Neurophysiological Oscillatory Mechanisms Underlying the Effect of Mirror Visual Feedback-Induced Illusion of Hand Movements on Nociception and Cortical Activation.

Mirror Visual Feedback (MVF)-induced illusion of hand movements produces beneficial effects in patients with chronic pain. However, neurophysiological mechanisms underlying these effects are poorly known. In this preliminary study, we test the novel hypothesis that such an MVF-induced movement illusion may exert its effects by changing the activity in midline cortical areas associated with pain processing. Electrical stimuli with individually fixed intensity were applied to the left hand of healthy adults to produce painful and non-painful sensations during unilateral right-hand movements with such an MVF illusion and right and bilateral hand movements without MVF. During these events, electroencephalographic (EEG) activity was recorded from 64 scalp electrodes. Event-related desynchronization (ERD) of EEG alpha rhythms (8-12 Hz) indexed the neurophysiological oscillatory mechanisms inducing cortical activation. Compared to the painful sensations, the non-painful sensations were specifically characterized by (1) lower alpha ERD estimated in the cortical midline, angular gyrus, and lateral parietal regions during the experimental condition with MVF and (2) higher alpha ERD estimated in the lateral prefrontal and parietal regions during the control conditions without MVF. These preliminary results suggest that the MVF-induced movement illusion may affect nociception and neurophysiological oscillatory mechanisms, reducing the activation in cortical limbic and default mode regions.

Successful Retrograde Percutaneous Coronary Intervention for Chronic Total Occlusion in a Patient with Dextrocardia.

Dextrocardia is a very rare congenital malposition, and most cardiologists are not familiar with the radiographic angiograms of this condition. Here, we first report a case of dextrocardia with a chronic total occlusion (CTO) lesion undergoing retrograde percutaneous coronary intervention (PCI). Significant difficulties in lesion interpretation and device manipulation were encountered with the original angiograms. These challenges were not significantly improved until we adopted the double-inversion technique. The procedure was finally accomplished by using the kissing wire technique with a poor angle of attack. Retrograde CTO PCI for patients with dextrocardia is feasible with adequate techniques.

Mitigating Trunk Compensatory Movements in Post-Stroke Survivors through Visual Feedback during Robotic-Assisted Arm Reaching Exercises.

Trunk compensatory movements frequently manifest during robotic-assisted arm reaching exercises for upper limb rehabilitation following a stroke, potentially impeding functional recovery. These aberrant movements are prevalent among stroke survivors and can hinder their progress in rehabilitation, making it crucial to address this issue. This study evaluated the efficacy of visual feedback, facilitated by an RGB-D camera, in reducing trunk compensation. In total, 17 able-bodied individuals and 18 stroke survivors performed reaching tasks under unrestricted trunk conditions and visual feedback conditions. In the visual feedback modalities, the target position was synchronized with trunk movement at ratios where the target moved at the same speed, double, and triple the trunk's motion speed, providing real-time feedback to the participants. Notably, trunk compensatory movements were significantly diminished when the target moved at the same speed and double the trunk's motion speed. Furthermore, these conditions exhibited an increase in the task completion time and perceived exertion among stroke survivors. This outcome suggests that visual feedback effectively heightened the task difficulty, thereby discouraging unnecessary trunk motion. The findings underscore the pivotal role of customized visual feedback in correcting aberrant upper limb movements among stroke survivors, potentially contributing to the advancement of robotic-assisted rehabilitation strategies. These insights advocate for the integration of visual feedback into rehabilitation exercises, highlighting its potential to foster more effective recovery pathways for post-stroke individuals by minimizing undesired compensatory motions.

Comparisons of three different modes of digital mirror therapy for post-stroke rehabilitation: Preliminary results of randomized controlled trial.

Objective: Technologically adapted mirror therapy shows promising results in improving motor function for stroke survivors. The treatment effects of a newly developed multi-mode stroke rehabilitation system offering multiple training modes in digital mirror therapy remain unknown. This study aimed to examine the effects of unilateral mirror visual feedback (MVF) with unimanual training (UM-UT), unilateral MVF with bimanual training (UM-BT), and bilateral MVF with bimanual training (BM-BT) on clinical outcomes in stroke survivors, compared to classical mirror therapy (CMT). Methods: Thirty-five participants were randomly assigned to one of four groups receiving fifteen 60-minute training sessions for 3-4 weeks. The Fugl-Meyer Assessment for Upper Extremity (FMA-UE), Chedoke Arm and Hand Activity Inventory (CAHAI), Revised Nottingham Sensory Assessment (rNSA), Motor Activity Log (MAL), and EQ-5D-5L were administered at pre- and post-intervention and at 1-month follow-up. Results: After intervention and follow-up, significant within-group treatment efficacies were found on most primary outcomes of the FMA-UE and CAHAI scores in all four groups. Significant within-group improvements in the secondary outcomes were found on the MAL and EQ-5D-5L index in the UM-BT group, and the rNSA tactile sensation and MAL quality of movement subscales in the BM-BT group. No significant between-group treatment efficacies were found. Conclusions: UM-UT, UM-BT, BM-BT, and CMT led to similar clinical effects on the FMA-UE and can be considered effective alternative interventions for post-stroke upper-limb motor rehabilitation. UM-BT and BM-BT showed within-group improvements in functional performance in the patients' affected upper limbs in real-life activities.

Cross-frequency modulation of postural fluctuations and scalp EEG in older adults: error amplification feedback for rapid balance adjustments.

Virtual error amplification (VEA) in visual feedback enhances attentive control over postural stability, although the neural mechanisms are still debated. This study investigated the distinct cortical control of unsteady stance in older adults using VEA through cross-frequency modulation of postural fluctuations and scalp EEG. Thirty-seven community-dwelling older adults (68.1 ± 3.6 years) maintained an upright stance on a stabilometer while receiving either VEA or real error feedback. Along with postural fluctuation dynamics, phase-amplitude coupling (PAC) and amplitude-amplitude coupling (AAC) were analyzed for postural fluctuations under 2 Hz and EEG sub-bands (theta, alpha, and beta). The results revealed a higher mean frequency of the postural fluctuation phase (p = .005) and a greater root mean square of the postural fluctuation amplitude (p = .003) with VEA compared to the control condition. VEA also reduced PAC between the postural fluctuation phase and beta-band EEG in the left frontal (p = .009), sensorimotor (p = .002), and occipital (p = .018) areas. Conversely, VEA increased the AAC of posture fluctuation amplitude and beta-band EEG in FP2 (p = .027). Neither theta nor alpha band PAC or AAC were affected by VEA. VEA optimizes postural strategies in older adults during stabilometer stance by enhancing visuospatial attentive control of postural responses and facilitating the transition of motor states against postural perturbations through a disinhibitory process. Incorporating VEA into virtual reality technology is advocated as a valuable strategy for optimizing therapeutic interventions in postural therapy, particularly to mitigate the risk of falls among older adults.

Influence of gaze, vision, and memory on hand kinematics in a placement task.

People usually reach for objects to place them in some position and orientation, but the placement component of this sequence is often ignored. For example, reaches are influenced by gaze position, visual feedback, and memory delays, but their influence on object placement is unclear. Here, we tested these factors in a task where participants placed and oriented a trapezoidal block against two-dimensional (2-D) visual templates displayed on a frontally located computer screen. In experiment 1, participants matched the block to three possible orientations: 0° (horizontal), +45° and -45°, with gaze fixated 10° to the left/right. The hand and template either remained illuminated (closed-loop), or visual feedback was removed (open-loop). Here, hand location consistently overshot the template relative to gaze, especially in the open-loop task; likewise, orientation was influenced by gaze position (depending on template orientation and visual feedback). In experiment 2, a memory delay was added, and participants sometimes performed saccades (toward, away from, or across the template). In this task, the influence of gaze on orientation vanished, but location errors were influenced by both template orientation and final gaze position. Contrary to our expectations, the previous saccade metrics also impacted placement overshoot. Overall, hand orientation was influenced by template orientation in a nonlinear fashion. These results demonstrate interactions between gaze and orientation signals in the planning and execution of hand placement and suggest different neural mechanisms for closed-loop, open-loop, and memory delay placement.NEW & NOTEWORTHY Eye-hand coordination studies usually focus on object acquisition, but placement is equally important. We investigated how gaze position influences object placement toward a 2-D template with different levels of visual feedback. Like reach, placement overestimated goal location relative to gaze and was influenced by previous saccade metrics. Gaze also modulated hand orientation, depending on template orientation and level of visual feedback. Gaze influence was feedback-dependent, with location errors having no significant effect after a memory delay.

Real-Time Visual Feedback Based on MIMUs Technology Reduces Bowing Errors in Beginner Violin Students.

Violin is one of the most complex musical instruments to learn. The learning process requires constant training and many hours of exercise and is primarily based on a student-teacher interaction where the latter guides the beginner through verbal instructions, visual demonstrations, and physical guidance. The teacher's instruction and practice allow the student to learn gradually how to perform the correct gesture autonomously. Unfortunately, these traditional teaching methods require the constant supervision of a teacher and the interpretation of non-real-time feedback provided after the performance. To address these limitations, this work presents a novel interface (Visual Interface for Bowing Evaluation-VIBE) to facilitate student's progression throughout the learning process, even in the absence of direct teacher intervention. The proposed interface allows two key parameters of bowing movements to be monitored, namely, the angle between the bow and the string (i.e., α angle) and the bow tilt (i.e., ß angle), providing real-time visual feedback on how to correctly move the bow. Results collected on 24 beginners (12 exposed to visual feedback, 12 in a control group) showed a positive effect of the real-time visual feedback on the improvement of bow control. Moreover, the subjects exposed to visual feedback judged the latter as useful to correct their movement and clear in terms of the presentation of data. Although the task was rated as harder when performed with the additional feedback, the subjects did not perceive the presence of a violin teacher as essential to interpret the feedback.

Through the looking-glass: Mirror feedback modulates temporal and spatial aspects of bimanual coordination.

Mirror therapy has become an effective and recommended intervention for a range of conditions affecting the upper limb (e.g. hemiparesis following stroke). However, little is known about how mirror feedback affects the control of bimanual movements (as performed during mirror therapy). In this study, in preparation for future clinical investigations, we examined the kinematics of bimanual circle drawing in unimpaired participants both with (Experiment 1) and without (Experiment 2) a visual template to guide movement. In both experiments, 15 unimpaired right-handed participants performed self-paced continuous bimanual circle-drawing movements with a mirror/symmetrical coordination pattern. For the mirror condition, vision was directed towards the mirror in order to monitor the reflected limb. In the no mirror condition, the direction of vision was unchanged, but the mirror was replaced with an opaque screen. Movements of both hands were recorded using motion capture apparatus. In both experiments, the most striking feature of movements was that the hand behind the mirror drifted spatially during the course of individual trials. Participants appeared to be largely unaware of this marked positional change of their unseen hand, which was most pronounced when a template to guide movement was visible (Experiment 1). Temporal asynchrony between the limbs was also affected by mirror feedback in both experiments; in the mirror condition, illusory vision of the unseen hand led to a relative phase lead for that limb. Our data highlight the remarkable impact that the introduction of a simple mirror can have on bimanual coordination. Modulation of spatial and temporal features is consistent with the mirror inducing a rapid and powerful visual illusion, the latter appearing to override proprioceptive signals.

Online corrections can occur within movement imagery: An investigation of the motor-cognitive model.

The motor-cognitive model proposes that movement imagery additionally requires conscious monitoring owing to an absence of veridical online sensory feedback. Therefore, it is predicted that there would be a comparatively limited ability for individuals to update or correct movement imagery as they could within execution. To investigate, participants executed and imagined target-directed aiming movements featuring either an unexpected target perturbation (Exp. 1) or removal of visual sensory feedback (Exp. 2). The results of both experiments indicated that the time-course of executed and imagined movements was equally influenced by each of these online visual manipulations. Thus, contrary to some of the tenets of the motor-cognitive model, movement imagery holds the capacity to interpolate online corrections despite the absence of veridical sensory feedback. The further theoretical implications of these findings are discussed.

Visual feedbacks influence short-term learning of torque versus motion profile with robotic guidance among young adults.

Robotic assistance can improve the learning of complex motor skills. However, the assistance designed and used up to now mainly guides motor commands for trajectory learning, not dynamics learning. The present study explored how a complex motor skill involving the right arm can be learned without suppressing task dynamics, by means of an innovative device with robotic guidance that allows a torque versus motion profile to be learned with admittance control. In addition, we assessed how concurrent visual feedback on this profile can enhance learning without creating dependency, by means of a fading procedure (i.e., feedback reduction across trials). On Day 1, a Control group performed an acquisition session (6 blocks) featuring concurrent visual feedback, while a Fading group performed the session with a gradual reduction in feedback (from 100% to 0% over the 6 blocks). On Day 2, both groups performed a block first without feedback (i.e., Transfer test), then with feedback (i.e., Retention test). Results revealed that on Day 1, movement rehearsal induced a significant improvement in spatiotemporal parameters for the Control group, compared with the Fading group. On Day 2, the opposite was found when this visual feedback was removed, as the Fading group performed significantly better than the Control group on the Transfer test. Vision allows a relationship to be established between the required torque and the motion profile. Its suppression then forces the processing of more intrinsic information, leading to the development of a stable internal representation of the task.

Effect of Mirror Therapy on Upper Limb Function in Children and Adolescents with Hemiplegic Cerebral Palsy: A Systematic Review and Meta-Analysis.

BACKGROUND: This review aimed to explore the effect of mirror therapy (MT) on upper limb function in children and adolescents with hemiplegic cerebral palsy (HCP). METHODS: MEDLINE, CENTRAL, Scopus, PEDro, and Web of Science were systematically searched. PEDro scale  was used for the quality assessment of included trials. Risk of Bias assessment was done using Cochrane Risk-of-bias tool version 2. Meta-analysis was performed on four of the seven studies included. RESULTS & CONCLUSION: The majority of the trials included in this review found MT efficacious in improving motor function in HCP. Quantitative analysis of the included trials using QUEST scores for evaluation of quality of upper extremity function revealed positive but non-significant difference between the groups (MD = -0.12; 95% CI = -2.57,2.33; Z = 0.09, p = .92). Pooled analysis of the included trials using BBT, however, favored control (MD = 4.98; 95% CI = 2.32,7.63; Z = 3.67, p = .0002).

Acoustic and Articulatory Visual Feedback in Classroom L2 Vowel Remediation.

This paper presents L2 vowel remediation in a classroom setting via two real-time visual feedback methods: articulatory ultrasound tongue imaging, which shows tongue shape and position, and a newly developed acoustic formant analyzer, which visualizes a point correlating with the combined effect of tongue position and lip rounding in a vowel quadrilateral. Ten Czech students of the Swedish language participated in the study. Swedish vowel production is difficult for Czech speakers since the languages differ significantly in their vowel systems. The students selected the vowel targets on their own and practiced in two classroom groups, with six students receiving two ultrasound training lessons, followed by one acoustic, and four students receiving two acoustic lessons, followed by one ultrasound. Audio data were collected pre-training, after the two sessions employing the first visual feedback method, and at post-training, allowing measuring Euclidean distance among selected groups of vowels and observing the direction of change within the vowel quadrilateral as a result of practice. Perception tests were performed before and after training, revealing that most learners perceived selected vowels correctly already before the practice. The study showed that both feedback methods can be successfully applied to L2 classroom learning, and both lead to the improvement in the pronunciation of the selected vowels, as well as the Swedish vowel set as a whole. However, ultrasound tongue imaging seems to have an advantage as it resulted in a greater number of improved targets.

Combined Effects of Listening to Preferred Music and Video Feedback, during Warm-Up, on Physical Performance in Young Kickboxers.

Although studies have indicated that the prior use of video feedback and music listening separately improves physical performance and positive feelings in various sports, to our knowledge, no studies have investigated their combined effect in combat-sports-specific tasks. The aim of this study was to determine the combined effect of listening to preferred music and video feedback on aerobic and anaerobic performance in male kickboxers. In a counterbalanced crossover study design, twenty kickboxers underwent three kicking exercises under one of three conditions: (1) control condition, (2) combined listening to preferred music and video feedback, and (3) video feedback during 10-min of rope warm-up. Kickboxers performed a ten-second kicking test, multiple ten-second kick test, and progressive taekwondo test. The total number of kicks, fatigue index, heart rate, rate of perceived exertion, and feeling scale were measured. The combined music and video feedback condition improved the number of kicks with a better positive feeling scale (F ≥ 7.4, p ≤ 0.002, ηp2 ≥ 0.28) than the video feedback and control conditions in all three kicking exercises, while the video feedback alone led to better kick performances and a better feeling scale than the control condition in the ten-second and multiple ten-second kicking tests (p ≤ 0.016). The combined listening to preferred music and video feedback condition was more effective at enhancing the positive feeling scale and repeated roundhouse kick performance. Future investigations should examine the application of video feedback and listening to music in various kickboxing tasks including punches and kicks.

Does Viewing Mirror-Reflected Body Image Affect Static and Dynamic Standing Balance?

In the present study, we examined the immediate effect of allowing healthy participants to view their mirror-reflected body image on static and dynamic balance. We placed a mirror to allow participants to frontally view their own body image while maintaining a quiet stance or while engaged in a dynamic postural standing task. On measures of body sway during quiet stance, there were no effects of this visual feedback, supporting the view that human beings have no central mechanism for viewing the mirror-reflected body image to control body sway during quiet stance. However, the body deviated forward during quiet stance while viewing the mirror-reflected body image, indicating that viewing the mirror-reflected body image contributed to the anterior-posterior positioning of the body, as mediated by an ankle control strategy. For the dynamic standing task, viewing the body image induced unstable peaks of rhythmic lateral shifting of the body weight over the feet. This indicates that viewing the body image caused unstable motor commands for rhythmic lateral weight shifting. When participants made a transition from a bipedal to a unipedal stance in response to a cue, viewing the body image shortened the onset latency of the body sway. Accordingly, viewing the body image seemed to accelerate the motor execution involved in lateral weight shifting, possibly due to predictive activation of the motor system before movement onset. Considered collectively, we found static and dynamic stance balance to be influenced by viewing one's mirror-reflected body image. Viewing the mirror-reflected body image may be a means of changing static and dynamic balance in patients with impaired postural control.

Hand hygiene compliance in nursing home wards: The effects of feedback with lights on alcohol-based hand rub dispensers.

BACKGROUND: Hand hygiene (HH) among health care workers (HCWs) is crucial in preventing infections in nursing homes. However, HH compliance (HHC) among HCWs remains low. This study aimed to investigate the effect of feedback lights on HCWs' HHC. METHODS: A 5-month interventional study was conducted in 3 wards in a nursing home in Denmark. During the intervention period, a green light with a smiley appeared on the alcohol-based hand rub (ABHR) dispensers when HCWs used the ABHR, acknowledging HCWs for using the ABHR. HHC was monitored using an automatic HH monitoring system (AHHMS). RESULTS: A total of 64 HCWs were enrolled. The AHHMS collected 23,696 HH opportunities in apartments and dirty utility rooms. Overall, HHC in the apartments increased from 50% at baseline (95% CI: 48, 53) to 56% (95% CI: 54, 58) during the intervention. However, the increased HHC level was not sustained during follow-up. CONCLUSIONS: The AHHMS enabled the assessment of the intervention. We found a significant effect of light-guided feedback in the apartments. However, the increased HHC was not sustained after the light was switched off.

Large nesting expression in deer mice remains stable under conditions of visual deprivation despite heightened limbic involvement: Perspectives on compulsive-like behavior.

Visual stimuli and limbic activation varyingly influence obsessive-compulsive symptom expression and so impact treatment outcomes. Some symptom phenotypes, for example, covert repugnant thoughts, are likely less sensitive to sensory stimuli compared to symptoms with an extrinsic focus, that is, symptoms related to contamination, safety, and "just-right-perceptions." Toward an improved understanding of the neurocognitive underpinnings of obsessive-compulsive psychobiology, work in naturalistic animal model systems is useful. Here, we explored the impact of visual feedback and limbic processes on 24 normal (NNB) and large (LNB) nesting deer mice, respectively (as far as possible, equally distributed between sexes). Briefly, after behavioral classification into either the NNB or LNB cohorts, mice of each cohort were separated into two groups each and assessed for nesting expression under either standard light conditions or conditions of complete visual deprivation (VD). Nesting outcomes were assessed in terms of size and neatness. After nesting assessment completion, mice were euthanized, and samples of frontal-cortical and hippocampal tissues were collected to determine serotonin and noradrenaline concentrations. Our results show that LNB, as opposed to NNB, represents an inflexible and excessive behavioral phenotype that is not dependent on visually guided action-outcome processing, and that it associates with increased frontal-cortical and hippocampal noradrenaline concentrations, irrespective of lighting condition. Collectively, the current results are informing of the neurocognitive underpinnings of nesting behavior. It also provides a valuable foundation for continued investigations into the noradrenergic mechanisms that may influence the development and promulgation of excessive, rigid, and inflexible behaviors.

Improving walking via real-time visual feedback after stroke in treadmill training (RE-VISIT): a protocol for randomized controlled trial / Melhorando a caminhada por meio de feedback visual em tempo real após acidente vascular cerebral em treinamento em esteira (RE-VISIT): um protocolo para ensaio clínico randomizado

BACKGROUND: After a stroke, most patients often suffer reduced walking ability and balance. Restoring walking ability and improving balance are major goals of stroke rehabilitation. Treadmills are often used in clinical setups to achieve these goals. Adding dimensions to the visual feedback in addition to the mirror for real-time frontal view is proven to enhance the gait. It is, therefore, important to design additional real-time visual feedback in treadmill training, in particular for the sagittal view involved side. OBJECTIVE: The objective of this study is to test if the real-time sagittal visual feedback during treadmill training is superior to the conventional mirror feedback treadmill training program of equivalent intensity in improving walking speed and balance after stroke. METHODS/DESIGN: The RE-VISIT trial (Real-time Visual feedback after Stroke in Treadmill training) is registered in the Clinical Trial Registry of India (CTRI/2023/10/058299). In this two-arm randomized control trial, which will be a single-blinded study, 42 eligible stroke survivors undergoing rehabilitation will be randomly allocated (1:1 ratio) to either real-time visual sagittal feedback along with front mirror (experimental) group or only front mirror treadmill training (control) group, all the participants will receive 15 sessions of treadmill training for up to 15 min at a safe self-selected speed over 5-6 weeks. The RE-VISIT (experimental) group will receive real-time, visual sagittal view feedback of the involved lower limb trajectory along with the routine front mirror view during treadmill training and will be asked to modify their gait pattern. The control group will receive treadmill walking training only with the routine front mirror view feedback. Clinical and gait assessments will be conducted at the baseline, immediately following the final session of training, and at the 9th week during follow-up. The outcome measures of interest are walking speed (primary) and balance (secondary), which will be measured prior to baseline, post 15 sessions of training, and at the 9th week following training. DISCUSSION: This REVISIT trial will provide insight and contribute to the existing innovation and modifications of incorporating realtime visual feedback during treadmill training in post-stroke gait rehabilitation. The findings will help the better designing of a gait rehabilitation program with a treadmill for post-stroke subjects to improve walking speed, and balance for those who have greater difficulties in community ambulation. We anticipate that those in the REVISIT training will demonstrate improved walking ability.

CONTEXTO: Após o acidente vascular cerebral, a maioria dos pacientes frequentemente sofre redução da capacidade de caminhar e do equilíbrio. Restaurar a capacidade de caminhar e melhorar o equilíbrio são os principais objetivos da reabilitação do AVC. As esteiras são frequentemente usadas em ambientes clínicos para atingir esses objetivos. Está comprovado que adicionar dimensões ao feedback visual, além do espelho para visão frontal em tempo real, melhora a marcha. É, portanto, importante projetar feedbacks visuais adicionais em tempo real no treinamento em esteira, em particular para o lado envolvido na visão sagital. OBJETIVO: O objetivo deste estudo é testar se o feedback visual sagital em tempo real durante o treinamento em esteira é superior ao programa de treinamento em esteira com feedback de espelho convencional de intensidade equivalente na melhoria da velocidade de caminhada e equilíbrio após acidente vascular cerebral. MÉTODOS/ DESENHO: O ensaio RE-VISIT (feedback visual em tempo real após acidente vascular cerebral no treinamento em esteira) está registrado no Registro de Ensaios Clínicos da Índia (CTRI/2023/10/058299). Neste ensaio de controle randomizado de dois braços, que será um estudo cego, 42 sobreviventes de AVC elegíveis em reabilitação serão alocados aleatoriamente (proporção de 1:1) para feedback sagital visual em tempo real junto com grupo de espelho frontal (experimental) ou apenas Grupo de treinamento em esteira com espelho frontal (controle), todos os participantes receberão 15 sessões de treinamento em esteira por até 15 minutos em uma velocidade segura e autosselecionada durante 5-6 semanas. O grupo RE-VISIT (experimental) receberá feedback visual em tempo real da visão sagital da trajetória dos membros inferiores envolvidos, juntamente com a visão rotineira do espelho frontal durante o treinamento em esteira e será solicitado a modificar seu padrão de marcha. O grupo de controle receberá treinamento de caminhada em esteira apenas com o feedback rotineiro da visão do espelho frontal. Avaliações clínicas e de marcha serão realizadas no início do estudo, imediatamente após a sessão final de treinamento e na 9ª semana durante o acompanhamento. As medidas de resultados de interesse são a velocidade de caminhada (primária) e o equilíbrio (secundário), que serão medidos antes da linha de base, após a 15ª sessão de treinamento e na 9ª semana após o treinamento. DISCUSSÃO: este ensaio REVISIT fornecerá insights e contribuirá para a inovação e modificações existentes na incorporação de feedbacks visuais em tempo real durante o treinamento em esteira na reabilitação da marcha pós-AVC. As descobertas ajudarão no melhor desenho de um programa de reabilitação da marcha com esteira para indivíduos pós-AVC para melhorar a velocidade de caminhada e o equilíbrio para aqueles que têm maiores dificuldades na deambulação comunitária. Prevemos que aqueles no treinamento REVISIT demonstrarão melhor capacidade de caminhada.

Improving motor imagery through a mirror box for BCI users.

The aim of this study was to evaluate mirror visual feedback (MVF) as a training tool for brain-computer interface (BCI) users. This is because approximately 20-30% of subjects require more training to operate a BCI system using motor imagery. Electroencephalograms (EEGs) were recorded from 18 healthy subjects, using event-related desynchronization (ERD) to observe the responses during the movement or movement intention of the hand for the conditions of control, imagination, and the MVF with the mirror box. We constituted two groups: group 1: control, imagination, and MVF; group 2: control, MVF, and imagination. There were significant differences in imagination conditions between groups using MVF before or after imagination (right-hand, P = 0.0403; left-hand, P = 0.00939). The illusion of movement through MVF is not possible in all subjects, but even in those cases, we found an increase in imagination when the subject used the MVF previously. The increase in the r2s of imagination in the right and left hands suggests cross-learning. The increase in motor imagery recorded with EEG after MVF suggests that the mirror box made it easier to imagine movements. Our results provide evidence that the MVF could be used as a training tool to improve motor imagery.NEW & NOTEWORTHY The increase in motor imagery recorded with EEG after MVF (mirror visual feedback) suggests that the mirror box made it easier to imagine movements. Our results demonstrate that MVF could be used as a training tool to improve motor imagery.

Effects of visual feedback and force level on bilateral ankle-dorsiflexion force control.

This study investigated the potential effects of visual feedback and force level on bilateral force control capabilities in the lower limbs. Thirty-nine healthy young adults performed bilateral ankle-dorsiflexion isometric force control tasks for different visual feedback conditions, including continuous visual feedback (CVF) and withdrawal of visual feedback (WVF), indicating the removal of visual feedback on force outputs during the task and force level conditions (i.e., 10 % and 40 % of the maximum voluntary contraction). Bilateral force control capabilities were estimated using force accuracy, variability, regularity, and absolute power in 0-4 Hz and interlimb coordination by cross-correlation with time lag and uncontrolled manifold (UCM) variables. Correlation analyses determined the relationship between changes in bilateral force control capabilities and interlimb coordination from the CVF to WVF conditions. The findings revealed better bilateral force control capabilities in the CVF condition as indicated by less force error, variability, regularity, absolute power in 0-4 Hz, and advanced interlimb force coordination. From CVF to WVF conditions, increased bad variability correlated with greater force control deficits. These findings suggest that visuomotor processing is an important resource for successful fine motor control in the lower limbs.

Effects of environmental and task related conditions on postural control under concurrent visual feedback.

BACKGROUND: Previous studies have yielded conflicting results on the facilitative effects of concurrent visual feedback (CVFB) on postural control. In addition, these effects have generally been assessed only during a single postural task, and their scope has been limited to training sessions in the acquisition phase but not in the later retention phase. One explanation for these conflicting results is that assessing postural control during a single postural task, such as quiet stance, may not be sufficiently challenging for the postural control system to infer balance abilities. We aimed to address these shortcomings by diversifying postural tasks and environmental conditions and by including acquisition and retention phases in the experiments. RESEARCH QUESTIONS: Does the provision of CVFB of the instantaneous COP position improve performance on a variety of postural tasks compared to no-CVFB controls? Are the effects of the CVFB retained the following day? Do the observed effect sizes differ in magnitude between the environmental and task conditions under CVFB? METHODS: Forty healthy young adults were randomly assigned to CVFB and no-CVFB control groups. The subjects performed three postural tasks: quiet, tandem, and single-leg stance, under two environmental conditions based on the stiffness of the supporting ground surface. Seven measures of postural sway, including ellipse area, mean speed, and sample entropy, were examined. RESULTS: The provision of CVFB significantly increased sample entropy and sway-path length of the normalized posturogram. In addition, ellipse area, standard deviation of resultant distance, and range in the anteroposterior direction were significantly reduced in the CVFB group compared to the no-CVFB controls; however, these effects were not retained the following day without the addition of CVFB augmentation. The postural sway measures under CVFB were affected by task and environmental constraints, with varying effect sizes. SIGNIFICANCE: This study demonstrated environment and task-specific changes in postural sway measures under CVFB, which facilitated postural control in a variety of postural tasks. Providing CVFB significantly increased sample entropy, indicating less regular postural sway. The features of CVFB that attract external attention and reduce cognitive overload are possible explanations for these findings.