scholarly journals Augmenting propulsion demands during split-belt walking increases locomotor adaptation in the asymmetric motor system

2019 ◽  
Author(s):  
Carly J. Sombric ◽  
Gelsy Torres-Oviedo
Keyword(s):  
Neurological Disorders ◽  
Motor System ◽  
Motor Behavior ◽  
Motor Adaptation ◽  
Chronic Phase ◽  
Step Length ◽  
After Effects ◽  
Post Stroke ◽  
Locomotor Adaptation ◽  
Rehabilitation Strategy

AbstractBackgroundPromising studies have shown that the mobility of individuals with hemiparesis due to brain lesions, such as stroke, can improve through motor adaptation protocols forcing patients to use their affected limb more. However, little is known about how to facilitate this process. Here we asked if increasing propulsion demands during split-belt walking (i.e., legs moving at different speeds) leads to more motor adaptation and more symmetric gait in survivors of a stroke, as we previously observed in subjects without neurological disorders.MethodsWe investigated the effect of propulsion forces on locomotor adaptation during and after split-belt walking in the asymmetric motor system post-stroke. To test this, 12 subjects in the chronic phase post-stroke experienced a split-belt protocol in a flat and incline session so as to contrast the effects of two different propulsion demands. Step length asymmetry and propulsion forces were used to compare the motor behavior between the two sessions because these are clinically relevant measures that are altered by split-belt walking.ResultsThe incline session resulted in more symmetric step lengths during late split-belt walking and larger after-effects following split-belt walking. In both testing sessions, subjects who have had a stroke adapted to regain speed and slope-specific leg orientations similarly to young, intact adults. Importantly, leg orientations during baseline walking were predictive of those achieved during split-belt walking, which in turn predicted each individual’s post-adaptation behavior.ConclusionThese results indicated that survivors of a stroke can adapt their movements to meet leg-specific kinetic demands. This promising finding suggests that augmenting propulsion demands during split-belt walking could favor symmetric walking in individuals who had a stroke, possibly making split-belt interventions a more effective gait rehabilitation strategy.

scholarly journals Persons with essential tremor can adapt to new walking patterns

2019 ◽  
Vol 122 (4) ◽  
pp. 1598-1605 ◽  
Author(s):  
Jaimie A. Roper ◽  
Sarah A. Brinkerhoff ◽  
Benjamin R. Harrison ◽  
Abigail C. Schmitt ◽  
Ryan T. Roemmich ◽  
...  
Keyword(s):  
Essential Tremor ◽  
Motor Adaptation ◽  
Step Length ◽  
Cross Sectional Study ◽  
Motor Deficits ◽  
Cross Sectional ◽  
Gait Adaptation ◽  
Locomotor Adaptation ◽  
Temporal Aspects ◽  
Walking Adaptation

Essential tremor (ET) is a common movement disorder that causes motor deficits similar to those seen in cerebellar disorders. These include kinetic tremor, gait ataxia, and impaired motor adaptation. Previous studies of motor adaptation in ET have focused on reaching while the effects of ET on gait adaptation are currently unknown. The purpose of this study was to contrast locomotor adaptation in persons with and without ET. We hypothesized that persons with ET would show impaired gait adaptation. In a cross-sectional study, persons with ET ( n = 14) and healthy matched controls ( n = 12) walked on a split-belt treadmill. Participants walked with the belts moving at a 2:1 ratio, followed by overground walking to test transfer, followed by a readaptation period and finally a deadaptation period. Step length asymmetry was measured to assess the rate of adaptation, amount of transfer, and rates of readaptation and deadaptation. Spatial, temporal, and velocity contributions to step length asymmetry were analyzed during adaptation. There were no group by condition interactions in step length asymmetry or contributions to step length asymmetry. Regardless of condition, persons with ET walked slower and exhibited lower temporal ( P < 0.001) and velocity ( P = 0.001) contributions to step length asymmetry than controls. Persons with ET demonstrated a preserved ability to adapt to, store, and transfer a new walking pattern. Despite probable cerebellar involvement in ET, locomotor adaptation is an available mechanism to teach persons with ET new gait patterns. NEW & NOTEWORTHY This study is the first to investigate walking adaptation abilities of people with essential tremor. Despite evidence of cerebellar impairment in this population, people with essential tremor can adapt their walking patterns. However, people with essential tremor do not modulate the timing of their footsteps to meet walking demands. Therefore, this study is the first to report impairments in the temporal aspects of walking in people with essential tremor during both typical and locomotor learning.

scholarly journals Contributions of spatial and temporal control of step length symmetry in the transfer of locomotor adaptation from a motorized to a non-motorized split-belt treadmill

2019 ◽  
Author(s):  
Daniel L. Gregory ◽  
Frank C. Sup ◽  
Julia T. Choi
Keyword(s):  
Repeated Measures ◽  
Step Length ◽  
Treadmill Walking ◽  
The Body ◽  
Speed Ratio ◽  
Temporal Control ◽  
After Effects ◽  
Locomotor Adaptation ◽  
Length Difference ◽  
Motor Outputs

AbstractBackgroundLocomotor adaptation during motorized split-belt walking depends on independent processes for spatial and temporal control of step length symmetry. The unique mechanics of motorized split-belt walking that constrains two limbs to move at different speeds during double support may limit transfer of step length adaptations to new walking contexts.Research questionHow do spatial and temporal locomotor outputs contribute to transfer of step length adaptation from constrained motorized split-belt walking to unconstrained non-motorized split-belt walking?MethodsWe built a non-motorized split-belt treadmill that allows the user to walk at their own pace while simultaneously allowing the two belts to be self-propelled at different speeds. 10 healthy young participants walked on the non-motorized split-belt treadmill after an initial 10-minute adaptation on the motorized split-belt with a 2:1 speed ratio. Foot placement relative to the body and timing between heel strikes were calculated to determine spatial and temporal motor outputs, respectively. Separate repeated measures ANOVAs were used for step length difference and its spatial and temporal components to assess for transfer to the non-motorized treadmill.ResultsWe found robust after-effects in step length difference during transfer to non-motorized split-belt treadmill walking that were primarily driven by changes in temporal motor outputs. Conversely, residual after-effects observed during motorized tied-belt treadmill walking (post-transfer) were driven by changes in spatial motor outputs.SignificanceOur data showed decoupling of adapted spatial and temporal locomotor outputs during the transfer to non-motorized split-belt walking, raising the new possibility of using a non-motorized split-belt treadmill to target specific spatial or temporal gait deficits.

scholarly journals Contributions of spatial and temporal control of step length symmetry in the transfer of locomotor adaptation from a motorized to a non-motorized split-belt treadmill

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Daniel L. Gregory ◽  
Frank C. Sup ◽  
Julia T. Choi
Keyword(s):  
Step Length ◽  
Treadmill Walking ◽  
Speed Ratio ◽  
Foot Placement ◽  
After Effects ◽  
Locomotor Adaptation ◽  
Locomotor Control ◽  
Length Difference ◽  
Limb Coordination ◽  
Healthy Participants

Walking requires control of where and when to step for stable interlimb coordination. Motorized split-belt treadmills which constrain each leg to move at different speeds lead to adaptive changes to limb coordination that result in after-effects (e.g. gait asymmetry) on return to normal treadmill walking. These after-effects indicate an underlying neural adaptation. Here, we assessed the transfer of motorized split-belt treadmill adaptations with a custom non-motorized split-belt treadmill where each belt can be self-propelled at different speeds. Transfer was indicated by the presence of after-effects in step length, foot placement and step timing differences. Ten healthy participants adapted on a motorized split-belt treadmill (2 : 1 speed ratio) and were then assessed for after-effects during subsequent non-motorized treadmill and motorized tied-belt treadmill walking. We found that after-effects in step length difference during transfer to non-motorized split-belt walking were primarily associated with step time differences. Conversely, residual after-effects during motorized tied-belt walking following transfer were associated with foot placement differences. Our data demonstrate decoupling of adapted spatial and temporal locomotor control during transfer to a novel context, suggesting that foot placement and step timing control can be independently modulated during walking.

scholarly journals Split-Belt walking induces changes in active, but not passive, perception of step length

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Carly Sombric ◽  
Marcela Gonzalez-Rubio ◽  
Gelsy Torres-Oviedo
Keyword(s):  
Motor Control ◽  
Motor Adaptation ◽  
Step Length ◽  
Accurate Estimation ◽  
Active Perception ◽  
Limb Position ◽  
Sensory Signals ◽  
Post Stroke ◽  
Young Subjects

Abstract Successful motor control requires accurate estimation of our body in space for planning, executing, and evaluating the outcome of our actions. It has been shown that the estimation of limb position is susceptible to motor adaptation. However, a similar effect has not been found in locomotion, possibly due to how it was tested. We hypothesized that split-belt walking with the legs moving at different speeds changes the estimation of the legs’ position when taking a step. Thus, we assessed young subjects’ perception of step length (i.e., inter-feet distance at foot landing) when they moved their legs (active perception) or when the legs were moved by the experimenter (passive perception). We found that the active perception of step length was substantially altered following split-belt walking, whereas passive perception exhibited minor changes. This suggests that split-belt walking induced the adaptation of efferent signals, without altering sensory signals. We also found that active perceptual shifts were sensitive to how they were tested: they were most salient in the trailing leg and at short step lengths. Our results suggest that split-belt walking could modulate the deficient perception of step length post-stroke, which may contribute to gait asymmetries impairing patients’ mobility.

scholarly journals Split-Belt walking induces changes in active, but not passive, perception of step length

2019 ◽  
Author(s):  
Carly Sombric ◽  
Marcela Gonzalez-Rubio ◽  
Gelsy Torres-Oviedo
Keyword(s):  
Motor Control ◽  
Motor Adaptation ◽  
Arm Movements ◽  
Step Length ◽  
Active Perception ◽  
Limb Position ◽  
Post Stroke ◽  
Gait Asymmetry ◽  
Sensory Changes ◽  
Young Subjects

AbstractThe estimation of limbs’ position is critical for motor control. While motor adaptation changes the estimation of limb position in volitional arm movements, this has not been observed in locomotion. We hypothesized that split-belt walking with the legs moving at different speeds changes the estimation of the legs’ position when taking a step. Thus, we assessed young subjects’ perception of step length (i.e., inter-feet distance at foot landing) when they moved their legs (active perception) or these were moved by the experimenter (passive perception). Step length’s active, but not passive perception was altered by split-belt walking; indicating that adapted efferent inputs changed the perceived limbs’ position without changing information from sensory signals. These perceptual shifts were sensitive to how they were tested: they were observed in the trailing, but not the leading leg, and they were more salient when tested with short than long step lengths. Our results suggest that sensory changes following motor adaptation might arise from mismatched limb position estimates from different sensory sources (i.e., proprioception and vision), which is less prominent in walking. We also speculate that split-belt walking could improve the deficient perception of step length post-stroke, which contributes to their gait asymmetry impairing patients’ mobility.

scholarly journals Effect of robotic-assisted gait training on objective biomechanical measures of gait in persons post-stroke: a systematic review and meta-analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Heidi Nedergård ◽  
Ashokan Arumugam ◽  
Marlene Sandlund ◽  
Anna Bråndal ◽  
Charlotte K. Häger
Keyword(s):  
Kinetic Parameters ◽  
Step Length ◽  
Gait Training ◽  
Risk Of Bias ◽  
Current Evidence ◽  
Temporal Asymmetry ◽  
Robotic Assisted ◽  
Post Stroke ◽  
Gait Biomechanics ◽  
Affected Side

Abstract Background Robotic-Assisted Gait Training (RAGT) may enable high-intensive and task-specific gait training post-stroke. The effect of RAGT on gait movement patterns has however not been comprehensively reviewed. The purpose of this review was to summarize the evidence for potentially superior effects of RAGT on biomechanical measures of gait post-stroke when compared with non-robotic gait training alone. Methods Nine databases were searched using database-specific search terms from their inception until January 2021. We included randomized controlled trials investigating the effects of RAGT (e.g., using exoskeletons or end-effectors) on spatiotemporal, kinematic and kinetic parameters among adults suffering from any stage of stroke. Screening, data extraction and judgement of risk of bias (using the Cochrane Risk of bias 2 tool) were performed by 2–3 independent reviewers. The Grading of Recommendations Assessment Development and Evaluation (GRADE) criteria were used to evaluate the certainty of evidence for the biomechanical gait measures of interest. Results Thirteen studies including a total of 412 individuals (mean age: 52–69 years; 264 males) met eligibility criteria and were included. RAGT was employed either as monotherapy or in combination with other therapies in a subacute or chronic phase post-stroke. The included studies showed a high risk of bias (n = 6), some concerns (n = 6) or a low risk of bias (n = 1). Meta-analyses using a random-effects model for gait speed, cadence, step length (non-affected side) and spatial asymmetry revealed no significant differences between the RAGT and comparator groups, while stride length (mean difference [MD] 2.86 cm), step length (affected side; MD 2.67 cm) and temporal asymmetry calculated in ratio-values (MD 0.09) improved slightly more in the RAGT groups. There were serious weaknesses with almost all GRADE domains (risk of bias, consistency, directness, or precision of the findings) for the included outcome measures (spatiotemporal and kinematic gait parameters). Kinetic parameters were not reported at all. Conclusion There were few relevant studies and the review synthesis revealed a very low certainty in current evidence for employing RAGT to improve gait biomechanics post-stroke. Further high-quality, robust clinical trials on RAGT that complement clinical data with biomechanical data are thus warranted to disentangle the potential effects of such interventions on gait biomechanics post-stroke.

Rehabilitation of Post Stroke Sensory Dysfunction—A Scoping Review

2021 ◽  
pp. 251660852098429
Author(s):  
Dorcas B. C. Gandhi ◽  
Ivy Anne Sebastian ◽  
Komal Bhanot
Keyword(s):  
Motor Behavior ◽  
Sensory Modality ◽  
Sensory System ◽  
Sensory Stimulation ◽  
Current Evidence ◽  
Cochrane Library ◽  
Post Stroke ◽  
Sensory Dysfunction ◽  
Electronic Database Search ◽  
External Stimuli

Sensory dysfunction is one of the common impairments that occurs post stroke. With sensory changes in all modalities, it also affects the quality of life and incites suicidal thoughts. The article attempts to review and describe the current evidence of various approaches of assessment and rehabilitation for post-stroke sensory dysfunction. After extensive electronic database search across Medline, Embase, EBSCO, and Cochrane library, it generated 2433 results. After screening according to inclusion and exclusion criteria, we included 11 studies. We categorized data based on type of sensory deficits and prevalence, role of sensory system on motor behavior, type of intervention, sensory modality targeted, and dosage of intervention and outcome measures used for rehabilitation. Results found the strong evidence of involvement of primary and secondary motor areas involved in processing and responding to somatosensation, respectively. We divided rehabilitation approaches into sensory stimulation approach and sensory retraining approach focused on using external stimuli and relearning, respectively. However, with varied aims and targeted sensory involvement, the study applicability is affected. Thus, this emerges the need of extensive research in future for evidence-based practice of assessments and rehabilitation on post-stroke sensory rehabilitation.

scholarly journals Rehabilitation strategy for post-stroke recovery using an innovative elbow exoskeleton

2019 ◽  
Vol 233 (6) ◽  
pp. 668-680 ◽  
Author(s):  
Soumya K Manna ◽  
Venketesh N Dubey
Keyword(s):  
Acute Stage ◽  
Joint Torque ◽  
Stroke Recovery ◽  
Structural Description ◽  
Post Stroke ◽  
Single Structure ◽  
Rate Of Recovery ◽  
Last Stage ◽  
Working Region ◽  
Rehabilitation Strategy

Intensive and adaptive rehabilitation therapy is beneficial for post-stroke recovery. Three modes of rehabilitation are generally performed at different stages after stroke: external force-based control in the acute stage, assistive force-based rehabilitation in the midway of recovery and resistive force-based rehabilitation in the last stage. To achieve the above requirements, an innovative elbow exoskeleton has been developed to incorporate the three modes of rehabilitation in a single structure. The structure of the exoskeleton has been designed in such a way that the whole working region is divided into three where each region can provide a different mode of rehabilitation. Recovery rate can be varied for individuals since it depends on various parameters. To evaluate the rate of recovery, three joint parameters have been identified: range of angular movement, angular velocity and joint torque. These parameters are incorporated into the framework of planning a novel rehabilitation strategy, which is discussed in this article along with the structural description of the designed exoskeleton.

scholarly journals Dynamics of language reorganization after left temporo-parietal and frontal stroke

Brain ◽  
2020 ◽  
Vol 143 (3) ◽  
pp. 844-861 ◽  
Author(s):  
Anika Stockert ◽  
Max Wawrzyniak ◽  
Julian Klingbeil ◽  
Katrin Wrede ◽  
Dorothee Kümmerer ◽  
...  
Keyword(s):  
Functional Mri ◽  
Chronic Phase ◽  
Global Network ◽  
Lesion Location ◽  
Post Stroke ◽  
Language Functions ◽  
Language Recovery ◽  
Patient Groups ◽  
The Impact ◽  
General Networks

Abstract The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying language recovery in patients with post-stroke aphasia putting particular emphasis on the impact of lesion site. To identify patterns of language-related activation, an auditory functional MRI sentence comprehension paradigm was administered to patients with circumscribed lesions of either left frontal (n = 17) or temporo-parietal (n = 17) cortex. Patients were examined repeatedly during the acute (≤1 week, t1), subacute (1–2 weeks, t2) and chronic phase (&gt;6 months, t3) post-stroke; healthy age-matched control subjects (n = 17) were tested once. The separation into two patient groups with circumscribed lesions allowed for a direct comparison of the contributions of distinct lesion-dependent network components to language reorganization between both groups. We hypothesized that activation of left hemisphere spared and perilesional cortex as well as lesion-homologue cortex in the right hemisphere varies between patient groups and across time. In addition, we expected that domain-general networks serving cognitive control independently contribute to language recovery. First, we found a global network disturbance in the acute phase that is characterized by reduced functional MRI language activation including areas distant to the lesion (i.e. diaschisis) and subsequent subacute network reactivation (i.e. resolution of diaschisis). These phenomena were driven by temporo-parietal lesions. Second, we identified a lesion-independent sequential activation pattern with increased activity of perilesional cortex and bilateral domain-general networks in the subacute phase followed by reorganization of left temporal language areas in the chronic phase. Third, we observed involvement of lesion-homologue cortex only in patients with frontal but not temporo-parietal lesions. Fourth, irrespective of lesion location, language reorganization predominantly occurred in pre-existing networks showing comparable activation in healthy controls. Finally, we detected different relationships of performance and activation in language and domain-general networks demonstrating the functional relevance for language recovery. Our findings highlight that the dynamics of language reorganization clearly depend on lesion location and hence open new perspectives for neurobiologically motivated strategies of language rehabilitation, such as individually-tailored targeted application of neuro-stimulation.

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