• Journal of Korean Physical Therapy Science
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• v.24 no.3
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• pp.1-11
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• 2017

Purpose: The purpose of this study was to investigate the effects of virtual reality based treadmill training on muscle architecture of gastrocnemius in chronic stroke patients. Methods: Thirty chronic stroke patients were randomly assigned to either the virtual reality based treadmill training (VRTT) group (n=15) or treadmill training (TT) group (n=15). Both groups participated in a standard rehabilitation program; in addition, the VRTT group participated in virtual reality based treadmill training for 30 minutes per day, three times per week, for 6 weeks, and TT group participated in treadmill walking training for 30 minutes per day, three times per week, for 6 weeks. Ultrasound image was used for measurement of pennation angle and muscle thickness of the medial gastrocnemius muscle at rest and during maximum voluntary contraction. Results: In the paretic side medial gastrocnemius muscle, greater improvement on the pennation angle and muscle thickness while resting and maximal voluntary contraction were observed in the VRTT group compared with the TT group. Conclusion: Findings of this study demonstrated that the virtual reality based treadmill training has an effect on muscle architecture of medial gastrocnemius in chronic stroke patients.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.79-90
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• 2020

The inconsistency in different sensory information causes virtual reality (VR) sickness. This research verifies whether the consistent sensory information reduces VR sickness within treadmill-based virtual reality. Furthermore, we examined the inconsistency between the visually perceived walking speed by optical flow in VR and the physically perceived walking speed in treadmill walking on VR sickness. In Experiment 1, participants reported VR sickness levels while experiencing an increase in the virtual reality. We compared the VR sickness level reported on the standing still condition with that on the treadmill-walking condition. Based on our results, less VR sickness and more sense of presence and immersion were reported on the treadmill-walking condition than on the standing still condition. In Experiment 2 and Experiment 3, the effect of inconsistency between perceived visual speed and perceived walking speed on VR sickness was examined. Interestingly, participants reported less sickness when the perceived visual speed was faster than the perceived walking speed, compared to when the sense of speed was consistent. These results imply that allowing participants to walk on a treadmill while experiencing virtual reality reduces VR sickness. Hence, the perceived visual-walking speed consistency is not necessarily required to reduce VR sickness.

• The Journal of Korean Physical Therapy
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• v.21 no.3
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• pp.33-40
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• 2009

Purpose: This study examined the effects of a virtual reality-based exercise program on the functional recovery of balance and gait in chronic stroke subjects. Methods: A total of 42 chronic stroke patients were enrolled in this study. The participants were allocated randomly to 2 groups: a VR (n=22) and control group (n=20). Both groups received treadmill training for 3 sessions (10 minutes each), 30 minutes per week over a 6 week period. The VR group practiced additional virtual reality programs consisting of 3 programs for 10 minutes each. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. Results: The virtual reality-based exercise group showed significant increases in gait velocity, cadence and stride length compared to the control group (p<0.05). However, there were no significant differences in static balance. Conclusion: These results support the perceived benefits of exercise programs that incorporate virtual reality to augment the balance and ambulation of stroke patients. Therefore, virtual reality is feasible and suitable for stroke patients

• Journal of Digital Convergence
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• v.14 no.11
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• pp.357-367
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• 2016

In this study, we examined the impact on balance ability and jump performance of soccer players with functional ankle instability using virtual reality based neuromuscular posture control fusion training. Soccer players were divided into 15 people of virtual reality-based neuromuscular posture control fusion training group and 15 people of common treadmill training group and performed for 30 minutes three times a week for 8 weeks. In order to evaluate the balance of ability, using biorescue, it measured surface area, whole path length, limit of stability. In order to measure jump performance, it measured counter movement jump with arm swing and standing long jump. The results showed the statistically significant difference in the balance comparison of surface area, whole path length, limited of stability and the jump performance comparison of counter movement jump with arm swing, standing long jump. As a result, virtual reality-based neuromuscular posture control fusion training was found to be more effective to improve its balance ability and jump performance than common treadmill training.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.185-190
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• 2020

Purpose: Gait and cognitive impairment in stroke patients exacerbate fall risk and mobility difficulties during multi-task walking. Virtual reality can provide interesting and challenging training in a community setting. This study evaluated the effect of community-based virtual reality gait training (VRGT) using a 360-degree image on the gait ability of chronic stroke patients. Methods: Forty-five chronic stroke patients who were admitted to a rehabilitation hospital participated in this study. Patients meeting the selection criteria were randomly divided into a VRGT group (n=23) and a control group (n=22). Both these groups received general rehabilitation. The VRGT group was evaluated using a 360-degree image that was recorded for 50 minutes a day, 5 days per week for a total of 6 weeks after their training. The control group received general treadmill training for the same amount of time as that of the VRGT group. The improvement in the spatiotemporal parameters of gait was evaluated using a gait analyzer system before and after training. Results: The spatiotemporal gait parameters showed significant improvements in both groups compare with the baseline measurements (p<0.05), and the VRGT group showed more improvement than the control group (p<0.05). Conclusion: Community-based VRGT has been shown to improve the walking ability of chronic stroke patients and is expected to be used in rehabilitation of stroke patients in the future.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.5
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• pp.505-511
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• 2011

In this paper, we have developed an automatic velocity control system of a small-sized commercial treadmill (belt length of 1.2 m and width of 0.5 m) which is widely used at home and health centers. The control objective is to automatically adjust the treadmill velocity so that the subject's position is maintained within the track when the subject walks at a variable velocity. The subject's position with respect to a reference point is measured by a low-cost sonar sensor located on the back of the subject. Based on an encoder sensor measurement at the treadmill motor, a state feedback control algorithm with Kalman filter was implemented to determine the velocity of the treadmill. In order to reduce the unnatural inertia force felt by the subject, a predefined acceleration limit was applied, which generated smooth velocity trajectories. The experimental results demonstrate the effectiveness of the proposed method in providing successful velocity changes in response to variable velocity walking without causing significant inertia force to the subject. In the pilot study with three subjects, users could change their walking velocity easily and naturally with small deviations during slow, medium, and fast walking. The proposed automatic velocity control algorithm can potentially be applied to any locomotion interface in an economical way without having to use sophisticated and expensive sensors and larger treadmills.