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 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 How Well Do Commonly Used Co-contraction Indices Approximate Lower Limb Joint Stiffness Trends During Gait for Individuals Post-stroke?

2021 ◽  
Vol 8 ◽  
Author(s):  
Geng Li ◽  
Mohammad S. Shourijeh ◽  
Di Ao ◽  
Carolynn Patten ◽  
Benjamin J. Fregly
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Joint Stiffness ◽  
Energetic Cost ◽  
Electromechanical Delay ◽  
Antagonist Muscle ◽  
Post Stroke ◽  
Methodological Choices ◽  
Model Based

Muscle co-contraction generates joint stiffness to improve stability and accuracy during limb movement but at the expense of higher energetic cost. However, quantification of joint stiffness is difficult using either experimental or computational means. In contrast, quantification of muscle co-contraction using an EMG-based Co-Contraction Index (CCI) is easier and may offer an alternative for estimating joint stiffness. This study investigated the feasibility of using two common CCIs to approximate lower limb joint stiffness trends during gait. Calibrated EMG-driven lower extremity musculoskeletal models constructed for two individuals post-stroke were used to generate the quantities required for CCI calculations and model-based estimation of joint stiffness. CCIs were calculated for various combinations of antagonist muscle pairs based on two common CCI formulations: Rudolph et al. (2000) (CCI1) and Falconer and Winter (1985) (CCI2). CCI1 measures antagonist muscle activation relative to not only total activation of agonist plus antagonist muscles but also agonist muscle activation, while CCI2 measures antagonist muscle activation relative to only total muscle activation. We computed the correlation between these two CCIs and model-based estimates of sagittal plane joint stiffness for the hip, knee, and ankle of both legs. Although we observed moderate to strong correlations between some CCI formulations and corresponding joint stiffness, these associations were highly dependent on the methodological choices made for CCI computation. Specifically, we found that: (1) CCI1 was generally more correlated with joint stiffness than was CCI2, (2) CCI calculation using EMG signals with calibrated electromechanical delay generally yielded the best correlations with joint stiffness, and (3) choice of antagonist muscle pairs significantly influenced CCI correlation with joint stiffness. By providing guidance on how methodological choices influence CCI correlation with joint stiffness trends, this study may facilitate a simpler alternate approach for studying joint stiffness during human movement.

Abstract P276: Aerobic Endurance and Leg Strength are Predictive of Gait Velocity among Community-Dwelling Stroke Survivors

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Ruth E Taylor-Piliae ◽  
L. Daniel Latt ◽  
Bruce M Coull
Keyword(s):  
Cognitive Impairment ◽  
Functional Disability ◽  
Chronic Stroke ◽  
Community Dwelling ◽  
Step Test ◽  
Gait Velocity ◽  
Stroke Survivors ◽  
Chair Stand ◽  
Post Stroke ◽  
Leg Strength

Background: Gait velocity is an objective, fundamental indicator of post-stroke walking ability. Most stroke survivors have diminished aerobic endurance and paretic leg strength, with one or both of these conditions affecting their gait velocity. Other reported underlying factors affecting gait velocity include functional disability, balance and cognitive impairment. Objective: To examine potential independent predictors of gait velocity in chronic stroke. Methods: Cross-sectional design using baseline data from the first 100 community-dwelling stroke survivors enrolled in an exercise intervention study. Eligible subjects included men and women aged ≥ 50 years and at ≥ 3 months post-stroke. Subjects completed a comprehensive, self-administered health survey prior to their baseline study visit. At the baseline visit, functional disability (Modified Rankin Scale), aerobic endurance (2-minute step-test), leg strength (timed 5-chair stand test), balance (single-leg stance) and cognitive impairment (Mini-Mental Status Exam) were assessed. Gait speed was assessed using a valid and reliable timed 4-meter walk test designed for older adults with disabilities; to calculate gait velocity (meters/second). Multiple linear regression was conducted to explore potential independent predictors of gait velocity. Results: Subjects (n=100) were on average 70±10 years old, and 39±49 months post-stroke. The majority reported an ischemic stroke (68/100) with hemiparesis (80/100); and were married (59/100), White/European-American (78/100), college-educated (79/100), men (54/100). Subjects had an average gait velocity of 0.75±0.23 meters/second, categorized as limited community walkers. Approximately 37% of the variance in gait velocity, could be explained by the optimal combination of the independent variables in the model: functional disability, aerobic endurance, leg strength, balance, and cognitive impairment (R 2 =0.37, F 5,74 =8.64, p<0.01). Only better aerobic endurance (t 1,74 =3.41, p<0.01) and leg strength (i.e. faster chair stand time) (t 1,74 =–2.23, p=0.03) contributed uniquely and significantly to faster gait velocity. Conclusion: A hallmark of gait dysfunction in chronic stroke is slow gait velocity, even among well-educated, community-dwelling survivors. Gait velocity is simple to measure requiring only a stopwatch and flat surface for walking. Our findings are similar to reports by others that diminished aerobic endurance and leg strength are major contributors to slow gait velocity in chronic stroke. Long term rehabilitation efforts are needed to improve gait velocity in chronic stroke, and may need to incorporate multifaceted strategies concurrently, focusing on aerobic endurance and leg strength, to maximize community ambulation and reintegration.

scholarly journals The Loop Tenodesis Procedure—From Biomechanics to First Clinical Results

2021 ◽  
Vol 10 (3) ◽  
pp. 432
Author(s):  
Moritz Riedl ◽  
Agnes Mayr ◽  
Stefan Greiner ◽  
Christian Pfeifer ◽  
Isabella Weiss ◽  
...  
Keyword(s):  
Constant Score ◽  
Biceps Tendon ◽  
Elbow Flexion ◽  
Clinical Results ◽  
Functional Impairments ◽  
Bicipital Groove ◽  
Short Term ◽  
Therapy Options ◽  
Supination Strength

(1) Introduction: Several surgical therapy options for the treatment of pathologies of the long biceps tendon (LHB) have been established. However, tenotomy, as well as established tenodesis techniques, has disadvantages, such as cosmetic deformities, functional impairments and residual shoulder pain. This study presents the first clinical and structural results of the recently introduced loop tenodesis procedure for the LHB, developed to overcome these issues. (2) Methods: 37 patients (11 women, 26 men, mean age 52 years), who underwent loop tenodesis of the LHB were examined six months after surgery. For the clinical evaluation the Constant score, as well as the LHB score, were used, complemented by elbow flexion and supination strength measurements. The integrity of the tenodesis construct was evaluated indirectly by sonographic detection of the LHB in the bicipital groove. (3) Results: Both, the overall Constant score as well as the LHB score showed significant improvements six months postoperatively, as compared to the preoperative value. Fourteen patients (38%) presented an examiner-dependent upper arm deformity, although only five patients (13%) reported subjective cosmetic deformities. Both, flexion and supination strength were preserved compared to the preoperative level. In 35 patients (95%), the tenodesis in the bicipital groove was proofed sonographically. (4) Conclusion: The loop tenodesis of the LHB provides good-to-excellent overall clinical results after a short-term follow-up of six month. The incidence of cosmetic deformities was inferior compared to conventional therapy options (tenotomy and anchor tenodesis).

scholarly journals Post-stroke depression: Prevalence and relationship with disability in chronic stroke survivors

2010 ◽  
Vol 13 (2) ◽  
pp. 123 ◽  
Author(s):  
Abhishek Srivastava ◽  
ArunB Taly ◽  
Anupam Gupta ◽  
Thyloth Murali
Keyword(s):  
Chronic Stroke ◽  
Stroke Survivors ◽  
Post Stroke ◽  
Depression Prevalence ◽  
Post Stroke Depression

scholarly journals Similar cognitive deficits in mice and humans in the chronic phase post-stroke identified using the touchscreen-based paired-associate learning task

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Zhen Chow ◽  
Lin Kooi Ong ◽  
Murielle G. Kluge ◽  
Prajwal Gyawali ◽  
Frederick R. Walker ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Paired Associate ◽  
Chronic Phase ◽  
Learning Task ◽  
Paired Associate Learning ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Associate Learning ◽  
Cross Sectional ◽  
Post Stroke

Abstract For many chronic stroke survivors, persisting cognitive dysfunction leads to significantly reduced quality of life. Translation of promising therapeutic strategies aimed at improving cognitive function is hampered by existing, disparate cognitive assessments in animals and humans. In this study, we assessed post-stroke cognitive function using a comparable touchscreen-based paired-associate learning task in a cross-sectional population of chronic stroke survivors (≥ 5 months post-stroke, n = 70), age-matched controls (n = 70), and in mice generated from a C57BL/6 mouse photothrombotic stroke model (at six months post-stroke). Cognitive performance of stroke survivors was analysed using linear regression adjusting for age, gender, diabetes, systolic blood pressure and waist circumference. Stroke survivors made significantly fewer correct choices across all tasks compared with controls. Similar cognitive impairment was observed in the mice post-stroke with fewer correct choices compared to shams. These results highlight the feasibility and potential value of analogous modelling of clinically meaningful cognitive impairments in chronic stroke survivors and in mice in chronic phase after stroke. Implementation of validated, parallel cross-species test platforms for cognitive assessment offer the potential of delivering a more useful framework for evaluating therapies aimed at improving long-term cognitive function post-stroke.

scholarly journals Pathway-specific modulatory effects of neuromuscular electrical stimulation during pedaling in chronic stroke survivors

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Shi-Chun Bao ◽  
Wing-Cheong Leung ◽  
Vincent C. K. Cheung ◽  
Ping Zhou ◽  
Kai-Yu Tong
Keyword(s):  
Electrical Stimulation ◽  
Healthy Subjects ◽  
Neuromuscular Electrical Stimulation ◽  
Neuromuscular Control ◽  
Chronic Stroke ◽  
Sensory Level ◽  
Stroke Survivors ◽  
Potential Contribution ◽  
Descending Pathways ◽  
Post Stroke

Abstract Background Neuromuscular electrical stimulation (NMES) is extensively used in stroke motor rehabilitation. How it promotes motor recovery remains only partially understood. NMES could change muscular properties, produce altered sensory inputs, and modulate fluctuations of cortical activities; but the potential contribution from cortico-muscular couplings during NMES synchronized with dynamic movement has rarely been discussed. Method We investigated cortico-muscular interactions during passive, active, and NMES rhythmic pedaling in healthy subjects and chronic stroke survivors. EEG (128 channels), EMG (4 unilateral lower limb muscles) and movement parameters were measured during 3 sessions of constant-speed pedaling. Sensory-level NMES (20 mA) was applied to the muscles, and cyclic stimulation patterns were synchronized with the EMG during pedaling cycles. Adaptive mixture independent component analysis was utilized to determine the movement-related electro-cortical sources and the source dipole clusters. A directed cortico-muscular coupling analysis was conducted between representative source clusters and the EMGs using generalized partial directed coherence (GPDC). The bidirectional GPDC was compared across muscles and pedaling sessions for post-stroke and healthy subjects. Results Directed cortico-muscular coupling of NMES cycling was more similar to that of active pedaling than to that of passive pedaling for the tested muscles. For healthy subjects, sensory-level NMES could modulate GPDC of both ascending and descending pathways. Whereas for stroke survivors, NMES could modulate GPDC of only the ascending pathways. Conclusions By clarifying how NMES influences neuromuscular control during pedaling in healthy and post-stroke subjects, our results indicate the potential limitation of sensory-level NMES in promoting sensorimotor recovery in chronic stroke survivors.

scholarly journals Backward locomotor treadmill training combined with transcutaneous spinal direct current stimulation in stroke: a randomized pilot feasibility and safety study

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Oluwole O Awosika ◽  
Saira Matthews ◽  
Emily J Staggs ◽  
Pierce Boyne ◽  
Xiao Song ◽  
...  
Keyword(s):  
Direct Current ◽  
Walking Speed ◽  
Chronic Stroke ◽  
Treadmill Training ◽  
Stroke Survivors ◽  
Post Intervention ◽  
Direct Current Stimulation ◽  
Post Stroke ◽  
Walking Capacity ◽  
Walking Recovery

Abstract Walking impairment impacts nearly 66% of stroke survivors and is a rising cause of morbidity worldwide. Despite conventional post-stroke rehabilitative care, the majority of stroke survivors experience continued limitations in their walking speed, temporospatial dynamics and walking capacity. Hence, novel and comprehensive approaches are needed to improve the trajectory of walking recovery in stroke survivors. Herein, we test the safety, feasibility and preliminary efficacy of two approaches for post-stroke walking recovery: backward locomotor treadmill training and transcutaneous spinal direct current stimulation. In this double-blinded study, 30 chronic stroke survivors (&gt;6 months post-stroke) with mild-severe residual walking impairment underwent six 30-min sessions (three sessions/week) of backward locomotor treadmill training, with concurrent anodal (N = 19) or sham transcutaneous spinal direct current stimulation (N = 11) over the thoracolumbar spine, in a 2:1 stratified randomized fashion. The primary outcomes were: per cent participant completion, safety and tolerability of these two approaches. In addition, we collected data on training-related changes in overground walking speed, cadence, stride length (baseline, daily, 24-h post-intervention, 2 weeks post-intervention) and walking capacity (baseline, 24-h post-intervention, 2 weeks post-intervention), as secondary exploratory aims testing the preliminary efficacy of these interventions. Eighty-seven per cent (N = 26) of randomized participants completed the study protocol. The majority of the study attrition involved participants with severe baseline walking impairment. There were no serious adverse events in either the backward locomotor treadmill training or transcutaneous spinal direct current stimulation approaches. Also, both groups experienced a clinically meaningful improvement in walking speed immediately post-intervention that persisted at the 2-week follow-up. However, in contrast to our working hypothesis, anodal-transcutaneous spinal direct current stimulation did not enhance the degree of improvement in walking speed and capacity, relative to backward locomotor treadmill training + sham, in our sample. Backward locomotor treadmill training and transcutaneous spinal direct current stimulation are safe and feasible approaches for walking recovery in chronic stroke survivors. Definitive efficacy studies are needed to validate our findings on backward locomotor treadmill training-related changes in walking performance. The results raise interesting questions about mechanisms of locomotor learning in stroke, and well-powered transcutaneous spinal direct current stimulation dosing studies are needed to understand better its potential role as a neuromodulatory adjunct for walking rehabilitation.

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