• Journal of the Ergonomics Society of Korea
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• v.31 no.6
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• pp.725-731
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• 2012

Objective: The aim of this study is to investigate visual feedback effects and human performance in the foot mouse control. Background: Generally, computer mouse tasks are controlled by visual feedback. In order to understand the characteristics of a foot mouse control, it is important to investigate the patterns of visual feedback involved in foot-mouse control tasks. Human performance of foot mouse control is also an important factor to understand the foot mouse control. Method: Three types of mouse control were determined to investigate visual feedback effects and human performance in the foot mouse control. Visual feedback effects in the foot mouse control were compared with those of a typical hand mouse. The cursor movement speed and mental workload were measured in the three types of tasks and two types of mouses. Results: Mouse control tasks with an element of homing-in to the target were more quickly performed by the hand mouse than the foot mouse. Mental workload was also higher in the foot mouse than the hand mouse. However, in the steering movement, human performance of the foot mouse control was not lower than that of the hand mouse control. Visual feedback in the foot mouse control was less required than in the hand mouse control. Conclusion: The foot mouse was not efficient in the most mouse control tasks, compared to the hand mouse. However, the foot mouse was efficient in the steering movement, moving a cursor within a path with lateral constraints. Application: The results of this study might help to develop the foot mouse.

• Korean Journal of Applied Biomechanics
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• v.30 no.3
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• pp.247-253
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• 2020

Objective: This study aimed to examine the effects of real-time visual feedback gait training on gait stability in older adults. Method: Twelve older adults participated in this study, being divided into 2 groups including a) visual feedback (VF) and b) non-visual feedback (NVF) groups. For 4 weeks, VF performed a treadmill walking training with real-time visual feedback about their postural information while NVF performed a normal treadmill walking training. For evaluations of gait stability, kinematic data of 15-minute treadmill walking were collected from depth-based motion capture system (30 Hz, exbody, Korea). Given that step lengths in both right and left sides were determined based on kinematic data, three variables including step difference, coefficient of variation, approximate entropy were calculated to evaluate gait symmetry, variability and complexity, respectively. Results: For research findings, VF exhibited significant improvements in gait stability after 4-week training in comparison to NVF, particularly in gait symmetry and complexity measures. However, greater improvement in gait variability was observed in NVF than VF. Conclusion: Given that visual feedback walking gives potential effectiveness on gait stability in older adults, gait training with visual feedback may be a robust therapeutic intervention in people with gait disturbances like instability or falls.

• The Journal of Korean Physical Therapy
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• v.30 no.2
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• pp.47-53
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• 2018

Purpose: To find the effect of visual feedback of head angle with using a mobile posture-aware system on craniocervical angle and neck and shoulder muscles fatigue for preventing or decreasing the forward head posture. Methods: Twenty-four healthy young adults in Chungbuk to participate in this study. The subjects started to watch a movie clip for 10 minutes with visual feedback in $0^{\circ}$, $30^{\circ}$, and $60^{\circ}$ of head angles. During the task, surface electromyography (EMG) was used to collect data from the upper trapezius (UT), sternocleidomasetoid muscle (SCM), cervical erecter spinae (CES) during watching the smartphone. Craniocervical angles were measured using a sagittal-view photograph of the subject in a sitting posture. A one-way repeated analysis of variance with a significant level of 0.05 used for statistical analysis. Results: Craniocervical angle with $0^{\circ}$ visual feedback was significantly greater than $30^{\circ}$ and $60^{\circ}$. Craniocervical angle with $30^{\circ}$ visual feedback was significantly greater than $60^{\circ}$. In addition, MDF of UT muscles in $0^{\circ}$ and $30^{\circ}$ of visual feedback was significantly greater than $60^{\circ}$. Conclusion: We concluded that $0^{\circ}$ visual feedback of head angle with using a mobile posture-aware system would be beneficial to prevent or decrease forward head posture during watching a smartphone. We also could recommend using of $30^{\circ}$ visual feedback in case of caring UT muscle fatigue primarily.

• PNF and Movement
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• v.8 no.2
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• pp.17-24
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• 2010

Purpose : The purpose of present study was to determine effects of a visual feedback training on balance ability in poststroke hemiparetic subjects. Methods : Fourteen chronic stroke patients participated. Participants were randomly divided into either visual feedback training group(7 experimental group, 7 control group). All of participated were inpatients at local rehabilitation center and had been receiving a traditional rehabilitation program, five days a week. Exprimental group have additionally undergone for four weeks, three days a week, the visual feedback training but control group was not received any additional program except the traditional rehabilitation program. The Berg Balance Scale(BBS), the FICSIT-4, the MTD-balance system to measure a balance ability were carried out twice before and after training. Results : After participation in the program, subjects of visual feedback training demonstrated a significant improvement in the scores of the BBS, the FICSIT-4, the MTD-Balance system. The control group had no change on the any tests. After the training, the result to improve significantly in visual feedback training group compared to post-test of control group were the score of BBS and the FICSIT-4 and the MTD-Balance system. Conclusions : The present study suggests that the visual feedback training program may become a useful strategy for enhancing balance ability in the rehabilitation of stroke patiens.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.287-294
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• 2020

Objective: This study aimed to investigate the effects of an ultrasound-based bar graph proportional to the quadriceps muscle thickness as a real-time visual feedback training tool in the elderly. Design: Cross-sectional study. Methods: Twenty-four elderly persons participated in this study and were randomly divided into three groups: oral training group (n=8, group 1), ultrasound imaging group (n=8, group 2), and graph group (n=8, group 3). In the pre condition, all participants performed maximal voluntary isometric contraction (MVIC) of the quadriceps with knee extension three times with oral training. In the post condition, group 1 performed MVIC of the quadriceps with oral training, group 2 performed MVIC of the quadriceps with real-time visual feedback using ultrasound imaging, and group 3 performed MVIC of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness, three times for all groups. Muscle thickness, activity (mean, peak), tone, stiffness, logarithmic decrement, relaxation, and creep were measured in both conditions in all participants. Results: Visual feedback with a bar graph showed significant effects on muscle thickness, mean muscle activity, and peak muscle activity compared with oral training and visual feedback with ultrasound imaging (p<0.05). Conclusions: Isometric training of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness may be more effective than other methods in improving muscle thickness and muscle activity. This study presented a tool that can help increase muscle thickness in the elderly.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.153-163
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• 2011

Purpose: This study was conducted to compare the effect of visual feedback training using mirror and the training without mirror on the balance in people with hemiplegic paralysis. Methods: A total of 26 stroke patients were enrolled in this study. The participants were allocated randomly to 2 groups : visual feedback training group(n=13) and control group(n=13). Both groups received PNF(proprioceptive neuromuscular facilitation) for 5 times(each 30 minutes) per week over 6 weeks period. The group, which is enrolled in visual feed back training, performed additional exercise in front of mirror for 30 minutes. The control group performed same exercise without mirror. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. Results: The visual feedback training group showed significantly increased foot pressure and total pressure compared to the control group(p<.05) and significantly decreased body sway compared to the control group (p<.05). Also, visual feedback training group showed significant increase on the Berg Balance Scale(BBS), Timed Up and Go test(TUG) compared to the control group(p<.05). Conclusion: These results support the perceived benefits of visual feedback training using mirror to augment the balance of stroke patients. Therefore, visual feedback training using mirror is feasible and suitable for stroke patients.

• Journal of Korean Physical Therapy Science
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• v.5 no.3
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• pp.691-696
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• 1998

Objectives : Asymmetrical weight bearing during standing has been identified as a common problem in persons with hemiplegia. This study examined the effect of auditory and visual feedback on symmetric weight bearing with hemiplegia. Method: The intervention program was instituted for 10 min each day with a total of twelve treatment sessions. The machine which was used for this study is the Weight Balancer, OG GIKEN, WB-202, Japan Result: There was a significant improvement of symmetric weight distribution in auditory feedback group whereas the visual feedback group disclosed some improvement but not significantly. There was no significant change in control group. Conclusion: Results of this study suggest that an auditary feedback group can be more effective than visual feedback group or control group in helping the persons with hemiplegia achieve symmetric stance.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.59-68
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• 2015

PURPOSE: The purpose of this study was to determine the comparison of visual and auditory biofeedback during sit-to-stand training in patients with stroke. METHODS: Thirty-five subjects with chronic stroke were divided into three groups: a visual feedback group (12 subjects), an auditory feedback group (12 subjects) and a control group (11 subjects). All Groups received neurodevelopmental treatment, and sit-to-stand training for 30minutes three times a week for four weeks. During the sit to stand training, the experimental groups received visual feedback and auditory feedback, whereas the control group performed sit-to-stand training without feedback. Five times sit-to-stand test (FTSST), motion analysis and postural sway during sit-to-stand were used to evaluate sit to stand performance ability. In addition, Berg balance scale (BBS) was performed for evaluation of balance function in participants. RESULTS: All groups showed significant increase on FTSST and BBS between pre- and post-intervention. The BBS scores in visual feedback group was significant increase than control group. The motion analysis and postural sway, more improvement was observed in the visual and auditory feedback groups compared with the control group. The only visual feedback group was a better performance of midline excursion during sit-to-stand than control group. CONCLUSION: These findings suggest that sit-to-stand training using a biofeedback may help to improve sit to stand performance and balance ability of stroke patients.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.1
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• pp.27-34
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• 2014

This paper proposes a new approach to the designed of visual feedback control system based on visual servoing method. The main focus of this paper is presented how it is effective to use many features for improving the accuracy of the visual feedback control of industrial articulated robot for assembling and inspection of parts. Some rank conditions, which relate the image Jacobian, and the control performance are derived. It is also proven that the accuracy is improved by increasing the number of features. The effectiveness of redundant features is verified by the real time experiments on a SCARA type robot(FARA) made in samsung electronics company.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.35-42
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• 2013

This paper proposes a new approach to the designed of visual feedback control system based on visual servoing method. The main focus of this paper is presented how it is effective to use many features for improving the accuracy of the visual feedback control of industrial articulated robot for assembling and inspection of parts. Some rank conditions, which relate the image Jacobian, and the control performance are derived. It is also proven that the accuracy is improved by increasing the number of features. The effectiveness of redundant features is verified by the real time experiments on a SCARA type robot(FARA) made in samsung electronics company.