Feasibility of using a depth camera or pressure mat for visual feedback balance training with functional electrical stimulation.

Individuals with incomplete spinal-cord injury/disease are at an increased risk of falling due to their impaired ability to maintain balance. Our research group has developed a closed-loop visual-feedback balance training (VFBT) system coupled with functional electrical stimulation (FES) for rehabilitation of standing balance (FES + VFBT system); however, clinical usage of this system is limited by the use of force plates, which are expensive and not easily accessible. This study aimed to investigate the feasibility of a more affordable and accessible sensor such as a depth camera or pressure mat in place of the force plate. Ten able-bodied participants (7 males, 3 females) performed three sets of four different standing balance exercises using the FES + VFBT system with the force plate. A depth camera and pressure mat collected centre of mass and centre of pressure data passively, respectively. The depth camera showed higher Pearson's correlation (r > 98) and lower root mean squared error (RMSE < 10 mm) than the pressure mat (r > 0.82; RMSE < 4.5 mm) when compared with the force plate overall. Stimulation based on the depth camera showed lower RMSE than that based on the pressure mat relative to the FES + VFBT system. The depth camera shows potential as a replacement sensor to the force plate for providing feedback to the FES + VFBT system.

Effectiveness of Repetitive Transcranial Magnetic Stimulation Combined with Visual Feedback Training in Improving Neuroplasticity and Lower Limb Function after Chronic Stroke: A Pilot Study.

After a stroke, sustained gait impairment can restrict participation in the activities listed in the International Classification of Functioning, Disability, and Health model and cause poor quality of life. The present study investigated the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and visual feedback training (VF) training in improving lower limb motor performance, gait, and corticospinal excitability in patients with chronic stroke. Thirty patients were randomized into three groups that received either rTMS or sham stimulation over the contralesional leg region accompanied by VF training groups in addition to the conventional rehabilitation group. All participants underwent intervention sessions three times per week for four weeks. Outcome measures included the motor-evoked potential (MEP) of the anterior tibialis muscle, Berg Balance Scale (BBS) scores, Timed Up and Go (TUG) test scores, and Fugl-Meyer Assessment of Lower Extremity scores. After the intervention, the rTMS and VF group had significantly improved in MEP latency (p = 0.011), TUG scores (p = 0.008), and BBS scores (p = 0.011). The sham rTMS and VF group had improved MEP latency (p = 0.027). The rTMS and VF training may enhance the cortical excitability and walking ability of individuals with chronic stroke. The potential benefits encourage a larger trial to determine the efficacy in stroke patients.

sEMG-Based Hand Posture Recognition and Visual Feedback Training for the Forearm Amputee.

sEMG-based gesture recognition is useful for human-computer interactions, especially for technology supporting rehabilitation training and the control of electric prostheses. However, high variability in the sEMG signals of untrained users degrades the performance of gesture recognition algorithms. In this study, the hand posture recognition algorithm and radar plot-based visual feedback training were developed using multichannel sEMG sensors. Ten healthy adults and one bilateral forearm amputee participated by repeating twelve hand postures ten times. The visual feedback training was performed for two days and five days in healthy adults and a forearm amputee, respectively. Artificial neural network classifiers were trained with two types of feature vectors: a single feature vector and a combination of feature vectors. The classification accuracy of the forearm amputee increased significantly after three days of hand posture training. These results indicate that the visual feedback training efficiently improved the performance of sEMG-based hand posture recognition by reducing variability in the sEMG signal. Furthermore, a bilateral forearm amputee was able to participate in the rehabilitation training by using a radar plot, and the radar plot-based visual feedback training would help the amputees to control various electric prostheses.

Effects of training with a custom-made visual feedback device on balance and functional lower-extremity strength in older adults: A randomized controlled trial.

INTRODUCTION: Training with a slow and sustained mechanical load, such as standing on one leg, is an effective method for improving balance and increasing lower-extremity strength. Also, visual feedback during motor learning is important in facilitating efficient postural responses and balance skills. In this study, a custom-made visual feedback device was invented to provide the training modality and program based on single-leg standing combined with augmented visual feedback training. This study aimed to investigate the effects of visual feedback training using the custom-made visual feedback device on balance and functional lower-extremity strength in older adults. METHODS: Thirty-four independent older adults were randomly allocated to a training group (TG) and a control group (CG). The participants in the TG received training with the custom-made visual feedback device. The training duration was three sessions per week, for four weeks. The participants in the CG continued their routine activities. Balance (static and dynamic balances, and balance confidence) and functional lower-extremity strength were assessed pre- and post-training. RESULTS: Improvements in static balance (sway velocity and limit of balance during one-leg standing with eyes open) and dynamic balance (directional control of limits of stability in the backward direction) were found after training in the TG compared with the CG. No significant differences in balance confidence or functional lower-extremity strength were found between groups after training. CONCLUSION: In older adults, training with a custom-made visual feedback device could be used to improve both static and dynamic balances, but not balance confidence and functional lower-extremity strength.

Comparison of the effects of visual feedback training and unstable surface training on static and dynamic balance in patients with stroke.

[Purpose] This study compared the effects of visual feedback training and unstable surface training on the static and dynamic balance of stroke patients. [Subjects and Methods] The study enrolled 20 stroke patients and randomly assigned them to visual feedback training and unstable surface training groups. Both groups performed 30 minutes of conventional exercise therapy twice a week for 4 weeks. In addition, the subjects in the visual feedback training group completed a visual feedback training regimen and the subjects in the unstable surface training group completed training on an unstable surface (30-minute session three times a week for 4 weeks in both groups). Static and dynamic balance parameters were recorded immediately before and after the 4 weeks of training. For data analysis, the paired and independent t-test was used to compare the two groups. [Results] In the visual feedback training group, the sway line at the postural sway of the center of pressure and trace length decreased significantly after training. In both groups, the sway range at the limits of stability in the anteroposterior and mediolateral directions increased significantly after training. [Conclusion] Visual feedback training was better at improving static and dynamic balance than unstable surface training in stroke patients.

Adaptation effects in static postural control by providing simultaneous visual feedback of center of pressure and center of gravity.

BACKGROUND: The benefit of visual feedback of the center of pressure (COP) on quiet standing is still debatable. This study aimed to investigate the adaptation effects of visual feedback training using both the COP and center of gravity (COG) during quiet standing. METHODS: Thirty-four healthy young adults were divided into three groups randomly (COP + COG, COP, and control groups). A force plate was used to calculate the coordinates of the COP in the anteroposterior (COPAP) and mediolateral (COPML) directions. A motion analysis system was used to calculate the coordinates of the center of mass (COM) in both directions (COMAP and COMML). The coordinates of the COG in the AP direction (COGAP) were obtained from the force plate signals. Augmented visual feedback was presented on a screen in the form of fluctuation circles in the vertical direction that moved upward as the COPAP and/or COGAP moved forward and vice versa. The COP + COG group received the real-time COPAP and COGAP feedback simultaneously, whereas the COP group received the real-time COPAP feedback only. The control group received no visual feedback. In the training session, the COP + COG group was required to maintain an even distance between the COPAP and COGAP and reduce the COGAP fluctuation, whereas the COP group was required to reduce the COPAP fluctuation while standing on a foam pad. In test sessions, participants were instructed to keep their standing posture as quiet as possible on the foam pad before (pre-session) and after (post-session) the training sessions. RESULTS: In the post-session, the velocity and root mean square of COMAP in the COP + COG group were lower than those in the control group. In addition, the absolute value of the sum of the COP - COM distances in the COP + COG group was lower than that in the COP group. Furthermore, positive correlations were found between the COMAP velocity and COP - COM parameters. CONCLUSIONS: The results suggest that the novel visual feedback training that incorporates the COPAP-COGAP interaction reduces postural sway better than the training using the COPAP alone during quiet standing. That is, even COPAP fluctuation around the COGAP would be effective in reducing the COMAP velocity.

Effects of Balance Visual Feedback Training on Balance Function and Walking Capacity in Patients with Hemiplegia / 中国康复理论与实践

@#Objective To observe the effects of balance visual feedback training on balance function and walking capacity in patients with hemiplegia. Methods40 patients with hemiplegia were divided into the visual feedback group (n=20) and balance board training group (n=20). They were assessed with the Berg Balance Scale (BBS) and the Holden Walking Classification before and 5 weeks after treatment. ResultsThere was no significant difference between groups before treatment in both BBS and Holden Walking Classification (P>0.05). The visual feedback group improved more than the balance board training group (P<0.01). ConclusionThe balancer visual feedback training is more effective on balance function and walking ability in stroke patients with hemiplegia.