• 국제물리치료학회지
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• 제2권1호
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• pp.229-236
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• 2011

The purpose of this study was to comparatively analyze the active stability of shoulder joints according to the frequency of overhead motions, such as serving and spiking, engaged in by female professional volleyball athletes who play different positions, and to provide the results as the basic data for developing exercise programs to prevent shoulder joint injuries. The subjects of this study were 50 Korean female professional volleyball players and positions were as follows: left and right attackers, centers, setters, and liberos. The external rotation and internal rotation muscle strength and muscle strength ratios of the dominant and non-dominant arms of all subjects were measured using Biodex. The results of this study are as follows: Frist, no significant differences were found in the internal and external rotation muscle strength of the dominant and non-dominant arms between positions. Second, for the shoulder joint muscle strength ratio of the dominant arm, by position, the setter showed significantly greater stability compared to the other positions. Third, for the shoulder joint muscle strength ratio of the non-dominant arm, by position, no significant difference in stability between positions was found. Fourth, it was found that the dominant arm had significantly greater instability of the shoulder joint than the non-dominant arm for attackers and centers, but no significant difference was found for setters and liberos. This study comparatively analyzed the muscle strength ratios of the external/internal rotations and dominant/non-dominant arms, which can determine the stability of the shoulder joints between female professional volleyball playing positions that engage in jumps and spikes using only the dominant hand and positions that do not.

• 한국운동역학회지
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• 제17권1호
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• pp.135-144
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• 2007

The purpose of this study was to identify the effect of the subtalar sling ankle taping, by measuring changes in peak plantar pressure and subtalar angle during jump landing and walking in healthy subjects with subtalar sling ankle taping applied of the ankle joint. Fifty healthy subjects(8 males and 7 female, aged 22 to 25) were randomly divided into a participated in this study. They were free of musculoskeletal injury and neurologic deficit in lower extremity. The subjects were asked to perform 5M walking and single leg jump landing by under the guidance of physical therapists. Subtalar motions were typically measured as the angle made between the posterior aspect of the calcaneous and the posterior aspect of the lower leg during walking with taping or not. This measurement were made using a video system (30Hz sampling rate, rectified 60 Hz sampling rate). At the same time, peak lateral and vertical pressure were investigated using pressure distribution platforms(MatScan system) under foot during walking and single leg jump landing with taping or not. Statistical analysis was done by paired t-test and intraclass correlation coefficient [ICC(3.1)], using software SPSS. We have recently demonstrated significantly altered patterns of subtalr joint and peak plantar pressure when applied subtalar sling ankle taping(p<.05). Inversion angle of subtalar joint significantly decreased with taping(p<.05). The result suggest that pressure patterns observed in subjects are likely to result due to significant decrease in stress on ankle joint structures during jump landing and walking. Also, the result that the subtalar sling ankle taping procedure provides greater restiction of motion associated with ankle inversion. However, this study involved asymptomatic subjects without history of ankle inversion injury, further research is needed to assess the motion restraining effect of the subtalar sling ankle taping in subjects with lateral ankle instability.

• 대한정형도수물리치료학회지
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• 제29권3호
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• pp.85-99
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• 2023

Background: This study aimed to investigate the effects of a complex manual therapy program on hip and knee pain occurring together with menstrual pain and iliotibial band tightness in a woman with sacroiliac joint dysfunction. Methods: This study was carried out over a period of 3 months by dividing the treatment process into three sequential stages. Intensities of menstrual pain, hip pain, and knee pain, and hip range of motion (ROM) in the participant were assessed at baseline and at the end of each stage, and a modified intervention was applied according to results of assessments after each stage. Results: There was a decrease in the intensity of menstrual pain after the first and third stages of treatment, and there were reductions in the intensities of hip and knee pain after the third stage. Hip ROM was rather decreased after the second stage, but it was increased after the third stage. Conclusion: The findings of this study indicate that treatment of the instability and positional fault of sacroiliac joint can relieve hip and knee pain, improve hip ROM, and alleviate primary dysmenorrhea in patients with sacroiliac joint dysfunction.

• 대한정형외과스포츠의학회지
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• 제7권1호
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• pp.19-23
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• 2008

족관절 만성 외측 불안정증을 비해부학적인 방법으로 재건한 후에 발생하는 여러가지 문제점들을 해결하기 위하여 해부학적으로 재건하는 여러가지 방법이 보고되었다. 해부학적인 위치로 재건하는 것이 정상 관절 역학과 안정성을 회복하는데 중요하다. 해부학적인 재건 방법의 가장 큰 문제점은 인대를 정상적인 주행 방향으로 재건하는 것이 매우 어렵다는 점인데, 저자는 전거비 인대와 종비 인대가 서로 인접하여 위치하므로 두 인대의 비골측 부착부에 한 개의 터널을 만드는 것이 각각의 인대가 통과 할 별도의 터널을 만드는 것보다 좀 더 해부학적이라고 생각하였다. 이 논문에서는 외측 인대의 해부학적 재건에 필요한 기초 지식을 알아보고 반건양건을 이용한 재건 수술 방법을 소개하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1664-1670
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• 1991

For kinematically redundant manipulators, conventional dynamic control methods of local torque optimization showed the instability which resulted in physically unachievable torque requirements. In order to guarantee stability of the null space vector method which resolves redundancy at the acceleration level, Maciejewski[1] analyzed the kinetic behavior of homogeneous solution component and proposed the condition to identify regions of stability and instability for this method. 'In this paper, a modified null space vector method is first presented based on the Maciejewski's condition which is a function of a manipulator's configuration. Secondly, a new control method which is based on the concept of aspects is proposed. It was shown by computer simulations that the modified null space vector method and the proposed method have a common property that a preferred aspect is preserved during the execution of a task. It was also illustrated that both methods demonstrate a drastic reduction of torque loadings at the joints in the tracking motion of a long trajectory when compared with the null space vector method, and thus guarantee the stability of joint torque.

• 제어로봇시스템학회논문지
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• 제13권5호
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• pp.399-405
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• 2007

This paper deals with the controller for a stable walking of a humanoid robot using genetic algorithm. A humanoid robot has instability during walking because it isn't fixed on the ground, and its nonlinearities of the joints increase its instability. If controller isn't robust, the robot may fall down at the ground during walking because of its nonlinearities. To solve this problem, robust controller is required to reduce the effect of nonlinearities and to gain the good tracking performance. In this paper, motion controller that is based on fuzzy-sliding mode controller is proposed. This controller can remove the effect of the saturation by limitation of the input voltage. It also includes compensator for reducing the effect of the nonlinearity by backlash and PI controller improving the tracking performance. In here, genetic algorithm is used for searching the optimal gains of the controller. From the given controller, a humanoid robot can moved more preciously. All the processes are investigated through simulations and are verified experimentally in a real joint system for a humanoid robot.

• 국제물리치료학회지
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• 제9권1호
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• pp.1398-1405
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• 2018

The purpose of this study was to investigate the effect of heel off stairway walking exercise on the increase of muscle activity and balance activity of the ankle joint muscles in university students with functional ankle instability. The conservative treatment for the control group consisted of stairway walking (n=10) and the experimental group consisted of heel off stairway walking (n=11). The therapeutic intervention of the control and experimental groups was performed a total of 12 exercise sessions, 3 times per week for 4 weeks. To compare the two groups, the level of ankle disability was assessed by using the EMG, BT4 and Pedoscan in pre-treatment and post-treatment. Muscle activity increased in both the experimental groups and control groups in each group, however there was no significant difference between the groups. Balance ability did not show any significant difference. This study demonstrates that heel-off stairway walking is effective in significantly increasing muscle activity, however did not significantly improve balance ability.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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• pp.75-82
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• 2004

Many researcher's efforts have made a significant advancement of space frame structure with various portion, and it becomes the most outsanding one of space structures. However, with the characteristics of thin and long term of spacing, the unstable behavior of space structure is shown by initial imperfection, erection procedure or joint, especially space frame structure represents more. This kind of unstable problem could not be set up clearly and there is a huge difference between theory and experiment. Moreover, the discrete structure such as space frame has more complex solution, this it is not easy to derive the formulation of design about space structure. In this space frame structure, the character of rise-span ratio or load mode is represented by the instability of space frame structure with initial imperfection, and snap-through or bifurcation might be the main phenomenon. Therefore, in this study, space frame structure which has a lot of aesthetic effect and profitable for large space covering single layer is dealt. And because that the unstable behavior due to variation of inner force resistance in the elastic range is very important collapse mechanism, I would like to investigate unstable character as a nonlinear behavior with a geometric nonlinear. In order to study the instability. I derive tangent stiffness matrix using finite element method and with displacement incremental method perform nonlinear analysis of unit space structure, star dome and 3-ring star dome considering rise-span $ratio(\mu}$ and load $ratio(R_L)$ for analyzing unstable phenomenon.

• 대한정형도수물리치료학회지
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• 제22권2호
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• pp.57-63
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• 2016

Background: Instability due to ankle sprains will be accompanied by a problem of balance and pain change. Balance trainer is used to improve the ankle strength and balance ability. The purpose of this study was to evaluate the change of pain and postural balance ability in ankle joint after balance trainer application in patients with ankle sprain and instability. Methods: Twenty patients in K hospital in Incheon were enrolled. Balance trainer was applied to 10 subjects in the experimental group and 10 subjects in the Balance cushion under the same conditions as the experimental group to compare the pain and balance ability. Results: In the experimental group, there was a significant difference in the change of the pain variation. In the postural balance ability comparison, there was a significant difference in total and post - posterior comparison compared to the control, but there was no significant difference in the postural balance ability comparison. Conclusion: Pain and postural balance ability of patients with instability due to ankle sprain improved the pain and balance ability of the Balance trainer group compared to the Balance cushion training group.

• 대한물리치료과학회지
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• 제15권3호
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• pp.19-29
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• 2008

Background : Ankle inversion sprains are one of the most common injuries in sports and activities of daily living that mostly concern physically active individuals. In most researches, proprioceptive deficit, muscle weakness and/or absent coordination have been regarded as a contributing factors. Despite the high incidence of ankle sprain and instability, therapeutic approaches to properly manage the symptoms have rarely been investigated. This study aimed to identify the effect of proprioceptive exercise program that is easy to integrate in normal training program. Methods : Subjects were randomly allocated to control group and experimental group consisting of 11 and 10 patients, respectively. The conservative treatment for the control group consisted of hot packs, ultrasound and TENS. In addition, the experimental group performed 7 exercises to enhance proprioceptive function of ankle joint. The therapeutic intervention of the controland experimental groups was performed a total of 20 exercise sessions, averaging 50 hour each, 5 times per week for 4 weeks. To compare the two groups, the level of ankle disability was assessed by using the ankle injury score scale in pre- and post-treatment. Results : On assessment of post-treatment, there were statistically significant differences in the scores of all sub-items, except for ankle laxity and range of motion, and the total score of ankle injury score scale between the two groups(p<0.05). In comparison between pre- and post-treatments, the significant difference in the scores of all sub-items and total score didn't appear for the control group, while the scores of most sub-items and total score of the experimental group were shown the statistically significant difference(p<0.05). Conclusion : The findings suggest that the proprioceptive exercise program is more effective for relieving ankle disability than conservative treatment therefore, the program to improve proprioceptive function should be recommended for prevention and rehabilitation of recurrent ankle inversion injuries.