Increase In Step Length Research Articles

Effects of 12-week supervised treadmill training on spatio-temporal gait parameters in patients with claudication

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).Implications for RehabilitationTwelve-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.

A System for Real-Time Feedback to Improve Gait and Posture in Parkinson's Disease.

For people with Parkinson's disease (PD), gait and postural impairments can significantly affect their ability to perform activities of daily living. Presentation of appropriate cues has been shown to improve gait in PD. Based on this, a treadmill-based system and experimental paradigm were developed to determine if people with PD can utilize real-time feedback (RTFB) of step length or back angle (uprightness) to improve gait and posture. Eleven subjects (mean age 67 ± 8 years) with mild-to-moderate PD (Hoehn and Yahr stage I-III) were evaluated regarding their ability to successfully utilize RTFB of back angle or step length during quiet standing and treadmill walking tasks during a single session in their medication-on state. Changes in back angle and step length due to feedback were compared using Friedman nonparametric tests with Wilcoxon Signed-Rank tests for post-hoc comparisons. Improvements in uprightness were observed as an increase in back angle during quiet standing (p = 0.005) and during treadmill walking (p = 0.005) with back angle feedback when compared to corresponding tasks without feedback. Improvements in gait were also observed as an increase in step length (p = 0.005) during step length feedback compared to tasks without feedback. These results indicate that people with mild-to-moderate PD can utilize RTFB to improve upright posture and gait. Future work will investigate the long-term effects of this RTFB paradigm and the development of systems for clinical or home-based use.

Effect of 24-h continuous rotigotine treatment on stationary and non-stationary locomotion in de novo patients with Parkinson disease in an open-label uncontrolled study.

The aim of this study was to investigate the effect of a rotigotine transdermal patch on stationary and non-stationary locomotion in de novo Parkinson disease (PD) patients in an open-label uncontrolled study. A 3-D gait analysis system was used to investigate four different locomotor tasks: steady-state linear walking, gait initiation, gait termination and 180°-turning. A series of gait variables were measured for each locomotor task. PD patients who received rotigotine treatment (4-8 mg) displayed: (1) increased step length, gait speed, cadence and arm oscillations, and reduced double support duration and step asymmetry during steady-state linear gait; (2) increased initial step length during gait initiation; (3) increased final step length and gait speed, and decreased stability index during gait termination; (4) decreased duration of turning and head-pelvis delays during 180°-turning. The main finding that emerges from the present study is that the dopamine agonist rotigotine can improve various aspects of gait in de novo PD patients.

Effects of a wearable exoskeleton stride management assist system (SMA®) on spatiotemporal gait characteristics in individuals after stroke: a randomized controlled trial.

BackgroundRobots offer an alternative, potentially advantageous method of providing repetitive, high-dosage, and high-intensity training to address the gait impairments caused by stroke. In this study, we compared the effects of the Stride Management Assist (SMA®) System, a new wearable robotic device developed by Honda R&D Corporation, Japan, with functional task specific training (FTST) on spatiotemporal gait parameters in stroke survivors.MethodsA single blinded randomized control trial was performed to assess the effect of FTST and task-specific walking training with the SMA® device on spatiotemporal gait parameters. Participants (n = 50) were randomly assigned to FTST or SMA. Subjects in both groups received training 3 times per week for 6–8 weeks for a maximum of 18 training sessions. The GAITRite® system was used to collect data on subjects’ spatiotemporal gait characteristics before training (baseline), at mid-training, post-training, and at a 3-month follow-up.ResultsAfter training, significant improvements in gait parameters were observed in both training groups compared to baseline, including an increase in velocity and cadence, a decrease in swing time on the impaired side, a decrease in double support time, an increase in stride length on impaired and non-impaired sides, and an increase in step length on impaired and non-impaired sides. No significant differences were observed between training groups; except for SMA group, step length on the impaired side increased significantly during self-selected walking speed trials and spatial asymmetry decreased significantly during fast-velocity walking trials.ConclusionsSMA and FTST interventions provided similar, significant improvements in spatiotemporal gait parameters; however, the SMA group showed additional improvements across more parameters at various time points. These results indicate that the SMA® device could be a useful therapeutic tool to improve spatiotemporal parameters and contribute to improved functional mobility in stroke survivors. Further research is needed to determine the feasibility of using this device in a home setting vs a clinic setting, and whether such home use provides continued benefits.Trial registrationThis study is registered under the title “Development of walk assist device to improve community ambulation” and can be located in clinicaltrials.gov with the study identifier: NCT01994395.

Gait Alterations During Constant Pace Treadmill Racewalking.

Racewalking is an Olympic event requiring great endurance, and racewalkers often use treadmills in training because of the benefits of having a flat unchanging surface where pace judgment can be learned and because inclement weather can be avoided. The effects of fatigue associated with racewalking on a treadmill have not been studied and could be informative with regard to the maintenance of legal technique. The aim of this study was to measure key gait variables during a physically demanding treadmill racewalk. Fourteen international racewalkers completed 10 km on an instrumented treadmill at a pace equivalent to 103% of their recent best time. Spatiotemporal and ground reaction force data were recorded at 4 distances. High-speed videography data were simultaneously recorded to analyze changes in knee angle between the early and late stages. Increases in step length and corresponding decreases in cadence were found, although the small changes were not considered meaningful. There was also a small increase in flight time and a small decrease in push-off force. There were no other significant changes for any other variables (including knee angles). The increase in flight time might be important given that racewalkers are not permitted a visible loss of contact and suggests that fatiguing sessions on a treadmill can lead to the adoption of nonlegal technique. However, this disadvantage of treadmill training can be negated if the coach scrutinizes athletes throughout the session, and overall the consistent technique used is of benefit with regard to learning correct form and pacing ability.

Mobile Phone-Connected Wearable Motion Sensors to Assess Postoperative Mobilization

BackgroundEarly mobilization after surgery reduces the incidence of a wide range of complications. Wearable motion sensors measure movements over time and transmit this data wirelessly, which has the potential to monitor patient recovery and encourages patients to engage in their own rehabilitation.ObjectiveWe sought to determine the ability of off-the-shelf activity sensors to remotely monitor patient postoperative mobility.MethodsConsecutive subjects were recruited under the Department of Neurosurgery at Columbia University. Patients were enrolled during physical therapy sessions. The total number of steps counted by the two blinded researchers was compared to the steps recorded on four activity sensors positioned at different body locations.ResultsA total of 148 motion data points were generated. The start time, end time, and duration of each walking session were accurately recorded by the devices and were remotely available for the researchers to analyze. The sensor accuracy was significantly greater when placed over the ankles than over the hips (P<.001). Our multivariate analysis showed that step length was an independent predictor of sensor accuracy. On linear regression, there was a modest positive correlation between increasing step length and increased ankle sensor accuracy (r=.640, r 2=.397) that reached statistical significance on the multivariate model (P=.03). Increased gait speed also correlated with increased ankle sensor accuracy, although less strongly (r=.444, r 2=.197). We did not note an effect of unilateral weakness on the accuracy of left- versus right-sided sensors. Accuracy was also affected by several specific measures of a patient’s level of physical assistance, for which we generated a model to mathematically adjust for systematic underestimation as well as disease severity.ConclusionsWe provide one of the first assessments of the accuracy and utility of widely available and wirelessly connected activity sensors in a postoperative patient population. Our results show that activity sensors are able to provide invaluable information about a patient’s mobility status and can transmit this data wirelessly, although there is a systematic underestimation bias in more debilitated patients.

Balance and Gait Impairment in Transient Ischemic Attack and Minor Stroke

There has been little research into gait and balance impairment in transient ischemic attack (TIA) and minor stroke, despite these conditions affecting large numbers of people and the potential impact on function. The aim of this study was to determine the impact of TIA and minor stroke on gait and balance. Twelve people with TIA or minor stroke without previous gait/balance problems and 12 age- and sex-matched controls were recruited. Participants (mean age 67 years) underwent a comprehensive assessment including physiological, balance, and gait measures (clinical and computerized [NeuroCom/GAITRite]). Matched-pairs analysis was undertaken. Groups were similar in body mass index, vision, leg proprioception/strength, and reaction time. Cognition was worse in the TIA/minor stroke group: mean Montreal Cognitive Assessment score 22.2 versus 26.6, P = .001. People with TIA/minor stroke were significantly worse on all but one clinical test. Median scores for TIA/minor stroke versus control were as follows: Timed Up and Go (TUG), 9.4 versus 7.6 seconds, P = .019; TUG dual task, 12.3 versus 8.5 seconds, P = .012; Four Square Step Test, 10.9 versus 7.2 seconds, P = .006. Mean Step Test score for TIA/minor stroke versus control was 14.1 versus 17.7, P = .021. The TIA/minor stroke group also had significantly worse performance on computerized tests: increased turn time/sway, increased step length, slower comfortable/fast gait speeds, and greater proportion of gait cycle spent in double support. This study found that people with TIA/minor stroke have gait and balance dysfunction despite having no obvious physiological impairments. Intervention studies aimed at improving balance and gait in this population are needed.

Patients with chronic non-specific low back pain who reported reduction in pain and improvement in function also demonstrated an improvement in gait pattern.

To assess the changes in gait pattern and clinical symptoms of patients with chronic non-specific low back pain (CNSLBP) following a home-based biomechanical treatment (HBBT). This was a retrospective analysis of 60 CNSLBP patients. All patients underwent a gait evaluation and completed self-assessment questionnaires at pre-treatment and after 3 and 6months of a HBBT (AposTherapy). Twenty-four healthy, aged-matched individuals served as a reference group. Significant differences were found in all gait parameters and clinical symptoms between patients with CNSLBP and healthy people before treatment. Significant improvements were found in all gait parameters and clinical measures following 6months of therapy including an increase in gait velocity (10.6%), step length (5.6%), cadence (5%), and quality of life and a decrease in pain (13.3%). There were no significant differences between groups in the gait parameters following 6months of treatment. Significant differences exist between patients with CNSLBP and healthy controls in terms of gait pattern and self-assessed health status. The examined HBBT led to significant improvements in gait pattern, reduction in pain, improved function and increased quality of life. However, future studies should validate these results while comparing this treatment to other treatment modalities.

Do measures of reactive balance control predict falls in people with stroke returning to the community?

ObjectiveTo determine if reactive balance control measures predict falls after discharge from stroke rehabilitation. DesignProspective cohort study. SettingRehabilitation hospital and community. ParticipantsIndependently ambulatory individuals with stroke who were discharged home after inpatient rehabilitation (n=95). Main outcome measuresBalance and gait measures were obtained from a clinical assessment at discharge from inpatient stroke rehabilitation. Measures of reactive balance control were obtained: (1) during quiet standing; (2) when walking; and (3) in response to large postural perturbations. Participants reported falls and activity levels up to 6 months post-discharge. Logistic and Poisson regressions were used to identify measures of reactive balance control that were related to falls post-discharge. ResultsDecreased paretic limb contribution to standing balance control [rate ratio 0.8, 95% confidence interval (CI) 0.7 to 1.0; P=0.011], reduced between-limb synchronisation of quiet standing balance control (rate ratio 0.9, 95% CI 0.8 to 0.9; P<0.0001), increased step length variability (rate ratio 1.4, 95% CI 1.2 to 1.7; P=0.0011) and inability to step with the blocked limb (rate ratio 1.2, 95% CI 1.0 to 1.3; P=0.013) were significantly associated with increased fall rates when controlling for age, stroke severity, functional balance and daily walking activity. ConclusionsImpaired reactive balance control in standing and walking predicted increased risk of falls post-discharge from stroke rehabilitation. Specifically, measures that revealed the capacity of both limbs to respond to instability were related to increased risk of falls. These results suggest that post-stroke rehabilitation strategies for falls prevention should train responses to instability, and focus on remediating dyscontrol in the more-affected limb.

Adaptation to large-magnitude treadmill-based perturbations: improvements in reactive balance response.

We aimed to examine the trial-to-trial changes in the reactive balance response to large magnitude slip-like treadmill perturbations in stance and whether the acquired adaptive changes could be appropriately scaled to a higher intensity perturbation. Seventeen young adults experienced 15 slips for training on level I intensity. Pre- and post-training slips were delivered at a higher intensity (20% > level I). Pre- and post-slip onset stability (at liftoff and touchdown of stepping limb) was measured as the shortest distance of the center of mass (COM) position (XCOM/BOS) and velocity (ẊCOM/BOS) relative to base of support (BOS) from a predicted threshold for backward loss of balance. The number of steps to recover balance, compensatory step length and peak trunk angle were recorded. The post-slip onset stability (at liftoff and touchdown) significantly increased across the trials with no change in preslip stability. Improvement in stability at touchdown positively correlated with an anterior shift in XCOM/BOS but not with ẊCOM/BOS. Consequently, the number of steps required to recover balance declined. The adaptive change in XCOM/BOS resulted from an increase in compensatory step length and reduced trunk extension. Individuals also improved post-slip onset stability on a higher intensity perturbation post-training compared with the pre-training trial. The results support that the CNS adapts to fixed intensity slip-like perturbations primarily by improving the reactive stability via modulation in compensatory step length and trunk extension. Furthermore, based on prior experience from the training phase, the acquired adaptive response can be successfully calibrated to a higher intensity perturbation.

Effects of a light touch on fixed or mobile supports on gait parameters in visually restricted young adults

We investigated the effects of lightly touching fixed and mobile supports on gait parameters and center of mass oscillations in visually restricted young adults. Fourteen healthy male and female adults of mean=23.6 years (SD=1.6 years). Twelve walking conditions were completed on the GAITRite measurement system, resulting from crossing 3 conditions of visual restriction (no restriction, partial restriction, blindfolded) and 4 conditions of haptic supplementation (no supplementation, with a cane used as “light touch”, with a cane sliding on the ground, while touching a soft elastic handrail). Gait speed, stance time, step length and the basis of support were measured. Accelerations of center of mass were also recorded through an accelerometer and the displacements of center of mass were analyzed. Results showed that visual restriction decreased in gait speed, reduced step length, while it increased the base of support and the amplitude of CoM displacements. In the full restriction condition, haptic supplementation provided by the use of the classic cane improved normalized stance time (%). In addition, in the no vision condition, both the classic cane and the soft handrail increased step length and reduced medio-lateral oscillations of the CoM. These results suggest that in visually restricted healthy adults, lightly touching a fixed (soft handrail) or a mobile (classic cane) support contributes to adaptation of gait parameters and postural control during locomotion.

Evaluation of toddler different strategies during the first six-months of independent walking: A longitudinal study

Twenty infants (age 10–16 month) were analyzed using inertial sensors over a 6-month period after the onset of independent walking. Changes in gait temporal parameters, coordination and gait strategies were evaluated. Gait temporal parameters showed a developmental shift at 2 months of walking experience: after this period, a change in the developmental trend was present in most of the analyzed parameters. Cadence results showed that the increased velocity is more due to an increase in step length than to an increase in cadence, after the first two months of independent walking. Different gait strategies were identified during the first month of independent gait based on collected data; after one month, characteristics of the pendulum mechanism were present in each examined toddler.

Dose-Associated Changes in Gait Parameters in Response to Exercise Programs after Total Knee Arthroplasty: Secondary Analysis of Two Randomized Studies.

BackgroundRehabilitation plays an important role to improve the outcomes of total knee arthroplasty (TKA). Evidence about the appropriate dose of exercise to recover gait dysfunction after TKA is limited. We posed the research question: In patients during the post-acute stage after TKA, is increased dose of exercise associated with larger improvements in gait parameters such as step length and single support time?MethodsThis was a secondary analysis from two randomized studies on exercise after TKA to investigate dose-dependence of gait parameters in response to exercise. Participants were 50 years or older who underwent unilateral TKA at least two months prior. They participated in 2 months of supervised exercises followed by 4 months of a home exercise program. The primary outcome was change in gait parameters from baseline to 6 months. Participants were divided in three groups according to the dose of exercise: group 1 (light-to-moderate intensity exercise), group 2 (high intensity + functional exercise), and group 3 (high intensity + functional + balance exercise). Jonckheere-Terpstra test was used to test if the magnitude of changes in gait parameters increased from group 1 to group 3 in an ordered fashion.ResultsIncreased dose of exercise was associated with progressive increases in step length in the operated-limb (p=0.008) and decreases in step length in the non-operated limb (p=0.011). Increased dose of exercise was associated with ordinal decreases in loading response time (p=0.049) and increases in single-leg support time (p=0.021) on the operated- limb, but not on the non-operated-limb. Increased dose of exercise was associated with decreases in unloading time on the non-operated-limb (p=0.011) but not on the operated-limb (p=0.400).ConclusionsSignificant dose-response of exercise on gait parameters support the promotion of more intensive exercise programs that combine functional and balance training programs after TKA.

Church Pew Exercise Integrated With Conventional Physical Therapy Following Total Knee Arthroplasty (TKA): Case Report

Background and Purpose: Physical therapy treatment following Total knee Arthroplasty (TKA) consists of a combination of strengthening and range of motion exercises. The exercise technique, church pew exercise (CPE), has been proposed to enhance quadriceps facilitation and improve function. This is a technique that has the patient standing and rocking forward/back. The backward motion is arrested by engagement of the upper calf against a solid object, creating a sudden flexion torque at the knee and a sudden extension torque at the hip. The combination of CPE with standard physical therapy is claimed to provide better quadriceps control and faster walking post TKA. In this case study, a 51-year-old female with decreased knee active and passive range of motion (ROM), decreased lower extremity (LE) muscle strength, and limited ambulation post left knee TKA, received conventional physical therapy treatment plus CPE. Methods: The patient received 11 physical therapy home sessions. The first 8 sessions were used to strengthen her knee and increase active and passive ROM. The CPE intervention was performed 3 weeks post-surgery, during the last 3 physical therapy sessions. At these three sessions the patient performed the Timed Up and Go (TUG) before and after CPE. Outcomes: At initial evaluation, 4 days post left knee TKA, this patient’s left knee active ROM was only 15 to 76 degrees, and manual muscle testing at her hip and knee indicated strengths of 2- (hip flexors), 3- (hamstrings and quadriceps), and 3+ (hip abductors), all out of 5, and her times on two trials of the TUG were 30.31 and 30.65 sec, indicating impaired functional ability. At all CPE sessions (3 weeks post-surgery) the patient demonstrated increased gait speeds (i.e. shorter times) on the TUG after the CPE (pre CPE mean = 13.2 sec; post CPE mean = 11.2), increased stance time on her affected lower extremity, and increased step length on her contra-lateral lower extremity. The patient reported increased knee stability. Clinical Relevance: Rationale for CPE is based on neurological facilitation of quadriceps and other lower extremity muscles. However, to engage in this exercise the patient must have the ability to balance and to control the hip and knee joints. This patient required several weeks of strengthening and active and passive ROM exercises before she could perform the CPE. Once able to perform the CPE, she demonstrated improvements in her walking ability, and she expressed greater confidence. Conclusion: Provided a minimal level of strength and active and passive ROM has been attained, CPE may be a valuable short-term supplement to current strengthening regimens addressing quadriceps functional deficits following TKA. Other conditions that involve gait problems related to quadriceps insufficiency might also benefit. The long-term efficacy of CPE remains to be determined.

Effects of Nordic walking and walking on spatiotemporal gait parameters and ground reaction force.

[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.

Laminar Wall Jet Flow and Heat Transfer over a Shallow Cavity.

This paper presents the detailed simulation of two-dimensional incompressible laminar wall jet flow over a shallow cavity. The flow characteristics of wall jet with respect to aspect ratio (AR), step length (X u), and Reynolds number (Re) of the shallow cavity are expressed. For higher accuracy, third-order discretization is applied for momentum equation which is solved using QUICK scheme with SIMPLE algorithm for pressure-velocity coupling. Low Reynolds numbers 25, 50, 100, 200, 400, and 600 are assigned for simulation. Results are presented for streamline contour, velocity contour, and vorticity formation at wall and also velocity profiles are reported. The detailed study of vortex formation on shallow cavity region is presented for various AR, X u, and Re conditions which led to key findings as Re increases and vortex formation moves from leading edge to trailing edge of the wall. Distance between vortices increases when the step length (X u) increases. When Re increases, the maximum temperature contour distributions take place in shallow cavity region and highest convection heat transfer is obtained in heated walls. The finite volume code (FLUENT) is used for solving Navier-Stokes equations and GAMBIT for modeling and meshing.

1F5-3 歩幅増大が歩行フォームに及ぼす影響

1F5-3 歩幅増大が歩行フォームに及ぼす影響

Lower limb kinematics and physiological responses to prolonged load carriage in untrained individuals

The aim of this study was to simultaneously assess the changes in physiology, and kinematic and spatiotemporal features of gait, during prolonged load carriage in individuals without load carriage experience. Eleven males, representative of new military recruits, walked for 120 min at 5.5 km h− 1, 0% grade, on a motorised treadmill while carrying a 22 kg load. The load ( ≤ 30% body mass) was distributed over a weighted vest, combat webbing and replica model firearm, to reflect a patrol order load. Oxygen consumption and heart rate increased throughout the trial; however, apart from a minor increase in step length, there were no changes in the kinematic or spatiotemporal parameters, despite an increase in perceived exertion and discomfort. These data suggest that individuals with no experience in load carriage are able to maintain normal gait during 2 h of fixed speed walking, while carrying a patrol order load ≤ 30% body mass.

Effects of walking-induced fatigue on gait function and tripping risks in older adults.

BackgroundFatigue and ageing contribute to impaired control of walking and are linked to falls. In this project, fatigue was induced by maximum speed walking to examine fatigue effects on lower limb trajectory control and associated tripping risk and overall gait functions of older adults.MethodsEleven young (18–35 years) and eleven older adults (>65 years) conducted 5-minute preferred speed treadmill walking prior to and following 6-minute maximum fast walking. Spatio-temporal gait parameters and minimum foot clearance (MFC) were obtained. Maximal muscle strength (hamstrings and quadriceps) was measured on an isokinetic dynamometer. Heart rate (HR) and rating of perceived exertion (RPE) assessed physiological effort and subjective fatigue. Physiological Cost Index computed walking efficiency.ResultsFatigue due to fast walking increased step length, double support time and variability of step width. Only older adults reduced MFC due to fatigue. A trend of longer double support with greater MFC was found in the non-dominant limb. Lower walking efficiency was characterised as the ageing effect. Older adults did not increase HR during fast walking but higher RPE scores were observed.ConclusionsOlder adults can increase tripping risk by 6 minutes of fast walking possibly by both impaired walking efficiency based on cardiac capacity and higher perceived fatigue due to elevated caution level. Regardless of age, increased step width variability due to fatigue was observed, a sign of impaired balance. Longer double support and greater MFC observed in the older adults’ non-dominant limb could be an asymmetrical gait adaptation for safety.Electronic supplementary materialThe online version of this article (doi:10.1186/1743-0003-11-155) contains supplementary material, which is available to authorized users.

Anticipatory changes in control of swing foot and lower limb joints when walking onto a moving surface traveling at constant speed

Adapting to a predictable moving surface such as an escalator is a crucial part of daily locomotor tasks in modern cities. However, the associated biomechanics have remained unexplored. In a gait laboratory, fifteen young adults walked from the ground onto a moving or a static surface while their kinematic and kinetic data were obtained for calculating foot and pelvis motions, as well as the angles and moments of the lower limb joints. Between-surface-condition comparisons were performed using a paired t-test (α=0.05). The results showed that anticipatory locomotor adjustments occurred at least a stride before successfully walking onto the moving surface, including increasing step length and speed in the trailing step (p<0.05), but the opposite in the leading step (p<0.05). These modifications reduced the plantarflexor moment of the trailing ankle needed for stabilizing the body, while placing increased demand on the knee extensors of the trailing stance limb. For a smooth landing and to reduce the risk of instability, the subjects adopted a flat foot contact pattern with reduced leading toe-clearance (p<0.05) at an instantaneous speed matching that of the moving surface (p>0.05), mainly through reduced extension of the trailing hip but increased pelvic anterior tilt and leading swing ankle plantarflexion (p<0.05). The current results provide baseline data for future studies on other populations, which will contribute to the design and development of strategies to address falls while transferring onto moving surfaces such as escalators.