Posts Tagged visual feedback
[Abstract+References] Design and test of a Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during training of upper limb movement
The present paper describes the design and test of a low-cost Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during the execution of an upper limb exercise.
Eleven sub-acute stroke patients with varying degrees of upper limb function were recruited. Each subject participated in a control session (repeated twice) and a feedback session (repeated twice). In each session, the subjects were presented with a rectangular pattern displayed on a vertical mounted monitor embedded in the table in front of the patient.
The subjects were asked to move a marker inside the rectangular pattern by using their most affected hand. During the feedback session, the thickness of the rectangular pattern was changed according to the performance of the subject, and the color of the marker changed according to its position, thereby guiding the subject’s movements. In the control session, the thickness of the rectangular pattern and the color of the marker did not change.
The results showed that the movement similarity and smoothness was higher in the feedback session than in the control session while the duration of the movement was longer. The present study showed that adaptive visual feedback delivered by use of the Kinect sensor can increase the similarity and smoothness of upper limb movement in stroke patients.
[ARTICLE] Effects of Mirror Therapy on the Lower Limb Functionality Hemiparesis after Stroke – Full Text PDF
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Purpose of Review
Ramachandran (Nature 377:489–490, 1995) showed that in amputees, phantom limb pain described as a spasming or immobile phantom limb can be alleviated by watching their reflection of the intact limb in a parasagittally placed mirror while moving the intact limb and the phantom simultaneously. This suggested that therapy via mirror visual feedback—mirror therapy—might be considered for other diseases and conditions characterized by poor mobility. We were the first to show that mirror therapy might be beneficial for hemiparesis following stroke. There have now been numerous case reports and studies of mirror therapy for hemiparesis following stroke.
Overall, the majority of studies done thus far on patients with hemiparesis in the subacute or chronic phase following stroke find mirror therapy to be more beneficial than control treatments. Even when mirror therapy is not superior to control therapy, the reason for this is there are similar improvements in both groups. There have not been adverse effects in patients that perform mirror therapy for hemiparesis following stroke.
There appears to be a benefit of mirror therapy for hemiparesis following stroke in the subacute and chronic phase. Trial of mirror therapy for hemiparesis may be warranted. Further study of mirror therapy for hemiparesis following stroke will be welcomed; in particular, it would be important to study different groups of patients given the heterogeneity of stroke.
[ARTICLE] Effects of Visual Feedback on Motion Mimicry Ability during Video-Based Rehabilitation – Full Text PDF
The motion mimicry ability of patients facilitates execution of therapy moves based on visual observation of rehabilitation exercise videos, which can help speed up the recovery process.
This study investigates the effects of visual feedback on the mimicking ability of human subjects in video-based rehabilitation. Inertial Measurement Unit (IMU) sensors was used, which provide a portable system to detect human motion tracking, allowing for experiments to be conducted without space restrictions and provide a greater variety of actions that can be tested. In the experiment, healthy subjects were shown a video of an instructor performing a certain movement task and had to mimic actions to the best of their ability.
A real-time visual feedback system, based on input data from IMU sensors, was introduced to inform subjects of the accuracy of their mimicking actions. Subjects were tested with and without feedback and the relevant joint angle data was collected to determine the individual’s mimicking ability.
Our results showed a significant improvement in subject’s mimicking ability from ‘no feedback’ to ‘feedback’ condition. The key implication of the findings is that visual feedback provides an extrinsic source that allows patients to better synchronize their hand-eye coordination during mimicry. Potential prospective works will investigate the relevance of motion mimicry mechanism in home-based rehabilitation.
[THESIS] Effects of Treadmill Walking With Visual Feedback on Gait Outcomes in People Post Stroke. – Text PDF
Compromised gait is prevalent in people post stroke. Gait training is one of the major components in stroke rehabilitation. Treadmill walking is often used for gait training in people post stroke. Limited studies have examined the effects of a visual feedback system in combination with treadmill-based gait training.
Purpose: The purpose of this study was to investigate the effects of treadmill walking with realtime visual feedback on gait outcomes in people post stroke.
Methods: 6 participants (age 59.3+/-12.34 years old) participated in this case study. They were assigned to either visual feedback gait training group or control based on initial walking speed. Both groups performed 30 minutes of treadmill walking, three times a week, for eight weeks. The control group performed the training with no visual feedback (NVF). The experimental treatment group received real-time visual feedback (VF) on a LCD screen which displayed foot placement and prompts. Data collection was performed before and after the eight weeks, as well as four weeks after the completion of intervention. The kinematic and spatiotemporal variables were recorded and analyzed by using a 3D motion analysis system. (VICON Bonita System). Data process and analysis was performed using VICON Polygon software.
Results: Group averages demonstrated an increase in walking speed and cadence in the VF group. The VF group demonstrated an increase of 11.7% in cadence of the AF and NAF limb. Walking speed of the VF group increased by 21.7% from .95m/s to 1.16m/s. NVF group revealed no notable change in spatiotemporal, or kinematic variables. Neither VF nor NVF group demonstrated notable changes in the kinematic values or gait symmetry.
Conclusion: The findings indicate that gait training with visual feedback can be more effective in improving gait spatiotemporal values than conventional treadmill walking.
[ARTICLE] A changing stroke rehabilitation environment: Implications for upper limb interventions – Full Text PDF
Functional recovery of the upper limb is poor and as many as 50% of stroke survivors still have impairments at 6 months post stroke, despite rehabilitation efforts. With the move towards early supported discharge and community-based rehabilitation, novel solutions are needed to deliver the amount of quality therapy that is required for optimum recovery. We propose a rehabilitation aid that provides patients with augmented visual feedback of their motor performance during task orientated upper limb therapy with the aim of facilitating motor relearning and maximising patients functional outcomes.
[ARTICLE] Reflections on Mirror Therapy – A Systematic Review of the Effect of Mirror Visual Feedback on the Brain
Background. Mirror visual feedback (MVF), a phenomenon where movement of one limb is perceived as movement of the other limb, has the capacity to alleviate phantom limb pain or promote motor recovery of the upper limbs after stroke. The tool has received great interest from health professionals; however, a clear understanding of the mechanisms underlying the neural recovery owing to MVF is lacking.
Objective. We performed a systematic review to assess the effect of MVF on brain activation during a motor task.
Methods. We searched PubMed, CINAHL, and EMBASE databases for neuroimaging studies investigating the effect of MVF on the brain. Key details for each study regarding participants, imaging methods, and results were extracted.
Results. The database search yielded 347 article, of which we identified 33 suitable for inclusion. Compared with a control condition, MVF increases neural activity in areas involved with allocation of attention and cognitive control (dorsolateral prefrontal cortex, posterior cingulate cortex, S1 and S2, precuneus). Apart from activation in the superior temporal gyrus and premotor cortex, there is little evidence that MVF activates the mirror neuron system. MVF increases the excitability of the ipsilateral primary motor cortex (M1) that projects to the “untrained” hand/arm. There is also evidence for ipsilateral projections from the contralateral M1 to the untrained/affected hand as a consequence of training with MVF.
Conclusion. MVF can exert a strong influence on the motor network, mainly through increased cognitive penetration in action control, though the variance in methodology and the lack of studies that shed light on the functional connectivity between areas still limit insight into the actual underlying mechanisms.
…Mirror visual feedback (MVF), a phenomenon where movement of one limb is perceived as movement of the other limb, has the capacity to alleviate phantom limb pain or promote motor recovery of the upper limbs after stroke. The tool has received great interest from health professionals; however, a clear understanding of the mechanisms underlying the neural recovery owing to MVF is lacking…