• Journal of Biosystems Engineering
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• 제40권3호
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• pp.289-295
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• 2015

Purpose: From the perspective of biomechanics, joint moments quantitatively show a subject's ability to perform actions. In this study, the effect of normalization in the fast and asymmetric motions of a golf swing was investigated by applying three different normalization methods to the raw joint moment. Methods: The study included 13 subjects with no previous history of musculoskeletal diseases. Golf swing analyses were performed with six infrared cameras and two force plates. The majority of the raw peak joint moments showed a significant correlation at p < 0.05. Additionally, the resulting effects after applying body weight (BW), body weight multiplied by height (BWH), and body weight multiplied by leg length (BWL) normalization methods were analyzed through correlation and regression analysis. Results: The BW, BWH, and BWL normalization methods normalized 8, 10, and 11 peak joint moments out of 18, respectively. The best method for normalizing the golf swing was found to be the BWL method, which showed significant statistical differences. Several raw peak joint moments showed no significant correlation with measured anthropometrics, which was considered to be related to the muscle coordination that occurs in the swing of skilled professional golfers. Conclusions: The results of this study show that the BWL normalization method can effectively remove differences due to physical characteristics in the golf swing analysis.

• 한국운동역학회지
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• 제19권2호
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• pp.245-255
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• 2009

본 연구는 낙상을 경험한 여성노인 20명을 각각 10명씩 연령으로 집단을 구분하고 보행 시 하지관절의 협응 능력을 분석하여 운동과학적인 기초자료를 제시하고, 불안정적인 측면의 요소에 효과적으로 대처할 수 있도록 하기 위한 것이다. 이를 위해 보행 시 하지관절의 균형에 대한 기전과 차이를 동작분석과 근전도를 이용하여 비교 분석하여 다음과 같은 결론을 얻었다. 첫째, 보행 시 고관절의 움직임에서 연령증가로 인해 충분하지 못한 지지역할로 보행자세가 저하되어 안정적 이지 못한 패턴을 보였다. 둘째, 무릎관절의 움직임에서 좌우측의 보행패턴이 상이하게 이루어지는 경향을 나타내었다. 셋째, 발목관절의 움직임에서 연령증가와 함께 활보패턴이 비정상적인 경향을 나타내었다. 또한 보행 시 하지 주요근육의 활성정도에 대해 대퇴직근과 대퇴이두근은 무릎의 굴곡을 막기 위해 근수축 활성이 증가되어 전진하는 전기적 특성을 보였고, 전경골근과 내측비복근은 이동 시 높은 전기적 수요를 나타내어 저측굴곡의 비율을 줄여 보행하는 특성을 나타내었다.

• 한국운동역학회지
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• 제17권1호
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• pp.111-119
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• 2007

The purpose of this study was to investigate muscle activity and gait pattern in lower limb depending on the outsole of heel rockers. Fifteen healthy men volunteered for this experiment. Each subject performed totally three trails with two pairs of different heel rocker shoes and a pair of normal running shoes at speed of 1.33m/s for 1 minute during walking on a treadmill. Kinematic data gathered in 100Hz was recorded and analyzed by using the 3D motion capture system to measure the trunk tilt and joint angle of the right lower limb. And the lower extremity muscle activities were simultaneously recorded in 1000Hz and assessed by using EMG. The statistical analysis was the one-way ANOVA with the repeated measures to compare among the three kinds of shoes. The level of statistical significance for all tests was 0.05. Joint angle of lower limb was showed statistically significant different in MST(hip joint), LHS(ankle joint), and RTO(knee and ankle joint). Muscle activity of rectus femoris and biceps femoris was statistically increased in both heel rocker shoes during gait cycle on treadmill. The maximum peak time of tibialis anterior in the negative heel rocker showed the delay of approximately 23.8%time than normal shoes. Gait pattern variability of the negative heel rocker was increased in the first half of the stance phase and the variability of the positive heel rocker was increased in the terminal stance phase. In Conclusion, stability was decreased in between joints of lower limb on positive heel rocker than negative heel rocker. This study found that there were different joint angle, muscle activity, gait pattern and coordinate system of the lower limb in each kind of shoes. These unstability affected the lower extremity and the whole body. A further study has to be continued with study of rehabilitation and exercise for a long-term.

• 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.

• 한국운동역학회지
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• 제30권2호
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• pp.185-195
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• 2020

Objective: The purpose of this study was to identify recent domestic and international research trends regarding shoes carried out in biomechanics field and to suggest the direction of shoe research later. Method: To achieve this goal of research, the Web of Science, Scopus, PubMed, Korea Education and Research Information Service and Korean Citation Index were searched to identify trends in 64 domestic and international research. Also, classified into the interaction of the human body, usability evaluation of functional shoes, smart shoe development research, and suggested the following are the suggestions for future research directions. Conclusion: A study for the coordination of muscle activity, control of motion and prevention of injury should be sought by developing shoes of eco-friendly materials, and scientific evidence such as physical aspects, materials, floor shapes and friction should be supported. Second, a study on elite athletes in various sports is needed based on functional shoes using new materials to improve their performance along with cooperation in muscle activities and prevention of injury. Third, various information and energy production are possible in real time through human behavioral information, and the application of Human Machine Interface (HMI) technology through shoe-sensor-human interaction should be explored.

• The Journal of Korean Physical Therapy
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• 제26권6호
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• pp.449-452
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• 2014

Purpose: The purpose of this study was to analyze the coordination between trunk flexion and lower limb extension contributing to vertical propulsion during sit-to-stand (STS) at different chair heights in the elderly. Methods: Ten elderly subjects were asked to stand up at their natural speed from different chair heights : (1) $90^{\circ}$ knee flexion; (2) $100^{\circ}$ knee flexion; (3) $110^{\circ}$ knee flexion; and (4) $120^{\circ}$ knee flexion. A standard chair without a backrest or armrests was used in this study. To remove inertial effects of upper limb movements, subjects were asked to stand up from a chair with their arms crossed at the chest. Mean of results of three trials were used in the analysis at different knee flexion angles. Distances moved by the shoulder for compensatory trunk movement was recorded by motion analysis and vertical force was recorded under foot using force plates. Distances moved by the shoulder and vertical ground reaction force measurements were analyzed using repeated ANOVA. Results: Distances moved by the shoulder significantly decreased with higher chair (p<0.05). Vertical forces were not significant difference on chair heights (p>0.05), but results of pairwise comparisons for vertical force revealed significant difference between $90^{\circ}$ knee flexion and $120^{\circ}$ knee flexion (p<0.05). Conclusion: Trunk movement is probably used as a compensatory mechanism at low chair heights to increase lift-off from sitting by the elderly.

• 재활복지공학회논문지
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• 제10권3호
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• pp.207-214
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• 2016

본 연구의 목적은 무릎 신전 제한형 보조기 착용 후 보행시 하지 내 협응에 미치는 영향을 평가하는 하는 것이다. 본 연구에는 7명의 건강한 성인 남성($32.3{\pm}2.7$ 세, $175.2{\pm}3.8cm$, $76.2{\pm}8.7kg$)이 참여하였다. 이들은 무릎보조기를 착용하거나 착용하지 않고 10m의 평지를 보행하였다. 이때 시공간적 파라미터, 하지의 각도, 하지 내 연속상대 위상(CRP)를 측정 및 계산하였다. 그 결과 시공간적 요인은 차이가 없었다 (all p > 0.05). 무릎보조기 착용 시 엉덩관절의 가동범위 및 각도 변화는 없었으나, 무릎관절의 가동범위는 감소하였으며 ($65.5{\pm}3.75^{\circ}$ vs. $60.5{\pm}3.5^{\circ}$, p < 0.05), 최대 굴곡 역시 감소하였다 (입각기: $31.9{\pm}4.6$ vs. $25.6{\pm}5.5$, 유각기: $76.7{\pm}3.1$ vs. $68.9{\pm}3.4$, all p < 0.05). 발목관절의 가동범위는 변화가 없었으나, 최대 배측굴곡 ($22.4{\pm}2.6$ vs. $19.2{\pm}2.1$, p< 0.05)은 감소하였으며, 최대 족저굴곡이 증가하였다 ($9.5{\pm}3.0$ vs. $15.7{\pm}2.2$, p<0.05). 대부분의 CRP는 차이가 없었으며, 유각기 엉덩관절과 무릎관절 사이의 CRP만 감소하였다 ($93.0{\pm}7.8$ vs, $84.7{\pm}4.9$, p < 0.05). CRP의 표준편차는 대부분 증가하였다 (유각기 엉덩관절과 무릎관절사이: $25.1{\pm}6.7$ vs. $32.4{\pm}1.9$, 입각기 무릎관절과 발목관절사이: $46.0{\pm}12.9$ vs. $80.1{\pm}31.1$, 유각기 무릎관절과 발목관절 사이: $34.5{\pm}4.1$ vs. $37.6{\pm}3.1$, all p < 0.05). 이와 같은 결과로부터 무릎 신전 제한형 보조기 착용은 관절의 각도, 하지 내 협응에는 영향을 미치지만, 보행특성에는 큰 영향을 미치는 않는다는 것을 확인하였다.

• 한국운동역학회지
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• 제24권2호
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• pp.173-180
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• 2014

The purpose of this study was to investigate the effect of combined exercise on injury risk factors of lower extremity during landing. Ten sports talented athletes participated in this study. Sports talented athletes participated in a combined exercise (sports talented exercise, coordination) for 16 weeks. A three-dimensional motion analysis was performed using eight infrared cameras (sampling rate of 100 Hz), one force plate, and electromyography system (sampling rate of 1000 Hz) during landing. Kinetic, and kinematics analysis including average impulsive force, angle of lower extremity, vertical stiffness, onset of muscle activation were calculated by Matlab2009a software. Paired t-test was performed at alpha=.05. The average impulsive force in landing phase was not statistically significant (t=-.748, p=.474). The hip joint angle was more decreased in post test compared to pre test (E1: t=2.682, p=.025, E2: t=5.609, p=.000, E3: t=2.538, p=.032). The knee joint (E1: t=-.343, p=.739, E2: t=1.319, p=.220, E3: t=.589, p=.570) and ankle joint (E1: t=.081, p=.937, E2: t=.784, p=.453, E3: t=.392, p=.704) angle were tended to decrease after combined exercise. The vertical stiffness was tended to decrease after combined exercise (t=1.972, p=.080). Onset of quadriceps femoris (t=.698, p=.503) and medial gastocnemius (t=1.858, p=.096) were tended to be faster than biceps femoris (t=-.333, p=.747) after combined exercise. Although thses findings were not statistically significant except on a hip joint angle, risk factors of lower extremity such as joint angle, vertical stiffness and onset of quadriceps femoris, medial gastrocnemius were positively changed after the combined exercise but an additional training for improved onset of biceps femoris would be required in the future.

• 한국의학물리학회지:의학물리
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• 제10권2호
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• pp.63-71
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• 1999

입체조형 치료와 전신 방사선 수술에의 이용을 목적으로 3차원 전신 정위 방사선 치료 장치를 개발하였다. Couch 위에 놓을 수 있는 전신 정위 치료판을 제작하여 방사선 비투과성 카테타 선을 이용하여 치료판 위에 좌표계를 설치하고, MeV-Green(전성 물산, 한국)으로 고정틀을 만들어 환자 자세를 고정시키고, 플라스틱 봉과 봉 지지판을 이용하여 고정틀을 고정하였다. 이러한 설계, 제작으로 입체 조형 치료 등에서 갠트리 회전에 의한 기하학적 제약을 최소화하고 방사선 조사 투과율 이 특정한 방향에서 영향을 받는 문제점을 해소하였다. CT 영상을 통해 치료 표적의 위치를 파악하고 치료판 기준점에 대하여 좌표화하여 모의 치료시와 방사선 치료시의 환자 자세 변화 오차를 줄였다. 3대의 CCTV 카메라를 사용하여 환자 자세 변화를 감지, 수정함으로써 체표변의 외곽선으로 부터 setup 오차를 최소화 할 수 있었다. 치료 효용성을 높이기 위해 이러한 과정을 모니터를 보면서 실시간으로 처리 할 수 있도록 하였고, IDL(Interactive Data Language, RSI, U.S.A.)을 사용하여 image subtraction 방식으로 환자 자세 변화를 가시화하여 오차를 줄이도록 하였다. 내부 장기 움직임에 따른 표적의 움직임을 추적할 목적으로 rotating X-ray 장치를 제작하였다. Landmark 나사를 표적주위 뼈나 표적중심에 삽입하여 이 rotating X-ray 장치를 이용해서 anterior, lateral 두 방향에서 얻은 영상 정보로부터 marker 에 대한 표적의 위치 변화를 가시화 하여 내부 표적의 움직임에 따른 setup 오차를 줄였다. CT 모의치료를 할 수 있도록 IDL 을 이용하여 PC용 모의치료 프로그램을 GUI 환경에서 구현하였고 이 프로그램을 통해서 치료 계획을 위해 CT 에서 수집된 영상정 보를 이용하여 표적을 포함한 장기들의 그래픽 처리, 편집, 전송 등의 작업을 수행하도록 하였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권3호
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• pp.322-331
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• 2003

3차원 게임은 게임 시나리오의 다양한 요소에 의한 복잡도가 증가함에 따라 게임 객체들의 상호 관계를 제어하기 위한 문제점을 가진다. 그러므로, 게임 시스템은 각 게임 객체들의 응답을 조정하는 방법의 필요성을 가진다. 또한, 게임 시나리오의 결과에 따라 게임 객체들의 행동 애니메이션을 제어하기 위한 개념들도 필요하다. 사실적 게임 시뮬레이션을 생성하기 위해 시스템은 게임 객체들의 상호작용을 디자인 할 수 있는 구조를 포함해야 한다. 본 논문에서 게임 시나리오상에 게임 객체들의 상호작용 설계를 위해 동적 제어를 디자인하는 기법을 소개한다. 이 방법을 위해 특정 규칙을 이용한 의사결정이 가능한 지능적 에이전트 기반 구조로써 게임 에이전트 시스템을 제안한다. 게임 에이전트 시스템은 환경 데이터 처리, 게임 객체 시뮬레이션, 게임 객체들간의 상호작용 제어, 게임 객체들의 다양한 상호 관계를 정의할수 있는 시각 저작 인터페이스를 제공하기 위해 이용되어진다. 이들 기술들은 게임 객체의 자율성과 연관된 충돌 회피 기법 등을 처리한다. 또한, 장면의 변경으로부터 게임 객체들의 일관된 의사 결정력을 가능하게 한다. 본 논문에서는 규칙기반 행동 제어가 게임 객체의 시뮬레이션을 안내하기 위해 디자인되어졌다. 시각적 요소들로 구성된 에이전트 상태 결정 네트워크는 정보전달과 게임 객체들 사이의 현상태를 추론할 수 있다. 이들 기법들은 실시간으로 게임 객체들간의 동작 상태 변이를 체크하고 모니터링 할 수 있다. 마지막으로 간단한 사례 연구 예와 함께 제어 기법의 타당성을 제시한다.