scholarly journals Stroke survivors show task-dependent modulation of motor variability during bimanual coordination

2018 ◽  
Author(s):  
Rajiv Ranganathan ◽  
Rani Gebara ◽  
Michael Andary ◽  
Jim Sylvain
Keyword(s):  
Bimanual Coordination ◽  
Weighted Average ◽  
The Body ◽  
Stroke Survivors ◽  
Movement Variability ◽  
Task Context ◽  
Bimanual Task ◽  
Affected Relative ◽  
Cursor Position ◽  
Bimanual Reaching

ABSTRACTStroke often results in hemiparesis, leaving one side of the body ‘affected’ relative to the other side. Prior research has shown that the affected arm has higher variability – however, the extent to which this variability can be modulated is unclear. Here we used a shared bimanual task to examine the degree to which participants could modulate the variability in the affected arm after stroke. Participants with chronic stroke (n = 11), and age-matched controls (n = 11) performed unimanual and bimanual reaching movements to move a cursor on a screen to different targets. In the unimanual condition, the cursor was controlled only by the movement of a single arm whereas in the bimanual condition, the cursor position was “shared” between the two arms by using a weighted average of the two hand positions. Unknown to the participants, we altered the weightings of the affected and unaffected arms to cursor motion and examined how the movement variability on each arm changed depending on its contribution to the task. Results showed that stroke survivors had higher movement variability on the affected arm – however, like age-matched controls, they were able to modulate the variability in both the affected and unaffected arms according to the weighting condition. Specifically, as the weighting on a particular arm increased (i.e. it became more important to the task), the movement variability decreased. These results show that stroke survivors are capable of modulating variability depending on the task context, and this feature may potentially be exploited for rehabilitation paradigms

scholarly journals Chronic stroke survivors show task-dependent modulation of motor variability during bimanual coordination

2019 ◽  
Vol 121 (3) ◽  
pp. 756-763 ◽  
Author(s):  
Rajiv Ranganathan ◽  
Rani Gebara ◽  
Michael Andary ◽  
Jim Sylvain
Keyword(s):  
Weighted Average ◽  
Chronic Stroke ◽  
The Body ◽  
Stroke Survivors ◽  
Movement Variability ◽  
Bimanual Task ◽  
Affected Relative ◽  
Cursor Position ◽  
Bimanual Reaching ◽  
Bimanual Tasks

Stroke often results in hemiparesis, leaving one side of the body “affected” relative to the other side. Prior research has shown that the affected arm has higher variability; however, the extent to which this variability can be modulated is unclear. Here we used a shared bimanual task to examine the degree to which participants could modulate the variability in the affected arm after stroke. Participants with chronic stroke ( n = 11) and age-matched controls ( n = 11) performed unimanual and bimanual reaching movements to move a cursor on a screen to different targets. In the unimanual condition, the cursor was controlled only by the movement of a single arm, whereas, in the bimanual condition, the cursor position was “shared” between the two arms by using a weighted average of the two hand positions. Unknown to the participants, we altered the weightings of the affected and unaffected arms to cursor motion and examined how the movement variability on each arm changed depending on its contribution to the task. Results showed that stroke survivors had higher movement variability on the affected arm; however, like age-matched controls, they were able to modulate the variability in both the affected and unaffected arms according to the weighting condition. Specifically, as the weighting on a particular arm increased (i.e., it became more important to the task), the movement variability decreased. These results show that stroke survivors are capable of modulating variability depending on the task context, and this feature may potentially be exploited for rehabilitation paradigms. NEW & NOTEWORTHY We show that chronic stroke survivors, similar to age-matched controls, are able to modulate variability in their affected and unaffected limbs in redundant bimanual tasks as a function of how these limbs contribute to the task. Specifically, in both affected and unaffected limbs, the variability of the limb increases as its contribution to the task decreases. This feature may potentially be exploited in rehabilitation paradigms using bimanual tasks.

scholarly journals ‘Somebody stuck me in a bag of sand’: Lived experiences of the altered and uncomfortable body after stroke

2021 ◽  
pp. 026921552110007
Author(s):  
Hannah Stott ◽  
Mary Cramp ◽  
Stuart McClean ◽  
Ailie Turton
Keyword(s):  
Support Groups ◽  
Phenomenological Study ◽  
Community Support ◽  
Phenomenological Approach ◽  
The Body ◽  
Stroke Survivors ◽  
Post Stroke ◽  
Personal Perceptions ◽  
Psychological Sense ◽  
Qualitative Phenomenological

Objective: This study explored stroke survivors’ experiences of altered body perception, whether these perceptions cause discomfort, and the need for clinical interventions to improve comfort. Design: A qualitative phenomenological study. Setting: Participants’ homes. Participants: A purposive sample of 16 stroke survivors were recruited from community support groups. Participants (median: age 59; time post stroke >2 years), were at least six-months post-stroke, experiencing motor or sensory impairments and able to communicate verbally. Interventions: Semi-structured, face-to-face interviews were analysed using an interpretive phenomenological approach and presented thematically. Results: Four themes or experiences were identified: Participants described (1) a body that did not exist; (2) a body hindered by strange sensations and distorted perceptions; (3) an uncontrollable body; and (4) a body isolated from social and clinical support. Discomfort was apparent in a physical and psychological sense and body experiences were difficult to comprehend and communicate to healthcare staff. Participants wished for interventions to improve their comfort but were doubtful that such treatments existed. Conclusion: Indications are that altered body perceptions cause multifaceted physical and psychosocial discomfort for stroke survivors. Discussions with patients about their personal perceptions and experiences of the body may facilitate better understanding and management to improve comfort after stroke.

scholarly journals Gait Assistive Exoskeleton Device For Semi Paralyzed Stroke Survivors

2019 ◽  
Vol 8 (5C) ◽  
pp. 1562-1566
Keyword(s):  
Time Management ◽  
The Body ◽  
Human Gait ◽  
Stroke Survivors ◽  
Walking Ability ◽  
Software System ◽  
Measuring Device ◽  
True Time ◽  
Exoskeleton Device

dominant human gait could be a dynamic and time crucial activity and so it needs a true time management surroundings. the most objective is to regain the walking ability for semi-paralyzed stroke affected patients and to assist them walk severally with none support. MEMS measuring device device senses the walking movements of the patient’s healthy leg. By victimisation these values as reference, microcontroller is programmed and interfaced to the motor fastened within the body covering device. Microcontroller is employed to manage the motor in line with the input given by the measuring device. Microcontroller is programmed victimisation PIC CCS Compiler software system. Associate in Nursing body covering device for semi paralytic patients is developed to exercise their muscles and to revive the sensation of walking in their legs at a way lower value than that is offered on the market nowadays

scholarly journals Corpus callosal microstructure predicts bimanual motor performance in chronic stroke survivors

2021 ◽  
Author(s):  
Rini Varghese ◽  
Brianna Chang ◽  
Bokkyu Kim ◽  
Sook-Lei Liew ◽  
Nicolas Schweighofer ◽  
...  
Keyword(s):  
Structural Damage ◽  
Diffusion Tensor ◽  
Lesion Size ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Bimanual Performance ◽  
Paretic Limb ◽  
Bimanual Task ◽  
Effect Of Age ◽  
Bimanual Tasks

Much of the research using diffusion tensor imaging (DTI) in stroke focuses on characterizing the microstructural status of corticospinal tracts and its utility as a prognostic biomarker. However, the ischemic event in the lesioned cortex also triggers structural and functional alterations in its contralateral homolog through the corpus callosum (CC), known as transcallosal diaschisis. The few studies that have characterized the microstructural status of the CC using DTI only examine its relationship with paretic limb performance. Given the well-established role of the CC for bimanual coordination, especially fibers connecting the larger sensorimotor networks such as prefrontal, premotor and supplementary motor regions, we examine the relationship between the microstructural status of the CC and bimanual performance in chronic stroke survivors (n = 41). We used movement times for two self-initiated and self-paced bimanual tasks to capture bimanual performance. Using publicly available control datasets (n = 52), matched closely for acquisition parameters, including sequence, diffusion gradient strength and number of directions, we also explored the effect of age and stroke on callosal microstructure. We found that callosal microstructure was significantly associated with bimanual performance in chronic stroke survivors such that those with lower callosal FA were slower at completing the bimanual task. Notably, while the primary sensorimotor regions (CC3) showed the strongest relationship with bimanual performance, this was closely followed by the premotor/supplementary motor (CC2) and the prefrontal (CC1) regions. We used multiple mixed regression to systematically account for loss of callosal axons (i.e., normalized callosal volume) as well as differences in lesion size and other metrics of structural damage. Chronic stroke survivors presented with significantly greater loss of callosal fiber orientation (lower mean FA) compared to neurologically intact, age-similar controls, who in turn presented with lower callosal FA compared to younger controls. The effect of age and stroke were observed for all regions of the CC except the splenium. These preliminary findings suggest that in chronic stroke survivors with relatively localized lesions, callosal microstructure can be expected to change beyond the primary sensorimotor regions and might impact coordinated performance of self-initiated and cooperative bimanual tasks.

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.

An investigation into the validity and reliability of mHealth devices for counting steps in chronic stroke survivors

2019 ◽  
Vol 34 (3) ◽  
pp. 394-403
Author(s):  
Pollyana Helena Vieira Costa ◽  
Thainá Paula Dias de Jesus ◽  
Carolee Winstein ◽  
Camila Torriani-Pasin ◽  
Janaine Cunha Polese
Keyword(s):  
Repeated Measures ◽  
Chronic Stroke ◽  
Community Dwelling ◽  
The Body ◽  
Stroke Survivors ◽  
Validity And Reliability ◽  
Paretic Side ◽  
Body Location ◽  
Step Counting ◽  
Iphone Application

Objective: To investigate the validity and test–retest reliability of mHealth devices (Google Fit, Health, STEPZ, Pacer, and Fitbit Ultra) to estimate the number of steps in individuals after chronic stroke and to compare whether the measurement of the number of steps is affected by their location on the body (paretic and non-paretic side). Design: Observational study with repeated measures. Setting: University laboratory. Subjects: Fifty-five community-dwelling individuals with chronic stroke. Intervention: Not applicable. Main measures: The number of steps was measured using mHealth devices (Google Fit, Health, STEPZ, Pacer, and Fitbit Ultra), and compared against criterion-standard measure during the Two-Minute Walk Test using habitual speed. Results: Our sample was 54.5% men, mean age of 62.5 years (SD 14.9) with a chronicity after stroke of 66.8 months (SD 55.9). There was a statistically significant association between the actual number of steps and those estimated by the Google Fit, STEPZ Iphone and Android applications, Pacer iphone and Android, and Fitbit Ultra (0.30 ⩽  r ⩾ 0.80). The Pacer iphone application demonstrated the highest reliability coefficient (ICC(2,1) = 0.80; P < 0.001). There were no statistically significant differences in device measurements that depended on body location. Conclusions: mHealth devices (Pacer–iphone, Fitbit Ultra, Google Fit, and Pacer–Android) are valid and reliable for step counting in chronic stroke survivors. Body location (paretic or non-paretic side) does not affect validity or reliability of the step count metric.

Sensory and Motor Interhemispheric Integration after Section of Different Portions of the Anterior Corpus Callosum in Nonepileptic Patients

Neurosurgery ◽  
2005 ◽  
Vol 57 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Stéphanie Caillé ◽  
Hannelore C. Sauerwein ◽  
Alessandra Schiavetto ◽  
Jean-Guy Villemure ◽  
Maryse Lassonde
Keyword(s):  
Corpus Callosum ◽  
Bimanual Coordination ◽  
Motor Coordination ◽  
Response Times ◽  
Motor Planning ◽  
The Body ◽  
Anterior Portion ◽  
Interhemispheric Transmission ◽  
Intraventricular Cyst ◽  
Anterior Body

Abstract OBJECTIVE: We evaluated somatosensory and motor interhemispheric integration in four patients who underwent transection of different portions of the anterior corpus callosum (CC) for removal of an intraventricular cyst. The study goal was to relate their performances to the topographical organization of the CC. METHODS: Experimental tasks included bimanual coordination, tactile cross-localization, and intermanual and interfield comparisons of somesthetic information. Response accuracy and response times were measured. In addition, interhemispheric transmission times were obtained in the somesthetic modality. RESULTS: Section of the middle portion of the genu caused a deficit in motor coordination, which was absent in patients with more posteriorly located lesions, whereas section of more rostral portions of the genu seemed to interfere with motor planning. The most posterior section in our sample, including the anterior portion of the body of the corpus, abolished interhemispheric transfer of simple somesthetic information (perception of touch) but not tactile discrimination (intermanual comparisons of shapes). We speculate that more complex somesthetic information is transferred through the caudal region of the body of the CC, which was spared in all patients. Thus, it seems that section of different portions of the anterior CC (genu and anterior body) produces specific deficits in interhemispheric integration in the motor and somesthetic modalities. These deficits are consistent with the anteroposterior topography of anterior callosal fibers. CONCLUSION: The specific disconnections deficits observed in this study may provide the surgeon with information regarding the consequences of anterior callosotomy and allow for remedial measures to be implemented if required.

Bimanual coordination in alcohol-exposed children: Role of the corpus callosum

2004 ◽  
Vol 10 (4) ◽  
pp. 536-548 ◽  
Author(s):  
TRESA M. ROEBUCK-SPENCER ◽  
SARAH N. MATTSON ◽  
SARAH DEBOARD MARION ◽  
WARREN S. BROWN ◽  
EDWARD P. RILEY
Keyword(s):  
Corpus Callosum ◽  
Visual Feedback ◽  
Bimanual Coordination ◽  
Fetal Alcohol Spectrum Disorders ◽  
Task Complexity ◽  
Brain Structures ◽  
The Body ◽  
Group Differences ◽  
Interhemispheric Interaction ◽  
Significant Group

The corpus callosum (CC) is one of several brain structures affected in children prenatally exposed to alcohol. This structure plays a major role in coordinating motor activity from opposite sides of the body, and deficits in bimanual coordination have been documented in individuals with agenesis of or damage to the CC, particularly when the task is performed without visual feedback. The Bimanual Coordination Test was used to assess speed and accuracy on a task where both hands must coordinate to guide a cursor through angled pathways providing measures of interhemispheric interaction or the ability of the two hemispheres to coordinate activity via the corpus callosum. Twenty-one children with fetal alcohol spectrum disorders (FASD) and 17 non-exposed control children (CON), matched closely in age, sex, and ethnicity were tested. For trials with visual feedback (WV), children with FASD were slower than CON children but were equally accurate. Although statistically significant group differences were not observed on most trials completed without visual feedback (WOV), accuracy of the FASD group on WOV trials was highly variable. Group differences in accuracy on WOV angles approached significance after accounting for performance on the WV angles, and children with FASD were significantly less accurate on an individual angle believed to be particularly sensitive to interhemispheric interaction. These results indicate that children with FASD are slower than CON children but equally accurate on basic visuomotor tasks. However, as task complexity and reliance on interhemispheric interaction increases, children with FASD demonstrate variable and inaccurate performance. Preliminary analyses suggest that inaccurate performance on the bimanual coordination task, and presumably impaired callosal functioning, may be related to the attention and problem solving impairments commonly reported in children with FASD. (JINS, 2004, 10, 536–548.)

scholarly journals Multisensory Interactions in Head and Body Centered Perception of Verticality

2021 ◽  
Vol 14 ◽  
Author(s):  
Ksander N. De Winkel ◽  
Ellen Edel ◽  
Riender Happee ◽  
Heinrich H. Bülthoff
Keyword(s):  
Force Plate ◽  
Head Tilt ◽  
Weighted Average ◽  
The Body ◽  
Body Tilt ◽  
Motion Platform ◽  
Postural Responses ◽  
Body Sensors ◽  
Multisensory Interactions ◽  
Perception Of Verticality

Percepts of verticality are thought to be constructed as a weighted average of multisensory inputs, but the observed weights differ considerably between studies. In the present study, we evaluate whether this can be explained by differences in how visual, somatosensory and proprioceptive cues contribute to representations of the Head In Space (HIS) and Body In Space (BIS). Participants (10) were standing on a force plate on top of a motion platform while wearing a visualization device that allowed us to artificially tilt their visual surroundings. They were presented with (in)congruent combinations of visual, platform, and head tilt, and performed Rod &amp; Frame Test (RFT) and Subjective Postural Vertical (SPV) tasks. We also recorded postural responses to evaluate the relation between perception and balance. The perception data shows that body tilt, head tilt, and visual tilt affect the HIS and BIS in both experimental tasks. For the RFT task, visual tilt induced considerable biases (≈ 10° for 36° visual tilt) in the direction of the vertical expressed in the visual scene; for the SPV task, participants also adjusted platform tilt to correct for illusory body tilt induced by the visual stimuli, but effects were much smaller (≈ 0.25°). Likewise, postural data from the SPV task indicate participants slightly shifted their weight to counteract visual tilt (0.3° for 36° visual tilt). The data reveal a striking dissociation of visual effects between the two tasks. We find that the data can be explained well using a model where percepts of the HIS and BIS are constructed from direct signals from head and body sensors, respectively, and indirect signals based on body and head signals but corrected for perceived neck tilt. These findings show that perception of the HIS and BIS derive from the same sensory signals, but see profoundly different weighting factors. We conclude that observations of different weightings between studies likely result from querying of distinct latent constructs referenced to the body or head in space.

scholarly journals Assessment of a Cognitive-Motor Training Program in Adults at Risk for Developing Dementia

2020 ◽  
Vol 23 (2) ◽  
pp. 190-198
Author(s):  
Holly V. Echlin ◽  
Diana J. Gorbet ◽  
Lauren E. Sergio
Keyword(s):  
At Risk ◽  
Daily Living ◽  
Bimanual Coordination ◽  
Movement Control ◽  
Training Group ◽  
Therapeutic Interventions ◽  
Training Intervention ◽  
Brain Training ◽  
Movement Variability ◽  
Training Approach

Background With the prevalence of dementia increasing each year, pre-clinically implemented therapeutic interventions are needed. It has been suggested that cascading neural network failures may bring on behavioural deficits associated with Alzheimer’s disease. Methods Previously we have shown that cognitive-motor integration (CMI) training in adults with cognitive impairments generalized to improved global cognitive and activities of daily living scores. Here we employ a novel movement control–based training approach involving CMI rather than traditional cognition-only brain training. We hypothesized that such training would stimulate widespread neural networks and enhance rule-based visuomotor ability in at-risk individuals. Results We observed a significant improvement in bimanual coordination in the at-risk training group. We also observed significant decreases in movement variability for the most complex CMI condition in the at-risk and healthy training groups. Conclusions These data suggest that integrating cognition into action in a training intervention may be effective at strengthening vulnerable brain networks in asymptomatic adults at risk for developing dementia.

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