scholarly journals StartReact increases the probability of muscle activity and distance in severe/moderate stroke survivors during two-dimensional reaching task

2020 ◽  
Vol 238 (5) ◽  
pp. 1219-1227 ◽  
Author(s):  
Marziye Rahimi ◽  
Claire F. Honeycutt
Keyword(s):  
Muscle Activity ◽  
Stroke Survivors ◽  
Two Dimensional ◽  
Reaching Task

scholarly journals StartReact increases probability of muscle activity and distance in severe/moderate stroke survivors during two-dimensional reaching task

2019 ◽  
Author(s):  
Marziye Rahimi ◽  
Claire F. Honeycutt
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Stroke Survivors ◽  
Two Dimensional ◽  
Future Studies ◽  
Reaching Task ◽  
Movement Distance ◽  
Final Error ◽  
Activity Onset ◽  
Point To Point

AbstractObjectiveStartReact elicits faster, larger, and more appropriate muscle activation in stroke survivors but has been only cursorily studied to date during multi-jointed reaching. Our objective was to evaluate StartReact on unrestricted, two-dimensional point-to-point reaching tasks post-stroke.MethodData from 23 individuals with stroke was collected during point-to-point reaching. Voluntary and StartReact trials were compared between mild, severe/moderate, and the unimpaired arm.ResultsStartReact showed an increase in probability of muscle activity, larger muscle activity amplitude and faster muscle activity onset. Despite changes in muscle activity, metrics of movement (distance, final error, linear deviation) were largely the same between StartReact and Voluntary trials except in severe/moderate stroke who had larger reaching distances during StartReact.ConclusionWhile StartReact impacted many metrics of muscle activity, the most profound effect was on probability of muscle activity increasing 34% compared to Voluntary which allowed severe/moderate subjects to increase reaching distance but did not translate to decrease in final error suggesting that the additional movement was not always directed towards the appropriate target.SignificanceThese results indicate that SR has the capacity to activate paralyzed muscle in severe/moderate patients, but future studies are needed to explore the possible use of SR in the rehabilitation.

scholarly journals Chronic Stroke Survivors Improve Reaching Accuracy by Reducing Movement Variability at the Trained Movement Speed

2017 ◽  
Vol 31 (6) ◽  
pp. 499-508 ◽  
Author(s):  
Ulrike Hammerbeck ◽  
Nada Yousif ◽  
Damon Hoad ◽  
Richard Greenwood ◽  
Jörn Diedrichsen ◽  
...  
Keyword(s):  
Chronic Phase ◽  
Training Group ◽  
Chronic Stroke ◽  
Movement Speed ◽  
Stroke Survivors ◽  
Movement Variability ◽  
Reaching Task ◽  
Arm Reaching ◽  
Fast Training ◽  
Elbow Movement

Background. Recovery from stroke is often said to have “plateaued” after 6 to 12 months. Yet training can still improve performance even in the chronic phase. Here we investigate the biomechanics of accuracy improvements during a reaching task and test whether they are affected by the speed at which movements are practiced. Method. We trained 36 chronic stroke survivors (57.5 years, SD ± 11.5; 10 females) over 4 consecutive days to improve endpoint accuracy in an arm-reaching task (420 repetitions/day). Half of the group trained using fast movements and the other half slow movements. The trunk was constrained allowing only shoulder and elbow movement for task performance. Results. Before training, movements were variable, tended to undershoot the target, and terminated in contralateral workspace (flexion bias). Both groups improved movement accuracy by reducing trial-to-trial variability; however, change in endpoint bias (systematic error) was not significant. Improvements were greatest at the trained movement speed and generalized to other speeds in the fast training group. Small but significant improvements were observed in clinical measures in the fast training group. Conclusions. The reduction in trial-to-trial variability without an alteration to endpoint bias suggests that improvements are achieved by better control over motor commands within the existing repertoire. Thus, 4 days’ training allows stroke survivors to improve movements that they can already make. Whether new movement patterns can be acquired in the chronic phase will need to be tested in longer term studies. We recommend that training needs to be performed at slow and fast movement speeds to enhance generalization.

scholarly journals Myofascial trigger points alter the modular control during the execution of a reaching task: a pilot study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tommaso Geri ◽  
Leonardo Gizzi ◽  
Anna Di Marco ◽  
Marco Testa
Keyword(s):  
Motor Control ◽  
Muscle Activity ◽  
Shoulder Girdle ◽  
Reciprocal Inhibition ◽  
Trigger Points ◽  
Preliminary Evidence ◽  
Myofascial Trigger Points ◽  
Reaching Task ◽  
Weighting Coefficients ◽  
Dominant Condition

Abstract Myofascial trigger points (TP) constitute a conundrum in research and clinical practice as their etiopathogenesis is debated. Several studies investigating one or few muscles have shown that both active and latent TP causes an increased muscle activity, however the influence of TP on modular motor control during a reaching task is still unclear. Electromyographic signals, recorded from the muscles of the shoulder girdle and upper arm during a reaching task, were decomposed with Non-Negative Matrix Factorization algorithm. The extracted matrices of motor modules and activation signals were used to label the muscles condition as dominant or non-dominant. The presence of latent and active TP was detected in each muscle with manual examination. Despite a similar muscle activity was observed, we found that muscles with active TP had increased weighting coefficients when labeled in the dominant condition. No influences were found when muscles were in the non-dominant condition. These findings suggest that TP altered the motor control without co-contraction patterns. As a preliminary evidence, the present results suggest that the increased weighting coefficients in presence of TPs are associated with an alteration of the modular motor control without affecting the dimensionality of motor modules for each individual and reciprocal inhibition.

scholarly journals Cerebral contribution to the execution, but not recalibration, of motor commands in a novel walking environment

2019 ◽  
Author(s):  
D. de Kam ◽  
P.A. Iturralde ◽  
G. Torres-Oviedo
Keyword(s):  
Muscle Activity ◽  
Disease Model ◽  
Stroke Survivors ◽  
Healthy Individuals ◽  
Cerebral Lesions ◽  
Motor Commands ◽  
Human Movements ◽  
Environmental Transitions ◽  
Walking Environment ◽  
Muscle Responses

AbstractHuman movements are flexible as they continuously adapt to changes in the environment by updating planned actions and generating corrective movements. Planned actions are updated upon repeated exposure to predictable changes in the environment, whereas corrective responses serve to overcome unexpected environmental transitions. It has been shown that corrective muscle responses are tuned through sensorimotor adaptation induced by persistent exposure to a novel situation. Here, we asked whether cerebral structures contribute to this recalibration using stroke as a disease model. To this end, we characterized changes in muscle activity in stroke survivors and unimpaired individuals before, during, and after walking on a split-belt treadmill moving the legs at different speeds, which has been shown to induce recalibration of corrective responses in walking in healthy individuals. We found that the recalibration of corrective muscle activity was comparable between stroke survivors and controls, which was surprising given then known deficits in feedback responses post-stroke. Also, the intact recalibration in the group of stroke survivors contrasted the patients’ limited ability to adjust their muscle activity during steady state split-belt walking compared to controls. Our results suggest that the recalibration and execution of motor commands in new environments are partially dissociable: cerebral lesions interfere with the execution, but not the recalibration, of motor commands upon novel movement demands.

scholarly journals Does the Score on the MRC Strength Scale Reflect Instrumented Measures of Maximal Torque and Muscle Activity in Post-Stroke Survivors?

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8175
Author(s):  
Pawel Kiper ◽  
Daniele Rimini ◽  
Deborah Falla ◽  
Alfonc Baba ◽  
Sebastian Rutkowski ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Hemorrhagic Stroke ◽  
Biceps Brachii ◽  
Treatment Session ◽  
Stroke Survivors ◽  
Triceps Brachii ◽  
Post Intervention ◽  
Post Stroke ◽  
Scale Scores ◽  
Before And After

It remains unknown whether variation of scores on the Medical Research Council (MRC) scale for muscle strength is associated with operator-independent techniques: dynamometry and surface electromyography (sEMG). This study aimed to evaluate whether the scores of the MRC strength scale are associated with instrumented measures of torque and muscle activity in post-stroke survivors with severe hemiparesis both before and after an intervention. Patients affected by a first ischemic or hemorrhagic stroke within 6 months before enrollment and with complete paresis were included in the study. The pre- and post-treatment assessments included the MRC strength scale, sEMG, and dynamometry assessment of the triceps brachii (TB) and biceps brachii (BB) as measures of maximal elbow extension and flexion torque, respectively. Proprioceptive-based training was used as a treatment model, which consisted of multidirectional exercises with verbal feedback. Each treatment session lasted 1 h/day, 5 days a week for a total 15 sessions. Nineteen individuals with stroke participated in the study. A significant correlation between outcome measures for the BB (MRC and sEMG p = 0.0177, ρ = 0.601; MRC and torque p = 0.0001, ρ = 0.867) and TB (MRC and sEMG p = 0.0026, ρ = 0.717; MRC and torque p = 0.0001, ρ = 0.873) were observed post intervention. Regression models revealed a relationship between the MRC score and sEMG and torque measures for both the TB and BB. The results confirmed that variation on the MRC strength scale is associated with variation in sEMG and torque measures, especially post intervention. The regression model showed a causal relationship between MRC scale scores, sEMG, and torque assessments.

The effects of closed and open kinetic chain exercises on lower limb muscle activity and balance in stroke survivors

2013 ◽  
Vol 33 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Na Kyung Lee ◽  
Jung Won Kwon ◽  
Sung Min Son ◽  
Kyung Woo Kang ◽  
Kyoung Kim ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Stroke Survivors ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Kinetic Chain ◽  
Open Kinetic Chain
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