Search

Joint absence in people with upper-limb-difference leads to compensatory motions. Such compensation has long been a topic of study, but typically only for a single object/user layout, which is unlikely to spatially generalize. We seek to understand how motion varies over a planar workspace for different target orientations and wrist mobility conditions. We therefore present a study that records arm and torso pose during grasping of 49 equally spaced cylindrical targets. Furthermore, we seek to validate the research practice of using wrist-immobilizing bypass sockets on able-bodied participants to simulate prostheses without wrists. Participants were 2 transradial amputees and 7 able-bodied individuals who conducted the study with and without wrist braces, generating 2450 trajectories. Heat-maps illustrate variation over the workspace in Mean Joint Angle, Range of Joint Motion and Distance Travelled by Body Segment. Results indicate that greater wrist restriction primarily exacerbated shoulder internal rotation and elbow flexion, not the trunk. We observed that bypass sockets do not fully simulate amputee behavior. Furthermore, amputee reaching with their intact limb is different to the reaching motion of normative participants, implying that transradial limb-difference affects both sides of the body. Differences in participant behavior were also observed between horizontal and vertical target orientations.

Objective: To determine whether robotic metrics: (1) correlate with the Nine-Hole Peg Test (9HPT; good convergent validity); and (2) differentiate between those self-reporting “some hand problems” versus “no hand problems” (good criterion validity). Design: Cross-sectional validation analyses. Setting: Rehabilitation research laboratory located within a hospital. Participants: People with multiple sclerosis self-reporting “some” (n=21; mean age, 52.52±10.69 y; females, n=16; disease duration, 18.81±10.38 y) versus “no” (n=21; age, 51.24±12.73 y; females, n=14; disease duration, 17.71±10.16 y) hand problems. Main Outcome Measures: We assessed hand function using the criterion standard 9HPT and robotic testing. Robotic outcomes included an overall task score, as well as 2 movement planning (ie, reaction time and initial direction angle) and 2 movement correction (ie, movement time and path length ratio) spatiotemporal values. We identified participants reporting “some” versus “no” hand problems via the Multiple Sclerosis Impact Scale-29. We analyzed our nonparametric data using a Mann–Whitney U test and Spearman rank-order correlation. Results: Those reporting “some hand problems” included more right-handed individuals (P=.038); otherwise, the 2 groups were characteristically similar. Visually guided reaching task score and movement planning but not movement correction spatiotemporal values demonstrated moderate correlations with 9HPT for both the dominant (reaction time: r=0.489, P=.001; initial direction angle: r=0.429, P=.005) and nondominant (reaction time: r=0.521, P

Objectives: Previous studies showed that the central nervous system (CNS) controls movements by recruiting a low-dimensional set of modules, usually referred to as muscle synergies. Stroke alters the structure and recruitment patterns of muscle synergies, leading to abnormal motor performances. Some studies have shown that muscle synergies can be used as biomarkers for assessing motor function. However, coordination patterns of muscle synergies in poststroke patients need more investigation to characterize how they are modified in functional movements. Methods: Thirteen mild-to-moderate stroke patients and twenty age-matched healthy subjects were recruited to perform two upper-limb movements, hand-tomouth movement and reaching movement. Muscle synergies were extracted with nonnegative matrix factorization. We identified a set of reference synergies (i.e., averaged across healthy subjects) and typical synergies (i.e., averaged across stroke subjects) from the healthy group and stroke group respectively, and extracted affected synergies from each patient. Synergy similarity between groups was computed and analyzed. Synergy reconstruction analysis was performed to verify synergy coordination patterns in post-stroke patients. Results: On average, three synergies were extracted from both the healthy and stroke groups, while the mild impairment group had a significantly higher number of synergies than the healthy group. The similarity analysis showed that synergy structure was more consistent in the healthy group, and stroke instead altered synergy structure and induced more variability. Synergy reconstruction analysis at group and individual levels showed that muscle synergies of patients often showed a combination of healthy reference synergies in the analyzed movements. Finally, this study associated four synergy coordination patterns with patients: merging (equilibrium and disequilibrium), sharing (equilibrium and disequilibrium), losing, and preservation. The preservation was mainly represented in the mild impairment group, and the moderate impairment group showed more merging and sharing. Conclusion: This study concludes that stroke shows more synergy variability compared to the healthy group and the alterations of muscle synergies can be described as a combination of reference synergies by four synergy coordination patterns. These findings deepen the understanding of the underlying neurophysiological mechanisms and possible motor control strategies adopted by the CNS in post-stroke patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is equivocal evidence regarding the effectiveness of robotic guidance on the (re)learning of voluntary motor skills. Robotic guidance can improve the performance of continuous/ tracking skills, although being seldom more effective than unassisted practice alone. However, most of the previous studies employed robotic guidance on all intervention trials. Recently, we showed that mixing robotic guidance with unassisted practice (i.e., mixed practice) can significantly improve the learning of a golf putting task. Yet, these mixed practice studies involved self-paced movements in a standing posture, thus less applicable to rehabilitation contexts. OBJECTIVE: The current study aimed to investigate the influence of mixed practice on the timing accuracy of an upper-limb, rhythmic, sequential task. The goal was to assess the feasibility of integrating mixed practice with music-based interventions. METHODS: Two groups of participants performed circle-drawing sequences in synchrony with rhythmic auditory signals. They completed a pre-test and an acquisition phase, followed by immediate retention and transfer tests. One group received robotic guidance on 50% of the acquisition trials (i.e., mixed practice), whereas another group always practiced unassisted. The pre-test, retention, and transfer tests were performed unassisted. RESULTS: Both groups significantly improved their timing accuracy and precision between the pre-test and the retention test. CONCLUSION: This study provides further evidence that mixed practice can facilitate the (re)learning of voluntary actions, especially with the type of externally paced upper-limb movements employed in music-based interventions. [ABSTRACT FROM AUTHOR]

Engagement with upper limb rehabilitation post-stroke can improve rehabilitation outcomes. Virtual Reality can be used to make rehabilitation more engaging. In this paper, we propose a multiple case study to determine: (1) whether game design principles (identified in an earlier study as being likely to engage) actually do engage, in practice, a sample of stroke survivors with a Desktop Virtual Reality-based Serious Game designed for upper limb rehabilitation; and (2) what game design factors support the existence of these principles in the game. In this study, we considered 15 principles: awareness, feedback, interactivity, flow, challenge, attention, interest, involvement, psychological absorption, motivation, effort, clear instructions, usability, purpose, and a first-person view. Four stroke survivors used, for a period of 12 weeks, a Virtual Reality-based upper limb rehabilitation system called the Neuromender Rehabilitation System. The stroke survivors were then asked how well each of the 15 principles was supported by the Neuromender Rehabilitation System and how much they felt each principle supported their engagement with the system. All the 15 tested principles had good or reasonable support from the participants as being engaging. Use of feedback was emphasised as an important design factor for supporting the design principles, but there was otherwise little agreement in important design factors among the participants. This indicates that more personalised experiences may be necessary for optimised engagement. The insight gained can be used to inform the design of a larger scale statistical study into what engages stroke survivors with Desktop Virtual Reality-based upper limb rehabilitation.

The rejection rates of upper-limb prosthetic devices in adults are high, currently averaging 26% and 23% for body-powered and electric devices, respectively. While many factors influence acceptance, prosthesis training methods relying on novel virtual reality systems have been cited as a critical factor capable of increasing the likelihood of long-term, full-time use. Despite that, these implementations have not yet garnered widespread traction in the clinical setting, and their use remains immaterial. This review aims to explore the reasons behind this situation by identifying trends in existing research that seek to advance Extended Reality “X-Reality” systems for the sake of upper-limb prosthesis rehabilitation and, secondly, analyzing barriers and presenting potential pathways to deployment for successful adoption in the future. The search yielded 42 research papers that were divided into two categories. The first category included articles that focused on the technical aspect of virtual prosthesis training. Articles in the second category utilize user evaluation procedures to ensure applicability in a clinical environment. The review showed that 75% of articles that conducted whole system testing experimented with non-immersive virtual systems. Furthermore, there is a shortage of experiments performed with amputee subjects. From the large-scale studies analyzed, 71% of those recruited solely non-disabled participants. This paper shows that X-Reality technologies for prosthesis rehabilitation of upper-limb amputees carry significant benefits. Nevertheless, much still must be done so that the technology reaches widespread clinical use.

Assessment and therapy for individuals who have hand paresis requires force sensing approaches that can measure a wide range of finger forces in multiple dimensions. Here we present a novel strain-gauge force sensor with 3 degrees of freedom (DOF) designed for use in a hand assessment and rehabilitation device. The sensor features a fiberglass printed circuit board substrate to which eight strain gauges are bonded. All circuity for the sensor is routed directly through the board, which is secured to a larger rehabilitative device via an aluminum frame. After design, the sensing package was characterized for weight, capacity, and resolution requirements. Furthermore, a test sensor was calibrated in a three-axis configuration and validated in the larger spherical workspace to understand how accurate and precise the sensor is, while the sensor has slight shortcomings with validation error, it does satisfy the precision, calibration accuracy, and fine sensing requirements in orthogonal loading, and all structural specifications are met. The sensor is therefore a great candidate for sensing technology in rehabilitation devices that assess dexterity in patients with impaired hand function. [ABSTRACT FROM AUTHOR]

The rejection rates of upper-limb prosthetic devices in adults are high, currently averaging 26% and 23% for body-powered and electric devices, respectively. While many factors influence acceptance, prosthesis training methods relying on novel virtual reality systems have been cited as a critical factor capable of increasing the likelihood of long-term, full-time use. Despite that, these implementations have not yet garnered widespread traction in the clinical setting, and their use remains immaterial. This review aims to explore the reasons behind this situation by identifying trends in existing research that seek to advance Extended Reality “X-Reality” systems for the sake of upper-limb prosthesis rehabilitation and, secondly, analyzing barriers and presenting potential pathways to deployment for successful adoption in the future. The search yielded 42 research papers that were divided into two categories. The first category included articles that focused on the technical aspect of virtual prosthesis training. Articles in the second category utilize user evaluation procedures to ensure applicability in a clinical environment. The review showed that 75% of articles that conducted whole system testing experimented with non-immersive virtual systems. Furthermore, there is a shortage of experiments performed with amputee subjects. From the large-scale studies analyzed, 71% of those recruited solely non-disabled participants. This paper shows that X-Reality technologies for prosthesis rehabilitation of upper-limb amputees carry significant benefits. Nevertheless, much still must be done so that the technology reaches widespread clinical use. [ABSTRACT FROM AUTHOR]

Robot-assisted movement training improves arm movement ability following acute and chronic stroke. Such training involves two interacting processes: the patient trying to move and the robot applying forces to the patient's arm. A fundamental principle of motor learning is that movement practice improves motor function; the role of applied robotic forces in improving motor function is still unclear. This article reviews our work addressing this question. Our pilot study using the Assisted Rehabilitation and Measurement (ARM) Guide, a linear robotic trainer, found that mechanically assisted reaching improved motor recovery similar to unassisted reaching practice. This finding is inconclusive because of the small sample size (n = 19), but suggest that future studies should carefully control the amount of voluntary movement practice delivered to justify the use of robotic forces. We are optimistic that robotic forces will ultimately show additional therapeutic benefits when coupled with movement practice. We justify this optimism here by comparing results from the ARM Guide and the Mirror Image Movement Enabler robotic trainer. This comparison suggests that requiring a patient to generate specific patterns of force before allowing movement is more effective than mechanically completing movements for the patient. We describe the engineering implementation of this "guided-force training" algorithm.

Virtual rehabilitation has been used during decades to provide a more personalized, controlled, and enjoyable experience on upper-limb motor rehabilitation. Since novel virtual reality (VR) technologies are now accessible and highly immersive, the challenge for a wide dissemination of virtual rehabilitation in clinical scenarios has shifted from the hardware robustness to the software intelligence. A sophisticated technique that provides physiological intelligence to novel human-computer interaction (HCI) applications is biocybernetic adaptation. The concept emerges from the electrophysiological computing field, and it proposes using body signals to detect human states (e.g. workload or fatigue) and modulate the virtual activity accordingly. This paper evaluates the effects of using biocybernetic adaptation in a virtual rehabilitation game that aims to encourage users to exert at a desirable intensity level while interacting with the virtual environment. The system relies on surface-electromyography (sEMG) signals to detect fatigue levels in real-time and adapt the game challenge dynamically. Perceived fatigue levels, game user experience, and game performance parameters are assessed after playing the game, considering two different visualization modalities: non-immersive (conventional flat screen) and immersive (VR headset). Results revealed how the biocybernetic system in the immersive condition not only produced lower levels of perceived fatigue compared with the non-immersive, but also, created a more enjoyable and positive experience in a controlled experiment with 24 healthy subjects. Moreover, participants in the immersive condition showed a better performance in the virtual game and higher usability levels scored by users compared with the non-immersive condition. To conclude, we highlight the importance of combining novel immersive approaches with physiologically aware systems to enhance the benefits of virtual rehabilitation therapies. [ABSTRACT FROM AUTHOR]

Recovery of therapeutic or functional ambulatory capacity in patients with rotator cuff injury is a primary goal of rehabilitation. Wearable powered exoskeletons allow patients to perform repetitive practice with large movements to maximize recovery, even immediately after the acute event. The aim of this paper is to describe the usability, acceptability and acceptance of a hybrid exoskeleton for upper-limb passive rehabilitation using the System Usability Scale (SUS) questionnaire. This equipment, called ExoFlex, is defined as a hybrid exoskeleton since it is made up of rigid and soft components. The exoskeleton mechanical description is presented along with its control system and the way motion is structured in rehabilitation sessions. Seven patients (six women and one man) have participated in the evaluation of this equipment, which are in the range of 50 to 79 years old. Preliminary evidence of the acceptance and usability by both patients and clinicians are very promising, obtaining an average score of 80.71 in the SUS test, as well as good results in a questionnaire that evaluates the clinicians’ perceived usability of ExoFlex.

Impaired motor control post-stroke is typically measured using clinical assessments employing categorical and subjective scoring. We investigated quantitative kinematic parameters of a complex movement with therapy in chronic stroke. Tri-axial accelerometry of the more-affected arm of 24 patients was recorded during early- (day 2–3) and late- (days 12–14) therapy, and for 13 patients at 6-month follow-up. Clinical assessments included the classification of motor-function as low, moderate, or high. Kinematic parameters were measured during Wii-baseball swings to assess the effect of time and the level of motor-function. Clinical tests improved over time (all p < 0.01). Increased acceleration magnitude over time was significant only at proximal sensors (p < 0.05), and there was an effect of motor-function at distal sensors (p < 0.05). Normalized velocity decreased (p < 0.05) at all sensors over time. Peak acceleration and peak deceleration increased over time, predominately at proximal sensors. Kinematic parameters provide an objective and quantitative measure of change in motor-function that is not possible with clinical assessments. The complex patterns of change were not consistent between and within levels of motor-function but reflected improved motor control that was sustained over time. These data emphasize the potential for ongoing improvements in motor capacity in chronic stroke with additional rehabilitation. [ABSTRACT FROM AUTHOR]

The kinematic character of hand trajectory in reaching tasks varies by movement direction. Often, direction is not included as a factor in the analysis of data collected during multi-directional reach tasks; consequently, this directionally insensitive model (DI) may be prone to type-II error due to unexplained variance. On the other hand, directionally specific models (DS) that account separately for each movement direction, may reduce statistical power by increasing the amount of data groupings. We propose a clustered-by-similarity (CS) in which movement directions with similar kinematic features are grouped together, maximizing model fit by decreasing unexplained variance while also decreasing uninformative sub-groupings. We tested model quality in measuring change over time in 10 kinematic features extracted from 72 chronic stroke patients participating in the VA-ROBOTICS trial, performing a targeted reaching task over 16 movement directions (8 targets, back- and forth from center) in the horizontal plane. Across 49 participants surviving a quality control sieve, 4.3 ± 1.1 (min: 3; max: 7) clusters were found among the 16 movement directions; clusters varied between participants. Among 49 participants, and averaged across 10 features, the better-fitting model for predicting change in features was found to be CS assessed by the Akaike Information criterion (61.6 ± 7.3%), versus DS (31.0 ± 7.8%) and DI (7.1 ± 7.1%). Confirmatory analysis via Extra Sum of Squares F-test showed the DS and CS models out-performed the DI model in head-to-head (pairwise) comparison in >85% of all specimens. Thus, we find overwhelming evidence that it is necessary to adjust for direction in the models of multi-directional movements, and that clustering kinematic data by feature similarly may yield the optimal configuration for this co-variate.

This paper presents a comprehensive review of high-level control techniques for upper-limb robotic training. It aims to compare and discuss the potentials of these different control algorithms, and specify future research direction. Included studies mainly come from selected papers in four review articles. To make selected studies complete and comprehensive, especially some recently-developed upper-limb robotic devices, a search was further conducted in IEEE Xplore, Google Scholar, Scopus and Web of Science using keywords ('upper limb*' or 'upper body*') and ('rehabilitation*' or 'treatment*') and ('robot*' or 'device*' or 'exoskeleton*'). The search is limited to English-language articles published between January 2013 and December 2017. Valuable references in related publications were also screened. Comparative analysis shows that high-level interaction control strategies can be implemented in a range of methods, mainly including impedance/admittance based strategies, adaptive control techniques, and physiological signal control. Even though the potentials of existing interactive control strategies have been demonstrated, it is hard to identify the one leading to maximum encouragement from human users. However, it is reasonable to suggest that future studies should combine different control strategies to be application specific, and deliver appropriate robotic assistance based on physical disability levels of human users. [ABSTRACT FROM AUTHOR]

The purpose of this perspective is to outline the role of the treating physician, often a physiatrist, in caring for people with upperlimb loss with regard to prosthetic options. The rehabilitation process begins by encouraging the individual with amputation to take ownership in his or her care by establishing goals, researching prosthetic options, and directing the decision making of their team. The systematic review of the literature confirmed that there is limited empirical evidence to guide the prosthetic selection process. Many obstacles hinder the selection process including cost/insurance coverage, access to experienced training in prosthetic use, and unrealistic expectations for the prosthesis to restore the patient's limb. Standards of care vary greatly among institutions, both nationally and worldwide, exposing the need for a practical civilian model system of care using available resources to achieve the best possible outcomes. Guidelines must incorporate evidence-based practice when available along with expert opinion while integrating surgical and technological advances as these mature. Using goal-oriented, patient-centered shared decision making optimizes prosthetic selection. [ABSTRACT FROM AUTHOR]

The purpose of this perspective is to outline the role of the treating physician, often a physiatrist, in caring for people with upper-limb loss with regard to prosthetic options. The rehabilitation process begins by encouraging the individual with amputation to take ownership in his or her care by establishing goals, researching prosthetic options, and directing the decision making of their team. The systematic review of the literature confirmed that there is limited empirical evidence to guide the prosthetic selection process. Many obstacles hinder the selection process including cost/insurance coverage, access to experienced training in prosthetic use, and unrealistic expectations for the prosthesis to restore the patient's limb. Standards of care vary greatly among institutions, both nationally and worldwide, exposing the need for a practical civilian model system of care using available resources to achieve the best possible outcomes. Guidelines must incorporate evidence-based practice when available along with expert opinion while integrating surgical and technological advances as these mature. Using goal-oriented, patient-centered shared decision making optimizes prosthetic selection. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of functional strengthening (using functional movements) and analytical strengthening (using repetitive movements) on level of activity and muscular strength gain in patients with chronic hemiparesis after stroke. Method: A randomized, assessor-blinded trial was conducted in a therapist-supervised home rehabilitation program. Twenty-seven patients with chronic stroke were randomly allocated one of two groups: functional strengthening (FS) (n=13) and analytical strengthening (AS) (n=14). Each group received a five-week muscle strengthening protocol (30 minutes per day, three times per week) including functional movements or analytical movements, respectively. Pre-, post-, and ten-month follow-up outcomes included the Upper-Extremity Performance Test (primary outcome), Shoulder and Grip Strength, Active Shoulder Range of Motion (ROM), the Fugl-Meyer Assessment, and the Modified Ashworth Scale (MAS) (secondary outcomes). Results: There was significant improvement in the Upper- Extremity Performance Test for the combined unilateral and bilateral task scores in the FS Group (mean difference 2.4; 95% CI=0.14 to 4.6) in the 10-month follow-up. No significant difference was observed between groups in the other outcomes (p>0.05). Conclusion: A five-week home-based functional muscle strengthening induced positive results for the upper-extremity level of activity of patients with moderate impairment after chronic stroke. [ABSTRACT FROM AUTHOR]

Background: Nowadays, stroke is a leading cause of disability in adults. Assessment of motor performance has played an important role in rehabilitation for post stroke patients. Therefore, it is quite important to develop an automatic assessment system of motor function.Objective: The purpose of this study is to assess the performance of the single task upper-limb movements quantitatively among stroke survivors.Methods: Eleven normal subjects and thirty-five subjects with stroke were involved in this study. The subjects, who were wearing the micro-sensor motion capture system, performed shoulder flexion in a sitting position. The system recorded three-dimensional kinematics data of limb movements in quaternions. By extracting the significant features from these data, we built a linear model to acquire the functional assessment score (FAS).Results: All of the kinematics features have a significant statistical difference (P < 0.05) between patients and healthy people, while the feature values have a high correlation with Fugl-Meyer (FM) scores (r > 0.5, p < 0.05), indicating that these features are able to reflect the level of motion impairment. Furthermore, most samples of the linear model locate in the confidence interval after regression, with the residual approaching a normal distribution. These results show that the FAS is capable of motor function assessment for stroke survivors.Conclusion: These findings represent an important step towards a system that can be utilized for precise single task motor evaluation after stroke, applicable to clinical research and as a tool for rehabilitation. [ABSTRACT FROM AUTHOR]

The very first application of active exoskeleton robot was to provide external power to a soldier so that he can carry additional weight than his strength. Since then this technology has focused on developing systems for assisting and augmenting human power. Later this technology is expanded into other applications such as limb rehabilitation and tele-operations. Exoskeleton research is still a growing area and demands multi-disciplinary approaches in solving complex technical issues. In this paper, the developments of active upper-limb exoskeleton robots are reviewed. This paper presents the major developments occurred in the history, the key milestones during the evolution and major research challenges in the present day context of hardware systems of upper-limb exoskeleton robots. Moreover, the paper provides a classification, a comparison and a design overview of mechanisms, actuation and power transmission of most of the upper-limb exoskeleton robots that have been found in the literature. A brief review on the control methods of upper-limb exoskeleton robots is also presented. At the end, a discussion on the future directions of the upper-limb exoskeleton robots was included. [ABSTRACT FROM AUTHOR]

BACKGROUND: Robotic guidance has been shown to facilitate motor skill acquisition, through altered sensorimotor control, in neurologically impaired and healthy populations. OBJECTIVE: To determine if robot-guided practice and online visual feedback availability primarily influences movement planning or online control mechanisms. METHODS: In this two-experiment study, participants first performed a pre-test involving reaches with or without vision, to obtain baseline measures. In both experiments, participants then underwent an acquisition phase where they either actively followed robot-guided trajectories or trained unassisted. Only in the second experiment, robot-guided or unassisted acquisition was performed either with or without online vision. Following acquisition, all participants completed a post-test that was the same as the pre-test. Planning and online control mechanisms were assessed through endpoint error and kinematic analyses. RESULTS: The robot-guided and unassisted groups generally exhibited comparable changes in endpoint accuracy and precision. Kinematic analyses revealed that only participants who practiced with the robot exhibited significantly reduced the proportion of movement time spent during the limb deceleration phase (i.e., time after peak velocity). This was true regardless of online visual feedback availability during training. CONCLUSION: The influence of robot-assisted motor skill acquisition is best explained by improved motor planning processes. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To assess the efficacy of transcranial direct current stimulation (tDCS) on decreasing upper-limb (UL) muscle tone after stroke. Design: A prospective, sham-controlled, randomized controlled trial with 4-weeks follow-up. Randomization into the tDCS group or the control group. Setting: Rehabilitation education and research hospital. Participants: Inpatients (N=90, 45 per group; age range, 15–70y; 69 men, 21 women; duration of stroke, 2–12mo) with poststroke UL spasticity. No participant withdrew because of adverse effects. Intervention: The tDCS group received tDCS to the primary sensorimotor cortex of the affected side with cathodal stimulation, 20 minutes per day, 5 days per week, for 4 weeks and conventional physical therapy. The control group received sham stimulation (same area as the tDCS group) and conventional physical therapy. Main Outcome Measures: Modified Ashworth scale (MAS), Fugl-Meyer Assessment of motor recovery, and Barthel Index. All outcomes were measured at admission, after treatment, and after follow-up. A clinically important difference (CID) was defined as a reduction of ≥1 in the MAS score. Results: Compared with the sham tDCS group, the active tDCS group had significantly more patients with a clinically important difference after treatment (80% and 78% vs 6% and 9%) and at 4-week follow-up (84% and 82% vs 7% and 4%), and UL motor function and activities of daily living (ADL) assessment improved more significantly in the active tDCS group (Fugl-Meyer Assessment of motor recovery from 12 [range, 4–26] to 22 [range, 7–50] to 32 [range, 28–41], Barthel Index from 55 [range, 0–85] to 85 [range, 5–100] to 90 [range, 10–100 vs Fugl-Meyer Assessment of motor recovery from 8 [range, 3–34] to 10 [range, 8–25] to 15 [range, 6–40], Barthel Index from 55 [range, 25–95] to 65 [range, 30–100] to 75 [range, 40–100], respectively, P<.01). Conclusions: UL muscle tone after stroke can be decreased using cathodal tDCS. Combined with conventional physical therapy, tDCS appears to improve motor function and ADL. Cathodal tDCS over ipsilesional primary sensorimotor cortex may inhibit primary sensorimotor cortex hyperactivation, resulting in significant reductions in muscle tone. [Copyright &y& Elsevier]

In the present paper, we review the main concepts of the dynamical systems approach to bimanual coordination and propose applications to therapeutic intervention for functional recovery of coordinated movements in stroke. Further, we describe the behavioral alterations of discrete bimanual coordination resulting from cerebral vascular accident (CVA) lesions and speculate on the possibility of mimicking the mechanisms of CVA lesions via symmetry breaking in dynamic systems. [ABSTRACT FROM AUTHOR]

We studied the relationship between grip force and external forearm pressure in nondisabled subjects using force myography (FMG). FMG uses a sensorized cuff surrounding the forearm to register the distributed mechanical force, detecting pressure on the sensors generated by the volumetric changes of the underlying musculo-tendinous complex. Each of nine nondisabled subjects donned the FMG cuff and applied grip forces to a cylindrical dynamometer; grip forces ranged from 0% to 100% of the subjects' maximum voluntary contraction. The cuff was positioned with seven force sensors located on both the anterior and posterior surfaces of the proximal forearm, but no attempt was made to match sensor placement with particular muscles or sites. Grip prediction was simply encoded as the rectified sum of the FMG sensor outputs. During grip and release cycles, the FMG waveforms of each subject correlated closely with his or her force waveforms (r > 0.89). FMG also correlated highly with the timing of grip onset and release (intraclass correlation coefficient (ICC(A,2)) = 0.99) and time to peak (ICC(A,2) = 0.91), with negligible lag. These results demonstrate that when applied to the forearm, FMG represents a grip force signature that may be useful for near-real-time proportional control of upper-limb prosthetic devices. [ABSTRACT FROM AUTHOR]