• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.131-140
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• 2015

Purpose : The purpose of this study was to analyze the coordination of the trunk tilting angle and bilateral lower limbs according to the stirrups length during trot in equestrian. Methods : Participants selected as subject were consisted of adult male(n=7, mean age: $45.00{\pm}3.78yrs$, mean height: $172.50{\pm}2.44cm$, mean body mass: $76.95{\pm}4.40kg$, mean, mean leg length: $97.30{\pm}2.60cm$). They were divided into 3-types of stirrups lengths(67 cm, 72 cm, 77 cm) during trot. The variables analyzed were consisted of the trunk front-rear angle, lower limb joint(Right Left hip, knee, ankle), overall movement index(OMI) of the lower limbs(thigh, shank, foot) and asymmetry index(AI%) during trot. Results : The average angle in hip and knee joint showed more extended posture according to the increase of stirrups lengths and ankle angle showed more plantarflexion posture according to increase of stirrups length during 1 stride in trot. Also, average angle showed more extended posture in right hip and ankle joint than that of left. The angle of knee joint didn't show significant difference statistically between right and left. Also asymmetric index in average angle of hip, knee and ankle joint didn't show significant difference statistically in between lower limbs, but hip joint showed higher asymmetric index in stirrup length of 77 cm and ankle joint showed higher asymmetric index in stirrup length of 67 cm than that of the others respectively. The FR angle in trunk of horse-rider showed relative backward leaning motions at stirrup length of 67 cm and 77 cm than that of stirrup length of 72 cm during stance and swing phase. OMI in thigh, shank, and foot limbs didn't show significant difference statistically according to the stirrups length of right and left lower limbs, but left lower limbs showed higher index than that of right lower limb. Stirrup length of 72 cm in shank and foot limbs showed higher index than that of stirrup length of 67 cm and 77 cm. But stirrup length of 72 cm showed higher asymmetric index than that of stirrups length of 67 cm and 77 cm. Conclusions : When considering the above, 72 cm(ratio of lower limb 74.04%) stirrup lengths could be useful in posture correction and stabilization than 67cm(ratio of lower limb 68.69%) and 77 cm(ratio of lower limb 79.18%) stirrup lengths during trot in horse back riding.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1504-1508
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• 2003

The functional behavior of each body segments were investigated with respect to human standing posture when they were exposed to the horizontal vibration in the sagittal plane. This study is processed by experimental approach. The data is analyzed, both in the time domain and in the frequency domain. Random and multisinusoidal vibration was used as input. The ankle, hip, and head were employed as the significant body segments. High relative movements were present between hip and head, and there was no significant relationship between ankle and head. Variations of visual input produced a significant postural effect.

• Journal of Korean Academy of Medicine & Therapy Science
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• v.10 no.2
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• pp.5-11
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• 2018

Objective: The purpose of the present study is to investigate whether intensive ankle training using biofeedback to increase proprioceptive senses and ankle-joint muscle strength effectively improves the balance of normal adults. Method: This study included 20 voluntary participants with normal adults. The subjects were randomly divided into 2 groups: the biofeedback intensive ankle training group (n=10) and the ankle training group (n=10). The biofeedback group used a visual biofeedback program. Subjects of the group that underwent ankle training only tried to keep their bodies balanced as well as possible on an Aero-Step. Both groups performed the exercise equally for three 30-minute sessions weekly for six weeks. The differences between the measurements before and after the experiment were analyzed using Wilcoxon signed-rank tests. Mann-Whitney U tests were used to analyze the differences in variations between the groups. Results: The biofeedback group showed significant differences in the weight distributions A, B, C, D, LEFT, and HEEL and on the weight-distribution index. In contrast, the ankle training group showed significant differences in the weight distributions A, C, and LEFT. A comparison of the differences between the two groups found significant differences between them in the weight distributions A, B, C, D, LEFT, and HEEL. Conclusion: The biofeedback group showed a greater ability to control weight distribution. A longer experimental period involving more subjects would aid in developing exercise programs that are more diverse.

• IE interfaces
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• v.18 no.3
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• pp.288-296
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• 2005

Many jobs and activities in our daily lives require squatting postures. The fore part includes housekeepers, farmers, and welders and the latter includes a wide variety of activities such as housekeeping; planting, cultivating and harvesting various agricultural products; grinding, welding, etc. It is speculated that prolonged squatting postures without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is conducted to examine the proper height of stools according to the position of the working materials and to develop wearable stools for workers with squatting posture. Forty male and female subjects participated in the experiment to find the proper height of stools according to the position of the working materials. Subjects were asked to squat and work with 3 different working positions: floor level; ankle level; shank level of 3 different stool height conditions: 10cm height; 15cm height; and 20cm height. After 5 minutes of maintaining a squatting work posture while sitting on the different height stools, Likert summated rating method as well as pairwise ranking test was applied to evaluate the user preferences for provided stools under the conditions of different working positions. The results of statistical analysis show that the subjects preferred 10cm height stool for floor level, 15cm height stool for ankle level, 20cm height stool for knee level. We thus strongly recommend to use appropriate height stools in accordance with the different working positions. Moreover, a prototype wearable stool was designed such that workers with squatting posture do not need to move the stool while they are moving about. The purpose of developing wearable stool was to decrease the physical stress and hence promote worker's health who work with squatting posture.

• 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.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.433-442
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• 2012

PURPOSE: This study investigated to correlation between foot and knee posture characteristics in knee osteoarthritis patients. METHODS: The subjects of this study were 103 patients with clinically and radiographically-confirmed knee osteoarthritis was investigated using the quadriceps angle (QA), distance of both knee (DBK), ankle dorsiflexion angle (ADA), navicular drop (ND). One-way ANOVA and Pearson's correlation were used to investigate the correlation between foot and knee posture measurements. All of whom agreed to participate in the study. In order to assure the statistical significance of the results, we used for SPSS ver. 18.0 for windows. RESULTS: The results of this study were as follows : 1) There were statistically significant difference in the correlation between QA and DBK. 2) There were statistically significant difference in the correlation between DBK and ADA. CONCLUSION: According the results of this study, patients with osteoarthritis exhibit more genu varus knee posture. Moreover patients with osteoarthritis were not correlation between foot and knee Posture characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.77.2-77
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• 2002

Human upright standing posture in the sagittal plane is studied, when it exposed in the antero-posterior vibration. A two link inverted pendulum model is considered and described its functional behavior in terms of ankle and hip joint according to the dominant joints that provides the largest contribution to the corresponding human reactionary motion. The data is analyzed, both in the time domain and the frequency domain. Subjects behave as a non-rigid pendulum with a mass and a spring throughout the whole period of the platform motion. When vision was allowed, each segment of body shows more stabilized.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.3
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• pp.69-77
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• 2022

Background: Ankle sprains, and the resulting ankle instability worsen to chronic due to recurrent ankle injuries or sprains, 78% of which are accompanied by posture instability and damage due to changes in the position of the talus of the ankle. The purpose of this study is to investigate the immediate effect of applying MWM taping on the patient's muscle strength and balance ability in patients with chronic ankle instability. Methods: 15 people with MWM taping and 15 people with Kinesio taping were applied, and after applying the taping of the ankle, 10 minutes of walking treadmill and 10 times of forward lunge operation, the change in ankle muscle strength and balance ability was confirmed. The strength test of the ankle was performed using a test device called Biodex system 4 (USA) for the movement of the dorsi-flexion and plantar flexion of the foot, and the balance of the two groups was measured using Biodex balance system (USA) to test balance ability. Results: The comparison of muscle strength changes in the ankle does not show a significant increase in the group applying MWM compared to the group applying kinesio taping (p<.05). In the comparison of equilibrium capabilities, the MWM taping group also showed a significant increase in the MWM taping group compared to the kinesio taping group (p<.05). Conclusion: When applying MWM taping and kinesio taping to patients with chronic ankle instability, there was no significant difference in comparison of muscle strength changes, but there was a significant difference in comparison of balance ability.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.241-250
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• 2023

This paper describes the posture stabilization control of a bipedal transformer robot being developed for military use. An inverted pendulum model with a rectangular that considers the robot's inertia is proposed, and a posture stabilization moment that can maintain the body tilt angle is derived by applying disturbance observer and state feedback control. In addition, vertical force and posture stabilization moments that can maintain the body height and balance are derived through QP optimization to obtain the necessary torques and vertical force for each foot. The roll and pitch angles of the IMU sensor attached to the robot's feet are reflected in the ankle joint to enable flexible adaptation to changes in ground inclination. Finally, the effectiveness of the proposed algorithm in posture stabilization is verified by comparing and analyzing the difference in body tilt angle due to disturbances and ground inclination changes with and without algorithm application, using Gazebo dynamic simulation and a down-scale test platform.

• The Journal of Korean Physical Therapy
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• v.32 no.4
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• pp.233-237
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• 2020

Purpose: This study compared the electromyographic activity of the tibialis anterior (TA) and isometric dorsiflexor strength during dorsiflexion according to the toe postures in individuals with ankle dorsiflexor weakness. Methods: Twenty subjects with ankle dorsiflexor weakness participated in this study. The electromyographic activity of the TA and isometric dorsiflexor strength during dorsiflexion between with toe flexion, extension, and neutral postures were measured using an electromyography device and a hand-held dynamometer in individuals with ankle dorsiflexor weakness. One-way repeated measured analysis of variance, and a Bonferroni post hoc test was used. The level of statistical significance was set to α=0.01. Results: The electromyographic activity of the TA was greater with toe flexion during dorsiflexion than with toe extension and neutral postures (p<0.01). The isometric dorsiflexor strength was smaller with toe flexion during dorsiflexion than with toe extension and neutral postures (p<0.01). Conclusions: In individuals with ankle dorsiflexor weakness, the dorsiflexion with toe flexion can help improve the TA electromyographic activity. The toe posture during dorsiflexion for selective TA activation should be considered, especially in individuals with ankle dorsiflexor weakness.