The effects of sensory loss and walking speed on the orbital dynamic stability of human walking

2007 ◽  
Vol 40 (8) ◽  
pp. 1723-1730 ◽  
Author(s):  
Jonathan B. Dingwell ◽  
Hyun Gu Kang ◽  
Laura C. Marin
Keyword(s):  
Dynamic Stability ◽  
Walking Speed ◽  
Sensory Loss ◽  
Human Walking

scholarly journals Does dynamic stability govern propulsive force generation in human walking?

2017 ◽  
Vol 4 (11) ◽  
pp. 171673 ◽  
Author(s):  
Michael G. Browne ◽  
Jason R. Franz
Keyword(s):  
Young Adults ◽  
Dynamic Stability ◽  
Walking Speed ◽  
Balance Control ◽  
Human Walking ◽  
Propulsive Force ◽  
Visual Biofeedback ◽  
Trade Offs ◽  
Independent Effects ◽  
Walking Speeds

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.

scholarly journals The Association of Vision, Hearing, and Dual-Sensory Loss with Walking Speed and Incident Slow Walking: Longitudinal and Time to Event Analyses in the Health and Retirement Study

2021 ◽  
Vol 42 (01) ◽  
pp. 075-084
Author(s):  
Ahmed F. Shakarchi ◽  
Lama Assi ◽  
Abhishek Gami ◽  
Christina Kohn ◽  
Joshua R. Ehrlich ◽  
...  
Keyword(s):  
Walking Speed ◽  
Linear Models ◽  
Sensory Loss ◽  
Health And Retirement Study ◽  
Time To Event ◽  
Slow Walking ◽  
Public Health Challenges ◽  
Nationally Representative ◽  
Retirement Study ◽  
Slow Walking Speed

AbstractWith the aging of the population, vision (VL), hearing (HL), and dual-sensory (DSL, concurrent VL and HL) loss will likely constitute important public health challenges. Walking speed is an indicator of functional status and is associated with mortality. Using the Health and Retirement Study, a nationally representative U.S. cohort, we analyzed the longitudinal relationship between sensory loss and walking speed. In multivariable mixed effects linear models, baseline walking speed was slower by 0.05 m/s (95% confidence interval [CI] = 0.04–0.07) for VL, 0.02 (95% CI = 0.003–0.03) for HL, and 0.07 (95% CI = 0.05–0.08) for DSL compared with those without sensory loss. Similar annual declines in walking speeds occurred in all groups. In time-to-event analyses, the risk of incident slow walking speed (walking speed < 0.6 m/s) was 43% (95% CI = 25–65%), 29% (95% CI = 13–48%), and 35% (95% CI = 13–61%) higher among those with VL, HL, and DSL respectively, relative to those without sensory loss. The risk of incident very slow walking speed (walking speed < 0.4 m/s) was significantly higher among those with HL and DSL relative to those without sensory loss, and significantly higher among those with DSL relative to those with VL or HL alone. Addressing sensory loss and teaching compensatory strategies may help mitigate the effect of sensory loss on walking speed.

Changes in the Dynamic Stability of Walking in Active Healthy Older Adults Independent of Changes in Walking Speed

2008 ◽  
Author(s):  
Hyun Gu Kang ◽  
Jonathan B. Dingwell
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Dynamic Stability ◽  
Walking Speed ◽  
Age Groups ◽  
Leg Strength ◽  
Age Related ◽  
Increased Risk ◽  
Risk Of Falls ◽  
Walking Speeds

Older adults commonly walk slower, which many believe helps improve their walking stability. However, they remain at increased risk of falls. We investigated how differences in age and walking speed independently affect dynamic stability during walking, and how age-related changes in leg strength and ROM affected this relationship. Eighteen active healthy older and 17 younger adults walked on a treadmill for 5 minutes each at each of 5 speeds (80–120% of preferred). Local divergence exponents and maximum Floquet multipliers (FM) were calculated to quantify each subject’s responses to small inherent perturbations during walking. These older adults exhibited the same preferred walking speeds as the younger subjects (p = 0.860). However, these older adults still exhibited greater local divergence exponents (p&lt;0.0001) and higher maximum FM (p&lt;0.007) than young adults at all walking speeds. These older adults remained more unstable (p&lt;0.04) even after adjusting for declines in both strength and ROM. In both age groups, local divergence exponents decreased at slower speeds and increased at faster speeds (p&lt;0.0001). Maximum FM showed similar changes with speed (p&lt;0.02). The older adults in this study were healthy enough to walk at normal speeds. However, these adults were still more unstable than the young adults, independent of walking speed. This greater instability was not explained by loss of leg strength and ROM. Slower speeds led to decreased instability in both groups.

scholarly journals Interlimb communication following unexpected changes in treadmill velocity during human walking

2015 ◽  
Vol 113 (9) ◽  
pp. 3151-3158 ◽  
Author(s):  
Andrew J. T. Stevenson ◽  
Svend S. Geertsen ◽  
Thomas Sinkjær ◽  
Jens B. Nielsen ◽  
Natalie Mrachacz-Kersting
Keyword(s):  
Dynamic Stability ◽  
Stance Phase ◽  
Biceps Femoris ◽  
The Body ◽  
Context Dependency ◽  
Human Walking ◽  
Human Gait ◽  
Velocity Change ◽  
Leg Muscles ◽  
Interlimb Reflex

Interlimb reflexes play an important role in human walking, particularly when dynamic stability is threatened by external perturbations or changes in the walking surface. Interlimb reflexes have recently been demonstrated in the contralateral biceps femoris (cBF) following knee joint rotations applied to the ipsilateral leg (iKnee) during the late stance phase of human gait (Stevenson AJ, Geertsen SS, Andersen JB, Sinkjær T, Nielsen JB, Mrachacz-Kersting N. J Physiol 591: 4921–4935, 2013). This interlimb reflex likely acts to slow the forward progression of the body to maintain dynamic stability following the perturbations. We examined this hypothesis by unexpectedly increasing or decreasing the velocity of the treadmill before (−100 and −50 ms), at the same time, or following (+50 ms) the onset of iKnee perturbations in 12 healthy volunteers. We quantified the cBF reflex amplitude when the iKnee perturbation was delivered alone, the treadmill velocity change was delivered alone, or when the two perturbations were combined. When the treadmill velocity was suddenly increased (or decreased) 100 or 50 ms before the iKnee perturbations, the combined cBF reflex was significantly larger (or smaller) than the algebraic sum of the two perturbations delivered separately. Furthermore, unexpected changes in treadmill velocity increased the incidence of reflexes in other contralateral leg muscles when the iKnee perturbations were elicited alone. These results suggest a context dependency for interlimb reflexes. They also show that the cBF reflex changed in a predictable manner to slow the forward progression of the body and maintaining dynamic stability during walking, thus signifying a functional role for interlimb reflexes.

The effects of walking speed on orbital stability of human walking

2006 ◽  
Vol 39 ◽  
pp. S114
Author(s):  
J.B. Dingwell ◽  
H.G. Kang ◽  
L.C. Marin
Keyword(s):  
Walking Speed ◽  
Orbital Stability ◽  
Human Walking

scholarly journals Effects of Visual Deprivation on Gait Dynamic Stability

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Marco Iosa ◽  
Augusto Fusco ◽  
Giovanni Morone ◽  
Stefano Paolucci
Keyword(s):  
Dynamic Stability ◽  
Visual Feedback ◽  
Walking Speed ◽  
Visual Deprivation ◽  
Upper Body ◽  
Spatiotemporal Parameters ◽  
Main Factor ◽  
Visual Conditions

Vision can improve bipedal upright stability during standing and affect spatiotemporal parameters during walking. However, little is known about the effects of visual deprivation on gait dynamic stability. We have tested 28 subjects during walking under two different visual conditions, full vision (FV) and no vision (NV), measuring their upper body accelerations. Lower accelerations were found in NV for the reduced walking speed. However, the normalized accelerations were higher in the NV than in the FV condition, both in anteroposterior (1.05±0.21versus0.88±0.16,P=0.001) and laterolateral (0.99±0.26versus0.78±0.19,P<0.001) directions. Vision also affected the gait anteroposterior harmony (P=0.026) and, interacting with the environment, also the latero-lateral one (P=0.017). Directly (as main factor of the ANOVA) or indirectly (by means of significant interactions with other factors), vision affected all the measured parameters. In conclusion, participants showed an environment-dependent reduction of upper body stability and harmony when deprived by visual feedback.

scholarly journals Characterization of Human Gait using Fuzzy Logic

10.14311/1789 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Patrik Kutilek ◽  
Slavka Viteckova ◽  
Zdenek Svoboda
Keyword(s):  
Fuzzy Logic ◽  
Expert System ◽  
Inclination Angle ◽  
Walking Speed ◽  
Fuzzy Logic System ◽  
Human Walking ◽  
Human Gait ◽  
Fuzzy Expert System ◽  
Movement Type ◽  
Logic System

In medical practice, there is no appropriate widely-used application of a system based on fuzzy logic for identifying the lower limb movement type or type of walking. The object of our study was to determine characteristics of the cyclogram to identify the gait behavior by using a fuzzy logic system. The set of data for setting and testing the fuzzy logic system was measured on 10 volunteers recruited from healthy students of the Czech Technical University in Prague. The human walking speed was defined by the treadmill speed, and the inclination angle of the surface was defined by the treadmill and terrain slope. The input to the fuzzy expert system is based on the following variables: the area and the inclination angle of the cyclogram. The output variables from the fuzzy expert system are: the inclination angle of the surface, and the walking speed. We also tested the method with input based on the angle of inclination of the surface and the walking speed, and with the output based on the area and the inclination angle of the cyclogram. We found that identifying the type of terrain and walking speed on the basis of an evaluation of the cyclogram could be sufficiently accurate and suitable if we need to know the approximate type of walking and the approximate inclination angle of the surface. According to the method described here, the cyclograms could provide information about human walking, and we can infer the walking speed and the angle of inclination of the terrain.

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