scholarly journals Characterization and clinical implications of ankle impedance during walking in chronic stroke

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanda L. Shorter ◽  
James K. Richardson ◽  
Suzanne B. Finucane ◽  
Varun Joshi ◽  
Keith Gordon ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Stance Phase ◽  
Clinical Care ◽  
Joint Stiffness ◽  
Mechanical Impedance ◽  
Chronic Stroke ◽  
Joint Mechanics ◽  
Clinical Assessments ◽  
Post Stroke ◽  
Joint Damping

AbstractIndividuals post-stroke experience persisting gait deficits due to altered joint mechanics, known clinically as spasticity, hypertonia, and paresis. In engineering, these concepts are described as stiffness and damping, or collectively as joint mechanical impedance, when considered with limb inertia. Typical clinical assessments of these properties are obtained while the patient is at rest using qualitative measures, and the link between the assessments and functional outcomes and mobility is unclear. In this study we quantify ankle mechanical impedance dynamically during walking in individuals post-stroke and in age-speed matched control subjects, and examine the relationships between mechanical impedance and clinical measures of mobility and impairment. Perturbations were applied to the ankle joint during the stance phase of walking, and least-squares system identification techniques were used to estimate mechanical impedance. Stiffness of the paretic ankle was decreased during mid-stance when compared to the non-paretic side; a change independent of muscle activity. Inter-limb differences in ankle joint damping, but not joint stiffness or passive clinical assessments, strongly predicted walking speed and distance. This work provides the first insights into how stroke alters joint mechanical impedance during walking, as well as how these changes relate to existing outcome measures. Our results inform clinical care, suggesting a focus on correcting stance phase mechanics could potentially improve mobility of chronic stroke survivors.

scholarly journals The Function Axis of Rotation of the Ankle Joint during Simulated Gait

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0003
Author(s):  
Daniel Sturnick ◽  
Constantine Demetracopoulos ◽  
Guilherme Honda Saito
Keyword(s):  
Ankle Joint ◽  
Stance Phase ◽  
Force Plate ◽  
Implant Design ◽  
Joint Mechanics ◽  
Center Of Rotation ◽  
Axis Of Rotation ◽  
Ankle Kinematics ◽  
Flexion Extension ◽  
Joint Center

Category: Ankle, Ankle Arthritis, Hindfoot Introduction/Purpose: Implant component positioning is considered as an important factor in function and longevity in total ankle arthroplasty (TAA). However, accurate and repeatable positioning remains a limitation with current techniques and instrumentation. In addition, further investigation is needed to objectively define the optimum component positioning. Cadaveric gait simulation is a valuable tool for investigating foot and ankle joint mechanics during functional tasks such as the stance phase of gait. The objective of this study was to investigate the functional axis of rotation of the native ankle joint during simulated gait. Methods: The stance phase of healthy gait was simulated with six mid-tibia cadaveric specimens using a previously validated device and methodology. A robotic platform reproduced tibial-ground kinematics by moving a force plate relative to the stationary specimen while physiologic loads were applied to the extrinsic tendons to actuate the foot. (Figure 1A). Ankle kinematics were measured from reflective markers attached to the tibia and talus via surgical pins. The helical axes of rotation of the talus with respect to the tibia was calculated during three portions of stance: initial plantarflexion during earlier-stance after heal strike, dorsiflexion during mid-stance, and final plantarflexion during late-stance. The position and orientation of these kinematic-defined axes of rotation were compared to the transmalleolar axis and reduced to its anteroposterior position and transverse plane angle (Figure 1B). Results: Analyses revealed that ankle joint functional axis of rotation varied from the anatomic reference throughout stance. The kinematic center of rotation was located 16.4 ± 5.8 mm, 16.5 ± 6.6 mm, and 15.6 ± 6.5 mm anterior to the transmalleolar axis during early-, mid- and late-portions of stance, respectively. Conclusion: This study revealed that the position of the flexion-extension axis varies greatly between specimens during simulated gait. While previous reports have suggested that the transmalleolar axis is an acceptable approximation for the ankle joint center, these findings suggest that further research in warranted to better describe the complex tibiotalar kinematics. This work may provide future insight to guide implant design and advance techniques, to better place articular constraints of a total ankle in the native center of rotation of the joint.

scholarly journals Effect of Stretching of Spastic Elbow Under Intelligent Control in Chronic Stroke Survivors—A Pilot Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Sanjana Rao ◽  
Meizhen Huang ◽  
Sun Gun Chung ◽  
Li-Qun Zhang
Keyword(s):  
Elbow Joint ◽  
Sagittal Plane ◽  
Biceps Tendon ◽  
Joint Stiffness ◽  
Elbow Flexion ◽  
Passive Movement ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Short Term ◽  
Post Stroke

Objective: To assess the short-term effects of strenuous dynamic stretching of the elbow joint using an intelligent stretching device in chronic spastic stroke survivors.Methods: The intelligent stretching device was utilized to provide a single session of intensive stretching to the spastic elbow joint in the sagittal plane (i.e., elbow flexion and extension). The stretching was provided to the extreme range, safely, with control of the stretching velocity and torque to increase the joint range of motion (ROM) and reduce spasticity and joint stiffness. Eight chronic stroke survivors (age: 52.6 ± 8.2 years, post-stroke duration: 9.5 ± 3.6 years) completed a single 40-min stretching intervention session. Elbow passive and active ROM, strength, passive stiffness (quantifying the non-reflex component of spasticity), and instrumented tendon reflex test of the biceps tendon (quantifying the reflex component of the spasticity) were measured before and after stretching.Results: After stretching, there was a significant increase in passive ROM of elbow flexion (p = 0.021, r = 0.59) and extension (p = 0.026, r = 0.59). Also, elbow active ROM and the spastic elbow flexors showed a trend of increase in their strength.Conclusion: The intelligent stretching had a short-term positive influence on the passive movement ROM. Hence, intelligent stretching can potentially be used to repeatedly and regularly stretch spastic elbow joints, which subsequently helps to reduce upper limb impairments post-stroke.

scholarly journals Feasibility of a specific task-oriented training versus its combination with manual therapy on balance and mobility in people post stroke at the chronic stage: study protocol for a pilot randomised controlled trial

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kristina Traxler ◽  
Franz Schinabeck ◽  
Eva Baum ◽  
Edith Klotz ◽  
Barbara Seebacher
Keyword(s):  
Randomised Controlled Trial ◽  
Ankle Joint ◽  
Manual Therapy ◽  
Controlled Trial ◽  
Daily Activities ◽  
Control Group ◽  
Chronic Stage ◽  
Post Stroke ◽  
Randomised Controlled ◽  
Task Oriented

Abstract Background Large studies have shown that stroke is among the most relevant causes of acquired adult disability. Walking and balance impairment in stroke survivors often contribute to a restriction in daily activities and social participation. Task-oriented training (TOT) is an effective treatment strategy and manual therapy (MT) is used successfully to enhance ankle joint flexibility in this population. No study, however, has compared TOT against its combination with MT in a randomised controlled trial. Aims of this pilot study are therefore to explore the feasibility of a full-scale RCT using predefined feasibility criteria. Secondary aims are to explore the preliminary effects of specific TOT with a combined specific TOT-MT versus a control group in people post stroke. Methods This is a protocol of a 4-week prospective randomised controlled parallel pilot trial in people post stroke at the chronic stage with limited upper ankle joint mobility and an impairment in balance and mobility. At a German outpatient therapy centre using 1:1:1 allocation, 36 patients will be randomised into one of three groups: 15-min talocrural joint MT plus 30-min specific TOT (group A), 45-min specific TOT (group B), and controls (group C). Training will be goal-oriented including tasks that are based on daily activities and increased in difficulty utilising predefined progression criteria based on patients’ skill levels. Interventions will be provided face-to-face 2 times per week, for 4 weeks, in addition to 20-min concurrent x4 weekly home-based training sessions. Data will be collected by blinded assessors at baseline, post-intervention and 4-week follow-up. The primary outcome will be feasibility assessed by recruitment, retention and adherence rates, compliance, adverse events, falls and the acceptability of the intervention. Secondary outcomes will be walking speed, single and dual tasking functional mobility, ankle range of motion, disability and health-related quality of life. Discussion Feasibility provided, results from this study will be used to calculate the sample size of a larger randomised controlled trial to investigate the effects of specific TOT and specific TOT-MT compared to a post stroke control group. Trial registration German Clinical Trials Register, DRKS00023068. Registered on 21.09.2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023068.

scholarly journals Measurement of passive ankle stiffness in subjects with chronic hemiparesis using a novel ankle robot

2011 ◽  
Vol 105 (5) ◽  
pp. 2132-2149 ◽  
Author(s):  
Anindo Roy ◽  
Hermano I. Krebs ◽  
Christopher T. Bever ◽  
Larry W. Forrester ◽  
Richard F. Macko ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Frontal Plane ◽  
Chronic Stroke ◽  
Healthy Adults ◽  
Stroke Survivors ◽  
Passive Stiffness ◽  
Mechanical Stiffness ◽  
Treatment Protocols ◽  
Ankle Stiffness ◽  
Hemiparetic Stroke

Our objective in this study was to assess passive mechanical stiffness in the ankle of chronic hemiparetic stroke survivors and to compare it with those of healthy young and older (age-matched) individuals. Given the importance of the ankle during locomotion, an accurate estimate of passive ankle stiffness would be valuable for locomotor rehabilitation, potentially providing a measure of recovery and a quantitative basis to design treatment protocols. Using a novel ankle robot, we characterized passive ankle stiffness both in sagittal and in frontal planes by applying perturbations to the ankle joint over the entire range of motion with subjects in a relaxed state. We found that passive stiffness of the affected ankle joint was significantly higher in chronic stroke survivors than in healthy adults of a similar cohort, both in the sagittal as well as frontal plane of movement, in three out of four directions tested with indistinguishable stiffness values in plantarflexion direction. Our findings are comparable to the literature, thus indicating its plausibility, and, to our knowledge, report for the first time passive stiffness in the frontal plane for persons with chronic stroke and older healthy adults.

scholarly journals Effects of a specific task-oriented training versus its combination with manual therapy on balance and mobility in people post stroke at the chronic stage: study protocol for a pilot randomised controlled trial

2020 ◽  
Author(s):  
Kristina Traxler ◽  
Franz Schinabeck ◽  
Eva Baum ◽  
Edith Klotz ◽  
Barbara Seebacher
Keyword(s):  
Randomised Controlled Trial ◽  
Ankle Joint ◽  
Manual Therapy ◽  
Controlled Trial ◽  
Daily Activities ◽  
Control Group ◽  
Chronic Stage ◽  
Post Stroke ◽  
Randomised Controlled ◽  
Task Oriented

Abstract Background: Large studies have shown that stroke is among the most relevant causes of acquired adult disability. Walking and balance impairment in stroke survivors often contribute to a restriction in daily activities and social participation. Task-oriented training (TOT) is an effective treatment strategy and manual therapy (MT) is used successfully to enhance ankle joint flexibility in this population. No study, however, has compared TOT against its combination with MT in a randomised controlled trial. Aims of this pilot study are therefore to explore the feasibility of a full-scale RCT and the preliminary effects of specific TOT with a combined specific TOT-MT versus a control group in people post stroke.Methods: This is a protocol of a 4-week prospective randomised controlled parallel pilot trial in people post stroke at the chronic stage with limited upper ankle joint mobility and an impairment in balance and mobility. At a German outpatient therapy centre using 1:1:1 allocation, 36 patients will be randomised into one of three groups: 15-minute talocrural joint MT plus 30-minute specific TOT (Group A); 45-minute specific TOT (Group B); controls (Group C). Training will be goal-oriented including tasks that are based on daily activities and increased in difficulty ulilising predefined progression criteria. Interventions will be provided face-to-face 2 times per week, for 4 weeks, in addition to 20-minute concurrent x4 weekly homebased training sessions. Data will be collected by blinded assessors at baseline, post-intervention and 4-week follow-up. The primary outcome will be feasibility assessed by recruitment, retention and adherence rates, compliance, adverse events, falls and the acceptability of the intervention. Secondary outcomes will be walking speed, single and dual tasking functional mobility, ankle range of motion, disability and health-related quality of life.Discussion: Results from this study will inform a larger randomised controlled trial to investigate the effects of specific TOT and specific TOT-MT compared to a post stroke control group. We hope that the study findings help to enhance stroke rehabilitation.Trial registration: German Clinical Trials Register, DRKS00023068. Registered on 21.09.2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023068.

Abstract P352: Racial Disparity in Post-stroke Readmission - a South Carolina Perspective

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Pratik Y Chhatbar ◽  
Jihad S Obeid ◽  
Daniel T Lackland ◽  
Suzanne P Burns ◽  
Joy N Buie ◽  
...  
Keyword(s):  
South Carolina ◽  
Quality Of Care ◽  
African Americans ◽  
Racial Disparity ◽  
Clinical Care ◽  
University Of South Carolina ◽  
Readmission Rates ◽  
Post Stroke ◽  
Medical University

Background: Readmissions after acute hospitalizations are a cause of both risk and expense, and many of them are potentially preventable. Importantly, risk-standardized hospital readmission rates are sometimes used as a yardstick of the quality of care offered. However, racial variability in readmissions might involve factors beyond quality of care and has not been studied extensively. During our pilot investigation using 90-day post-stroke readmissions data at Medical University of South Carolina (MUSC), we found significant disparities between African Americans and Caucasians. Objective: To identify differences in readmissions between African Americans and other races and determine preventable readmissions from a pragmatic viewpoint. Methods: We obtained deidentified data from Health Sciences South Carolina (HSSC) Clinical Data Warehouse (CDW). The data was comprised of three institutions: Medical University of South Carolina (MUSC), Palmetto Health and Greenville Hospital System University Medical Center. The data consisted of on adult admissions with index diagnosis considered as an ischemic stroke (or closely related) using International Classification of Diseases, Ninth and Tenth Revision (ICD-9, ICD-10) codes between January 2011 and April 2017. Of these, we will determine readmission and reason for readmission over 90-day period. Readmission can be hospital or emergency room readmission. Results: Our database contains 32,548 patients who have been provided clinical care for stroke. Out of these patients 8,308 (25.5%), 23,085 (70.9%) and 1,155 (3.5%) are African Americans, Caucasians and others, respectively. We will present weekly readmission trends over 90 days and evaluate if there are disparities across races. We will apply chi-square test and Student’s t-test to determine statistical significance. For weekly readmission trends over 90 days, we will apply Kolmogorov-Smirnov test to identify difference in readmission patterns across races. We will also identify confounders like socioeconomic status and age and their influence in the racial disparity. Conclusions: From a single center retrospective data, we found that 90-days readmission rates involve African Americans in a disproportionate manner. This multicenter data analysis will further shed light on the etiology of readmission, confounders and the care offered.

Abstract TP150: Two Weeks of Ischemic Preconditioning Training on the Paretic Leg Improves Leg Strength and Delays Muscle Fatigue in Chronic Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Matthew J Durand ◽  
Spencer A Murphy ◽  
Brian D Schmit ◽  
David D Gutterman ◽  
Allison S Hyngstrom
Keyword(s):  
Motor Function ◽  
Ischemic Preconditioning ◽  
Vascular Function ◽  
Knee Extensor ◽  
Chronic Stroke ◽  
Muscle Performance ◽  
Walking Ability ◽  
Post Stroke ◽  
Leg Strength ◽  
Improve Motor Function

Introduction: Individuals living with chronic stroke have weakness and increased neuromuscular fatigue in the paretic leg, which can limit walking ability and endurance. In cardiac and healthy populations, ischemic preconditioning (IPC) is a widely studied, effective, non-invasive stimulus which not only improves vascular function, but also motor performance. IPC occurs when the tissue of interest is exposed to repeated, short bouts of ischemia, which can improve motor function by enhancing vascular, neural and muscle function. IPC has not been tested as a method to improve motor function in individuals post-stroke. Hypothesis: Two weeks of IPC training on the paretic leg will improve leg strength and time-to-task failure (TTF) during a fatiguing muscle contraction. Methods: A feasibility study of 4 individuals (3 female, 1 male) with chronic stroke (20 ± 4 years) was conducted. A Biodex dynamometer was used to assess paretic leg knee extensor maximal voluntary contraction (MVC). To assess muscle fatigability, subjects maintained a sustained contraction equal to 30% of their MVC until failure using visual feedback. After baseline testing, subjects made six visits to the laboratory over a two week period to have IPC performed on their paretic leg. A blood pressure cuff was inflated on the thigh to 225 mmHg for five, five-minute bouts per session. Five minutes of rest was given between inflation cycles. After the last session, subjects returned within 48 hours to have MVC and TTF reassessed. Results: Three subjects completed all study procedures. One subject withdrew for medical reasons unrelated to the study. The IPC procedure was well tolerated by all subjects. After two-week IPC training, knee extensor MVC increased in the paretic leg (45.0 ± 2.7 Nm vs. 52.6 ± 5.7 Nm). Fatigability of the muscles was dramatically reduced after IPC training as TTF tripled (359 ± 180 seconds vs. 1097 ± 343 seconds). Conclusions: We are the first group to show that IPC is a well-tolerated and effective stimulus to improve paretic leg strength and reduce muscle fatigability in subjects with chronic stroke. The results of this pilot study warrant a larger study to determine whether IPC improves muscle performance post-stroke through neural, vascular, or muscle-related mechanisms.

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