• The Journal of Korean Physical Therapy
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• v.27 no.4
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• pp.196-200
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• 2015

Purpose: The purpose of this study was to examine the muscle activity of the trunk muscles during balance exercises on a stable and unstable surface in patients with stroke. Methods: Thirteen subjects (8 males, 5 females) with stroke were enrolled in the study. Muscle activity was recorded using surface EMG electrodes from the affected side of the erector spinae, external oblique, and internal oblique muscles. The exercise was performed under three conditions. For the first condition for balance exercise, subjects were instructed to sit on an exercise mat with legs extended. The second condition was to sit with legs extended, with a balance pad under their buttocks. The third condition was to sit with legs extended, have a balance pad under the buttocks and a balance cushion under the lower legs. Results: This study showed significant differences in EMG activities during both arm lifting exercise and weight shifting exercise between conditions. This study showed that the EMG activities of the erector spinae, external oblique, and internal oblique muscles were significantly higher when the trunk exercise was performed using the balance pad with balance ball than when using the stable surface. Conclusion: In conclusion, performing balance exercises using an unstable surface is a useful method for facilitating trunk-muscle strength and hence trunk stability.

• Physical Therapy Korea
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• v.16 no.2
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• pp.31-39
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• 2009

This study is performed to investigate the difference of the spinal stability system with and without low back pain. There were 9 participants with low back pain and 9 asymptomatic subjects to be recruited, they were measured thoracic and lumbar curvature, trunk muscle activation in upright sitting postures and slump sitting, back muscle endurance, and lumbar proprioception. Spinal curvature and surface electromyography of 4 trunk muscles were measured in an upright sitting postures and slump sitting in 18 subjects. The result of the study was that there were significant differences between the groups in spinal curvature (p<.05), significantly higher external oblique activity and less internal oblique in the low back pain group than the healthy subjects (p<.05), and significantly less proprioception in the low back pain group (p<.05). But there was not a significant difference between the trunk muscle endurance groups. According to the result, the low back pain group had greater thoracic extension and higher global muscle activity in the upright sitting posture and less proprioception. This study was useful to suggest postural training for normal muscle activation, selective muscle strengthening to prevent chronic deterioration, and helpful in making a treatment plan to indicate a synthetic care method that includes increasing proprioception.

• PNF and Movement
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• v.15 no.1
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• pp.67-75
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• 2017

Purpose: The purpose of this study was to determine the effects of a functional movement correction exercise on the functional movement screen scores of badminton players. Methods: The participants consisted of 25 badminton players who were randomly assigned to an experimental group (n = 13) or a control group (n = 12); they engaged in exercise three times per week for eight weeks. The experimental group engaged in the functional movement correction exercise, while the control group engaged in general exercise. An FMS kit (USA) was used to measure the following: FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push up, and rotary stability. Results: The FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, and trunk stability push up, and rotary stability showed significant improvement in the experimental group (p < 0.05). Conclusion: The experiment confirmed that the functional movement screen scores of badminton players improve with effective exercise interventions.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.85.2-85
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• 2002

If a biped humanoid robot walks stably on even and uneven planes like a human being, it should have a control system capable of compensating for moments generated by motions of its lower-limbs, upper-limbs and head. In this paper, a compensatory motion control method is described for the stability of biped humanoid robots. This control method calculates the combined motion of the trunk and the waist that cancels the generated moments by using an iteration algorithm. During the biped walking, the combined motion is employed only for stability while the motion of the lower-limbs is used only for locomotion. This method is useful for not only a steady walking but also a transient walking. The e...

• Korean Journal of Applied Biomechanics
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• v.31 no.1
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• pp.24-29
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• 2021

Objective: The goal of this study is to calculate and compare the Maximum Lyapunov Exponent (MLE) for the anteroposterior, mediolateral and vertical displacement of the markers attached to bony land marks of the trunk and foot. Method: Ten young and healthy male subjects (age: 26.5±3.27 years, height: 167.44±5.12 cm, and weight 69.5±7.36) participated in the study. Three-dimensional positional coordinate of eight different trunk and foot marker during walking on tread mill were analysed. Results: MLE values for anteroposterior displacement of the marker were found to be significantly different with MLE values for mediolateral and vertical displacement whereas MLE values for mediolateral displacement of the marker shows no significant difference with the MLE values for vertical displacement of the markers at significance level 0.05. Conclusion: Finding of this study suggest that it is essential to consider the displacement in all three direction to examine the real characteristic of a gait signal.

• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.57-69
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• 2019

Background: The purpose of this study was to compare and analyze the effects of neck and trunk combined exercise program and single exercise on neck angle and neck and shoulder muscle activity. Design: Randomized controlled trial. Methods: In the single exercise group, the basic stretching, head bending and neck bending exercises were performed. The neck and trunk combined exercise group performed torso strength and trunk stability exercises to stabilize the trunk, and then performed the same neck exercise as the single exercise group. The exercise program was conducted 5 days per week for 2 weeks. One-way repeated ANOVA was used to investigate the statistical analysis of neck angle, neck and upper and middle trapezius muscle activity. Results: 1) There was no significant difference in neck angle degree after exercise in neck single exercise group. 2) In the neck and trunk combined exercise, the neck angle degree decreased continuously with the increase of the experimental period and showed a significant difference. 3) In the single exercise group, the muscles which showed significant difference compared to the post-exercise were the right upper, left and right middle trapezius. 4) In the neck and trunk combined exercise group, the right neck muscles showed significant difference after the exercise before the experiment. Conclusion: It was found that the neck and trunk combined exercise was more effective in reducing neck angle and the muscle activity of the subjects with forward head posture was decreased and increased. However, both exercises showed positive effects.

• Physical Therapy Korea
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• v.30 no.3
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• pp.245-252
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• 2023

Background: Various functional tests such as upper quarter Y-balance test (UQYBT) are used to evaluate shoulder stability and mobility in clinical or sports fields. Previous studies have been conducted to determine the correlation between the scapular or trunk muscle and UQYBT. However, the correlation between UQYBT and hip flexor, which can be considered as a core muscle, has not been confirmed. Objects: To verify the relationship between the UQYBT and scapular muscle (scapular protractor and lower trapezius [LT]), trunk muscle, and hip flexor strengths in healthy male participants. Methods: A total of 37 healthy male participants were recruited and underwent UQYBT in the push-up posture. The isometric strength of the scapular protractor, LT, trunk flexor and extensor, and hip flexors were measured using a smart KEMA strength sensor (KOREATECH Inc.). Results: The superolateral direction of the UQYBT was moderately to strongly related to trunk extensor (r = 0.443, p < 0.01), scapular protractor (r = 0.412, p < 0.05), LT (r = 0.436, p < 0.01), and both sides of the hip flexors (supporting-side: r = 0.669, p < 0.01; non-supporting-side: r = 0.641, p < 0.01). The inferolateral direction of the UQYBT was moderately related to the scapular protractor (r = 0.429, p < 0.01), LT (r = 0.511, p < 0.01), and both sides of hip flexors (supporting-side: r = 0.481, p < 0.01; non-supporting-side: r = 0.521, p < 0.01). The medial direction of the UQYBT was moderately to strongly related with the scapular protractor (r = 0.522, p < 0.01), LT (r = 0.541, p < 0.01), and both sides of hip flexors (supporting-side: r = 0.605, p < 0.01; non-supporting-side: r = 0.561, p < 0.01). Conclusion: This study showed that the strength of the scapular muscles, trunk muscles, and hip flexor muscles correlated to the UQYBT. Therefore, the strength of not only the scapular and trunk muscles but also the hip flexor muscles should be considered to improve the UQYBT.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.327-336
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• 2012

Objective: The purpose of this study is to find the problems of stability when people use the bassinet as an ambulatory aid for old people. Background: Many aged people use a bassinet as ambulatory aid. But the safety of using the bassinet as ambulatory aid has not been verified yet. Method: The 13 university-students who don't have musculoskeletal disorders volunteered to participate in this study. According to structural analysis of the both tools, we compared the structural stability of an outdoor rollator with the structural stability of a bassinet. And when the participants walked using both tools, the motions were captured and analysed. We measured the angle of shoulder joint and the angle of trunk from the ground when the participants were walking. And we found the distance from participants' pressure cone apex and greater trochanter. Results: Following the structural analysis, the bassinet has the lower structural stability than the outdoor rollator. When the people used the bassinet as ambulatory aid, the angle of the shoulder joint was bigger than to use the outdoor rollator. The angle of trunk wasn't different between the outdoor rollator and the bassinet. And distance from pressure cone apex to greater trochanter was far to use the bassinet than to use the outdoor rollator. Conclusion: Through the structure analysis and gait analysis of the bassinet and the outdoor rollator, we can be aware of that the bassinet has problem of stability. Therefore the people who use the bassinet as an ambulatory aid, especially supporting body weight, may be hurt due to the problems of stability. Application: This research can be used for developing a study of the ambulatory aid and preventing the accident when the aged people use the ambulatory aid.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.279-285
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• 2019

Purpose: This study examined the effects of spinal stabilization exercises using visual feedback on the gross motor function and balance of the sitting posture in children with cerebral palsy. Methods: The subjects were 18 children with cerebral palsy aged 8-15 years in the I-III stages of the Gross Motor Function Classification System. The subjects were divided into an experimental group (n=9) and control group (n=9). The experimental group was treated with 30 minutes of neurodevelopmental treatment and 20 minutes of spinal stabilization exercises using visual feedback. The control group was treated with 30 minutes of neurodevelopmental treatment and 20 minutes of spinal stabilization exercises without visual feedback. Both groups participated in the experiment twice a week for eight weeks. The Gross Motor Function Measurement was performed to evaluate the changes between pre- and the post-intervention in gross motor function. The Seated Limit of Stability Surface Area was measured to evaluate the changes in trunk balance. Results: Both experimental and control groups showed a significant increase in the gross motor function and trunk balance (p<0.05). The experimental group showed a significant increase in gross motor function compared to the control group (p<0.05). The experimental group showed a significant increase in the dynamic trunk balance in all directions when measuring the Seated Limit of Stability Surface Area (p<0.05). Conclusion: Spinal stabilization exercises using visual feedback for the neurodevelopmental treatment of children with cerebral palsy can improve their gross motor function and trunk balance when in a sitting posture more effectively.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.24 no.2
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• pp.29-36
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• 2018

Background: The purpose of this study was to investigate the effect of leg lift difference on serratus and upper trapezius when exercising in a scapula in a prone position, a typical waist stabilization exercise for subjects with a winged scapula. Method: Twenty normal adults and 20 subjects with winged scapula participated in the experiment. The surface EMG recordings were obtained from external oblique muscle and internal oblique muscle during scapula protraction exercise. The presence or absence of winging of the shoulder bone was measured using an electronic digital caliper for the distance the medial border of the scapula is lifted to the rear. In prostrate pier movement posture in both groups, both legs supporting, dominant leg lifting, and non-dominant leg lifting including the scapula protraction were conducted respectively. Results: In the results of comparison between the two groups, the dominant external oblique muscle and the non-dominant internal oblique muscle tended to increase according to the difference of the leg lifting of normal people. In the winged scapula group, internal oblique muscle showed increased muscle activity more than external oblique muscle. Conclusion: It was most effective to exercise with lifting the same position leg for strengthening the same external oblique muscle, and the opposite internal oblique muscle. Also, it is effective to exercise in prone pier movement posture for trunk stability. In addition, internal oblique muscle shows increased muscle activity in subjects with winged scapula. Therefore, appropriate adjustment of external oblique muscle and internal oblique muscle may have a positive effect on scapula dysfunction for trunk stability.