scholarly journals Individual differences in locomotor function predict the capacity to reduce asymmetry and modify the energetic cost of walking post-stroke

2017 ◽  
Author(s):  
Natalia Sánchez ◽  
James M. Finley
Keyword(s):  
Individual Differences ◽  
Visual Feedback ◽  
Metabolic Cost ◽  
Step Length ◽  
Energetic Cost ◽  
Stroke Survivors ◽  
Locomotor Function ◽  
Post Stroke ◽  
Paretic Limb ◽  
Over Ground Walking

AbstractChanges in the control of the lower extremities post-stroke lead to persistent biomechanical asymmetries during walking. These asymmetries are associated with an increase in energetic cost, leading to the possibility that reduction of asymmetry can improve economy. However, the influence of asymmetry on economy may depend on the direction and cause of asymmetry. For example, impairments with paretic limb advancement may result in shorter paretic steps while deficits in paretic support or propulsion result in shorter non-paretic steps. Given differences in the underlying impairments responsible for each type of step length asymmetry, the capacity to reduce asymmetry, and the associated changes in energetic cost may not be consistent across this population. Here, we identified factors explaining individual differences in the capacity to voluntarily reduce step length asymmetry and modify energetic cost during walking. Twenty-four individuals post-stroke walked on a treadmill with visual feedback of their step lengths to aid explicit modification of asymmetry. We found that individuals who naturally took longer paretic steps had a greater capacity to reduce asymmetry, and were better able to transfer the effects of training to over-ground walking. In addition, baseline energetic cost was negatively correlated with reductions in cost, such that participants with a more economical gait were more likely to reduce energetic cost by improving symmetry. These results demonstrate that many stroke survivors retain the capacity to voluntarily walk more symmetrically on a treadmill and over-ground. However, whether reductions in asymmetry reduce metabolic cost depends on individual differences in impairments affecting locomotor function.

scholarly journals Individual Differences in Locomotor Function Predict the Capacity to Reduce Asymmetry and Modify the Energetic Cost of Walking Poststroke

2018 ◽  
Vol 32 (8) ◽  
pp. 701-713 ◽  
Author(s):  
Natalia Sánchez ◽  
James M. Finley
Keyword(s):  
Individual Differences ◽  
Metabolic Cost ◽  
Step Length ◽  
Energetic Cost ◽  
Cost Of Transport ◽  
Locomotor Function ◽  
Paretic Limb ◽  
Residual Capacity ◽  
Walking Economy ◽  
Baseline Cost

Changes in the control of the lower extremities poststroke lead to persistent biomechanical asymmetries during walking. These asymmetries are associated with an increase in energetic cost, leading to the possibility that reducing asymmetry can improve walking economy. However, the influence of asymmetry on economy may depend on the direction and cause of asymmetry. For example, impairments with paretic limb advancement may result in shorter paretic steps, whereas deficits in paretic support or propulsion result in shorter nonparetic steps. Given differences in the underlying impairments responsible for step length asymmetry, the capacity to reduce asymmetry and the associated changes in energetic cost may not be consistent across this population. Here, we identified factors explaining individual differences in the capacity to voluntarily reduce step length asymmetry and modify energetic cost during walking. A total of 24 individuals poststroke walked on a treadmill, with visual feedback of their step lengths to aid explicit modification of asymmetry. We found that individuals who took longer paretic steps had a greater capacity to reduce asymmetry and were better able to transfer the effects of practice to overground walking than individuals who took shorter paretic steps. In addition, changes in metabolic cost depended on the direction of asymmetry, baseline cost of transport, and reductions in specific features of spatiotemporal asymmetry. These results demonstrate that many stroke survivors retain the residual capacity to voluntarily walk more symmetrically on a treadmill and overground. However, whether reductions in asymmetry reduce metabolic cost depends on individual differences in impairments affecting locomotor function.

scholarly journals Persons post-stroke improve step length symmetry by walking asymmetrically

2020 ◽  
Author(s):  
Purnima Padmanabhan ◽  
Keerthana Sreekanth ◽  
Shivam Gulhar ◽  
Kendra M. Cherry-Allen ◽  
Kristan A. Leech ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Metabolic Cost ◽  
Step Length ◽  
Gait Pattern ◽  
Future Research ◽  
Cost Of Transport ◽  
Post Stroke ◽  
Paretic Limb ◽  
Gait Parameters ◽  
The Many

Abstract Background Restoration of step length symmetry is a common rehabilitation goal after stroke. Persons post-stroke often retain the ability to walk with symmetric step lengths ("symmetric steps") at an elevated metabolic cost relative to healthy adults. Two key questions with direct implications for rehabilitation have emerged: 1) how do persons post-stroke generate symmetric steps, and 2) why do symmetric steps remain so effortful? Here, we aimed to understand how persons post-stroke generate symmetric steps and explored how the resulting gait pattern may relate to the metabolic cost of transport. Methods We recorded kinematic, kinetic, and metabolic data as nine persons post-stroke walked on an instrumented treadmill under two conditions: preferred walking and symmetric stepping (using visual feedback). Results Gait kinematics and kinetics remained markedly asymmetric even when persons post-stroke improved step length symmetry. Impaired paretic propulsion and abnormal movement of the center of mass were evident during both preferred walking and symmetric stepping. These deficits contributed to diminished positive work performed by the paretic limb on the center of mass in both conditions. Within each condition, decreased positive paretic work correlated with increased metabolic cost of transport and decreased walking speed across participants. Conclusions It is critical to consider the mechanics used to restore symmetric steps when designing interventions to improve walking after stroke. Future research should consider the many dimensions of asymmetry in post-stroke gait, and additional within-participant manipulations of gait parameters are needed to improve our understanding of the elevated metabolic cost of walking after stroke.

scholarly journals Persons post-stroke improve step length symmetry by walking asymmetrically

2020 ◽  
Author(s):  
Purnima Padmanabhan ◽  
Keerthana Sreekanth ◽  
Shivam Gulhar ◽  
Kendra M. Cherry-Allen ◽  
Kristan A. Leech ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Metabolic Cost ◽  
Step Length ◽  
Gait Pattern ◽  
Future Research ◽  
Cost Of Transport ◽  
Post Stroke ◽  
Paretic Limb ◽  
Gait Parameters ◽  
The Many

Abstract Background Restoration of step length symmetry is a common rehabilitation goal after stroke. Persons post-stroke often retain the ability to walk with symmetric step lengths ("symmetric steps"); however, the resulting walking pattern remains effortful. Two key questions with direct implications for rehabilitation have emerged: 1) how do persons post-stroke generate symmetric steps, and 2) why do symmetric steps remain so effortful? Here, we aimed to understand how persons post-stroke generate symmetric steps and explored how the resulting gait pattern may relate to the metabolic cost of transport. Methods We recorded kinematic, kinetic, and metabolic data as nine persons post-stroke walked on an instrumented treadmill under two conditions: preferred walking and symmetric stepping (using visual feedback). Results Gait kinematics and kinetics remained markedly asymmetric even when persons post-stroke improved step length symmetry. Impaired paretic propulsion and aberrant movement of the center of mass were evident during both preferred walking and symmetric stepping. These deficits contributed to diminished positive work performed by the paretic limb on the center of mass in both conditions. Within each condition, decreased positive paretic work correlated with increased metabolic cost of transport and decreased walking speed across participants. Conclusions It is critical to consider the mechanics used to restore symmetric steps when designing interventions to improve walking after stroke. Future research should consider the many dimensions of asymmetry in post-stroke gait, and additional within-participant manipulations of gait parameters are needed to improve our understanding of the elevated metabolic cost of walking after stroke.

scholarly journals Persons post-stroke restore step length symmetry by walking asymmetrically

2019 ◽  
Author(s):  
Purnima Padmanabhan ◽  
Keerthana Sreekanth Rao ◽  
Shivam Gulhar ◽  
Kendra M. Cherry-Allen ◽  
Kristan A. Leech ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Metabolic Cost ◽  
Step Length ◽  
Gait Pattern ◽  
Vertical Movement ◽  
Cost Of Transport ◽  
Post Stroke ◽  
Paretic Limb ◽  
Rehabilitation Goal ◽  
Limb Kinematics

ABSTRACTBackgroundRestoration of step length symmetry is a common rehabilitation goal after stroke. Persons post-stroke often retain the capacity to walk with symmetric step lengths (“symmetric steps”); however, the resulting walking pattern remains effortful. Two key questions with direct implications for rehabilitation have emerged: 1) how do persons post-stroke generate symmetric steps, and 2) why do symmetric steps remain so effortful?ObjectiveTo understand how persons post-stroke generate symmetric steps and how the resulting gait pattern relates to the metabolic cost of transport.MethodsTen persons post-stroke walked on an instrumented treadmill under two conditions: preferred walking and symmetric stepping (using visual feedback). We recorded kinematic, kinetic, and metabolic data during both conditions.ResultsPersons post-stroke restored step length symmetry using energetically expensive, asymmetric patterns. Impaired paretic propulsion and abnormal vertical movement of the center of mass were evident during both preferred walking and symmetric stepping. These deficits contributed to diminished positive work performed by the paretic limb on the center of mass in both conditions. Decreased positive paretic work correlated with increased metabolic cost of transport, decreased self-selected walking speed, and increased asymmetry in limb kinematics.ConclusionsIt is important to consider the mechanics used to restore symmetric steps when designing interventions to improve walking after stroke. Facilitating symmetric steps via increased paretic propulsion or enabling paretic limb advancement without excessive vertical movement may enable persons post-stroke to walk with a less effortful, more symmetric gait pattern.

scholarly journals Persons post-stroke restore step length symmetry by walking asymmetrically

2020 ◽  
Author(s):  
Purnima Padmanabhan ◽  
Keerthana Sreekanth ◽  
Shivam Gulhar ◽  
Kendra M. Cherry-Allen ◽  
Kristan A. Leech ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Metabolic Cost ◽  
Step Length ◽  
Gait Pattern ◽  
Vertical Movement ◽  
Cost Of Transport ◽  
Post Stroke ◽  
Paretic Limb ◽  
Rehabilitation Goal ◽  
Limb Kinematics

Abstract Background: Restoration of step length symmetry is a common rehabilitation goal after stroke. Persons post-stroke often retain the ability to walk with symmetric step lengths (“symmetric steps”); however, the resulting walking pattern remains effortful. Two key questions with direct implications for rehabilitation have emerged: 1) how do persons post-stroke generate symmetric steps, and 2) why do symmetric steps remain so effortful? The objective of this study was to understand how persons post-stroke generate symmetric steps and how the resulting gait pattern relates to the metabolic cost of transport. Methods: We recorded kinematic, kinetic, and metabolic data as ten persons post-stroke walked on an instrumented treadmill under two conditions: preferred walking and symmetric stepping (using visual feedback).Results: Persons post-stroke restored step length symmetry using energetically costly, asymmetric patterns. Impaired paretic propulsion and abnormal vertical movement of the center of mass were evident during both preferred walking and symmetric stepping. These deficits contributed to diminished positive work performed by the paretic limb on the center of mass in both conditions. Decreased positive paretic work correlated with increased metabolic cost of transport, decreased self-selected walking speed, and increased asymmetry in limb kinematics.Conclusions: It is critical to consider the mechanics used to restore symmetric steps when designing interventions to improve walking after stroke. Facilitating symmetric steps via increased paretic propulsion or enabling paretic limb advancement without excessive vertical movement may enable persons post-stroke to walk with a less effortful gait pattern.

scholarly journals Disentangling the energetic costs of step time asymmetry and step length asymmetry in human walking

2021 ◽  
Author(s):  
Jan Stenum ◽  
Julia T. Choi
Keyword(s):  
Energy Cost ◽  
Metabolic Cost ◽  
Step Length ◽  
Human Walking ◽  
Metabolic Power ◽  
Healthy Human ◽  
Time Asymmetry ◽  
Double Support ◽  
Post Stroke ◽  
The Cost

The metabolic cost of walking in healthy individuals increases with spatiotemporal gait asymmetries. Pathological gait, such as post-stroke, often has asymmetry in step lengths and step times which may contribute to an increased energy cost. But paradoxically, enforcing step length symmetry does not reduce metabolic cost of post-stroke walking. The isolated and interacting costs of asymmetry in step times and step lengths remain unclear, because previous studies did not simultaneously enforce spatial and temporal gait asymmetries. Here, we delineate isolated costs of asymmetry in step times and step lengths in healthy human walking. We first show that the cost of step length asymmetry is predicted by the cost of taking two non-preferred step lengths (one short and one long), but that step time asymmetry adds an extra cost beyond the cost of non-preferred step times. The metabolic power of step time asymmetry is about 2.5 times greater than the cost of step length asymmetry. Furthermore, the costs are not additive when walking with asymmetric step times and step lengths: metabolic power of concurrent asymmetry in step lengths and step times is driven by the cost of step time asymmetry alone. The metabolic power of asymmetry is explained by positive mechanical power produced during single support phases to compensate for a net loss of center of mass power incurred during double support phases. These data may explain why metabolic cost remains invariant to step length asymmetry in post-stroke walking and suggests how effects of asymmetry on energy cost can be attenuated.

scholarly journals Evaluation of spatio-temporal parameters of the non-paretic limb in the gait performance of post stroke patients

2021 ◽  
Author(s):  
Rodrigo Andreola Serraglio ◽  
Ana Carolina Pauleto ◽  
Guilherme Augusto de Oliveira
Keyword(s):  
Functional Dependence ◽  
Step Length ◽  
The Body ◽  
Stroke Patients ◽  
Post Stroke ◽  
Swing Time ◽  
Paretic Limb ◽  
Spatio Temporal ◽  
High Level ◽  
Support Phase

The objective of this study is to evaluate the compensation of the non-paretic side in the gait of post-stroke hemiparetic patients submitted to computerized gait analysis in the Centro Hospitalar de Reabilitação Ana Carolina Moura Xavier, Curitiba - PR, in a study carried out in 2015. Spatio-temporal data were evaluated: speed, stride and step length, swing time and support of both members. The sample consisted of twenty individuals with a mean time after stroke of 6.9 months. The results showed that the median speed was equivalent to 16.17% of the normal standard value, stride length to 31.22%, step length of the non-paretic limb to 31.69%. The swing time on the nonparetic side corresponded to 35% of the total cycle and the support time corresponded to 86%. There is a favoring of the paretic limb over the non-paretic one, as a compensation mechanism for weakness and impaired balance. Thus, the non-paretic limb spends more time in the support phase to allow a longer step length of the paretic limb while in swing. In contrast, the paretic limb is unable to support the body in the support phase for a long time, reducing the step length of the non-paretic limb. The significant reduction in gait speed indicates the high level of functional dependence in these patients. If there is an opportunity to act early in the rehabilitation of post-stroke patients, still in the acute phase, it is possible to quantify the improvement in the ability to walk.

scholarly journals Use of explicit processes during a visually guided locomotor learning task predicts 24-hour retention after stroke

2020 ◽  
Author(s):  
Margaret A French ◽  
Susanne M. Morton ◽  
Darcy S. Reisman
Keyword(s):  
Visual Feedback ◽  
Step Length ◽  
Learning Task ◽  
Learning Processes ◽  
Healthy Adults ◽  
Stroke Survivors ◽  
Visually Guided ◽  
Implicit Processes ◽  
Explicit Processes ◽  
Implicit And Explicit

Implicit and explicit processes can occur within a single locomotor learning task. The combination of these learning processes may impact how individuals acquire/retain the task. Because these learning processes rely on distinct neural pathways, neurologic conditions may selectively impact the processes that occur, thus, impacting learning and retention. Thus, our purpose was to examine the contribution of implicit and explicit processes during a visually guided walking task and characterize the relationship between explicit processes and performance/retention in stroke survivors and age-matched healthy adults. Twenty chronic stroke survivors and twenty healthy adults participated in a 2-day treadmill study. Day 1 included Baseline, Acquisition1, Catch, Acquisition2, and Immediate Retention phases and Day 2 included 24-hour Retention. During acquisition phases, subjects learned to take a longer step with one leg through distorted visual feedback. During Catch and retention phases, visual feedback was removed and subjects were instructed to walk normally (Catch) or how they walked during the acquisition phases (retention). Change in step length from Baseline to Catch represented implicit processes. Change in step length from Catch to the end of Acquisition2 represented explicit processes. A mixed ANOVA found no difference in the type of learning between groups (p=0.74). There was a significant relationship between explicit processes and 24-hour retention in stroke survivors (r=0.47, p=0.04), but not in healthy adults (r=0.34, p=0.15). These results suggest that stroke may not affect the underlying learning mechanisms used during locomotor learning, but that these mechanisms impact how well stroke survivors retain the new walking pattern.

Sign in / Sign up

Export Citation Format

Share Document