Impact of unilateral and bilateral impairments on bimanual force production following stroke

But you created NO protocols on bimanual or bilateral movements to get survivors recoverd! So, useless crapola done!

 Impact of unilateral and bilateral impairments on bimanual force production following stroke

NARIC Accession Number: J94491. What's this?
Author(s): Nguyen, Hien, Phan, Thanh, Shadmehr, Reza, Lee, Sang W..
Publication Year: 2323.
Abstract: This study examined how unilateral and bilateral impairments in stroke survivors affect their bimanual task performance. Ten chronic stroke survivors and 13 neurologically intact subjects participated in an experiment where they produced bimanual forces at different hand locations. The force magnitude and directional deviation of the more-impaired arm were measured for unilateral impairments and bimanual coordination across locations for bilateral impairments. Force asymmetry and task error were used to define task performance. Significant unilateral impairments were observed in subjects with stroke; the maximal force capacity of their more-impaired arm was significantly lower than that of their less-impaired arm, with a higher degree of force deviation. However, its force contribution during submaximal tasks was greater than its relative force capacity. Significant bilateral impairments were also observed, as stroke survivors modulated two forces to a larger degree across hand locations but in a less coordinated manner than control subjects did. But only unilateral, not bilateral, impairments explained a significant amount of between-subject variability in force asymmetry across subjects with stroke. Task error, in contrast, was correlated with neither unilateral nor bilateral impairments. The results suggest that unilateral impairments of the more-impaired limb, both weakness and loss of directional control, mainly contribute to bimanual asymmetry, but stroke survivors generally produce higher force with their more-impaired limb than their relative capacity. Bilateral force coordination was significantly impaired in stroke survivors, but its degree of impairment was not related to their unilateral impairments.
Descriptor Terms: HEMIPLEGIA, LIMBS, MOBILITY IMPAIRMENTS, MOTOR SKILLS, MUSCULAR IMPAIRMENTS, STROKE, TASK ANALYSIS.


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Get this Document: https://doi.org/10.1152/jn.00125.2023.

Citation: Nguyen, Hien, Phan, Thanh, Shadmehr, Reza, Lee, Sang W.. (2323.) Impact of unilateral and bilateral impairments on bimanual force production following stroke. Journal of Neurophysiology., 130(3), Pgs. 608-618. Retrieved 4/17/2026, from REHABDATA database.

The Berlin bimanual test for stroke survivors (BeBiT-S): evaluating exoskeleton-assisted bimanual motor function after stroke

 With NO rehab protocols to fix problems after this 'evaluation'; COMPLETELY FUCKING USELESS! Does no one in stroke know how to think?

The Berlin bimanual test for stroke survivors (BeBiT-S): evaluating exoskeleton-assisted bimanual motor function after stroke

• Mareike Vermehren,
• Annalisa Colucci,
• Cornelius Angerhöfer,
• Niels Peekhaus,
• Won-Seok Kim,
• Won Kee Chang,
• Hyunji Kim,
• Volker Hömberg,
• Nam-Jong Paik &
• Surjo R. Soekadar 

We are providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.

Abstract

Background

Brain/neural hand exoskeletons (B/NHEs) can restore motor function after severe stroke, enabling bimanual tasks critical for various activities of daily living. Yet, reliable clinical tests for assessing bimanual function compatible with B/NHEs are lacking. Here, we introduce the Berlin Bimanual Test for Stroke (BeBiT-S), a 10-task assessment focused on everyday bimanual activities, and evaluate its psychometric properties as well as compatibility with assistive technologies such as B/NHEs.

Methods

BeBiT-S tasks were selected based on their relevance to daily activities, representation of various grasp types, and compatibility with current (neuro-)prosthetic devices. A scoring system was developed to assess key aspects of bimanual function—including reaching, grasping, stabilizing, manipulating, and lifting—based on video recordings of task performance. The BeBiT-S was administered without support of assistive technology (unassisted condition) to 24 stroke survivors (mean age = 56.5 years; 9 female) with upper-limb hemiparesis. We evaluated interrater reliability through the intraclass correlation coefficient (ICC) and construct validity through correlations with the Chedoke Arm and Hand Activity Inventory (CAHAI), and Stroke Impact Scale (SIS). A subgroup of 15 stroke survivors (mean age 50.3 years, 5 female) completed a second session supported by a B/NHE (B/NHE-assisted condition) to assess the BeBiT-S’ sensitivity to change related to B/NHE-application.

Results

The BeBiT-S demonstrated high interrater reliability in both the unassisted (ICC = 0.985, P < .001) and B/NHE-assisted (ICC = 0.862, P < .001) conditions. Unassisted BeBiT-S scores correlated with the CAHAI-8 (r(22) = 0.95, P < .001) and the SIS subscales “strength” (r(20) = 0.53, P = .012) and “hand function” (r(20) = 0.50, P = .018), indicating construct validity. BeBiT-S scores improved significantly with B/NHE assistance (Mdn = 60, P < .05), compared to when no assistance was provided (Mdn = 38, P < .05), demonstrating the test’s sensitivity to change following the application of a B/NHE.

Conclusions

The findings support that the BeBiT-S is a reliable and valid tool for evaluating bimanual task performance in stroke survivors and is compatible with the use of assistive technology such as B/NHEs.

Trial registration NCT04440709, submitted June 18th, 2020.

Quantifying intra- and interlimb use during unimanual and bimanual tasks in persons with hemiparesis post-stroke

 Quantification and prediction DO ABSOLUTELY NOTHING TO GET SURVIVORS RECOVERED.   Useless.

Quantifying intra- and interlimb use during unimanual and bimanual tasks in persons with hemiparesis post-stroke

• Susan V. Duff,
• Aaron Miller,
• Lori Quinn,
• Gregory Youdan Jr.,
• Lauri Bishop,
• Heather Ruthrauff &
• Eric Wade 

Journal of NeuroEngineering and Rehabilitation volume 19, Article number: 44 (2022) Cite this article

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Abstract

Background

Individuals with hemiparesis post-stroke often have difficulty with tasks requiring upper extremity (UE) intra- and interlimb use, yet methods to quantify both are limited.

Objective

To develop a quantitative yet sensitive method to identify distinct features of UE intra- and interlimb use during task performance.

Methods

Twenty adults post-stroke and 20 controls wore five inertial sensors (wrists, upper arms, sternum) during 12 seated UE tasks. Three sensor modalities (acceleration, angular rate of change, orientation) were examined for three metrics (peak to peak amplitude, time, and frequency). To allow for comparison between sensor data, the resultant values were combined into one motion parameter, per sensor pair, using a novel algorithm. This motion parameter was compared in a group-by-task analysis of variance as a similarity score (0–1) between key sensor pairs: sternum to wrist, wrist to wrist, and wrist to upper arm. A use ratio (paretic/non-paretic arm) was calculated in persons post-stroke from wrist sensor data for each modality and compared to scores from the Adult Assisting Hand Assessment (Ad-AHA Stroke) and UE Fugl-Meyer (UEFM).

Results

A significant group × task interaction in the similarity score was found for all key sensor pairs. Post-hoc tests between task type revealed significant differences in similarity for sensor pairs in 8/9 comparisons for controls and 3/9 comparisons for persons post stroke. The use ratio was significantly predictive of the Ad-AHA Stroke and UEFM scores for each modality.

Conclusions

Our algorithm and sensor data analyses distinguished task type within and between groups and were predictive of clinical scores. Future work will assess reliability and validity of this novel metric to allow development of an easy-to-use app for clinicians.

Introduction

Finely tuned upper extremity (UE) intra- and interlimb use is controlled through intact neural coupling [1], which requires timing of movements and sequential, rhythmic use of limb segments on one or both sides of the body [2]. This upper limb coupling enables interaction with the environment and the performance of goal-oriented tasks such as activities of daily living (ADLs). The type of tasks performed range from unimanual (single limb use), to bimanual symmetric (mirrored), to bimanual asymmetric with different motion exhibited in each limb. For persons with hemiparesis post-stroke, tasks requiring UE coupling can be difficult to execute due to limited strength, mobility, and motor control resulting in the execution of compensatory, yet functional, movement patterns [3,4,5]. Compensatory strategies may include increased trunk involvement during arm motion, limb disuse or asymmetry during mirrored bimanual tasks, and inefficient motion or atypical synergistic movements during task performance [6,7,8]. Although compensation promotes independence in everyday tasks, it can also impede recovery of intra- and interlimb use inherent in unimanual and bimanual performance [5, 9]. Determining the extent of coupling within and between the arms and how it changes with recovery and rehabilitation requires assessment measures sensitive to subtle changes in motion and task performance.

Most UE clinical assessments evaluate function of the paretic limb during unimanual tasks with limited emphasis on bimanual function [10,11,12]. An exception to this is the Assisting Hand Assessment (AHA) [13, 14], a tool originally designed to assess how effectively the more affected limb is used during bimanual tasks in children with unilateral UE dysfunction. The AHA has been recently adapted for use in adults post-stroke, i.e. the Adult AHA Stroke (Ad-AHA Stroke) [15]. However, as with other observation-based tools, the Ad-AHA Stroke may not be sensitive enough to detect small yet significant changes in motor behavior occurring with natural recovery or rehabilitation. A highly sensitive, objective measure requiring minimal equipment is needed to quantify intra- and interlimb use across a range of tasks and settings.

Inertial measurement units (IMU), are body-worn sensors that monitor and transmit changes in movement during the execution of everyday tasks [16]. IMU sensors have been used with individuals post-stroke and other neurological conditions, to capture the quality and quantity of motion during typical and atypical motor behaviors [16, 17]. These sensors can detect quantitative changes in movement patterns that differentiate between typical and atypical motor behavior. A challenge in using IMU sensors is that they produce derived, differential motion measures, such as linear acceleration and angular rate of change. Therefore, unlike traditional marker-based motion capture systems, raw data cannot be easily used to directly reconstruct changes in limb position. Instead, IMU data requires custom signal and data processing techniques to produce clinically relevant metrics [18].

Development of an accurate yet sensitive system using IMU data to identify distinct features of UE intra- and interlimb use is a sequential process. For our purposes, we operationalize intra- and interlimb use in regard to amplitude, time domain and frequency domain. Results of our pilot work suggest that development of a single motion parameter per sensor, using a novel algorithm, would allow comparison by task type between groups and allow for initial validation against widely used clinical measures [19]. The objectives of this current study were to: (1) evaluate the ability of sensor-derived motion parameters to distinguish between UE task type (unimanual, bimanual symmetric, and bimanual asymmetric tasks) in healthy controls; (2) evaluate the ability of motion parameters to differentiate between UE intra- and interlimb use in healthy controls and individuals post stroke; and (3) validate findings from sensor-derived motion parameters against clinical measures commonly used to assess performance in persons post-stroke, including the UE Fugl-Meyer (UEFM) and the Ad-AHA Stroke Assessments.

 

Bimanual motor skill learning with robotics in chronic stroke: comparison between minimally impaired and moderately impaired patients, and healthy individuals

Because this was for chronic it is mostly worthless unless you really think survivors can buy and do this on their own. So the research will need to be repeated on acute patients. The goal of all stroke research is usable stroke protocols by all survivors.  This doesn't even come close.

Bimanual motor skill learning with robotics in chronic stroke: comparison between minimally impaired and moderately impaired patients, and healthy individuals

 

• Eloïse Gerardin,
• Damien Bontemps,
• Nicolas-Thomas Babuin,
• Benoît Herman,
• Adrien Denis,
• Benoît Bihin,
• Maxime Regnier,
• Maria Leeuwerck,
• Thierry Deltombe,
• Audrey Riga &
• Yves Vandermeeren 

Journal of NeuroEngineering and Rehabilitation volume 19, Article number: 28 (2022) Cite this article

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Abstract

Background

Most activities of daily life (ADL) require cooperative bimanual movements. A unilateral stroke may severely impair bimanual ADL. How patients with stroke (re)learn to coordinate their upper limbs (ULs) is largely unknown. The objectives are to determine whether patients with chronic supratentorial stroke could achieve bimanual motor skill learning (bim-MSkL) and to compare bim-MSkL between patients and healthy individuals (HIs).

Methods

Twenty-four patients and ten HIs trained over 3 consecutive days on an asymmetrical bimanual coordination task (CIRCUIT) implemented as a serious game in the REAplan® robot. With a common cursor controlled by coordinated movements of the ULs through robotic handles, they performed as many laps as possible (speed constraint) on the CIRCUIT while keeping the cursor within the track (accuracy constraint). The primary outcome was a bimanual speed/accuracy trade-off (biSAT), we used a bimanual coordination factor (biCO) and bimanual forces (biFOP) for the secondary outcomes. Several clinical scales were used to evaluate motor and cognitive functions.

Results

Overall, the patients showed improvements on biSAT and biCO. Based on biSAT progression, the HI achieved a larger bim-MSkL than the patients with mild to moderate impairment (Fugl-Meyer Assessment Upper Extremity (FMA-UE): 28–55, n = 15) but not significantly different from those with minimal motor impairment (FMA-UE: 66, n = 9). There was a significant positive correlation between biSAT evolution and the FMA-UE and Stroke Impact Scale.

Conclusions

Both HI and patients with chronic stroke training on a robotic device achieved bim-MSkL, although the more impaired patients were less efficient. Bim-MSkL with REAplan® may be interesting for neurorehabilitation after stroke.

Trial registration: ClinicalTrial.gov identifier: NCT03974750. Registered 05 June 2019. https://clinicaltrials.gov/ct2/show/NCT03974750?cond=NCT03974750&draw=2&rank=1

Motor control and neural plasticity through interhemispheric interactions

 Sounds interesting, WHOM will take this and create stroke protocols out of it? WITH NO STROKE LEADERSHIP ANYWHERE, nothing will be done. It has only been nine years, I'm sure nothing has occurred.

Motor control and neural plasticity through interhemispheric interactions

Naoyuki Takeuchi,¹ Yutaka Oouchida,¹ and Shin-Ichi Izumi¹

¹Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Cho, Aoba-Ku, Sendai 980-8575, Japan

Academic Editor: Maurice Ptito

Received05 Sep 2012

Revised16 Nov 2012

Accepted03 Dec 2012

Published26 Dec 2012

Abstract

The corpus callosum, which is the largest white matter structure in the human brain, connects the 2 cerebral hemispheres. It plays a crucial role in maintaining the independent processing of the hemispheres and in integrating information between both hemispheres. The functional integrity of interhemispheric interactions can be tested electrophysiologically in humans by using transcranial magnetic stimulation, electroencephalography, and functional magnetic resonance imaging. As a brain structural imaging, diffusion tensor imaging has revealed the microstructural connectivity underlying interhemispheric interactions. Sex, age, and motor training in addition to the size of the corpus callosum influence interhemispheric interactions. Several neurological disorders change hemispheric asymmetry directly by impairing the corpus callosum. Moreover, stroke lesions and unilateral peripheral impairments such as amputation alter interhemispheric interactions indirectly. Noninvasive brain stimulation changes the interhemispheric interactions between both motor cortices. Recently, these brain stimulation techniques were applied in the clinical rehabilitation of patients with stroke by ameliorating the deteriorated modulation of interhemispheric interactions. Here, we review the interhemispheric interactions and mechanisms underlying the pathogenesis of these interactions and propose rehabilitative approaches for appropriate cortical reorganization.

1. Introduction

The corpus callosum, which is the largest white matter structure in the human brain, connects the homologous and nonhomologous areas of the 2 cerebral hemispheres [1, 2]. It plays a crucial role in the interhemispheric interactions that maintain independent processing and integrate information between both hemispheres [2, 3]. The functional integrity of interhemispheric interactions can be tested electrophysiologically in humans using single-pulse transcranial magnetic stimulation (TMS), double-pulse TMS, and electroencephalography [4–8]. These electrophysiological techniques were used to estimate interhemispheric transmission times (from 4 to 50 ms) [1, 3]. Structural studies using diffusion tensor imaging (DTI) have revealed the microstructural connectivity underlying interhemispheric interactions [9–12]. Moreover, functional magnetic resonance imaging (fMRI) studies have revealed interhemispheric interactions using resting-state functional and activity-dependent effective connectivity analyses [13, 14].

Research on the functions of interhemispheric interactions is based on studies of brain lateralization, which is thought to allow each hemisphere to process information without the interference of the contralateral hemisphere [15, 16]. Several studies have suggested that the speed of transcallosal conduction is limited in larger brains, which implies that the transfer and integration of information between both hemispheres through the corpus callosum require more time and energy in humans [3, 17]. Therefore, it may be more efficient to use one hemisphere and inhibit the other hemisphere during simple tasks (e.g., physical identity and face-matching tasks); this promotes intrahemispheric processing and brain lateralization [2, 18, 19].

However, processing tasks that share and integrate the information between hemispheres (e.g., dichotic word-listening task) require facilitative communication between hemispheres [20]. Even in motor tasks, the timing and accuracy of bimanual motor tasks are thought to be predominantly programmed by one of the hemispheres. To monitor the activity of the motor regions of the opposite hemisphere, sending an efference copy of the planned motor program to the opposite hemisphere through the corpus callosum allows the optimal timing of movements in both hands [21, 22]. Thus, the lateralization hypothesis can be explained by both the inhibitory and excitatory theories of interhemispheric interactions [2].

The ability to perform precisely coordinated movements using both hands is an important aspect of particular human abilities, such as tying a string, peeling a fruit with a knife, typing, and playing a musical instrument. It is now known that modulations of interhemispheric interactions are involved in the control of the unimanual and bimanual coordinations that generate the spatially and temporally precise coordinated limb movements that enable humans to perform different movements [1]. Moreover, it has been reported that interhemispheric interactions contribute to the acquisition of bimanual skills [1, 6].

Recent studies have revealed that the modulation of interhemispheric interactions relates to neural plasticity, which refers to the ability of the brain to develop new neuronal interconnections, acquire new functions, and compensate for impairments [23–25]. However, little is known about the mechanisms underlying the relation between cortical reorganization and changes in interhemispheric interaction resulting from various diseases or brain stimulation. This paper focuses on the following 4 important aspects of motor interhemispheric interactions: (1) the inhibitory and excitatory theories of interhemispheric interaction, (2) the finding that nonpathological factors can influence interhemispheric interactions, (3) the pathologies that alter interhemispheric interactions, and (4) the relation between interhemispheric interaction and neural plasticity. Assessments of interhemispheric interactions have elucidated the mechanisms underlying the physiological processes that modulate motor control and led to the formulation of interventional strategies that improve motor function after neurological disorders, which is a critical issue of clinical neurorehabilitation [25, 26]. The purposes of this paper were to provide a comprehensive overview of motor interhemispheric interactions to promote the understanding of their underlying mechanisms and to suggest approaches for appropriate neural plasticity.

 More at link.

Bimanual Haptic-desktop platform for upper-limb post-stroke rehabilitation:Practical trials

11 years and since we have fucking failures of stroke associations  that can't even create a database of all stroke research and protocols survivors will never figure out what happened when trials occurred with stroke persons.

Bimanual Haptic-desktop platform for upper-limb post-stroke rehabilitation:Practical trials

Published 2009
 Siqiao Li, A. Frisoli, C.A. Avizzano, M. Bergamasco Perceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy Bimanual rehabilitation has been pointed out as an effective way for the rehabilitation of patients with poor motor impairment of one upper extremity because of the bimanual nature of the therapy, i.e. the natural way to initiate and control the therapy and the mechanical-neurological coordination between two hands in human activities of daily living [1]. This study presents the development of a new bimanual rehabilitation system for the rehabilitation of upper–limb post stroke patients. The bimanual haptic desktop system (BHDS) is an integrated system which merges haptic functionalities and Video Display Terminal (VDT) systems into standalone application, shown in Fig. 1. The hardware integration has been designed to show ergonomic features and provide high-quality performance of human-computer-interaction (HCI) [2].
Two basic exercises, based on tracking task and lifting task, were carried out for the recovery of basic arm motion–coordination skills and steadiness of patients’ upper-limb. Secondly a catching task, was developed to compare online the performance of healthy upper-limb with impaired ones wherein hand-eye coordination exercise of the patient is included. To this end, the proposed exercises provide patients the potential methods to train their post–stroke upper-limbs malfunctions while reporting the quantitative parameters obtained to evaluate the improvement of patients recovery. Experimental results of a preliminary evaluation on healthy subjects are reported and discussed to visualize in near future a pilot medical trials of the system on impaired people.

Figure 2 Example of a robot assisted bimanual task. In the left panel it is shown the box, that is asked to be picked up with two hands and lifted up. In the right panel, the blue line is the grasping force, while the red line is the box position.

Figure 1 The BHDS System while used by an healthy subject

 

 

Transient changes in paretic and non-paretic isometric force control during bimanual submaximal and maximal contractions

Hope you can decipher these big words, because I can see nothing useful in this for recovery.  No protocol, just 'may facilitate progress'.  'May' should never be used in stroke research, survivors need EXACT PROTOCOLS.

Transient changes in paretic and non-paretic isometric force control during bimanual submaximal and maximal contractions

• Hyun Joon Kim,
• Nyeonju Kang &
• James H. Cauraugh 

Journal of NeuroEngineering and Rehabilitation volume 17, Article number: 64 (2020) Cite this article

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Abstract

Purpose

The purpose of this study was to investigate transient bimanual effects on the force control capabilities of the paretic and non-paretic arms in individuals post stroke across submaximal and maximal force control tasks.

Methods

Fourteen chronic stroke patients (mean age = 63.8 ± 15.9; stroke duration = 38.7 ± 45.2 months) completed two isometric force control tasks: (a) submaximal control and (b) maximal sustained force production. Participants executed both tasks with their wrist and fingers extending across unimanual (paretic and non-paretic arms) and bimanual conditions. Mean force, force variability using coefficient of variation, force regularity using sample entropy were calculated for each condition.

Results

During the submaximal force control tasks (i.e., 5, 25, and 50% of maximum voluntary contraction), the asymmetrical mean force between the paretic and non-paretic arms decreased from unimanual to bimanual conditions. The asymmetry of force variability and regularity between the two arms while executing unimanual force control tended to decrease in the bimanual condition because of greater increases in the force variability and regularity for the non-paretic arm than those for the paretic arm. During the maximal sustained force production tasks (i.e., 100% of maximum voluntary contraction), the paretic arm increased maximal forces and decreased force variability in the bimanual condition, whereas the non-paretic arm reduced maximal forces and elevated force variability from unimanual to bimanual conditions.(Wow. I suppose there is some meaning to this.)

Conclusions

The current findings support a proposition that repetitive bimanual isometric training with higher execution intensity may facilitate progress toward stroke motor recovery.

Background

Stroke typically causes hemiparesis implicating motor deficits on one of the upper extremities [1]. Thus, asymmetrical kinematic and kinetic functions between the paretic and non-paretic arms frequently appear in acute and subacute patients [2, 3], and further remain at the chronic stage of recovery [4]. To improve these long-term motor impairments, many stroke researchers and therapists have focused on bimanual training protocols requiring simultaneous paretic and non-paretic arm actions because of potential benefits on paretic arm functions through inter-limb coupling processes [4, 5]. A theoretical basis underlying the bimanual training protocols assumes that repetitive bimanual actions may facilitate balancing cortical excitation and inhibition patterns between more-affected and less-affected hemispheres contributing to motor recovery post stroke [6,7,8].
Interestingly, prior studies evidenced that a simple bimanual condition resulted in transient functional improvements in the paretic arm movement control. Harris-Love and colleagues reported that the paretic arm revealed an increase in peak velocity and acceleration during bimanual reaching tasks as compared to the unimanual conditions [9, 10]. Similarly, Rose and Winstein found higher peak velocity in the paretic arm and lower peak velocity in the non-paretic arm during bimanual aiming tasks than those during unimanual aiming tasks [11]. These findings indicated that the paretic arms revealed better kinematic functions while performing bimanual actions at maximal speeds. On the other hand, when individuals post stroke executed bimanual movements at their preferred speeds (i.e., submaximal movement condition), no motor improvements in the paretic arm were observed. Moreover, the non-paretic arm adapted movements closely aligned with the paretic arm in the bimanual condition, and no functional changes occurred in the paretic arm [12,13,14]. Finally, no changes in a reach-grasp-lift-release performance at preferred-speed across paretic and non-paretic arms between unimanual and bimanual conditions [15].
Similar to these kinematic findings, individuals post stroke showed better kinetic functions in their paretic arm during the maximal bimanual isometric force production tasks. For example, the bimanual conditions transiently increased maximal isometric handgrip force for the paretic arm [16] and maximal isometric wrist and fingers extension force [17] than those for the unimanual conditions. However, at the submaximal targeted force levels (e.g., 20–80% of maximum voluntary contraction: MVC) the paretic arm revealed no changes in mean handgrip force between the bimanual and unimanual conditions [16, 18]. Taken together, these kinematic and kinetic findings commonly support a proposition that bimanual training protocols requiring high intensity levels (e.g., maximal movement speed or force production) may be more effective on functional recovery of the paretic arm.
Importantly, during submaximal isometric force control tasks, the ability to maintain forces near targeted force levels with minimal variations is an additional crucial indicator estimating individual’s progress toward stroke motor recovery [19,20,21]. Indeed, individuals post stroke improved their isometric force control capabilities after completing rehabilitation protocols without an increase in force production [19, 20]. These findings lead to a possibility that the bimanual conditions change the force control capabilities of the paretic arm without altering force outputs as compared to the unimanual condition. Recently, Kang and Cauraugh [17] found that the paretic arm produced greater maximal force during simple bimanual wrist and fingers extension task than that during unimanual condition. However, during submaximal force production tasks, how the unimanual and bimanual conditions alter force control capabilities in the paretic arm is still unclear.
Traditional bimanual training protocols included homologous movements of the paretic and non-paretic arms because of the possibility that more motor improvements may occur after task-related training protocols typically requiring dynamic movements [22]. However, given that muscle weaknesses post stroke are highly related to deficits in activities of daily living, many stroke researchers additionally focused on various types of resistance training for restoring muscle strength in the paretic arm [23]. Specifically, several studies used isometric resistance training on the unimanual paretic arm, and reported improvements in muscle force [24, 25] and motor control ability [26]. Moreover, Saunders and colleagues found positive effects of an isometric resistance training protocol on reducing blood pressure [22]. Presumably, isometric resistance training can be an additional treatment protocol for optimizing stroke motor recovery, and further applying specific intensity (e.g., either submaximal or maximal) and contraction type (e.g., either unimanual or bimanual) may facilitate these beneficial effects on the paretic arm functions [8, 23]. Thus, investigating transient bimanual effects on paretic and non-paretic arm force control across submaximal and maximal targeted levels may provide useful information for developing potential bimanual training protocols based on isometric force production paradigms.
Beyond force production changes across submaximal and maximal force control tasks, quantifying the variability of force production within a trial is crucial for estimating an individual’s force control capabilities [21]. Specifically, force variability using either standard deviation or coefficient of variation (CV) is a conventional measurement to quantify noise of motor outputs so that greater variability increased instability of the motor system implicating impaired force control capabilities [27]. However, given that a motor system may acquire stability by solving environmental and biomechanical limitations as a nonlinear process, more force variability does not necessarily lead instability of the motor outputs interfering with task performance [27, 28]. Further, the force regularity, a temporal structure of variability (e.g., sample entropy: SampEn), is a nonlinear outcome measure indicating the adaptability of motor outputs. Although a certain level of force variability exists in the intact motor system, less force regularity denotes more adaptability contributing to better force control performance. However, these patterns may not appear in the paretic arm because of the impaired motor system post stroke. Indeed, individuals post stroke revealed more force variability with increased force regularity during isometric force control as compared to age-matched healthy controls [19, 29, 30]. Taken together, measuring both variability and regularity of force production is necessary to further elaborate altered force control capabilities across unimanual and bimanual conditions post stroke.
Thus, the current study examined force control capabilities in chronic stroke patients across unimanual and bimanual conditions to provide additional information regarding the beneficial effects of bimanual contraction on restoring paretic arm functions. Post stroke individuals performed isometric force control tasks with wrist and fingers extension at submaximal targeted force levels (i.e., 5, 25, and 50% of MVC) and a maximal level (i.e., maximal sustained force production) with their unimanual arms (i.e., paretic vs. non-paretic arms) and both arms simultaneously. We selected the three targeted force levels because many activities of daily living require submaximal force generation with 5–50% of the maximum efforts [31], and paretic arm functions potentially varied with these submaximal ranges [19, 21, 32]. Further, our force control outcome measures included force production, variability, and regularity. We hypothesized that bimanual conditions would increase force production and reduce force variability and regularity in the paretic arm during submaximal and maximal force control tasks when compared to the unimanual conditions.

Learning a Bimanual Cooperative Skill in Chronic Stroke Under Noninvasive Brain Stimulation: A Randomized Controlled Trial

You'll have to ask your doctor what bimanual is and when this will come to their hospital. Doesn't know and not coming are fireable reasons for that doctor, along with the stroke hospital president AND board of directors. A lot of dead wood needs to be removed in stroke.  

9 posts back to Dec. 2011 on bimanual that your doctor and therapists should have already set up a stroke protocol for your recovery. But I bet they have done nothing on this.

Learning a Bimanual Cooperative Skill in Chronic Stroke Under Noninvasive Brain Stimulation: A Randomized Controlled Trial 

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Maral Yeganeh Doost, PhD, Jean-Jacques Orban de Xivry, PhD, Benoît Herman, PhD, ...

First Published May 15, 2019 Research Article

https://doi.org/10.1177/1545968319847963

Article information

Abstract

Background. Transcranial direct current stimulation (tDCS)(Which one? HD? Cathodal? Anodal?)  has been suggested to improve poststroke recovery. However, its effects on bimanual motor learning after stroke have not previously been explored.
Objective. We investigated whether dual-tDCS of the primary motor cortex (M1), with cathodal and anodal tDCS applied over undamaged and damaged hemispheres, respectively, improves learning and retention of a new bimanual cooperative motor skill in stroke patients.  
Method. Twenty-one chronic hemiparetic patients were recruited for a randomized, double-blinded, cross-over, sham-controlled trial. While receiving real or sham dual-tDCS, they trained on a bimanual cooperative task called CIRCUIT. Changes in performance were quantified via bimanual speed/accuracy trade-off (Bi-SAT) and bimanual coordination factor (Bi-Co) before, during, and 0, 30, and 60 minutes after dual-tDCS, as well as one week later to measure retention. A generalization test then followed, where patients were asked to complete a new CIRCUIT layout.  
Results. The patients were able to learn and retain the bimanual cooperative skill. However, a general linear mixed model did not detect a significant difference in retention between the real and sham dual-tDCS conditions for either Bi-SAT or Bi-Co. Similarly, no difference in generalization was detected for Bi-SAT or Bi-Co.  
Conclusion. The chronic hemiparetic stroke patients learned and retained the complex bimanual cooperative task and generalized the newly acquired skills to other tasks, indicating that bimanual CIRCUIT training is promising as a neurorehabilitation approach. However, bimanual motor skill learning was not enhanced by dual-tDCS in these patients.

Keywords motor skill learning, bimanual coordination, stroke, neurorehabilitation, tDCS, noninvasive brain stimulation

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