ≤ 0.001) improvements in peak hip and knee flexion, ankle angle at foot off and at mid-swing. An implanted neuroprosthesis enabled a subject with incomplete SCI to walk longer distances with improved hip and knee flexion and ankle dorsiflexion resulting in decreased oxygen consumption and UE support. Further research is required to determine the robustness, generalizability and functional implications of implanted neuroprostheses for community ambulation after incomplete SCI.

Effects of physical guidance on short-term learning of walking on a narrow beam

PubMed Central

Domingo, Antoinette; Ferris, Daniel P.

2009-01-01

Physical guidance is often used in rehabilitation when teaching patients to re-learn movements. However, the effects of guidance on motor learning of complex skills, such as walking balance, are not clear. We tested four groups of healthy subjects that practiced walking on a narrow (1.27 cm) or wide (2.5 cm) treadmill-mounted balance beam, with or without physical guidance. Assistance was given by springs attached to a hip belt that applied restoring forces towards beam center. Subjects were evaluated while walking unassisted before and after training by calculating the number of times subjects stepped off of the beam per minute of successful walking on the beam (Failures per Minute). Subjects in Unassisted groups had greater performance improvements in walking balance from pre to post compared to subjects in Assisted groups. During training, Unassisted groups had more Failures per Minute than Assisted groups. Performance improvements were smaller in Narrow Beam groups than in Wide Beam groups. The Unassisted-Wide and Assisted-Narrow groups had similar Failures per Minute during training, but the Unassisted-Wide group had much greater performance gains after training. These results suggest that physical assistance can hinder motor learning of walking balance, assistance appears less detrimental for more difficult tasks, and task-specific dynamics are important to learning independent of error experience. PMID:19674900

Modelling nematode movement using time-fractional dynamics.

PubMed

Hapca, Simona; Crawford, John W; MacMillan, Keith; Wilson, Mike J; Young, Iain M

2007-09-07

We use a correlated random walk model in two dimensions to simulate the movement of the slug parasitic nematode Phasmarhabditis hermaphrodita in homogeneous environments. The model incorporates the observed statistical distributions of turning angle and speed derived from time-lapse studies of individual nematode trails. We identify strong temporal correlations between the turning angles and speed that preclude the case of a simple random walk in which successive steps are independent. These correlated random walks are appropriately modelled using an anomalous diffusion model, more precisely using a fractional sub-diffusion model for which the associated stochastic process is characterised by strong memory effects in the probability density function.

Muscle Synergies Facilitate Computational Prediction of Subject-Specific Walking Motions

PubMed Central

Meyer, Andrew J.; Eskinazi, Ilan; Jackson, Jennifer N.; Rao, Anil V.; Patten, Carolynn; Fregly, Benjamin J.

2016-01-01

Researchers have explored a variety of neurorehabilitation approaches to restore normal walking function following a stroke. However, there is currently no objective means for prescribing and implementing treatments that are likely to maximize recovery of walking function for any particular patient. As a first step toward optimizing neurorehabilitation effectiveness, this study develops and evaluates a patient-specific synergy-controlled neuromusculoskeletal simulation framework that can predict walking motions for an individual post-stroke. The main question we addressed was whether driving a subject-specific neuromusculoskeletal model with muscle synergy controls (5 per leg) facilitates generation of accurate walking predictions compared to a model driven by muscle activation controls (35 per leg) or joint torque controls (5 per leg). To explore this question, we developed a subject-specific neuromusculoskeletal model of a single high-functioning hemiparetic subject using instrumented treadmill walking data collected at the subject’s self-selected speed of 0.5 m/s. The model included subject-specific representations of lower-body kinematic structure, foot–ground contact behavior, electromyography-driven muscle force generation, and neural control limitations and remaining capabilities. Using direct collocation optimal control and the subject-specific model, we evaluated the ability of the three control approaches to predict the subject’s walking kinematics and kinetics at two speeds (0.5 and 0.8 m/s) for which experimental data were available from the subject. We also evaluated whether synergy controls could predict a physically realistic gait period at one speed (1.1 m/s) for which no experimental data were available. All three control approaches predicted the subject’s walking kinematics and kinetics (including ground reaction forces) well for the model calibration speed of 0.5 m/s. However, only activation and synergy controls could predict the subject’s walking kinematics and kinetics well for the faster non-calibration speed of 0.8 m/s, with synergy controls predicting the new gait period the most accurately. When used to predict how the subject would walk at 1.1 m/s, synergy controls predicted a gait period close to that estimated from the linear relationship between gait speed and stride length. These findings suggest that our neuromusculoskeletal simulation framework may be able to bridge the gap between patient-specific muscle synergy information and resulting functional capabilities and limitations. PMID:27790612

Kinesthetic Force Feedback and Belt Control for the Treadport Locomotion Interface.

PubMed

Hejrati, Babak; Crandall, Kyle L; Hollerbach, John M; Abbott, Jake J

2015-01-01

This paper describes an improved control system for the Treadport immersive locomotion interface, with results that generalize to any treadmill that utilizes an actuated tether to enable self-selected walking speed. A new belt controller is implemented to regulate the user's position; when combined with the user's own volition, this controller also enables the user to naturally self-select their walking speed as they would when walking over ground. A new kinesthetic-force-feedback controller is designed for the tether that applies forces to the user's torso. This new controller is derived based on maintaining the user's sense of balance during belt acceleration, rather than by rendering an inertial force as was done in our prior work. Based on the results of a human-subjects study, the improvements in both controllers significantly contribute to an improved perception of realistic walking on the Treadport. The improved control system uses intuitive dynamic-system and anatomical parameters and requires no ad hoc gain tuning. The control system simply requires three measurements to be made for a given user: the user's mass, the user's height, and the height of the tether attachment point on the user's torso.

Optimal foot shape for a passive dynamic biped.

PubMed

Kwan, Maxine; Hubbard, Mont

2007-09-21

Passive walking dynamics describe the motion of a biped that is able to "walk" down a shallow slope without any actuation or control. Instead, the walker relies on gravitational and inertial effects to propel itself forward, exhibiting a gait quite similar to that of humans. These purely passive models depend on potential energy to overcome the energy lost when the foot impacts the ground. Previous research has demonstrated that energy loss at heel-strike can vary widely for a given speed, depending on the nature of the collision. The point of foot contact with the ground (relative to the hip) can have a significant effect: semi-circular (round) feet soften the impact, resulting in much smaller losses than point-foot walkers. Collisional losses are also lower if a single impulse is broken up into a series of smaller impulses that gradually redirect the velocity of the center of mass rather than a single abrupt impulse. Using this principle, a model was created where foot-strike occurs over two impulses, "heel-strike" and "toe-strike," representative of the initial impact of the heel and the following impact as the ball of the foot strikes the ground. Having two collisions with the flat-foot model did improve efficiency over the point-foot model. Representation of the flat-foot walker as a rimless wheel helped to explain the optimal flat-foot shape, driven by symmetry of the virtual spoke angles. The optimal long period foot shape of the simple passive walking model was not very representative of the human foot shape, although a reasonably anthropometric foot shape was predicted by the short period solution.

The Effects of Functional Training, Bicycle Exercise, and Exergaming on Walking Capacity of Elderly Patients With Parkinson Disease: A Pilot Randomized Controlled Single-blinded Trial.

PubMed

Ferraz, Daniel Dominguez; Trippo, Karen Valadares; Duarte, Gabriel Pereira; Neto, Mansueto Gomes; Bernardes Santos, Kionna Oliveira; Filho, Jamary Oliveira

2018-05-01

To compare the effects of functional training, bicycle exercise, and exergaming on walking capacity of elderly with Parkinson disease (PD). A pilot randomized, controlled, single-blinded trial. A state reference health care center for elderly, a public reference outpatient clinic for the elderly. Elderly individuals (≥60 years of age; N=62) with idiopathic PD (stage 2 to 3 of modified Hoehn and Yahr staging scale) according to the London Brain Bank. The participants were randomly assigned to three groups. Group 1 (G1) participated in functional training (n=22); group 2 (G2) performed bicycle exercise (n=20), and group 3 (G3) trained with Kinect Adventures (Microsoft, Redmond, WA) exergames (n=20). The primary outcome measure was the 6-minute walk test (6MWT); secondary outcome measures were the 10-m walk test (10MWT), sitting-rising test (SRT), body mass index, Parkinson Disease Questionnaire-39, World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), and 15-item Geriatric Depression Scale. All groups showed significant improvements in 6MWT (G1 P=.008; G2 P=.001; G3 P=.005), SRT (G1 P<.001; G2 P=.001; G3 P=.003), and WHODAS 2.0 (G1 P=.018; G2 P=.019; G3 P=.041). Only G3 improved gait speed in 10MWT (P=.11). G1 (P=.014) and G3 (P=.004) improved quality of life. No difference was found between groups. Eight weeks of exergaming can improve the walking capacity of elderly patients with PD. Exergame training had similar outcomes compared with functional training and bicycle exercise. The three physical exercise modalities presented significant improvements on walking capacity, ability to stand up and sit, and functionality of the participants. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Home-based walking during pregnancy affects mood and birth outcomes among sedentary women: A randomized controlled trial.

PubMed

Taniguchi, Chie; Sato, Chifumi

2016-10-01

We examined the effects of home-based walking on sedentary Japanese women's pregnancy outcomes and mood. A randomized controlled trial was conducted, involving 118 women aged 22-36 years. Participants were randomly assigned to walking intervention (n = 60) or control (n = 58) groups. The walking group was instructed to walk briskly for 30 min, three times weekly from 30 weeks' gestation until delivery. Both groups counted their daily steps using pedometers. Pregnancy and delivery outcomes were assessed, participants completed the Profile of Mood States, and we used the intention-to-treat principle. Groups showed no differences regarding pregnancy or delivery outcomes. The walking group exhibited decreased scores on the depression-dejection and confusion subscales of the Profile of Mood States. Five of the 54 women in the intervention group who remained in the study (9.2%) completed 100% of the prescribed walking program; 32 (59.3%) women completed 80% or more. Unsupervised walking improves sedentary pregnant women's mood, indicating that regular walking during pregnancy should be promoted in this group. © 2016 John Wiley & Sons Australia, Ltd.

The Use of Classroom Walk-Through Observations as a Strategy to Improve Teaching and Learning: A Student Centered Perspective

ERIC Educational Resources Information Center

Sorensen, Thomas R., Jr.

2010-01-01

Due to the increasing pressure of meeting the demands of No Child Left Behind, and reducing the achievement gap between subgroups of school populations, school administrators across the nation have implemented a variety of short classroom walk-through observations. A walk-through is defined as a 3-5 minute observation of the classroom teacher by…

A mechanized gait trainer for restoring gait in nonambulatory subjects.

PubMed

Hesse, S; Uhlenbrock, D; Werner, C; Bardeleben, A

2000-09-01

To construct an advanced mechanized gait trainer to enable patients the repetitive practice of a gaitlike movement without overstraining therapists. DEVICE: Prototype gait trainer that simulates the phases of gait (by generating a ratio of 40% to 60% between swing and stance phases), supports the subjects according to their ability (lifts the foot during swing phase), and controls the center of mass in the vertical and horizontal directions. Two nonambulatory, hemiparetic patients who regained their walking ability after 4 weeks of daily training on the gait trainer, a 55-year-old woman and a 62-year-old man, both of whom had a first-time ischemic stroke. Four weeks of training, five times a week, each session 20 minutes long. Functional ambulation category (FAC, levels 0-5) to assess gait ability and ground level walking velocity. Rivermead motor assessment score (RMAS, 0-13) to assess gross motor function. Patient 1: At the end of treatment, she was able to walk independently on level ground with use of a walking stick. Her walking velocity had improved from .29m/sec to .59m/sec. Her RMAS score increased from 4 to 10, meaning she could walk at least 40 meters outside, pick up objects from floor, and climb stairs independently. Patient 2: At end of 4-week training, he could walk independently on even surfaces (FAC level 4), using an ankle-foot orthosis and a walking stick. His walking velocity improved from .14m/sec to .63m/sec. His RMAS increased from 3 to 10. The gait trainer enabled severely affected patients the repetitive practice of a gaitlike movement. Future studies may elucidate its value in gait rehabilitation of nonambulatory subjects.

Evaluation of Dalfampridine Extended Release 5 and 10 mg in Multiple Sclerosis

PubMed Central

Yapundich, Robert; Applebee, Angela; Bethoux, Francois; Goldman, Myla D.; Hutton, George J.; Mass, Michele; Pardo, Gabriel; Klingler, Michael; Henney, Herbert R.; Carrazana, Enrique J.

2015-01-01

Background: Dalfampridine extended-release (ER) tablets, 10 mg twice daily, have been shown to improve walking in people with multiple sclerosis. We evaluated the safety and efficacy of dalfampridine-ER 5 mg compared with 10 mg. Methods: Patients were randomized to double-blind treatment with twice-daily dalfampridine-ER tablets, 5 mg (n = 144) or 10 mg (n = 143), or placebo (n = 143) for 4 weeks. Primary efficacy endpoint was change from baseline walking speed by the Timed 25-Foot Walk 3 to 4 hours after the last dose. At 40% of sites, 2-week change from baseline walking distance was measured by the 6-Minute Walk test. Results: At 4 weeks, walking speed changes from baseline were 0.363, 0.423, and 0.478 ft/s (placebo, dalfampridine-ER 5 mg, and dalfampridine-ER 10 mg, respectively [P = NS]). Post hoc analysis of average changes between pretreatment and on-treatment showed that relative to placebo, only dalfampridine-ER 10 mg demonstrated a significant increase in walking speed (mean ± SE): 0.443 ± 0.042 ft/s versus 0.303 ± 0.038 ft/s (P = .014). Improvement in 6-Minute Walk distance was significantly greater with dalfampridine-ER 10 mg (128.6 ft, P = .014) but not with 5 mg (76.8 ft, P = .308) relative to placebo (41.7 ft). Adverse events were consistent with previous studies. No seizures were reported. Conclusions: Dalfampridine-ER 5 and 10 mg twice daily did not demonstrate efficacy on the planned endpoint. Post hoc analyses demonstrated significant increases in walking speed relative to placebo with dalfampridine-ER 10 mg. No new safety signals were observed. PMID:26052259

Effects of task-specific and impairment-based training compared with usual care on functional walking ability after inpatient stroke rehabilitation: LEAPS Trial.

PubMed

Nadeau, Stephen E; Wu, Samuel S; Dobkin, Bruce H; Azen, Stanley P; Rose, Dorian K; Tilson, Julie K; Cen, Steven Y; Duncan, Pamela W

2013-05-01

After inpatient stroke rehabilitation, many people still cannot participate in community activities because of limited walking ability. To compare the effectiveness of 2 conceptually different, early physical therapy (PT) interventions to usual care (UC) in improving walking 6 months after stroke. The locomotor experience applied post-stroke (LEAPS) study was a single-blind, randomized controlled trial conducted in 408 adults with disabling hemiparetic stroke. Participants were stratified at baseline (2 months) by impairment in walking speed: severe (<0.4 m/s) or moderate (0.4 to <0.8 m/s). Between 2 and 6 months, they received either only UC (n = 143) or UC plus 36 therapist-provided sessions of either (1) walking training on a treadmill using body-weight support and practice overground at clinics (locomotor training program [LTP], n = 139) or (2) impairment-based strength and balance exercise at home (home exercise program [HEP], n = 126). LTP participants were 18% more likely to transition to a higher functional walking level: severe to >0.4 m/s and moderate to >0.8 m/s than UC participants (95% confidence interval [CI] = 7%-29%), and HEP participants were 17% more likely to transition (95% CI = 5%-29%). Mean gain in walking speed in LTP participants was 0.13 m/s greater (95% CI = 0.09-0.18) and in HEP participants, 0.10 m/s greater (95% CI = 0.05-0.14) than in UC participants. Progressive PT, using either walking training on a treadmill and overground, conducted in a clinic, or strength and balance exercises conducted at home, was superior to UC in improving walking, regardless of severity of initial impairment.

Pilates exercise training vs. physical therapy for improving walking and balance in people with multiple sclerosis: a randomized controlled trial.

PubMed

Kalron, Alon; Rosenblum, Uri; Frid, Lior; Achiron, Anat

2017-03-01

Evaluate the effects of a Pilates exercise programme on walking and balance in people with multiple sclerosis and compare this exercise approach to conventional physical therapy sessions. Randomized controlled trial. Multiple Sclerosis Center, Sheba Medical Center, Tel-Hashomer, Israel. Forty-five people with multiple sclerosis, 29 females, mean age (SD) was 43.2 (11.6) years; mean Expanded Disability Status Scale (S.D) was 4.3 (1.3). Participants received 12 weekly training sessions of either Pilates ( n=22) or standardized physical therapy ( n=23) in an outpatient basis. Spatio-temporal parameters of walking and posturography parameters during static stance. Functional tests included the Time Up and Go Test, 2 and 6-minute walk test, Functional Reach Test, Berg Balance Scale and the Four Square Step Test. In addition, the following self-report forms included the Multiple Sclerosis Walking Scale and Modified Fatigue Impact Scale. At the termination, both groups had significantly increased their walking speed ( P=0.021) and mean step length ( P=0.023). According to the 2-minute and 6-minute walking tests, both groups at the end of the intervention program had increased their walking speed. Mean (SD) increase in the Pilates and physical therapy groups were 39.1 (78.3) and 25.3 (67.2) meters, respectively. There was no effect of group X time in all instrumented and clinical balance and gait measures. Pilates is a possible treatment option for people with multiple sclerosis in order to improve their walking and balance capabilities. However, this approach does not have any significant advantage over standardized physical therapy.

Multicomponent physical exercise with simultaneous cognitive training to enhance dual-task walking of older adults: a secondary analysis of a 6-month randomized controlled trial with 1-year follow-up.

PubMed

Eggenberger, Patrick; Theill, Nathan; Holenstein, Stefan; Schumacher, Vera; de Bruin, Eling D

2015-01-01

About one-third of people older than 65 years fall at least once a year. Physical exercise has been previously demonstrated to improve gait, enhance physical fitness, and prevent falls. Nonetheless, the addition of cognitive training components may potentially increase these effects, since cognitive impairment is related to gait irregularities and fall risk. We hypothesized that simultaneous cognitive-physical training would lead to greater improvements in dual-task (DT) gait compared to exclusive physical training. Elderly persons older than 70 years and without cognitive impairment were randomly assigned to the following groups: 1) virtual reality video game dancing (DANCE), 2) treadmill walking with simultaneous verbal memory training (MEMORY), or 3) treadmill walking (PHYS). Each program was complemented with strength and balance exercises. Two 1-hour training sessions per week over 6 months were applied. Gait variables, functional fitness (Short Physical Performance Battery, 6-minute walk), and fall frequencies were assessed at baseline, after 3 months and 6 months, and at 1-year follow-up. Multiple regression analyses with planned comparisons were carried out. Eighty-nine participants were randomized to three groups initially; 71 completed the training and 47 were available at 1-year follow-up. DANCE/MEMORY showed a significant advantage compared to PHYS in DT costs of step time variability at fast walking (P=0.044). Training-specific gait adaptations were found on comparing DANCE and MEMORY: DANCE reduced step time at fast walking (P=0.007) and MEMORY reduced gait variability in DT and DT costs at preferred walking speed (both trend P=0.062). Global linear time effects showed improved gait (P<0.05), functional fitness (P<0.05), and reduced fall frequency (-77%, P<0.001). Only single-task fast walking, gait variability at preferred walking speed, and Short Physical Performance Battery were reduced at follow-up (all P<0.05 or trend). Long-term multicomponent cognitive-physical and exclusive physical training programs demonstrated similar potential to counteract age-related decline in physical functioning.

Multicomponent physical exercise with simultaneous cognitive training to enhance dual-task walking of older adults: a secondary analysis of a 6-month randomized controlled trial with 1-year follow-up

PubMed Central

Eggenberger, Patrick; Theill, Nathan; Holenstein, Stefan; Schumacher, Vera; de Bruin, Eling D

2015-01-01

Background About one-third of people older than 65 years fall at least once a year. Physical exercise has been previously demonstrated to improve gait, enhance physical fitness, and prevent falls. Nonetheless, the addition of cognitive training components may potentially increase these effects, since cognitive impairment is related to gait irregularities and fall risk. We hypothesized that simultaneous cognitive–physical training would lead to greater improvements in dual-task (DT) gait compared to exclusive physical training. Methods Elderly persons older than 70 years and without cognitive impairment were randomly assigned to the following groups: 1) virtual reality video game dancing (DANCE), 2) treadmill walking with simultaneous verbal memory training (MEMORY), or 3) treadmill walking (PHYS). Each program was complemented with strength and balance exercises. Two 1-hour training sessions per week over 6 months were applied. Gait variables, functional fitness (Short Physical Performance Battery, 6-minute walk), and fall frequencies were assessed at baseline, after 3 months and 6 months, and at 1-year follow-up. Multiple regression analyses with planned comparisons were carried out. Results Eighty-nine participants were randomized to three groups initially; 71 completed the training and 47 were available at 1-year follow-up. DANCE/MEMORY showed a significant advantage compared to PHYS in DT costs of step time variability at fast walking (P=0.044). Training-specific gait adaptations were found on comparing DANCE and MEMORY: DANCE reduced step time at fast walking (P=0.007) and MEMORY reduced gait variability in DT and DT costs at preferred walking speed (both trend P=0.062). Global linear time effects showed improved gait (P<0.05), functional fitness (P<0.05), and reduced fall frequency (−77%, P<0.001). Only single-task fast walking, gait variability at preferred walking speed, and Short Physical Performance Battery were reduced at follow-up (all P<0.05 or trend). Conclusion Long-term multicomponent cognitive–physical and exclusive physical training programs demonstrated similar potential to counteract age-related decline in physical functioning. PMID:26604719

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

PubMed

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Quantum walks with an anisotropic coin II: scattering theory

NASA Astrophysics Data System (ADS)

Richard, S.; Suzuki, A.; de Aldecoa, R. Tiedra

2018-05-01

We perform the scattering analysis of the evolution operator of quantum walks with an anisotropic coin, and we prove a weak limit theorem for their asymptotic velocity. The quantum walks that we consider include one-defect models, two-phase quantum walks, and topological phase quantum walks as special cases. Our analysis is based on an abstract framework for the scattering theory of unitary operators in a two-Hilbert spaces setting, which is of independent interest.

A springy pendulum could describe the swing leg kinetics of human walking.

PubMed

Song, Hyunggwi; Park, Heewon; Park, Sukyung

2016-06-14

The dynamics of human walking during various walking conditions could be qualitatively captured by the springy legged dynamics, which have been used as a theoretical framework for bipedal robotics applications. However, the spring-loaded inverted pendulum model describes the motion of the center of mass (CoM), which combines the torso, swing and stance legs together and does not explicitly inform us as to whether the inter-limb dynamics share the springy legged dynamics characteristics of the CoM. In this study, we examined whether the swing leg dynamics could also be represented by springy mechanics and whether the swing leg stiffness shows a dependence on gait speed, as has been observed in CoM mechanics during walking. The swing leg was modeled as a spring-loaded pendulum hinged at the hip joint, which is under forward motion. The model parameters of the loaded mass were adopted from body parameters and anthropometric tables, whereas the free model parameters for the rest length of the spring and its stiffness were estimated to best match the data for the swing leg joint forces. The joint forces of the swing leg were well represented by the springy pendulum model at various walking speeds with a regression coefficient of R(2)>0.8. The swing leg stiffness increased with walking speed and was correlated with the swing frequency, which is consistent with previous observations from CoM dynamics described using the compliant leg. These results suggest that the swing leg also shares the springy dynamics, and the compliant walking model could be extended to better present swing leg dynamics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative Effectiveness of Two Walking Interventions on Participation, Step Counts, and Health.

PubMed

Smith-McLallen, Aaron; Heller, Debbie; Vernisi, Kristin; Gulick, Diana; Cruz, Samantha; Snyder, Richard L

2017-03-01

To (1) compare the effects of two worksite-based walking interventions on employee participation rates; (2) compare average daily step counts between conditions, and; (3) examine the effects of increases in average daily step counts on biometric and psychologic outcomes. We conducted a cluster-randomized trial in which six employer groups were randomly selected and randomly assigned to condition. Four manufacturing worksites and two office-based worksite served as the setting. A total of 474 employees from six employer groups were included. A standard walking program was compared to an enhanced program that included incentives, feedback, competitive challenges, and monthly wellness workshops. Walking was measured by self-reported daily step counts. Survey measures and biometric screenings were administered at baseline and 3, 6, and 9 months after baseline. Analysis used linear mixed models with repeated measures. During 9 months, participants in the enhanced condition averaged 726 more steps per day compared with those in the standard condition (p < .001). A 1000-step increase in average daily steps was associated with significant weight loss for both men (-3.8 lbs.) and women (-2.1 lbs.), and reductions in body mass index (-0.41 men, -0.31 women). Higher step counts were also associated with improvements in mood, having more energy, and higher ratings of overall health. An enhanced walking program significantly increases participation rates and daily step counts, which were associated with weight loss and reductions in body mass index.

Robots in human biomechanics--a study on ankle push-off in walking.

PubMed

Renjewski, Daniel; Seyfarth, André

2012-09-01

In biomechanics, explanatory template models are used to identify the basic mechanisms of human locomotion. However, model predictions often lack verification in a realistic environment. We present a method that uses template model mechanics as a blueprint for a bipedal robot and a corresponding computer simulation. The hypotheses derived from template model studies concerning the function of heel-off in walking are analysed and discrepancies between the template model and its real-world anchor are pointed out. Neither extending the ground clearance of the swinging leg nor an impact reduction at touch-down as an effect of heel lifting was supported by the experiments. To confirm the relevance of the experimental findings, a comparison of robot data to human walking data is discussed and we speculate on an alternative explanation of heel-off in human walking, i.e. that the push-off powers the following leg swing.

Effect of type of cognitive task and walking speed on cognitive-motor interference during dual-task walking.

PubMed

Patel, P; Lamar, M; Bhatt, T

2014-02-28

We aimed to determine the effect of distinctly different cognitive tasks and walking speed on cognitive-motor interference of dual-task walking. Fifteen healthy adults performed four cognitive tasks: visuomotor reaction time (VMRT) task, word list generation (WLG) task, serial subtraction (SS) task, and the Stroop (STR) task while sitting and during walking at preferred-speed (dual-task normal walking) and slow-speed (dual-task slow-speed walking). Gait speed was recorded to determine effect on walking. Motor and cognitive costs were measured. Dual-task walking had a significant effect on motor and cognitive parameters. At preferred-speed, the motor cost was lowest for the VMRT task and highest for the STR task. In contrast, the cognitive cost was highest for the VMRT task and lowest for the STR task. Dual-task slow walking resulted in increased motor cost and decreased cognitive cost only for the STR task. Results show that the motor and cognitive cost of dual-task walking depends heavily on the type and perceived complexity of the cognitive task being performed. Cognitive cost for the STR task was low irrespective of walking speed, suggesting that at preferred-speed individuals prioritize complex cognitive tasks requiring higher attentional and processing resources over walking. While performing VMRT task, individuals preferred to prioritize more complex walking task over VMRT task resulting in lesser motor cost and increased cognitive cost for VMRT task. Furthermore, slow walking can assist in diverting greater attention towards complex cognitive tasks, improving its performance while walking. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury.

PubMed

Evans, Nicholas; Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity.

Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury

PubMed Central

Hartigan, Clare; Kandilakis, Casey; Pharo, Elizabeth; Clesson, Ismari

2015-01-01

Background: Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated. Objective: The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds. Methods: Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance. Results: Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci. Conclusion: Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity. PMID:26364281

Learning gait of quadruped robot without prior knowledge of the environment

NASA Astrophysics Data System (ADS)

Xu, Tao; Chen, Qijun

2012-09-01

Walking is the basic skill of a legged robot, and one of the promising ways to improve the walking performance and its adaptation to environment changes is to let the robot learn its walking by itself. Currently, most of the walking learning methods are based on robot vision system or some external sensing equipment to estimate the walking performance of certain walking parameters, and therefore are usually only applicable under laboratory condition, where environment can be pre-defined. Inspired by the rhythmic swing movement during walking of legged animals and the behavior of their adjusting their walking gait on different walking surfaces, a concept of walking rhythmic pattern(WRP) is proposed to evaluate the walking specialty of legged robot, which is just based on the walking dynamics of the robot. Based on the onboard acceleration sensor data, a method to calculate WRP using power spectrum in frequency domain and diverse smooth filters is also presented. Since the evaluation of WRP is only based on the walking dynamics data of the robot's body, the proposed method doesn't require prior knowledge of environment and thus can be applied in unknown environment. A gait learning approach of legged robots based on WRP and evolution algorithm(EA) is introduced. By using the proposed approach, a quadruped robot can learn its locomotion by its onboard sensing in an unknown environment, where the robot has no prior knowledge about this place. The experimental result proves proportional relationship exits between WRP match score and walking performance of legged robot, which can be used to evaluate the walking performance in walking optimization under unknown environment.

Stock market context of the Lévy walks with varying velocity

NASA Astrophysics Data System (ADS)

Kutner, Ryszard

2002-11-01

We developed the most general Lévy walks with varying velocity, shorter called the Weierstrass walks (WW) model, by which one can describe both stationary and non-stationary stochastic time series. We considered a non-Brownian random walk where the walker moves, in general, with a velocity that assumes a different constant value between the successive turning points, i.e., the velocity is a piecewise constant function. This model is a kind of Lévy walks where we assume a hierarchical, self-similar in a stochastic sense, spatio-temporal representation of the main quantities such as waiting-time distribution and sojourn probability density (which are principal quantities in the continuous-time random walk formalism). The WW model makes possible to analyze both the structure of the Hurst exponent and the power-law behavior of kurtosis. This structure results from the hierarchical, spatio-temporal coupling between the walker displacement and the corresponding time of the walks. The analysis uses both the fractional diffusion and the super Burnett coefficients. We constructed the diffusion phase diagram which distinguishes regions occupied by classes of different universality. We study only such classes which are characteristic for stationary situations. We thus have a model ready for describing the data presented, e.g., in the form of moving averages; the operation is often used for stochastic time series, especially financial ones. The model was inspired by properties of financial time series and tested for empirical data extracted from the Warsaw stock exchange since it offers an opportunity to study in an unbiased way several features of stock exchange in its early stage.

Urban form and psychosocial factors: do they interact for leisure-time walking?

PubMed

Beenackers, Mariëlle A; Kamphuis, Carlijn B M; Prins, Richard G; Mackenbach, Johan P; Burdorf, Alex; van Lenthe, Frank J

2014-02-01

This cross-sectional study uses an adaptation of a social-ecological model on the hierarchy of walking needs to explore direct associations and interactions of urban-form characteristics and individual psychosocial factors for leisure-time walking. Questionnaire data (n = 736) from adults (25-74 yr) and systematic field observations within 14 neighborhoods in Eindhoven (the Netherlands) were used. Multilevel logistic regression models were used to relate the urban-form characteristics (accessibility, safety, comfort, and pleasurability) and individual psychosocial factors (attitude, self-efficacy, social influence, and intention) to two definitions of leisure-time walking, that is, any leisure-time walking and sufficient leisure-time walking according to the Dutch physical activity norm and to explore their interactions. Leisure-time walking was associated with psychosocial factors but not with characteristics of the urban environment. For sufficient leisure-time walking, interactions between attitude and several urban-form characteristics were found, indicating that positive urban-form characteristics contributed toward leisure-time walking only in residents with a less positive attitude toward physical activity. In contrast, living in a neighborhood that was accessible for walking was stronger associated with leisure-time walking among residents who experienced a positive social influence to engage in physical activity compared with those who reported less social influence. This study showed some evidence for an interaction between the neighborhood environment and the individual psychosocial factors in explaining leisure-time walking. The specific mechanism of interaction may depend on the specific combination of psychosocial factor and environmental factor. The lack of association between urban form and leisure-time walking could be partly due to the little variation in urban-form characteristics between neighborhoods.

The role of series ankle elasticity in bipedal walking

PubMed Central

Zelik, Karl E.; Huang, Tzu-Wei P.; Adamczyk, Peter G.; Kuo, Arthur D.

2014-01-01

The elastic stretch-shortening cycle of the Achilles tendon during walking can reduce the active work demands on the plantarflexor muscles in series. However, this does not explain why or when this ankle work, whether by muscle or tendon, needs to be performed during gait. We therefore employ a simple bipedal walking model to investigate how ankle work and series elasticity impact economical locomotion. Our model shows that ankle elasticity can use passive dynamics to aid push-off late in single support, redirecting the body's center-of-mass (COM) motion upward. An appropriately timed, elastic push-off helps to reduce dissipative collision losses at contralateral heelstrike, and therefore the positive work needed to offset those losses and power steady walking. Thus, the model demonstrates how elastic ankle work can reduce the total energetic demands of walking, including work required from more proximal knee and hip muscles. We found that the key requirement for using ankle elasticity to achieve economical gait is the proper ratio of ankle stiffness to foot length. Optimal combination of these parameters ensures proper timing of elastic energy release prior to contralateral heelstrike, and sufficient energy storage to redirect the COM velocity. In fact, there exist parameter combinations that theoretically yield collision-free walking, thus requiring zero active work, albeit with relatively high ankle torques. Ankle elasticity also allows the hip to power economical walking by contributing indirectly to push-off. Whether walking is powered by the ankle or hip, ankle elasticity may aid walking economy by reducing collision losses. PMID:24365635

The role of series ankle elasticity in bipedal walking.

PubMed

Zelik, Karl E; Huang, Tzu-Wei P; Adamczyk, Peter G; Kuo, Arthur D

2014-04-07

The elastic stretch-shortening cycle of the Achilles tendon during walking can reduce the active work demands on the plantarflexor muscles in series. However, this does not explain why or when this ankle work, whether by muscle or tendon, needs to be performed during gait. We therefore employ a simple bipedal walking model to investigate how ankle work and series elasticity impact economical locomotion. Our model shows that ankle elasticity can use passive dynamics to aid push-off late in single support, redirecting the body's center-of-mass (COM) motion upward. An appropriately timed, elastic push-off helps to reduce dissipative collision losses at contralateral heelstrike, and therefore the positive work needed to offset those losses and power steady walking. Thus, the model demonstrates how elastic ankle work can reduce the total energetic demands of walking, including work required from more proximal knee and hip muscles. We found that the key requirement for using ankle elasticity to achieve economical gait is the proper ratio of ankle stiffness to foot length. Optimal combination of these parameters ensures proper timing of elastic energy release prior to contralateral heelstrike, and sufficient energy storage to redirect the COM velocity. In fact, there exist parameter combinations that theoretically yield collision-free walking, thus requiring zero active work, albeit with relatively high ankle torques. Ankle elasticity also allows the hip to power economical walking by contributing indirectly to push-off. Whether walking is powered by the ankle or hip, ankle elasticity may aid walking economy by reducing collision losses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Clinical relevance of gait research applied to clinical trials in spinal cord injury.

PubMed

Ditunno, John; Scivoletto, Giorgio

2009-01-15

The restoration of walking function following SCI is extremely important to consumers and has stimulated a response of new treatments by scientists, the pharmaceutical industry and clinical entrepreneurs. Several of the proposed interventions: (1) the use of functional electrical stimulation (FES) and (2) locomotor training have been examined in clinical trials and recent reviews of the scientific literature. Each of these interventions is based on research of human locomotion. Therefore, the systematic study of walking function and gait in normal individuals and those with injury to the spinal cord has contributed to the identification of the impairments of walking, the development of new treatments and how they will be measured to determine effectiveness. In this context gait research applied to interventions to improve walking function is of high clinical relevance. This research helps identify walking impairments to be corrected and measures of walking function to be utilized as endpoints for clinical trials. The most common impairments following SCI diagnosed by observational gait analysis include inadequate hip extension during stance, persistent plantar flexion and hip/knee flexion during swing and foot placement at heel strike. FES has been employed as one strategy for correcting these impairments based on analysis that range from simple measures of speed, cadence and stride length to more sophisticated systems of three- dimensional video motion analysis and multichannel EMG tracings of integrated walking. A recent review of the entire FES literature identified 36 studies that merit comment and the full range of outcome measures for walking function were used from simple velocity to the video analysis of motion. In addition to measures of walking function developed for FES interventions, the first randomized multicenter clinical trial on locomotor training in subacute SCI was recently published with an extensive review of these measures. In this study outcome measures of motor strength (impairment), balance, Walking Index for SCI (WISCI), speed, 5min walk (walking capacities) and locomotor functional independence measure (L-FIM), a disability measure all showed improvement in walking function based on the strategy of the response of activity based plasticity to step training. Although the scientific basis for this intervention will be covered in other articles in this series, the evolution of clinical outcome measures of walking function continues to be important for the determination of effectiveness in clinical trials.

Calcaneal loading during walking and running

NASA Technical Reports Server (NTRS)

Giddings, V. L.; Beaupre, G. S.; Whalen, R. T.; Carter, D. R.

2000-01-01

PURPOSE: This study of the foot uses experimentally measured kinematic and kinetic data with a numerical model to evaluate in vivo calcaneal stresses during walking and running. METHODS: External ground reaction forces (GRF) and kinematic data were measured during walking and running using cineradiography and force plate measurements. A contact-coupled finite element model of the foot was developed to assess the forces acting on the calcaneus during gait. RESULTS: We found that the calculated force-time profiles of the joint contact, ligament, and Achilles tendon forces varied with the time-history curve of the moment about the ankle joint. The model predicted peak talocalcaneal and calcaneocuboid joint loads of 5.4 and 4.2 body weights (BW) during walking and 11.1 and 7.9 BW during running. The maximum predicted Achilles tendon forces were 3.9 and 7.7 BW for walking and running. CONCLUSIONS: Large magnitude forces and calcaneal stresses are generated late in the stance phase, with maximum loads occurring at approximately 70% of the stance phase during walking and at approximately 60% of the stance phase during running, for the gait velocities analyzed. The trajectories of the principal stresses, during both walking and running, corresponded to each other and qualitatively to the calcaneal trabecular architecture.

One-family walking technicolor in light of LHC Run II

NASA Astrophysics Data System (ADS)

Matsuzaki, Shinya

2017-12-01

The LHC Higgs can be identified as the technidilaton, a composite scalar, arising as a pseudo Nambu-Goldstone boson for the spontaneous breaking of scale symmetry in walking technicolor. One interesting candidate for the walking technicolor is the QCD with the large number of fermion flavors, involving the one-family model having the eight-fermion flavors. The smallness of the technidilaton mass can be ensured by the generic walking feature, Miransky scaling, and the presence of the “anti-Veneziano limit” characteristic to the large-flavor walking scenario. To tell the standard-model Higgs from the technidilaton, one needs to wait for the precise estimate of the Higgs couplings to the standard model particles, which is expected at the ongoing LHC Run II. In this talk the technidilaton phenomenology in comparison with the LHC Run-I data is summarized with the special emphasis placed on the presence of the anti-Veneziano limit supporting the lightness of technidilaton. Besides the technidilaton, the walking technicolor predicts the rich particle spectrum such as technipions and technirho mesons, arising as composite particles formed by technifermions. The LHC phenomenology of those technihadrons and the discovery channels are also discussed, which are smoking-guns of the walking technicolor, to be accessible at the LHC Run II.

Exercise improves gait, reaction time and postural stability in older adults with type 2 diabetes and neuropathy.

PubMed

Morrison, Steven; Colberg, Sheri R; Parson, Henri K; Vinik, Aaron I

2014-01-01

For older adults with type 2 diabetes (T2DM), declines in balance and walking ability are risk factors for falls, and peripheral neuropathy magnifies this risk. Exercise training may improve balance, gait and reduce the risk of falling. This study investigated the effects of 12weeks of aerobic exercise training on walking, balance, reaction time and falls risk metrics in older T2DM individuals with/without peripheral neuropathy. Adults with T2DM, 21 without (DM; age 58.7±1.7years) and 16 with neuropathy (DM-PN; age 58.9±1.9years), engaged in either moderate or intense supervised exercise training thrice-weekly for 12weeks. Pre/post-training assessments included falls risk (using the physiological profile assessment), standing balance, walking ability and hand/foot simple reaction time. Pre-training, the DM-PN group had higher falls risk, slower (hand) reaction times (232 vs. 219ms), walked at a slower speed (108 vs. 113cm/s) with shorter strides compared to the DM group. Following training, improvements in hand/foot reaction times and faster walking speed were seen for both groups. While falls risk was not significantly reduced, the observed changes in gait, reaction time and balance metrics suggest that aerobic exercise of varying intensities is beneficial for improving dynamic postural control in older T2DM adults with/without neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

Does dynamic stability govern propulsive force generation in human walking?

PubMed Central

Browne, Michael G.

2017-01-01

Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force (FP) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and FP generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their FP according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an FP at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds. PMID:29291129

Does dynamic stability govern propulsive force generation in human walking?

PubMed

Browne, Michael G; Franz, Jason R

2017-11-01

Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force ( F P ) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and F P generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their F P according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an F P at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds.

Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet

PubMed Central

Zhu, Yaguang; Jin, Bo; Wu, Yongsheng; Guo, Tong; Zhao, Xiangmo

2016-01-01

Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM) is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system. PMID:27589766

Freshwater availability and water fetching distance affect child health in sub-Saharan Africa.

PubMed

Pickering, Amy J; Davis, Jennifer

2012-02-21

Currently, more than two-thirds of the population in Africa must leave their home to fetch water for drinking and domestic use. The time burden of water fetching has been suggested to influence the volume of water collected by households as well as time spent on income generating activities and child care. However, little is known about the potential health benefits of reducing water fetching distances. Data from almost 200, 000 Demographic and Health Surveys carried out in 26 countries were used to assess the relationship between household walk time to water source and child health outcomes. To estimate the causal effect of decreased water fetching time on health, geographic variation in freshwater availability was employed as an instrumental variable for one-way walk time to water source in a two-stage regression model. Time spent walking to a household's main water source was found to be a significant determinant of under-five child health. A 15-min decrease in one-way walk time to water source is associated with a 41% average relative reduction in diarrhea prevalence, improved anthropometric indicators of child nutritional status, and a 11% relative reduction in under-five child mortality. These results suggest that reducing the time cost of fetching water should be a priority for water infrastructure investments in Africa.

Volcano monitoring using the Global Positioning System: Filtering strategies

USGS Publications Warehouse

Larson, K.M.; Cervelli, Peter; Lisowski, M.; Miklius, Asta; Segall, P.; Owen, S.

2001-01-01

Permanent Global Positioning System (GPS) networks are routinely used for producing improved orbits and monitoring secular tectonic deformation. For these applications, data are transferred to an analysis center each day and routinely processed in 24-hour segments. To use GPS for monitoring volcanic events, which may last only a few hours, real-time or near real-time data processing and subdaily position estimates are valuable. Strategies have been researched for obtaining station coordinates every 15 min using a Kalman filter; these strategies have been tested on data collected by a GPS network on Kilauea Volcano. Data from this network are tracked continuously, recorded every 30 s, and telemetered hourly to the Hawaiian Volcano Observatory. A white noise model is heavily impacted by data outages and poor satellite geometry, but a properly constrained random walk model fits the data well. Using a borehole tiltmeter at Kilauea's summit as ground-truth, solutions using different random walk constraints were compared. This study indicates that signals on the order of 5 mm/h are resolvable using a random walk standard deviation of 0.45 cm/???h. Values lower than this suppress small signals, and values greater than this have significantly higher noise at periods of 1-6 hours. Copyright 2001 by the American Geophysical Union.

Can Walking or Biking to Work Really Make a Difference? Compact Development, Observed Commuter Choice and Body Mass Index.

PubMed

Wojan, Timothy R; Hamrick, Karen S

2015-01-01

Promoting active commuting is viewed as one strategy to increase physical activity and improve the energy balance of more sedentary individuals thereby improving health outcomes. However, the potential effectiveness of promotion policies may be seriously undermined by the endogenous choice of commute mode. Policy to promote active commuting will be most effective if it can be demonstrated that 1) those in compact cities do not necessarily have a preference for more physical activity, and 2) that current active commuting is not explained by unobserved characteristics that may be the true source of a lower body mass index (BMI). Daily time-use diaries are used in combination with geographical characteristics of where respondents live and work to test 1) whether residents of more compact settlements are characterized by higher activity levels; and 2) whether residents of more compact settlements are more likely to bike or walk to work. An endogenous treatment model of active commuting allows testing whether reductions in BMI associated with walking or biking to work are in fact attributable to that activity or are more strongly associated with unobserved characteristics of these active commuters. The analysis of general activity levels confirms that residents of more compact cities do not expend more energy than residents of more sprawling cities, indicating that those in compact cities do not necessarily have a preference for more physical activity. The endogenous treatment model is consistent with walking or biking to work having an independent effect on BMI, as unobserved factors that contribute to a higher likelihood of active commuting are not associated with lower BMI. Despite evidence that more compact settlement patterns enable active commuting, only a small share of workers in these areas choose to walk or bike to work. In general, the activity level of residents in more compact cities and residents in more sprawling areas is very similar. But, there is a robust association between active commuting and lower body mass index that is not explained by unobserved attributes or preferences suggests that policies to promote active commuting may be effective. In particular, active commuting has a greater effect on BMI. Consequently, compact settlement appears to be an effective infrastructure for promoting more active lifestyles. The policy challenge is finding ways to ensure that this infrastructure is more widely utilized.

Can Walking or Biking to Work Really Make a Difference? Compact Development, Observed Commuter Choice and Body Mass Index

PubMed Central

Wojan, Timothy R.; Hamrick, Karen S.

2015-01-01

Objectives Promoting active commuting is viewed as one strategy to increase physical activity and improve the energy balance of more sedentary individuals thereby improving health outcomes. However, the potential effectiveness of promotion policies may be seriously undermined by the endogenous choice of commute mode. Policy to promote active commuting will be most effective if it can be demonstrated that 1) those in compact cities do not necessarily have a preference for more physical activity, and 2) that current active commuting is not explained by unobserved characteristics that may be the true source of a lower body mass index (BMI). Methods Daily time-use diaries are used in combination with geographical characteristics of where respondents live and work to test 1) whether residents of more compact settlements are characterized by higher activity levels; and 2) whether residents of more compact settlements are more likely to bike or walk to work. An endogenous treatment model of active commuting allows testing whether reductions in BMI associated with walking or biking to work are in fact attributable to that activity or are more strongly associated with unobserved characteristics of these active commuters. Results The analysis of general activity levels confirms that residents of more compact cities do not expend more energy than residents of more sprawling cities, indicating that those in compact cities do not necessarily have a preference for more physical activity. The endogenous treatment model is consistent with walking or biking to work having an independent effect on BMI, as unobserved factors that contribute to a higher likelihood of active commuting are not associated with lower BMI. Conclusions Despite evidence that more compact settlement patterns enable active commuting, only a small share of workers in these areas choose to walk or bike to work. In general, the activity level of residents in more compact cities and residents in more sprawling areas is very similar. But, there is a robust association between active commuting and lower body mass index that is not explained by unobserved attributes or preferences suggests that policies to promote active commuting may be effective. In particular, active commuting has a greater effect on BMI. Consequently, compact settlement appears to be an effective infrastructure for promoting more active lifestyles. The policy challenge is finding ways to ensure that this infrastructure is more widely utilized. PMID:26154176

From Lévy to Brownian: A Computational Model Based on Biological Fluctuation

PubMed Central

Nurzaman, Surya G.; Matsumoto, Yoshio; Nakamura, Yutaka; Shirai, Kazumichi; Koizumi, Satoshi; Ishiguro, Hiroshi

2011-01-01

Background Theoretical studies predict that Lévy walks maximizes the chance of encountering randomly distributed targets with a low density, but Brownian walks is favorable inside a patch of targets with high density. Recently, experimental data reports that some animals indeed show a Lévy and Brownian walk movement patterns when forage for foods in areas with low and high density. This paper presents a simple, Gaussian-noise utilizing computational model that can realize such behavior. Methodology/Principal Findings We extend Lévy walks model of one of the simplest creature, Escherichia coli, based on biological fluctuation framework. We build a simulation of a simple, generic animal to observe whether Lévy or Brownian walks will be performed properly depends on the target density, and investigate the emergent behavior in a commonly faced patchy environment where the density alternates. Conclusions/Significance Based on the model, animal behavior of choosing Lévy or Brownian walk movement patterns based on the target density is able to be generated, without changing the essence of the stochastic property in Escherichia coli physiological mechanism as explained by related researches. The emergent behavior and its benefits in a patchy environment are also discussed. The model provides a framework for further investigation on the role of internal noise in realizing adaptive and efficient foraging behavior. PMID:21304911

Biologically inspired adaptive walking of a quadruped robot.

PubMed

Kimura, Hiroshi; Fukuoka, Yasuhiro; Cohen, Avis H

2007-01-15

We describe here the efforts to induce a quadruped robot to walk with medium-walking speed on irregular terrain based on biological concepts. We propose the necessary conditions for stable dynamic walking on irregular terrain in general, and we design the mechanical and the neural systems by comparing biological concepts with those necessary conditions described in physical terms. PD-controller at joints constructs the virtual spring-damper system as the viscoelasticity model of a muscle. The neural system model consists of a central pattern generator (CPG), reflexes and responses. We validate the effectiveness of the proposed neural system model control using the quadruped robots called 'Tekken1&2'. MPEG footage of experiments can be seen at http://www.kimura.is.uec.ac.jp.

Association of Inflammation With Loss Of Ability to Walk 400 Meters: Longitudinal Findings From the Inchianti Study

PubMed Central

Vasunilashorn, Sarinnapha; Ferrucci, Luigi; Crimmins, Eileen M.; Bandinelli, Stefania; Guralnik, Jack M.; Patel, Kushang V.

2013-01-01

Objectives To examine relationships between eight markers of inflammation (interleukin [IL]-6, IL-6 receptor [R], C-reactive protein [CRP], tumor necrosis factor [TNF]-α, TNF receptor 1[R1], TNFR2, IL-1 receptor antagonist, IL-18) and incident loss of ability to walk 400 m. Design Prospective cohort study. Setting Older adults enrolled in the InvecchiareInChianti Study. Participants One thousand six community-dwelling participants aged 65+. Measurements The eight inflammatory markers were measured at baseline, and an inflammation score was calculated based on the number of inflammatory markers for which the participant was in the highest quartile. Incidence of mobility disability was determined among participants able to walk 400 m at baseline. Logistic regression models were used to determine whether each of the inflammatory markers and the inflammation score predicts loss of the ability to walk 400 m at six-year follow-up. Results After adjusting for covariates, individuals with aTNFR1 level in each of the top 3 quartiles (Q2, 3, 4) were more likely to be unable to walk 400 m at follow-up compared to those with TNFR1 levels in Q1. When adjusting for the same covariates, participants with an inflammation score of 3 or 4 were more likely to become unable to complete the 400 m walk at follow-up compared to participants with a score of 0. Conclusion These results bring additional evidence to the notion that inflammation is implicated in the mechanisms that cause incident mobility disability and suggest that a combined measure of inflammatory markers may improve our prediction of functional prognosis. PMID:24083386

Association of inflammation with loss of ability to walk 400 meters: longitudinal findings from the Invecchiare in Chianti Study.

PubMed

Vasunilashorn, Sarinnapha; Ferrucci, Luigi; Crimmins, Eileen M; Bandinelli, Stefania; Guralnik, Jack M; Patel, Kushang V

2013-10-01

To examine relationships between eight markers of inflammation (interleukin (IL)-6, IL-6 receptor (R), C-reactive protein (CRP), tumor necrosis factor (TNF)-alpha, TNF receptor 1 (R1), TNFR2, IL-1 receptor antagonist, IL-18) and incident loss of ability to walk 400 m. Prospective cohort study. Older adults enrolled in the Invecchiare in Chianti Study. Community-dwelling participants aged 65 and older (N = 1,006). The eight inflammatory markers were measured at baseline, and an inflammation score was calculated based on the number of inflammatory markers for which the participant was in the highest quartile. Incidence of mobility disability was determined in participants able to walk 400 m at baseline. Logistic regression models were used to determine whether each of the inflammatory markers and the inflammation score predicted loss of the ability to walk 400 m at 6-year follow-up. After adjusting for covariates, individuals with a TNFR1 level in each of the highest three quartiles (Q2, 3, 4) were more likely to be unable to walk 400 m at follow-up than those with TNFR1 levels in Q1. When adjusting for the same covariates, participants with an inflammation score of 3 or 4 were more likely to become unable to walk 400 m at follow-up than participants with a score of 0. These results provide additional evidence that inflammation is a factor in the mechanisms that cause incident mobility disability and suggest that a combined measure of inflammatory markers may improve prediction of functional prognosis. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

Effects of Descending Stair Walking on Health and Fitness of Elderly Obese Women.

PubMed

Chen, Trevor C; Hsieh, Chung-Chan; Tseng, Kuo-Wei; Ho, Chih-Chiao; Nosaka, Kazunori

2017-08-01

Eccentric exercise training produces positive fitness and health outcomes, but whether this is also the case for descending stair walking (DSW) is unknown. This study investigated the hypothesis that DSW would improve insulin sensitivity, lipid profiles and physical fitness better than ascending stair walking (ASW). Elderly (≥60 yr) obese women were placed to either DSW or ASW group (n = 15 per group). An elevator was used to eliminate ascending stairs for DSW, and descending stairs for ASW. Descending stair walking and ASW were performed twice a week for 12 wk by increasing the repetitions gradually. Overnight fasting blood samples were taken 3 d before the first training session and 4 d after the last training session, and analyzed for insulin sensitivity and lipid profile markers. Resting HR, systolic blood pressure, and diastolic blood pressure, bone mineral density, knee extensor maximal voluntary isometric contraction strength and several functional physical fitness measures were taken before and after the intervention. Average HR during DSW (88.6 ± 7.8 bpm) was lower (P < 0.05) than that of ASW (113.7 ± 10.9 bpm). Resting HR (-10%) and systolic blood pressure (-9%) decreased greater after DSW than ASW (-4% for both), and bone mineral density increased (6%) only for DSW (P < 0.05). Decreases in serum triacylglycerols, total and low-density lipoprotein cholesterols, glucose, insulin, homeostasis model assessment and whole blood glycosylated hemoglobin, and increases in high-density lipoprotein cholesterols were greater (P < 0.05) after DSW than ASW. Maximal voluntary isometric contraction strength increased greater for DSW (34%) than ASW (15%), and many of functional physical fitness measures showed greater (P < 0.05) improvement for DSW than ASW. These results supported the hypothesis and suggest that DSW is an effective exercise intervention for elderly obese women to improve their health and fitness.

Analysis of gait symmetry during over-ground walking in children with autism spectrum disorder.

PubMed

Eggleston, Jeffrey D; Harry, John R; Hickman, Robbin A; Dufek, Janet S

2017-06-01

Gait symmetry is utilized as an indicator of neurologic function. Healthy gait often exhibits minimal asymmetries, while pathological gait exhibits exaggerated asymmetries. The purpose of this study was to examine symmetry of mechanical gait parameters during over-ground walking in children with Autism Spectrum Disorder (ASD). Kinematic and kinetic data were obtained from 10 children (aged 5-12 years) with ASD. The Model Statistic procedure (α=0.05) was used to compare gait related parameters between limbs. Analysis revealed children with ASD exhibit significant lower extremity joint position and ground reaction force asymmetries throughout the gait cycle. The observed asymmetries were unique for each subject. These data do not support previous research relative to gait symmetry in children with ASD. Many individuals with ASD do not receive physical therapy interventions, however, precision medicine based interventions emphasizing lower extremity asymmetries may improve gait function and improve performance during activities of daily living. Copyright © 2017 Elsevier B.V. All rights reserved.

Project U-Turn: increasing active transportation in Jackson, Michigan.

PubMed

TenBrink, David S; McMunn, Randall; Panken, Sarah

2009-12-01

Jackson, Michigan, is a medium-sized city suffering from a bad economy and obesity-related health issues. Nearly 20% of the 36,000 residents live below the poverty line. It is a relatively young city (median age of 30 years) with a mixed ethnicity (20% black, 73% white, 4% Hispanic). The city offers many structured, active recreational opportunities, but has not integrated physical activity into daily life. Project U-Turn aimed to increase active transportation (e.g., biking, walking, and transit use) through an integrated approach to Active Living by Design's community action model and the Michigan Safe Routes to School model. Resources were focused on active living promotions and programs; partnership meetings were the source of changes in policy and physical projects. Each initiative was designed to introduce each of the 5Ps (preparation, promotion, programs, policy, and physical projects) to build support for the partnership's overall work. The partnership collected snapshot data of community walking and biking behavior, percentage of students walking to school, participation in events and programs, and new physical projects. Jackson saw a vast improvement in physical infrastructure and policy and a related increase in walking and biking in the community. The project engaged in purposeful partnership building to implement effective programs and promotions that built support for policy and physical projects. Limited resources were best used by encouraging partners to contribute and coordinate activities using existing staff, funding, and resources. Jackson has seen a shift toward awareness of the benefits of active living on community health, economic development, and environmental awareness.

Walking strategies of visually impaired people on trapezoidal- and sinusoidal-section tactile groundsurface indicators.

PubMed

Ranavolo, A; Conte, C; Iavicoli, S; Serrao, M; Silvetti, A; Sandrini, G; Pierelli, F; Draicchio, F

2011-03-01

The visual system in walking serves to perceive feedback or feed-forward signals. Therefore, visually impaired persons (VIP) have biased motor control mechanisms. The use of leading indicators (LIs) and long canes helps to improve their walking efficiency. The aims of this study were to compare the walking efficiency of VIP on trapezoidal- and sinusoidal-section LIs using an optoelectronic motion analysis system. VIP displayed a significantly longer stance phase, a shorter swing phase and shorter step and stride lengths when they walked on the sinusoidal LI than when they walked on the trapezoidal LI. Compared with the trapezoidal LI, VIP walking on the sinusoidal LI displayed significantly lower joint ranges of motion. The centre of mass lateral displacement was wider for VIP walking on the sinusoidal LI than on the trapezoidal LI. Some significant differences were also found in sighted persons walking on both LIs. In conclusion, the trapezoidal shape enabled visually impaired subjects to walk more efficiently, whereas the sinusoidal shape caused dynamic balance problems. STATEMENT OF RELEVANCE: These findings suggest that VIP can walk more efficiently, with a lower risk of falls, on trapezoidal-section than on sinusoidal-section LIs. These results should be considered when choosing the most appropriate ground tactile surface indicators for widespread use.

The Effects of Walking Speed on Tibiofemoral Loading Estimated Via Musculoskeletal Modeling

PubMed Central

Lerner, Zachary F.; Haight, Derek J.; DeMers, Matthew S.; Board, Wayne J.; Browning, Raymond C.

2015-01-01

Net muscle moments (NMMs) have been used as proxy measures of joint loading, but musculoskeletal models can estimate contact forces within joints. The purpose of this study was to use a musculoskeletal model to estimate tibiofemoral forces and to examine the relationship between NMMs and tibiofemoral forces across walking speeds. We collected kinematic, kinetic, and electromyographic data as ten adult participants walked on a dual-belt force-measuring treadmill at 0.75, 1.25, and 1.50 m/s. We scaled a musculoskeletal model to each participant and used OpenSim to calculate the NMMs and muscle forces through inverse dynamics and weighted static optimization, respectively. We determined tibiofemoral forces from the vector sum of intersegmental and muscle forces crossing the knee. Estimated tibiofemoral forces increased with walking speed. Peak early-stance compressive tibiofemoral forces increased 52% as walking speed increased from 0.75 to 1.50 m/s, whereas peak knee extension NMMs increased by 168%. During late stance, peak compressive tibiofemoral forces increased by 18% as speed increased. Although compressive loads at the knee did not increase in direct proportion to NMMs, faster walking resulted in greater compressive forces during weight acceptance and increased compressive and anterior/posterior tibiofemoral loading rates in addition to a greater abduction NMM. PMID:23878264

Recruitment of prefrontal-striatal circuit in response to skilled motor challenge.

PubMed

Guo, Yumei; Wang, Zhuo; Prathap, Sandhya; Holschneider, Daniel P

2017-12-13

A variety of physical fitness regimens have been shown to improve cognition, including executive function, yet our understanding of which parameters of motor training are important in optimizing outcomes remains limited. We used functional brain mapping to compare the ability of two motor challenges to acutely recruit the prefrontal-striatal circuit. The two motor tasks - walking in a complex running wheel with irregularly spaced rungs or walking in a running wheel with a smooth internal surface - differed only in the extent of skill required for their execution. Cerebral perfusion was mapped in rats by intravenous injection of [C]-iodoantipyrine during walking in either a motorized complex wheel or in a simple wheel. Regional cerebral blood flow (rCBF) was quantified by whole-brain autoradiography and analyzed in three-dimensional reconstructed brains by statistical parametric mapping and seed-based functional connectivity. Skilled or simple walking compared with rest, increased rCBF in regions of the motor circuit, somatosensory and visual cortex, as well as the hippocampus. Significantly greater rCBF increases were noted during skilled walking than for simple walking. Skilled walking, unlike simple walking or the resting condition, was associated with a significant positive functional connectivity in the prefrontal-striatal circuit (prelimbic cortex-dorsomedial striatum) and greater negative functional connectivity in the prefrontal-hippocampal circuit. Our findings suggest that the level of skill of a motor training task determines the extent of functional recruitment of the prefrontal-corticostriatal circuit, with implications for a new approach in neurorehabilitation that uses circuit-specific neuroplasticity to improve motor and cognitive functions.

Gait training with partial body weight support during overground walking for individuals with chronic stroke: a pilot study

PubMed Central

2011-01-01

Background It is not yet established if the use of body weight support (BWS) systems for gait training is effective per se or if it is the combination of BWS and treadmill that improves the locomotion of individuals with gait impairment. This study investigated the effects of gait training on ground level with partial BWS in individuals with stroke during overground walking with no BWS. Methods Twelve individuals with chronic stroke (53.17 ± 7.52 years old) participated of a gait training program with BWS during overground walking, and were evaluated before and after the gait training period. In both evaluations, individuals were videotaped walking at a self-selected comfortable speed with no BWS. Measurements were obtained for mean walking speed, step length, stride length and speed, toe-clearance, durations of total double stance and single-limb support, and minimum and maximum foot, shank, thigh, and trunk segmental angles. Results After gait training, individuals walked faster, with symmetrical steps, longer and faster strides, and increased toe-clearance. Also, they displayed increased rotation of foot, shank, thigh, and trunk segmental angles on both sides of the body. However, the duration of single-limb support remained asymmetrical between each side of the body after gait training. Conclusions Gait training individuals with chronic stroke with BWS during overground walking improved walking in terms of temporal-spatial parameters and segmental angles. This training strategy might be adopted as a safe, specific and promising strategy for gait rehabilitation after stroke. PMID:21864373

Effects of treadmill training with the eyes closed on gait and balance ability of chronic stroke patients.

PubMed

Kim, Yong-Wook; Moon, Sung-Jun

2015-09-01

[Purpose] The purpose of this study was to compare the effect of treadmill walking with the eyes closed and open on the gait and balance abilities of chronic stroke patients. [Subjects and Methods] Thirty patients with chronic stroke participated in this study. The treadmill gait training for each group lasted 40 minutes, and sessions were held 3 times a week for 4 weeks. Gait ability was measured using a Biodex Gait Trainer Treadmill System. Balance ability was measured using a Biodex Balance System. [Results] After the treadmill training' the treadmill training with eyes closed (TEC) group showed significant improvements in walking distance' step length' coefficient of variation' and limit of stability (overall' lateral affected' forward lateral unaffected) compared to the treadmill training with eyes open (TEO) group. [Conclusion] The walking and balance abilities of the TEC participants showed more improvement after the treadmill walking sessions than those of the TEO participants. Therefore' treadmill walking with visual deprivation may be useful for the rehabilitation of patients with chronic stroke.

Walking mediates associations between neighborhood activity supportiveness and BMI in the Women’s Health Initiative San Diego cohort

PubMed Central

Remigio-Baker, Rosemay A.; Anderson, Cheryl A. M.; Adams, Marc A.; Norman, Gregory J.; Kerr, Jacqueline; Criqui, Michael H.; Allison, Matthew

2016-01-01

Objectives To investigate whether walking mediates neighborhood built environment associations with weight status in middle- and older-aged women. Methods Participants (N=5085; mean age=64±7.7; 75.4% White non-Hispanic) were from the Women’s Health Initiative San Diego cohort baseline visits. Body mass index (BMI) and waist circumference were measured objectively. Walking was assessed via survey. The geographic information system (GIS)-based home neighborhood activity supportiveness index included residential density, street connectivity, land use mix, and number of parks. Results BMI was 0.22 units higher and the odds ratio for being obese (vs. normal or overweight) was 8% higher for every standard deviation decrease in neighborhood activity supportiveness. Walking partially mediated these associations (22–23% attenuation). Findings were less robust for waist circumference. Conclusions Findings suggest women who lived in activity-supportive neighborhoods had a lower BMI than their counterparts, in part because they walked more. Improving neighborhood activity supportiveness has population-level implications for improving weight status and health. PMID:26798961

Walking mediates associations between neighborhood activity supportiveness and BMI in the Women's Health Initiative San Diego cohort.

PubMed

Carlson, Jordan A; Remigio-Baker, Rosemay A; Anderson, Cheryl A M; Adams, Marc A; Norman, Gregory J; Kerr, Jacqueline; Criqui, Michael H; Allison, Matthew

2016-03-01

To investigate whether walking mediates neighborhood built environment associations with weight status in middle- and older-aged women. Participants (N=5085; mean age=64 ± 7.7; 75.4% White non-Hispanic) were from the Women's Health Initiative San Diego cohort baseline visits. Body mass index (BMI) and waist circumference were measured objectively. Walking was assessed via survey. The geographic information system (GIS)-based home neighborhood activity supportiveness index included residential density, street connectivity, land use mix, and number of parks. BMI was 0.22 units higher and the odds ratio for being obese (vs. normal or overweight) was 8% higher for every standard deviation decrease in neighborhood activity supportiveness. Walking partially mediated these associations (22-23% attenuation). Findings were less robust for waist circumference. Findings suggest women who lived in activity-supportive neighborhoods had a lower BMI than their counterparts, in part because they walked more. Improving neighborhood activity supportiveness has population-level implications for improving weight status and health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three-Dimensional Modeling of the Brain's ECS by Minimum Configurational Energy Packing of Fluid Vesicles

PubMed Central

Nandigam, Ravi K.; Kroll, Daniel M.

2007-01-01

The extracellular space of the brain is the heterogeneous porous medium formed by the spaces between the brain cells. Diffusion in this interstitial space is the mechanism by which glucose and oxygen are delivered to the brain cells from the vascular system. It is also a medium for the transport of certain informational substances between the cells (called volume transmission), and for drug delivery. This work involves three-dimensional modeling of the extracellular space as void space in close-packed arrays of fluid membrane vesicles. These packings are generated by minimizing the configurational energy using a Monte Carlo procedure. Both regular and random packs of vesicles are considered. A random walk algorithm is then used to compute the geometric tortuosities, and the results are compared with published experimental data. For the random packings, it is found that although the absolute values for the tortuosities differ, the dependence of the tortuosity on pore volume fraction is very similar to that observed in experiment. The tortuosities we measure are larger than those computed in previous studies of packings of convex polytopes, and modeling improvements, which require higher resolution studies and an improved modeling of brain cell shapes and mechanical properties, could help resolve remaining discrepancies between model simulations and experiment. It is also shown that the specular reflection scheme is the appropriate technique for implementing zero-flux boundary conditions in random walk simulations commonly encountered in diffusion problems. PMID:17307830

Three-dimensional modeling of the brain's ECS by minimum configurational energy packing of fluid vesicles.

PubMed

Nandigam, Ravi K; Kroll, Daniel M

2007-05-15

The extracellular space of the brain is the heterogeneous porous medium formed by the spaces between the brain cells. Diffusion in this interstitial space is the mechanism by which glucose and oxygen are delivered to the brain cells from the vascular system. It is also a medium for the transport of certain informational substances between the cells (called volume transmission), and for drug delivery. This work involves three-dimensional modeling of the extracellular space as void space in close-packed arrays of fluid membrane vesicles. These packings are generated by minimizing the configurational energy using a Monte Carlo procedure. Both regular and random packs of vesicles are considered. A random walk algorithm is then used to compute the geometric tortuosities, and the results are compared with published experimental data. For the random packings, it is found that although the absolute values for the tortuosities differ, the dependence of the tortuosity on pore volume fraction is very similar to that observed in experiment. The tortuosities we measure are larger than those computed in previous studies of packings of convex polytopes, and modeling improvements, which require higher resolution studies and an improved modeling of brain cell shapes and mechanical properties, could help resolve remaining discrepancies between model simulations and experiment. It is also shown that the specular reflection scheme is the appropriate technique for implementing zero-flux boundary conditions in random walk simulations commonly encountered in diffusion problems.

24 CFR 9.103 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... maintenance, re-roofing, painting, or wallpapering or changes to mechanical and electrical systems are not... buildings, structures, site improvements, complexes, equipment, roads, walks, passageways, parking lots... whole of one or more residential structures and appurtenant structures, equipment, roads, walks, and...

24 CFR 9.103 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... maintenance, re-roofing, painting, or wallpapering or changes to mechanical and electrical systems are not... buildings, structures, site improvements, complexes, equipment, roads, walks, passageways, parking lots... whole of one or more residential structures and appurtenant structures, equipment, roads, walks, and...

24 CFR 9.103 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... maintenance, re-roofing, painting, or wallpapering or changes to mechanical and electrical systems are not... buildings, structures, site improvements, complexes, equipment, roads, walks, passageways, parking lots... whole of one or more residential structures and appurtenant structures, equipment, roads, walks, and...

Functional effects of treadmill-based gait training at faster speeds in stroke survivors: a prospective, single-group study.

PubMed

Mohammadi, Roghayeh; Ershad, Navid; Rezayinejad, Marziyeh; Fatemi, Elham; Phadke, Chetan P

2017-09-01

To examine the functional effects of walking retraining at faster than self-selected speed (SSS). Ten individuals with chronic stroke participated in a 4-week training over a treadmill at walking speeds 40% faster than SSS, three times per week, 30 min/session. Outcome measures assessed before, after, and 2 months after the end of intervention were the Timed Up and Go, the 6-Minute Walk, the 10-Meter Walk test, the Modified Ashworth Scale, SSS, and fastest comfortable speed. After 4 weeks of training, all outcome measures showed clinically meaningful and statistically significant improvements (P<0.05) that were maintained at 2 months after the end of the training. The results showed that a strategy of training at a speed 40% faster than SSS can improve functional activity in individuals with chronic stroke, with effects lasting up to 2 months after the intervention.

Does acupuncture ameliorate motor impairment after stroke? An assessment using the CatWalk gait system.

PubMed

Cao, Yan; Sun, Ning; Yang, Jing-Wen; Zheng, Yang; Zhu, Wen; Zhang, Zhen-Hua; Wang, Xue-Rui; Shi, Guang-Xia; Liu, Cun-Zhi

2017-07-01

The effect of acupuncture on gait deficits after stroke is uncertain. This animal study was designed to determine whether acupuncture improves gait impairment following experimentally induced ischemic stroke. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in rats. After 7 days' of acupuncture treatment, assessment of gait changes using the CatWalk automated gait analysis system was performed. Comparison of the CatWalk gait parameters among the groups showed that gait function was impaired after ischemic stroke and acupuncture treatment was effective in improving a variety of gait parameters including intensity, stance and swing time, swing speed and stride length at postoperative day 8. This study demonstrates a beneficial effect of acupuncture on gait impairment in rats following ischemic stroke. Further studies aimed to investigate the effects of acupuncture at different stages during stroke using the CatWalk system are required. Copyright © 2016 Elsevier Ltd. All rights reserved.

A randomized controlled trial of movement strategies compared with exercise for people with Parkinson's disease.

PubMed

Morris, Meg E; Iansek, Robert; Kirkwood, Beth

2009-01-15

This randomized controlled clinical trial was conducted to compare the effects of movement rehabilitation strategies and exercise therapy in hospitalized patients with idiopathic Parkinson's disease. Participants were randomly assigned to a group that received movement strategy training or musculoskeletal exercises during 2 consecutive weeks of hospitalization. The primary outcome was disability as measured by the Unified Parkinson's Disease Rating Scale, UPDRS (motor and ADL components). Secondary outcomes were balance, walking speed, endurance, and quality of life. Assessments were carried out by blinded testers at baseline, after the 2 weeks of treatment and 3 months after discharge. The movement strategy group showed improvements on several outcome measures from admission to discharge, including the UPDRS, 10 m walk, 2 minute walk, balance, and PDQ39. However, from discharge to follow up there was significant regression in performance on the 2 minute walk and PDQ39. For the exercise group, quality of life improved significantly during inpatient hospitalization and this was retained at follow-up. Inpatient rehabilitation produces short term reductions in disability and improvements in quality of life in people with Parkinson's disease.

Motion Controlled Gait Enhancing Mobile Shoe for Rehabilitation

PubMed Central

Handzic, Ismet; Vasudevan, Erin V.; Reed, Kyle B.

2011-01-01

Walking on a split-belt treadmill, which has two belts that can be run at different speeds, has been shown to improve walking patterns post-stroke. However, these improvements are only temporarily retained once individuals transition to walking over ground. We hypothesize that longer-lasting effects would be observed if the training occurred during natural walking over ground, as opposed to on a treadmill. In order to study such long-term effects, we have developed a mobile and portable device which can simulate the same gait altering movements experienced on a split-belt treadmill. The new motion controlled gait enhancing mobile shoe improves upon the previous version’s drawbacks. This version of the GEMS has motion that is continuous, smooth, and regulated with on-board electronics. A vital component of this new design is the Archimedean spiral wheel shape that redirects the wearer’s downward force into a horizontal backward motion. The design is passive and does not utilize any motors. Its motion is regulated only by a small magnetic particle brake. Further experimentation is needed to evaluate the long-term after-effects. PMID:22275620

Bayesian latent structure modeling of walking behavior in a physical activity intervention

PubMed Central

Lawson, Andrew B; Ellerbe, Caitlyn; Carroll, Rachel; Alia, Kassandra; Coulon, Sandra; Wilson, Dawn K; VanHorn, M Lee; St George, Sara M

2017-01-01

The analysis of walking behavior in a physical activity intervention is considered. A Bayesian latent structure modeling approach is proposed whereby the ability and willingness of participants is modeled via latent effects. The dropout process is jointly modeled via a linked survival model. Computational issues are addressed via posterior sampling and a simulated evaluation of the longitudinal model’s ability to recover latent structure and predictor effects is considered. We evaluate the effect of a variety of socio-psychological and spatial neighborhood predictors on the propensity to walk and the estimation of latent ability and willingness in the full study. PMID:24741000

Evaluation of the Wii Balance Board for walking aids prediction: proof-of-concept study in total knee arthroplasty.

PubMed

Pua, Yong-Hao; Clark, Ross A; Ong, Peck-Hoon

2015-01-01

To provide proof-of-concept for the validity of the Wii Balance Board (WBB) measures to predict the type of walking aids required by inpatients with a recent (≤4 days) total knee arthroplasty (TKA). A cross-sectional sample of 89 inpatients (mean age, 67.0±8 years) with TKA was analyzed. A multivariable proportional odds prediction model was constructed using 8 pre-specified predictors – namely, age, sex, body mass index, knee pain, knee range-of-motion, active knee lag, and WBB-derived standing balance. The type of walking aids prescribed on day 4 post-surgery was the outcome of interest – an ordinal variable with 4 categories (walking stick, narrow- and broad-base quadstick, and walking frame). Women, increasing body mass index, and poorer standing balance were independently associated with greater odds for requiring walking aids with a larger base-of-support. The concordance-index of the prediction model was 0.74. The model comprising only WBB-derived standing balance had nearly half (44%) the explanatory power of the full model. Adding WBB-derived standing balance to conventional demographic and knee variables resulted in a continuous net reclassification index of 0.60 (95%CI,0.19-1.01), predominantly due to better identification of patients who required walking aids with a large base-of-support (sensitivity gain). The WBB was able to provide quantitative measures of standing balance which could assist healthcare professionals in prescribing the appropriate type of walking aids for patients. Further investigation is needed to assess whether using the WBB could lead to meaningful changes in clinical outcomes such as falls.

Evaluation of the Wii Balance Board for Walking Aids Prediction: Proof-of-Concept Study in Total Knee Arthroplasty

PubMed Central

Pua, Yong-Hao; Clark, Ross A.; Ong, Peck-Hoon

2015-01-01

Background and Objectives To provide proof-of-concept for the validity of the Wii Balance Board (WBB) measures to predict the type of walking aids required by inpatients with a recent (≤4days) total knee arthroplasty (TKA). Methods A cross-sectional sample of 89 inpatients (mean age, 67.0±8years) with TKA was analyzed. A multivariable proportional odds prediction model was constructed using 8 pre-specified predictors – namely, age, sex, body mass index, knee pain, knee range-of-motion, active knee lag, and WBB-derived standing balance. The type of walking aids prescribed on day 4 post-surgery was the outcome of interest – an ordinal variable with 4 categories (walking stick, narrow- and broad-base quadstick, and walking frame). Results Women, increasing body mass index, and poorer standing balance were independently associated with greater odds for requiring walking aids with a larger base-of-support. The concordance-index of the prediction model was 0.74. The model comprising only WBB-derived standing balance had nearly half (44%) the explanatory power of the full model. Adding WBB-derived standing balance to conventional demographic and knee variables resulted in a continuous net reclassification index of 0.60 (95%CI,0.19-1.01), predominantly due to better identification of patients who required walking aids with a large base-of-support (sensitivity gain). Conclusions The WBB was able to provide quantitative measures of standing balance which could assist healthcare professionals in prescribing the appropriate type of walking aids for patients. Further investigation is needed to assess whether using the WBB could lead to meaningful changes in clinical outcomes such as falls. PMID:25615952

An intervention to promote physical activity and self-management in people with stable chronic heart failure The Home-Heart-Walk study: study protocol for a randomized controlled trial

PubMed Central

2011-01-01

Background Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF. Methods/Design A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain). All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour. Discussion A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings. Trial Registration Australian New Zealand Clinical Trial Registry 12609000437268 PMID:21366927