• Physical Therapy Korea
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• v.22 no.4
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• pp.17-26
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• 2015

The purpose of this study was to investigate the effects of visual electromyography (EMG) biofeedback on the EMG activity of the lower trapezius (LT), serratus anterior (SA), and upper trapezius (UT) muscles, the LT/UT and SA/UT EMG activity ratios, and the scapular upward rotation angle during scapular posterior tilting exercise (SPTE). Twenty-four subjects with round-shoulder posture participated in this study. The EMG activities of the LT, SA, and UT were collected during SPTE both without and with visual EMG biofeedback. The scapular upward rotation angle was measured at the baseline, after SPTE without visual EMG biofeedback, and after SPTE with visual EMG biofeedback. The LT, SA, and UT EMG activities, and the LT/UT and SA/UT EMG activity ratios were analyzed by paired t-test. The scapular upward rotation angle was statistically analyzed using one-way repeated analysis of variance. If a significant difference was found, a Bonferroni correction was performed (p=.05/3=.017). The EMG activities of LT and SA significantly increased, and the EMG activity of UT significantly decreased during SPTE with visual EMG biofeedback compared to SPTE without visual EMG biofeedback (p<.05). In addition, the LT/UT and SA/UT EMG activity ratios significantly increased during SPTE with visual EMG biofeedback compared to SPTE without visual EMG biofeedback (p<.05). Significant increases were found in the scapular upward rotation angle after SPTE without and with visual EMG biofeedback compared to baseline (p<.017), and no significant differences were observed in the scapular upward rotation angle between SPTE without and with visual EMG biofeedback. In conclusion, SPTE using visual EMG biofeedback may be an effective method for increasing LT and SA activities while reducing UT activity.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.425-432
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• 2014

PURPOSE: The purpose of this study was to investigate that the differences in sternocleidomastoid muscle activity, neck rotation angle, neck lateral bending angle and neck lateral bending onset time between conditions with and without visual biofeedback during neck rotation. METHODS: Ten male and four female adults with condition of forward head posture were recruited in this study. Subjects conducted to left and right maximal neck rotation under the conditions with and without visual biofeedback. During neck rotation, kinematic data of neck rotation, neck lateral bending movement, and electromyography activities of bilateral sternocleidomastold muscles were collected. Differences in dependent variables between conditions with and without visual biofeedback were analyzed using paired t-test. RESULTS: There were significant decreases in lateral bending angle, while lateral bending movement onset time was delayed significantly when applying visual biofeedback (p<.05). However, there were no significant differences in the activation of left and right sternocleidomastoid muscles and neck rotation angle between conditions with and without visual biofeedback (p>.05). CONCLUSION: These findings suggest that visual biofeedback may be effective for axial rotation of cervical spine during neck rotation in adults with forward head posture.

• The Journal of Korean Physical Therapy
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• v.33 no.3
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• pp.162-167
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• 2021

Purpose: A hyperextended knee is described as knee pain associated with an impaired knee extensor mechanism. Additionally, a hyperextended knee may involve reduced position sense of the knee joint that decreases the individual's ability to control end-range knee extension movement. The purpose of this study was to investigate the effects of visual biofeedback information for plantar pressure distribution on knee joint angle and lower extremity muscle activities in participants with hyperextended knees. Methods: Twenty-three participants with hyperextended knees were recruited for the study. Surface electromyography signals were recorded for the biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior muscle activities. The plantar pressure distribution was displayed and measured using a pressure distribution measuring plate. Knee joint angle kinematic parameters were recorded using a motion analysis system. The visual biofeedback condition was the point at which the difference between the forefoot and backfoot plantar foot pressure on the monitor was minimized. The Wilcoxon signed-rank test was used to determine the significance between the visual biofeedback condition and the preferred condition. Results: The knee joint angle was significantly decreased in the visual biofeedback condition compared to that in the preferred condition (p<0.05). The rectus femoris and gastrocnemius muscle activities were significantly different between the visual biofeedback and preferred conditions (p<0.05). Conclusion: The results of this study showed that visual biofeedback of information about plantar pressure distribution is effective for correcting hyperextended knees.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.47-52
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• 2021

Purpose: Biofeedback using various ways has helped correct the sitting posture. This study compared the multifidus muscle activity, pelvic and 2nd sacrum tilting angle during typing in nonspecific lower back pain (NCLBP) subjects with and without visual biofeedback. Methods: Thirty subjects with NCLBP were enrolled in this study. An electromyography device was used to measure the multifidus muscle activity. An electromagnetic tracking motion device was used to measure the pelvic and 2nd sacrum tilting angle. The multifidus muscle activity, pelvic, and 2nd sacrum tilting angle were measured before and after typing for 30 minutes in the sitting position. An independent t-test was used to compare the changing values for 30 minutes between the group with and without visual biofeedback. Results: The changing values of the multifidus muscle activity, pelvic, and 2nd sacrum tilting angle were significantly smaller in the group with visual biofeedback than the group without visual biofeedback (p<0.05). Conclusions: In subjects with NCLBP, the visual biofeedback can be recommended to maintain the multifidus muscle activity, pelvic, and 2nd sacrum tilting angle during typing for 30 minutes.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.3
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• pp.1818-1822
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• 2019

Background: Ipsilateral pelvic elevation has been reported as a common compensatory movement during side-lying hip abduction. It has been reported that pelvic elevation inhibits sufficient contraction of gluteus medius. However, few studies have identified the effects of controlled pelvic elevation on the trunk and hip muscles. Objective: To examine the effects of controlled pelvic elevation using visual biofeedback on the muscle activity of the trunk and hip muscles. Design: Crossover study. Methods: Twelve healthy males performed side-lying hip abduction exercises with and without visual biofeedback for pelvic elevation. Electromyography (EMG) activities of the gluteus medius, quadratus lumborum, and multifidus were analyzed using a wireless EMG system while the ipsilateral pelvic elevation angle was measured using a motion sensor during side-lying hip abduction exercises. Results: EMG activities of the gluteus medius (p = .002), quadratus lumborum (p = .022), and multifidus (p = .020) were significantly increased and ipsilateral pelvic elevation was significantly decreased (p = .001) during side-lying hip abduction with visual biofeedback compared to without visual biofeedback. Conclusions: The results of this study suggest that the application of biofeedback for pelvic motion could improve the trunk and hip muscle activation pattern and decrease compensatory pelvic motion during side-lying hip abduction exercise.

• PNF and Movement
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• v.15 no.2
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• pp.201-208
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• 2017

Purpose: The purpose of this study is to determine the effects of visual biofeedback training on the recovery of balance function in stroke patients. Methods: A total of 30 patients with stroke were chosen as the subjects of this study. The subjects were randomly divided into either the visual biofeedback balance training group (experimental group; n=15) or the general balance training group (control group; n=15). The visual biofeedback balance training and general balance training were implemented for 30 minutes a day, three times a week, for a total of four weeks. The subjects' balance ability was measured before and after the interventions. Results: The shift length and surface area of the center of the body decreased in both the experimental group and the control group, with the difference being statistically significant. The shift length and surface area of the center of the body both decreased more in the experimental group than in the control group, and there was a statistically significant between-group difference. Conclusion: The experimental group showed a greater improvement in terms of the balance ability of patients with stroke than the control group. Therefore, we believe that visual biofeedback balance training can be effectively applied for the improvement of balance ability in patients with stroke.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.55-60
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• 2021

This study aims to investigate the effects of 4 weeks visual biofeedback training on the knee joint angle and muscle activities of lower extremity. The participants in this study were 15 volunteers with hyperextended knee. To improve the hyperextended knee, visual biofeedback training was used during 4 weeks. The training is an exercise to maintain the balance between the anterior weight bearing and posterior weight bearing of the plantar foot. The knee joint angle significantly increased and the muscle activity of tibialis anterior was significantly decreased after visual biofeedback training. It was confirmed that visual biofeedback training of correcting hyperextended knee through the information on the plantar pressure distribution has a therapeutic effect.

• Physical Therapy Korea
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• v.18 no.1
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• pp.9-17
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• 2011

The purpose of this study was to assess visual biofeedback's influence on trunk muscles' (EMG) activity and endurance holding time for correct position during whole-body tilt exercise. For the study, we recruited 14 volunteers who showed no symptom of lumbar disease during medical tests. We measured the EMG activity of their rectus abdominis, external abdominal oblique, internal abdominal oblique and erector spinae muscles, and their endurance holding time for correct position during $40^{\circ}$ anterior and posterior whole-body tilt under two conditions: whole-body tilt with and without visual biofeedback. Resistance with gravitational force on the trunk during whole-body tilt was applied by using a device that had a monitor on which the subjects could check their alignment and that sounded an alarm if a subject's alignment collapsed. The study showed an increase in the EMG activity of external abdominal oblique, internal abdominal oblique/rectus abdominis ratio and endurance holding time for correct position during both $40^{\circ}$ anterior and posterior whole-body tilt with visual biofeedback compared with without visual biofeedback (p<.05). We suggest that the whole-body tilt exercise with visual biofeedback could be a beneficial strategy for selectively strengthening the internal abdominal oblique muscle and minimizing the rectus abdominis muscle's activity while maintaining correct alignment during whole-body tilt exercise.

• Physical Therapy Korea
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• v.15 no.2
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• pp.38-43
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• 2008

To reduce winging scapula, various exercise protocols have been widely used by clinicians. Selective serratus anterior strengthening, and restoring balanced function, are especially recommended to reduce winging scapula. The purpose of this study was to investigate visual biofeedback using a real time video camera display system for monitoring scapular winging during arm lowering. For this study, 13 males with winging scapular were recruited during arm lowering. Electromyography (EMG) activity was recorded from the serratus anterior (SA) and upper trapezius (UT) of the right side and compared with normal EMG activity using a paired t-test. The study showed, through visual biofeedback, that EMG activity significantly increased in the SA and significantly decreased in the UT (p<.05). These results suggest that visual biofeedback can be recommended as an effective method for scapular eccentric control, to prevent scapular winging during arm lowering.

• Physical Therapy Korea
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• v.1 no.1
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• pp.17-24
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• 1994

Biofeedback devices have been used successfully to improve head control and symmetrical walking in cerebral palsied children. Biofeedback of postural sway was investigated as a therapeutic technique to reduce postural abnormality in 24 selected children with cerebral palsy. Subjects were evaluated their weight distribution of both sides during their standing before and after the visual and auditory feedback training. The effectiveness of biofeedback was compared to conventional physical therapy practices in reestabilishing symmetrical standing in cerebral palsied children. Our study found biofeedback was effective in training symmetrical standing posture.