scholarly journals Influence of walking speed on locomotor time production

2013 ◽  
Author(s):  
Fabrice MEGROT ◽  
Carole MEGROT
Keyword(s):  
Healthy Subjects ◽  
Walking Speed ◽  
The Other ◽  
Temporal Perception ◽  
Time Production ◽  
Fast Walking ◽  
Slow Walking ◽  
Perception Of Time ◽  
Walking Speeds

The aim of the present study was to determine whether or not walking speed affects temporal perception. It was hypothesized that fast walking would reduce the perceived length of time while slow walking increase production estimates. 16 healthy subjects were included. After a first « calibration » phase allowing the determination of different walking speeds, the subjects were instructed to demonstrate periods of time or « target times » of 3s and 7s, by a walking movement. Then, subjects were asked to simulate walking by raising one foot after the other without advancing. Finally, a third condition, Motionless, involved producing the target times while standing without movement. The results of this study suggest that movement does influence the perception of time, causing an overestimation of time. In agreement with the results of Denner et al. (1963) the subjects produced times which were longer than the target times.

scholarly journals Optimized hip–knee–ankle exoskeleton assistance at a range of walking speeds

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gwendolyn M. Bryan ◽  
Patrick W. Franks ◽  
Seungmoon Song ◽  
Alexandra S. Voloshina ◽  
Ricardo Reyes ◽  
...  
Keyword(s):  
Walking Speed ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Positive Power ◽  
Fast Walking ◽  
Slow Walking ◽  
Limited Success ◽  
Ankle Exoskeleton ◽  
Walking Speeds ◽  
The Relationship

Abstract Background Autonomous exoskeletons will need to be useful at a variety of walking speeds, but it is unclear how optimal hip–knee–ankle exoskeleton assistance should change with speed. Biological joint moments tend to increase with speed, and in some cases, optimized ankle exoskeleton torques follow a similar trend. Ideal hip–knee–ankle exoskeleton torque may also increase with speed. The purpose of this study was to characterize the relationship between walking speed, optimal hip–knee–ankle exoskeleton assistance, and the benefits to metabolic energy cost. Methods We optimized hip–knee–ankle exoskeleton assistance to reduce metabolic cost for three able-bodied participants walking at 1.0 m/s, 1.25 m/s and 1.5 m/s. We measured metabolic cost, muscle activity, exoskeleton assistance and kinematics. We performed Friedman’s tests to analyze trends across walking speeds and paired t-tests to determine if changes from the unassisted conditions to the assisted conditions were significant. Results Exoskeleton assistance reduced the metabolic cost of walking compared to wearing the exoskeleton with no torque applied by 26%, 47% and 50% at 1.0, 1.25 and 1.5 m/s, respectively. For all three participants, optimized exoskeleton ankle torque was the smallest for slow walking, while hip and knee torque changed slightly with speed in ways that varied across participants. Total applied positive power increased with speed for all three participants, largely due to increased joint velocities, which consistently increased with speed. Conclusions Exoskeleton assistance is effective at a range of speeds and is most effective at medium and fast walking speeds. Exoskeleton assistance was less effective for slow walking, which may explain the limited success in reducing metabolic cost for patient populations through exoskeleton assistance. Exoskeleton designers may have more success when targeting activities and groups with faster walking speeds. Speed-related changes in optimized exoskeleton assistance varied by participant, indicating either the benefit of participant-specific tuning or that a wide variety of torque profiles are similarly effective.

scholarly journals Bilateral vestibulopathy and age: experimental considerations for testing dynamic visual acuity on a treadmill

2020 ◽  
Vol 267 (S1) ◽  
pp. 265-272
Author(s):  
D. Starkov ◽  
M. Snelders ◽  
F. Lucieer ◽  
A. M. L. Janssen ◽  
M. Pleshkov ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Healthy Subjects ◽  
Walking Speed ◽  
Static Condition ◽  
Drop Out ◽  
Dynamic Visual Acuity ◽  
Bilateral Vestibulopathy ◽  
Drop Out Rate ◽  
Visual Acuity Loss ◽  
Walking Speeds

Abstract Introduction Bilateral vestibulopathy (BVP) can affect visual acuity in dynamic conditions, like walking. This can be assessed by testing Dynamic Visual Acuity (DVA) on a treadmill at different walking speeds. Apart from BVP, age itself might influence DVA and the ability to complete the test. The objective of this study was to investigate whether DVA tested while walking, and the drop-out rate (the inability to complete all walking speeds of the test) are significantly influenced by age in BVP-patients and healthy subjects. Methods Forty-four BVP-patients (20 male, mean age 59 years) and 63 healthy subjects (27 male, mean age 46 years) performed the DVA test on a treadmill at 0 (static condition), 2, 4 and 6 km/h (dynamic conditions). The dynamic visual acuity loss was calculated as the difference between visual acuity in the static condition and visual acuity in each walking condition. The dependency of the drop-out rate and dynamic visual acuity loss on BVP and age was investigated at all walking speeds, as well as the dependency of dynamic visual acuity loss on speed. Results Age and BVP significantly increased the drop-out rate (p ≤ 0.038). A significantly higher dynamic visual acuity loss was found at all speeds in BVP-patients compared to healthy subjects (p < 0.001). Age showed no effect on dynamic visual acuity loss in both groups. In BVP-patients, increasing walking speeds resulted in higher dynamic visual acuity loss (p ≤ 0.036). Conclusion DVA tested while walking on a treadmill, is one of the few “close to reality” functional outcome measures of vestibular function in the vertical plane. It is able to demonstrate significant loss of DVA in bilateral vestibulopathy patients. However, since bilateral vestibulopathy and age significantly increase the drop-out rate at faster walking speeds, it is recommended to use age-matched controls. Furthermore, it could be considered to use an individual “preferred” walking speed and to limit maximum walking speed in older subjects when testing DVA on a treadmill.

scholarly journals Optimized hip-knee-ankle exoskeleton assistance at a range of walking speeds

2021 ◽  
Author(s):  
Gwendolyn M Bryan ◽  
Patrick W. Franks ◽  
Seungmoon Song ◽  
Alexandra S Voloshina ◽  
Ricardo Reyes ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Metabolic Cost ◽  
Positive Power ◽  
Fast Walking ◽  
Know How ◽  
Ankle Torque ◽  
Slow Walking ◽  
Limited Success ◽  
Ankle Exoskeleton ◽  
Walking Speeds

Background: Effective autonomous exoskeletons will need to be useful at a variety of walking speeds, but we do not know how optimal exoskeleton assistance should change with speed. Optimal exoskeleton assistance may increase with speed similar to biological torque changes or a well-tuned assistance profile may be effective at a variety of speeds. Methods: We optimized hip-knee-ankle exoskeleton assistance to reduce metabolic cost for three participants walking at 1.0 m/s, 1.25 m/s and 1.5 m/s. We measured metabolic cost, muscle activity, exoskeleton assistance and kinematics. We performed two tailed paired t-tests to determine significance. Results: Exoskeleton assistance reduced the metabolic cost of walking compared to wearing the exoskeleton with no torque applied by 26%, 47% and 50% at 1.0, 1.25 and 1.5 m/s, respectively. For all three participants, optimized exoskeleton ankle torque was the smallest for slow walking, while hip and knee torque changed slightly with speed in ways that varied across participants. Total applied positive power increased with speed for all three participants, largely due to increased joint velocities, which consistently increased with speed. Conclusions: Exoskeleton assistance is effective at a range of speeds and is most effective at medium and fast walking speeds. Exoskeleton assistance was less effective for slow walking, which may explain the limited success in reducing metabolic cost for patient populations through exoskeleton assistance. Exoskeleton designers may have more success when targeting activities and groups with faster walking speeds. Speed-related changes in optimized exoskeleton assistance varied by participant, indicating either the benefit of participant-specific tuning or that a wide variety of torque profiles are similarly effective.

scholarly journals Simulating bipedal walking using a translating center of pressure

2019 ◽  
Author(s):  
Karna Potwar ◽  
Dongheui Lee
Keyword(s):  
Steady State ◽  
Walking Speed ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Bipedal Walking ◽  
Upper Body ◽  
Foot Placement ◽  
Fast Walking ◽  
Walking Speeds ◽  
Steady State Solutions

AbstractDuring walking, foot orientation and foot placement allow humans to stabilize their gait and to move forward. Consequently the upper body adapts to the ground reaction force (GRF) transmitted through the feet. The foot-ground contact is often modeled as a fixed pivot in bipedal models for analysis of locomotion. The fixed pivot models, however, cannot capture the effect of shift in the pivot point from heel to toe. In this study, we propose a novel bipedal model, called SLIPCOP, which employs a translating center of pressure (COP) in a spring loaded inverted pendulum (SLIP) model. The translating COP has two modes: one with a constant speed of translation and the other as the weighted function of the GRF in the fore aft direction. We use the relation between walking speed and touchdown (TD) angle as well as walking speed and COP speed, from existing literature, to restrict steady state solutions within the human walking domain. We find that with these relations, SLIPCOP provides steady state solutions for very slow to very fast walking speeds unlike SLIP. SLIPCOP for normal to very fast walking speed shows good accuracy in estimating COM amplitude and swing stance ratio. SLIPCOP is able to estimate the distance traveled by the COP during stance with high precision.

Interlimb Coordination During Slow Walking in the Cockroach: I. Effects of Substrate Alterations

1979 ◽  
Vol 78 (1) ◽  
pp. 233-243 ◽  
Author(s):  
CARL P. SPIRITO ◽  
DANIEL L. MUSHRUSH
Keyword(s):  
Control System ◽  
Walking Speed ◽  
Interlimb Coordination ◽  
Steering Control ◽  
Inclined Plane ◽  
Slow Walking ◽  
Tripod Gait ◽  
Walking Speeds

In this study, interlimb coordination in the cockroach during slow walking (2–7 steps/s) is described for a variety of substrate conditions. During normal free-walking, the animal utilizes an alternating tripod gait (both ipsilateral and contralateral phase close to 0.50). The protraction/retraction ratio varies linearly with walking speed. When tethered on a supported ball, the ipsilateral phase ranges from 0.32 to 0.46 at walking speeds of 2-7 steps/s, and contralateral phase is constant at 0.53. Protraction/retraction ratios are normal in this case. Blind free-walking animals use a gait which is indistinguishable from normal, but the protraction/retraction ratio is constant over speeds of 2-7 steps/s. When walking down an inclined plane (45°), the gait resembles ball-walking, with an average ipsilateral phase of 0.43 and contralateral phase of 0.53. These alterations of gait under different substrate conditions can be related to the animal's responses to loading, gravity, and steering control system.

scholarly journals Multicomponent Exercise Improves Physical Functioning but Not Cognition and Hemodynamic Parameters in Elderly Osteoarthritis Patients Regardless of Hypertension

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hélio José Coelho-Júnior ◽  
Ivan de Oliveira Gonçalvez ◽  
Iris Callado Sanches ◽  
Leandro Gonçalves ◽  
Erico Chagas Caperuto ◽  
...  
Keyword(s):  
Physical Functioning ◽  
Walking Speed ◽  
Exercise Program ◽  
The Other ◽  
Moderate Intensity ◽  
Hemodynamic Parameters ◽  
Physical Exercises ◽  
Before And After ◽  
Walking Speeds ◽  
The Impact

The present study aimed to investigate the impact of a 6-month multicomponent exercise program (MCEP) on physical function, cognition, and hemodynamic parameters of elderly normotensive (NTS) and hypertensive (HTS) osteoarthritis patients. A total of 99 elderly osteoarthritis patients (44 NTS and 55 HTS) were recruited and submitted to functional, cognitive, and hemodynamic evaluations before and after six months of a MCEP. The program of exercise was performed twice a week at moderate intensity. The physical exercises aggregated functional and walking exercises. Results indicate that 6 months of MCEP were able to improve one-leg stand and mobility (walking speeds) of osteoarthritis patients regardless of hypertension. On the other hand, cognitive and hemodynamic parameters were not altered after the MCEP. The findings of the present study demonstrate that 6 months of MCEP were able to improve the physical functioning (i.e., usual and maximal walking speed and balance) of osteoarthritis patients regardless of hypertensive condition.

scholarly journals The Association of Vision, Hearing, and Dual Sensory Impairments With Walking Speed and Incident Slow Walking

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 216-216
Author(s):  
Ahmed Shakarchi ◽  
Varshini Varadaraj ◽  
Lama Assi ◽  
Nicholas Reed ◽  
Bonnielin Swenor
Keyword(s):  
Older Adults ◽  
Walking Speed ◽  
Linear Models ◽  
Population Based ◽  
Adverse Outcomes ◽  
Sensory Impairment ◽  
Slow Walking ◽  
Increased Risk ◽  
Sensory Impairments ◽  
Walking Speeds

Abstract Vision (VI), hearing (HI) and dual sensory (DSI, concurrent VI and HI) impairments are increasing in prevalence as populations age. Walking speed is an established health indicator associated with adverse outcomes, including mortality. Using the population-based Health and Retirement Study, we analyzed the longitudinal relationship between sensory impairment and walking speed. In multivariable mixed-effects linear models, we found differences in baseline walking speed (m/s) by sensory impairment: Beta=-0.05 (95%CI=-0.07, -0.04), Beta=-0.02 (95%CI=--0.03, -0.003), and Beta=-0.07 (95%CI=--0.08, -0.05) for VI, HI and DSI, respectively, as compared to those without sensory impairment. However, similar annual declines (0.014 m/s) in walking speeds occurred in all groups. In time-to-event analyses, events were defined as “slow walking” (speed &lt;0.60m/s) and “very slow walking” (&lt;0.40m/s). Incident “slow walking” was 43% (95%CI=25%, 65%), 29% (95%CI=13%, 48%) and 35% (95%CI=13%, 61%) greater in VI, HI and DSI, respectively, than the no sensory impairment group, while incident “very slow walking” was 21% (95%CI=-4%, 54%), 30% (95%CI=3%, 63%) and 89% (95%CI=47%, 143%) greater; the increase was significantly greater in DSI than VI and HI. These results suggest that older adults with vision and hearing impairments walk slower and are at increased risk of slow walking than older adults without these sensory impairments. Additionally, older adults with DSI are at greatest risk of very slow walking.

Fast visual prediction and slow optimization of preferred walking speed

2012 ◽  
Vol 107 (9) ◽  
pp. 2549-2559 ◽  
Author(s):  
Shawn M. O'Connor ◽  
J. Maxwell Donelan
Keyword(s):  
Nervous System ◽  
Healthy Subjects ◽  
Walking Speed ◽  
Prior Experience ◽  
Sensory Information ◽  
Energetic Cost ◽  
The Subject ◽  
Walking Speeds ◽  
Visual Speed ◽  
Direction Opposite

People prefer walking speeds that minimize energetic cost. This may be accomplished by directly sensing metabolic rate and adapting gait to minimize it, but only slowly due to the compounded effects of sensing delays and iterative convergence. Visual and other sensory information is available more rapidly and could help predict which gait changes reduce energetic cost, but only approximately because it relies on prior experience and an indirect means to achieve economy. We used virtual reality to manipulate visually presented speed while 10 healthy subjects freely walked on a self-paced treadmill to test whether the nervous system beneficially combines these two mechanisms. Rather than manipulating the speed of visual flow directly, we coupled it to the walking speed selected by the subject and then manipulated the ratio between these two speeds. We then quantified the dynamics of walking speed adjustments in response to perturbations of the visual speed. For step changes in visual speed, subjects responded with rapid speed adjustments (lasting <2 s) and in a direction opposite to the perturbation and consistent with returning the visually presented speed toward their preferred walking speed, when visual speed was suddenly twice (one-half) the walking speed, subjects decreased (increased) their speed. Subjects did not maintain the new speed but instead gradually returned toward the speed preferred before the perturbation (lasting >300 s). The timing and direction of these responses strongly indicate that a rapid predictive process informed by visual feedback helps select preferred speed, perhaps to complement a slower optimization process that seeks to minimize energetic cost.

scholarly journals Effect of Walking Speeds on Complexity of Plantar Pressure Patterns

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ben-Yi Liau ◽  
Fu-Lien Wu ◽  
Yameng Li ◽  
Chi-Wen Lung ◽  
Ayman A. Mohamed ◽  
...  
Keyword(s):  
Plantar Pressure ◽  
Repeated Measures ◽  
Multiscale Entropy ◽  
Fast Walking ◽  
Slow Walking ◽  
Significant Difference ◽  
Nonlinear Features ◽  
Plantar Pressure Measurement ◽  
Walking Speeds ◽  
Pressure Measurement System

Various walking speeds may induce different responses on the plantar pressure patterns. Current methods used to analyze plantar pressure patterns are linear and ignore nonlinear features. The purpose of this study was to analyze the complexity of plantar pressure images after walking at various speeds using nonlinear bidimensional multiscale entropy (MSE2D). Twelve participants (age: 27.1 ± 5.8 years; height: 170.3 ± 10.0 cm; and weight: 63.5 ± 13.5 kg) were recruited for walking at three speeds (slow at 1.8 mph, moderate at 3.6 mph, and fast at 5.4 mph) for 20 minutes. A plantar pressure measurement system was used to measure plantar pressure patterns. Complexity index (CI), a summation of MSE2D from all time scales, was used to quantify the changes of complexity of plantar pressure images. The analysis of variance with repeated measures and Fisher’s least significant difference correction were used to examine the results of this study. The results showed that CI of plantar pressure images of 1.8 mph (1.780) was significantly lower compared with 3.6 (1.790) and 5.4 mph (1.792). The results also showed that CI significantly increased from the 1st min (1.780) to the 10th min (1.791) and 20th min (1.791) with slow walking (1.8 mph). Our results indicate that slow walking at 1.8 mph may not be good for postural control compared with moderate walking (3.6 mph) and fast walking (5.4 mph). This study demonstrates that bidimensional multiscale entropy is able to quantify complexity changes of plantar pressure images after different walking speeds.

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