• The Journal of Korean Physical Therapy
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• 제26권2호
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• pp.74-81
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• 2014

Purpose: The purpose of this study is to compare kinematics and kinetics on the knee joint between stair gait with unstable shoes and barefoot in healthy adult women. Methods: Seventeen healthy adult women were recruited for this study. The subjects performed stair ascent and descent with unstable shoes and barefoot. The experiment was repeated three times for each stair gait with unstable shoes and barefoot. Measurement and analysis of the movements of the knee joint were performed using a three-dimensional analysis system. Results: Statistically significant differences in the knee muscle force of semimembranosus, biceps femoris-long head, biceps femoris-short head and sartorius, patellar ligament, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Statistically significant differences in the knee muscle force of sartorius, rectus femoris, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair descent. Statistically significant differences in the knee flexor moment of semitendinosus, biceps femoris-long head, biceps femoris-short head, sartorius, rectus femoris, vastus intermedialis, medial gastrocnemius, and lateral gastrocnemius were observed between unstable shoes and barefoot gait during stair ascent. Conclusion: Therefore, wearing unstable shoes during stair gait in daily life is considered to influence knee joint kinematics and kinetics due to the unstable shoes, and thus suggest the possibility that reducing the risks of pain, and knee osteoarthritis, stabilizing the knee joint caused by changes in the loading of the knee joint.

• 한국응용과학기술학회지
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• 제37권2호
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• pp.296-302
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• 2020

The purpose of this study was to assess knee joint loading in the target knee during a golf swing compared to loading rates of high impact activities such as cutting and drop landings. Nine healthy competitive golfers completed golf swings with the target foot both straight and externally rotated 30 degrees, as well as drop landings and cutting maneuvers. Motion capture data was collected at 240 Hz and ground reaction force data was collected at 2400 Hz. The frontal and transverse knee moments were examined using repeated measures ANOVA through SPSS. The abduction moments were higher in golf swings as compared to the other high impact activities (p=.010), while the external rotation moments were lower (p=.003). There were no significant differences between externally rotated and neutral golf swings. These results suggest moments applied to the knee during a golf swing are similar to those applied during a high impact activity.

• The Journal of Korean Physical Therapy
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• 제11권1호
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• pp.167-177
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• 1999

Biomechanics is an important scientific foundation of physical therapy and is used to relate kinematics, kinetics, statics and dynamics for comprehencing human movement. The knee is well studied for demonstrating biomechanical analyses of joint because of its simplicity. The purposes of this study were 1)to provide categories and concepts of biomechanics, 2) to apply these concepts to knee movement involving daily living and gait, and 3) to review current and preceeding researches about biomechanics of knee. Thus, physical therapiestes in clinic may be helped understand of movement which includes considerations of description and production related force, moment and power.

• 디지털융복합연구
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• 제13권7호
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• pp.373-380
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• 2015

본 연구는 테니스 한손과 양손 백핸드 스트로크 동작에서 하지관절 움직임의 차이를 확인하여 유형별 특성을 밝히는데 그 목적이 있으며 그 결과는 다음과 같다. 볼의 속도를 결정하는 중요한 요인인 라켓헤드의 합성 속도는 양손 백핸드 스트로크 동작이 한손보다 빠른 속도를 나타냈다. 양손 백핸드 스트로크는 하체의 움직임을 최소화시키고 몸통 회전을 통한 스트로크를 하는 반면 한손 백핸드 스트로크는 몸통을 이용한 스트로크를 하기 보다는 공을 쫓아가듯이 스트로크 하는 것으로 나타났다. 슬관절의 신전모멘트는 한손 백핸드 스트로크가 큰 것으로 나타났지만, 내번모멘트와 회내모멘트 그리고 굴곡모멘트는 양손 스트로크에서 크게 나타났다. 고관절의 경우 신전, 내번, 회내 모멘트가 양손 백핸드 스트로크가 한손 보다 모두 큰 것으로 나타났는데 특히 내번모멘트의 경우 큰 차이를 나타난 반면, 외번모멘트는 한손 백핸드 스트로크가 큰 것으로 나타났다.

• 대한기계학회논문집B
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• 제41권3호
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• pp.153-160
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• 2017

보행 분석은 다양한 지형에서 수행되고 있으나 지형이 변화되는 시점에서의 보행 분석 연구는 보고된 바 없다. 본 연구의 목적은 삼각경사 보행 시 지형이 변화되는 시점에서 발목 및 무릎 관절의 운동학과 운동역학을 평지 보행과 비교 분석하는 것이다. 3차원 동작분석 시스템과 지면 반력기를 사용하여 성인 남성 18명의 하지 운동학 및 운동역학 자료를 획득하였다. 삼각경사 보행에서 최대 발목 배측굴곡각 및 모멘트와 최대 무릎 신전 모멘트가 평지보행과 비교하였을 때 증가하였다(p<0.05). 삼각경사의 상승경사 보행 시 $50^{\circ}$가 넘는 무릎 굽힘각과 그 시기에 발생하는 큰 무릎 신전 모멘트는 슬개대퇴증후군의 위험을 높일 수 있을 것으로 보인다. 또한 삼각경사의 하강경사 보행에서 증가된 발목 배측굴곡 운동범위는 비복근과 아킬레스건 부상 위험을 높일 수 있을 것으로 보인다.

• 한국운동역학회지
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• 제16권4호
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• pp.73-81
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• 2006

The purpose of this study was to investigate the effects of strength training on knee joint torque during walking in an adolescent with trisomy-21 Down syndrome. One adolescent with Down syndrome and one normal child participated in this study. Strength training consisted of eight exercises: squat, hamstring curl, hip adduction, hip abduction, knee extension, toe raise, sit-ups, and hyperextension of the waist. The participant with Down syndrome was participated in strength training for 12 weeks, three times a week, three sets, 10-15 RM; resistance was adjusted according to the principle of progressive overload. To measure the effect of strength training, isokinetic strength variables and knee joint torques were measured before training and after 12 weeks of training. The participant with Down syndrome had some abnormalities in controlling knee motion during walking due to muscle hypotonia, ligament laxity, and weakness of muscles. Post-training isokinetic strength increased compared to pre-training measurements. Knee range of motion were increased after strength training. Strength training did not affect ad/adduction and in/exteranl moments but did have an effect on flexor/extensor moment and timing.

• 한국운동역학회지
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• 제20권2호
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• pp.175-182
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• 2010

The purpose of this study was to evaluate the biomechanical effect of sports taping on the lower limb during drop landing. Twelve male university students who have no musculoskeletal disorder were recruited as the subjects. Principal strain, median frequency, vertical GRF, loading rate, angular velocity and resultant joint moment were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between taped and untaped conditions(p<.05). The results showed that principal strain of the thigh and the shank in taping group were significantly less than those found in control group. These indicated that sports taping may prevent excessive mechanical strain caused by impact force during the deceleration phase. Flexion(-)-extension(+) and varus(-)-valgus(+) resultant joint moment of the knee joint in taping group were greater than corresponding value for control group. It seems that extensor muscle of the knee joint were not only supported by sports taping during knee flexion but also sports taping is effective for minimizing the possibility of injury.

• 한국운동역학회지
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• 제28권3호
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• pp.175-180
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• 2018

Objective: Anterior cruciate ligament reconstruction (ACLR) has been considered the primary treatment for anterior cruciate ligament (ACL) injured patient. However, there is little biomechanical evidence regarding bilateral knee joint biomechanics during landing and cutting task after ACLR. Method: Eighteen females with ACLR participated in this investigation. Double leg jump landing (DLJL) and single leg jump cut (SLJC) biomechanics were assessed. Results: During DLJL, the healthy knee showed greater knee valgus angle at initial contact ($^{\circ}$) compared to the injured knee (Injured: $2.93{\pm}2.59$, Healthy: $4.20{\pm}2.46$, t=2.957, p=0.009). There was a significant difference in anterior tibial shear force ($N{\times}N^{-1}$) with greater in the injured knee (Injured: $1.41{\pm}0.39$, Healthy: $1.30{\pm}0.35$, t=2.201, p=0.042). During SLJC, injured knee showed greater knee extension moment ($N^*m{\times}[N^*m]^{-1}$) compared to healthy knee (Injured: $0.51{\pm}0.19$, Healthy: $0.47{\pm}0.17$, t=2.761, p=0.013). However, there was no significant differences between the knees in the other variables. Conclusion: ACLRfemales exhibited a greater knee valgus angle at initial contact and lesser anterior tibial shear force on the healthy knee during double leg jump landing. In addition, ACLR females showed a greater knee extension moment on the injured knee during single leg jump cut.

• 한국응용과학기술학회지
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• 제37권3호
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• pp.509-515
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• 2020

본 연구의 목적은 딥 스쿼트 동작 시 발목 관절 유연성이 무릎 관절의 운동역학적 요인들간의 관련성을 분석하는데 있었다. 본 연구는 최근 1년간 하지 근골격계 병력이 없는 성인 남성 19명과 여성 8명이 연구대상자로 참여하였다. 딥 스쿼드 시 발목 관절 유연성과 하지 관절의 운동역학적 요인들과 상관관계를 검증하기 위해 pearson의 적률상관계수(pearson's correlation coefficient)를 이용하였고(SPSS 24.0, Armonk, NY, USA), 통계적으로 유의미한 상관성을 나타낸 변인들은 단순회기분석(simple regression analysis)을 실시하였으며, 유의 수준은 .05로 설정하였다. 본 연구를 통해 발목 관절 유연성과 무릎 관절의 압력을 결정하는 최대 관절모멘트와 관절반발력 요인들 간의 관련성을 확인할 수 있었다. 그러므로 근력 트레이닝 시 딥 스쿼트와 같은 무릎 관절에 많은 부하를 발생시킬 수 있는 운동을 적용할 때 개인에 신체적 특성 중 발목 관절의 유연성의 정도를 확인하는 것은 신체의 안정성과 무릎 관절의 상해 위험성을 감소시킬 수 있는 운동 강도를 설정하는데 도움이 될 수 있을 것으로 기대한다.

• 대한인간공학회지
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• 제35권5호
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• pp.307-317
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• 2016

Objective: This study looks into biomechanical variables occurring when one moves in a sitting posture, and presents objective references to make improvements in work environments of farm workers. Background: The farmers have more common musculoskeletal disorders compared to other professions, because they are much more exposed to biomechanical risk factors. The sitting posture that is the representative form of the squatted, can cause typical knee joint diseases, such as osteoarthritis or patellofemoral pain syndrome of the knee joint. Therefore, a quantitative study of knee load upon the movement in a squatting posture is required. Method: In order to proceed with its investigation, the study examined movements in a sitting posture with and without a lower body supporter through a threedimensional image analysis and by using Surface EMG. The study compared and analyzed the average muscle activity and the maximum muscle activity as well. Results: Every movement in a sitting posture is related to loads onto the knee joints and, when the farm workers move to sides, the study observed a high level of bowlegged moment. The study also noticed differences in muscle activity of medial gastrocnemius with and without the lower body supporter. Conclusion and Application: The study argues that what has been discussed so far is evidence to prove how the farm working environments should be improved in consideration of these movements observed when the farm workers move in a sitting posture.