• Physical Therapy Korea
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• v.17 no.4
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• pp.1-7
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• 2010

The aim of this study was to investigate the effects of lumbar stabilization on both trunk and lower limb muscle activity and center of pressure (COP) in single leg standing. Surface electromyography (EMG) was used to collect muscle activity data, the mean velocity of COP was measured using a force plate, and a pressure biofeedback unit was used for lumbar stabilization training. The findings of this study are summarized as follows: 1) The EMG activity of the erector spinae decreased significantly and the activity of the rectus abdominis, internal oblique, external oblique, gluteus maximus, and gluteus medius increased significantly with lumbar stabilization single leg standing. 2) No differences in activity in the tibialis anterior, medial gastrocnemius, rectus femoris, and medial hamstrings were found with single leg standing. 3) The mean velocity of COP in the antero-posterior and medio-lateral directions in the lumbar stabilization single leg standing decreased significantly compared with the preferred single leg standing. The findings of this study therefore indicate that lumbar stabilization can facilitate the co-activation of deep stabilization and global muscles that improve postural control capability during single leg standing.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.533-538
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• 2013

PURPOSE: This study was performed to investigate the effect of Low-dye Taping on muscle activity during single-leg standing in subjects with flexible flatfoot. METHODS: Thirteen able-body volunteers who had flexible flatfoot were recruited for this study. Subjects were measured navicular drop test to evaluate pronation of foot and muscle activity during single-leg standing before and after taping. The muscle activity was recorded using surface EMG from the tibialis anterior and the peroneus longus during single-leg standing on stable and unstable surface. RESULTS: The results show that the navicular drop height and the tibialis anterior muscle activity were significantly decreased after Low-dye taping. CONCLUSION: The results suggest that Low-dye taping could be useful in managing overuse of the tibialis anterior by reducing their level of activation during single-leg standing.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.3
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• pp.67-71
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• 2017

PURPOSE: Muscle fatigue is a cause to change proprioception. The purpose of this study was to investigate the effects of calf muscle fatigue and visual control on postural balance during single-legged standing in healthy adults. METHODS: Nineteen healthy adults (male) were participated in this study (mean age: 24.36 years; mean height: 171.32 cm; mean weight: 64.58 kg). The postural balance (sway length, sway area, sway velocity of COG displacement) was measured by Balance Trainer System (BT4) in before and after calf muscle fatigue feeling in single legged stance. In this study, repetitive single-legged heel rise test was used to induce fatigue of the calf muscle. Paired t- test was used to compare the postural balance between before and after calf muscle fatigue. Data of subjects were analyzed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA). Level of significance was set to .05. RESULTS: The sway length, sway area, sway velocity of COG (center of gravity) displacement after calf muscle fatigue feeling was significantly increased compared to before calf muscle fatigue feeling during single leg standing both eye open and close conditions (p<.05). CONCLUSION: This study suggested that calf muscle fatigue feeling has affected on postural balance when standing one leg both eye open and close conditions and postural control was disturbed by muscle fatigue and visual feedback in single leg standing.

• Journal of Korean Physical Therapy Science
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• v.27 no.1
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• pp.34-42
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• 2020

Background: The purpose of this study was to investigate the effects of ipsilateral and contralateral load changes during single-leg standing on the leg muscle activities of healthy people. Design: Randomized controlled trial. Methods: For all the subjects, a load was randomly applied to the ipsilateral or the contralateral side. While the load was applied, the subject raised a hand and then performed single-leg standing for 10 seconds using the dominant side. Results: During single-leg standing, the muscle activity of the gluteus medius, peroneus longus on the supporting side increased statistically significantly when an upper limb load was applied contralaterally, but no statistically significant differences were detected in the muscle activities of the tibialis anterior and the gastrocnemius using a test of within-subjects effects. Conclusion: It can be seen that muscle activities increase during exercise when the amount and frequency of a load are increased and when the same load is applied to different sides of the body. Such muscle activity increases may be applied to change the intensity of exercise when one is in a static posture, such as during single-leg standing.

• PNF and Movement
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• v.20 no.3
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• pp.351-358
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• 2022

Purpose: This study aims to determine the correlation between the effects of contract-relax-antagonist-contract (CRAC) and contract-relax (CR) forms of proprioceptive neuromuscular facilitation (PNF) stretching on balance during single-leg standing in elderly people. Methods: The participants were 20 elderly people in healthy condition and divided equally into two groups: the CRAC stretching group and the CR stretching group. Subjects were made to walk on a treadmill for 6 minutes before the stretching as a warm-up. CR and CRAC stretching were performed on the soleus. The dependent variables used to assess single-leg standing balance were overall stability(OSI), anterior/posterior(A/P) movement, and medial/lateral(M/L) movement. The statistical methods used to assess the differences between groups were verified using the Mann-Whitney U test and the Wilcoxon signed-rank test. Results: The CRAC group had significantly increased OSI, A/P and M/L after the PNF stretching intervention (p < 0.05). The CR group had significantly increased OSI and A/P after the PNF stretching intervention (p < 0.05), but M/L did not significantly increase (p > 0.05). There was no significant difference in stretching between CRAC and CR (p > 0.05). Conclusion: The results of this study revealed that CR and CRAC PNF stretching improved single-leg standing balance. CARC stretching before exercise is helpful for elderly people, as it improves balance.

• The Journal of Korean Physical Therapy
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• v.23 no.4
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• pp.1-6
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• 2011

Purpose: We investigated the effects of single-leg stance training on standing balance and mobility in patients with subacute hemiplegia. Methods: Seventeen matched subjects were assigned randomly to the experimental group or the control group. The experimental group comprising of 8 subjects received single-leg stance training and conventional physical therapy interventions 5 times per week for 4 weeks. The control group comprising of 9 subjects received only conventional physical therapy interventions 5 times per week for 4 weeks. Outcome measures were assessed before and after 4 weeks of intervention using the Berg Balance Scale (BBS), gait speed, and weight bearing index of the affected side. Results: Both the exercise groups showed significant improvements in BBS, gait speed, and weight bearing index (p<0.05). After 4 weeks of intervention, there were statistically significant differences in BBS and weight bearing index between the two groups (p<0.05). Conclusion: These findings suggest that conventional physical therapy interventions along with single-leg stance training could be more effective than conventional physical therapy alone for improving standing balance and mobility in patients with subacute hemiplegia.

• Physical Therapy Rehabilitation Science
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• v.7 no.4
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• pp.164-171
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• 2018

Objective: The purpose of this research was to determine the immediate effects of wearing a foot-pressure-based insole (FPBI) on ankle dorsiflexion range of motion (DFROM), postural sway, and muscle activation in healthy individuals with genu varum. Design: Cross-sectional study. Methods: This study was conducted on thirteen adults, with six male and seven females subjects. The mean age was 24.08 years. Foot pressure was measured to apply the FPBI and the weight bearing lunge test was performed with the application of a flat insole (FI) and FPBI. Examination was randomly performed in four conditions to measure both postural sway and muscle activation. All participants applied both the FI and FPBI with four conditions. The four conditions were as follows: 1) Romberg test posture with eyes closed, 2) Romberg test posture with eyes opened, 3) dominant single leg standing with eyes opened, and 4) non-dominant single leg standing with eyes opened. Results: For ankle DFROM between the FI and FPBI, a significant increase was observed in both the dominant and non-dominant leg (p<0.05). For postural sway between the FI and FPBI in the Romberg test posture with eyes closed and dominant single leg standing with eyes opened conditions, a significant decrease was observed (p<0.05). However, the postural sway between FI and FPBI in the Romberg test posture with eyes opened and non-dominant single leg standing with eyes opened, no significant decrease was observed. Also, there were no significant effects on muscle activation between the application of the FI and FPBI. Conclusions: The result showed that FPBI immediately improved ankle DFROM and postural sway. It seems that FPBI may improve genu varum in healthy individuals with genu varum.

• The Journal of Korean Physical Therapy
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• v.24 no.3
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• pp.216-222
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• 2012

Purpose: Weight-bearing exercise is a type of physical exercise that is widely performed for rehabilitation after acquiring nervous-system diseases or sports-related injuries. It is one of the most commonly prescribed rehabilitation programs for strengthing of the lower extremities. Weight-bearing exercise is important for the conduct of such activity of daily living (ADLs) as walking, and up and down the stairs. The purpose of this study was to investigate the muscle activities during one-leg standing and one-leg squatting, the two most representative weight-bearing exercises. Methods: A total of 43 elderly (60~70 years old) males who could perform weight-bearing exercises were included in the study. During the one-leg standing and one-leg squatting, the electromyographic (EMG) signals were quantified as maximum voluntary isometric contraction (%MVIC) using surface EMG, and then the muscle activities of the lower extremities during the two exercises were compared. For statistical analysis, an independent sample t-test and one-way ANOVA were performed. Results: The results of the study are as follows: (1) in the one-leg standing, the activity of the gluteus medius was the greatest among the vastus medialis, vastus lateralis, bicep femoris, (2) in the one-leg squatting, the activity of the vastus medialis was the greatest; and (3) the activity was greater in the one-leg squatting than in the single-leg standing exercise. Conclusion: The one-leg standing and squatting exercises are suitable for strengthening the muscles for the prevention of and recovery from lower-extremity injury, and for functional ADL in elderly people. In addition, dynamic exercise was shown to be more effective than static exercise for strengthening the muscles.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.101-113
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• 2016

Objective: The purpose of this study was to investigate the effect of leg length discrepancy (LLD) on the human body during gait and standing posture. Methods: The study group comprised of 17 adult participants with LLDs of <1 cm. LLDs were artificially induced to 0, 1, 2, and 3 cm. The proportion of weight distribution, shift of the mean center of pressure, and Cobb's angle were measured in the standing position. Kinematic variables such as walking and striding width and time, and the proportion of stance phase for single- and double-limb gait were measured as well. The participants were required to either stand or walk on a treadmill (Zebris FDM) with a pressure plate, and the Cobb's angle measurements were obtained from radiographs. Results: A discrepancy of 3 cm in leg length resulted in a statistically significant shift of the center of pressure in the standing position. Moreover, the Cobb angle increased as the discrepancy became larger. The step length and width of the longer (left) leg during gait statistically significantly increased when the discrepancy was 2 cm. In addition, step time was statistically significant when the discrepancy between the longer (right) and shorter (left) legs was more than 2 cm. The proportion of single-limb stance phase was statistically significant as the discrepancy became larger, especially when the discrepancy was >2 cm for the longer (right) leg and 1 cm for the shorter (right) leg. Conclusion: The study showed that LLD influenced deformations of the human body and walking.

• Physical Therapy Korea
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• v.8 no.3
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• pp.97-105
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• 2001

The purpose of this study was to investigate the effect of functional strengthening exercise on static and dynamic standing balance in a child with cerebral palsy. The subject was a 7 year old boy with diplegia whose Gross Motor Function Measure (GMFM) score was 80% along with G1 of the lower extremities in Modified Ashworth Scale. The subject was ambulatory with some degree of limitation and demonstrated muscle weakness and strength asymmetry in the lower extremities. A changing criterion design for a single-subject research was used for this study. The functional strengthening exercise consisted of lower extremity ergometer exercise and knee exercise with grading movement in standing position, each for 20 minutes, which lasted 18 sessions for 6 weeks. A knee extensor strength test on both extremities and standing balance test were conducted after each functional strengthening exercise. Two types of standing balance were tested: one leg stance test and functional reach test. One leg stance test was to evaluate static standing balance, and functional reach test was to evaluate dynamic standing balance. The results showed that the functional strengthening exercise had some positive effects on improvement of both static and dynamic standing balance, and there was a positive correlation between the knee strength and standing balance.