• 한국운동역학회지
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• 제22권1호
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• pp.83-94
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• 2012

The purpose of this study was to analyse the effect of posture correction & stabilization according to horse rider's(n=10) skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot. First, Mean posture of 3 times experiments; Anterior & posterior leaning posture of trunk showed rather unstable according to progress of the stages of TD1, TO, TD2 phase, and also shoulder & elbow angle, which effects to the distance from bit to rein, showed unstable riding posture. There was close relationship between shoulder and elbow Angle in walk and hip, knee & ankle angle in trot. Second, Posture correction & stabilization according to riding skill levels; Anterior & posterior leaning posture of trunk did not show significant difference statistically but showed approaching tendency to trunk's vertical line and showed significant difference(p<.05) according to improvement of skill levels in walk & trot horse riding. Hip angle showed significant difference according to progress of the stages of TD1, TO, TD2 phase(p<.05) and showed tendency maintaining the larger thigh flexion according to improvement of skill levels in walk & trot. Knee angle showed more stable posture by maintaining the larger flexion between thigh and shank according to improvement of skill levels in walk & trot(p<.05). Ankle angle also showed tendency maintaining the larger plantar flexion of foot according to improvement of skill levels in walk & trot. When considering the above, regular horse riding program could be useful in posture correction & stabilization according to improvement of skill levels of novice(0wk), mid-skill(12wk) & skill(24wk) in walk & trot.

• 한국운동역학회지
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• 제14권3호
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• pp.259-270
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• 2004

The purpose of this study was to analysis of pelvis and lower extremity using orientation angles during a developpe a la seconde. Data were collected by Kwon3D program. Two females professional modem dancer were participated in this experiment. Subjects performed a developpe a la seconde in meddle heights(about 90 dog.) The results were as follows. The orientation angles of pelvis were, in most cases, caused by the movement of trunk and thigh. It was restricted the movement of pelvis within narrow limits because the movement of pelvis was very important to lower extremity alignment. The orientation angle of shank against thigh showed a change of angle about $3-6^{\circ}$ in internal external rotation. The orientation angle of foot against shank showed a change of angle about $6-7^{\circ}$ in internal external rotation.

• 한국운동역학회지
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• 제25권1호
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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.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.121-129
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• 2013

To find a healthy driving posture, in this study, survey and empirical analysis given onto measurement of car-seat angle has been performed. Among 153 male respondents, those drivers who has minimum 5 year experience and 2 hours daily driving has been selected by a multiple screening process. They were further confirmed to have no discomfort history in any body region caused by the driving task. Final 44 people verified that their actual driving posture is not significantly different (p = 0.692) from healthy one they think. And their data, accordingly, the healthy driving postures are clustered based on the same seat-cushion angle, seat-back angle and trunk-thigh angle. Consequently, three seat-angles of the 44 subjects showed a significant difference only with their height information which is the most effecting factor on driving posture among the physical characteristics. That is a first result categorized healthy driving posture classified physical, if it were departmentalized into additional study, could be able to reflected a factor of "healthy" on car seat design.

• 한국운동역학회지
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• 제24권4호
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• pp.329-338
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• 2014

The purpose of this study was to analyze of the rider postural alignments according to the fitting of stirrups lengths during walk of high level riders. Participants selected as subject were consisted of horse riders of high level (age: $47.66{\pm}3.51yrs$, height: $168.40{\pm}4.84cm$, body weight: $73.36{\pm}15.58kg$, low extremity length: $94.76{\pm}3.98cm$, career: $23.33{\pm}5.77yrs$) and walk with 3 types of stirrup lengths(ratio of low extremity 68.04%, 73.25%, 78.48%). The variables analyzed were consisted of the displacement of Y axis (center of mass, head, thigh, shank and foot), FR angle, LR angle, dynamic postural stability index (DPSI), coefficient of variation (CV%), and distance (X axis) of low extremity limb between right and left. The displacement of Y axis in COM, thigh, shank, foot limbs were not statistically significant, but movements of head showed greater distance of B type and C type than that of A type during 1 stride of walk. The FR and LR angle in trunk of horse rider, dynamic postural stability index and, coefficient of variation didn't show significant difference statistically according to the fitting of stirrup lengths. Also the distance (X axis) of low extremity in thigh and shank didn't show significant difference statistically in between right and left, but right and left foot showed greater distance in C type than that of B and A types during walk in horse back riding. The hip and ankle joint angle not statistically significant according to stirrups lengths, But knee joint angle showed more extended according to the increase of stirrups lengths during stance and swing phase in walk.

• 한국운동역학회지
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• 제18권4호
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• pp.179-189
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• 2008

본 연구는 9명의 남자 중학교 초보피험자들을 대상으로 태권도 옆차기 동작의 숙련정도에 따른 운동학적 협응과정을 살펴보는 데 목적을 두었다. 이용된 변인은 최대합성직선속도, 분절간 각속도, 각도 대 각도 도면이었다. 분석결과, 연습후기로 갈수록 인접한 분절간의 운동량 전이가 잘 이루어져 각 분절의 최대합성직선속도가 유의하게 증가하였으며 분절간 각속도에서 학습후기로 갈수록 몸통에서 대퇴, 하퇴분절로의 순차적인 전이를 보였으며 던지는 듯하면서 미는 듯한 동작형태를 보였다. 엉덩관절과 무릎관절의 각도-각도 도면에서는 학습초기에는 다이나믹스한 변화를 보였으나 학습이 됨에 따라 숙련된 피험자처럼 안정적인 협응 패턴을 보여주었다.

• 한국운동역학회지
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• 제27권2호
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• pp.91-97
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• 2017

Objective: To investigate rotation movement of segment for performing each position and its effect on knee/hip angulation, COM inclination, and edging angle changes. Method: Twelve Alpine skiers (age: $25.8{\pm}4.8years$, height: $173.8{\pm}5.9cm$, weight: $71.4{\pm}7.4kg$, length of career: $9.9{\pm}4.6years$) participated in this study. Each skier was asked to perform counter-rotation, neutral, and rotation positions. Results: Shank and thigh were less rotated in the counter-rotation position than in other positions, whereas the trunk and pelvis were more counter-rotated (p<.05). Hip angulation, COM inclination, and edging angle were significantly greater in the counter-rotation position than in other positions (p<.05). Conclusion: Our finding proved that the counter-rotation position increases hip angulation, COM inclination, and edging angle. Consequently, we suggest that skiers should perform counter-rotation of the trunk and pelvis relative to the ski direction in the vertical axis for the counter-rotation position. Further analysis will continue to investigate the effects of the counter-rotation position in real ski slope with kinetic analysis.

• 한국운동역학회지
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• 제20권3호
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• pp.319-325
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• 2010

The purpose of this research was to investigate the differences in the ski carving turn motion according to level of expertise. The posture and movement of 6 skiers nearby the fall-line was evaluated with a biomechanical approach focusing the rotational mechanics. The slope was at an angle of $9^{\circ}$ and the following variables were measured and calculated: tangential velocity, change of COM height after passing fall-line, width between feet, angle between upper body and thigh, trunk angle, average radius of curvature and average centripetal force. The expert skiers minimized their center of mass height movement and maintained the width of between their feet after the passing the fall-line in comparison with the beginners and intermediate skiers. The experts restrained themselves from pushing their upper body downward after the turn to maximize the centripetal force. The experts in comparison with the beginners and intermediate skiers during the turn didn't have to reduce their radius of curvature to maintain a high centripetal force. It was concluded, that the most important factor affecting the centripetal force, was for the beginners and intermediate skiers, to minimize their movement while using the appropriate amount of edging.

• 한국운동역학회지
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• 제18권2호
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• pp.95-104
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• 2008

본 연구는 남자 중학교 초보피험자들을 대상으로 태권도 돌려차기 동작의 숙련정도에 따른 운동학적 협응과 제어과정을 살펴보는 데 목적을 두었다. 이용된 변인은 최대합성직선속도와 각도 대 각도 도면이었다. 분석결과, 연습후기로 갈수록 인접한 분절간의 운동량 전이가 잘 이루어져 각 분절의 최대합성직선속도가 증가하였으며 무릎관절 최대굴곡 시까지는 엉덩관절과 무릎관절이 동형동조 협응형태로 변해갔으며, 최대굴곡 후 타격 시까지는 모든 숙련 단계에 있어서 이형동조 협응패턴을 나타내었다. 발목관절은 무릎관절 최대굴곡 시까지 배측굴곡 상태에서 저측굴곡으로 변했으며, 최대굴곡 후 타격시점까지는 발목관절은 고정시키고, 무릎관절은 신전시키는 자유도 고정 제어기전을 나타내었다.

• 한국운동역학회지
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• 제15권4호
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• pp.25-42
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• 2005

The study was to investigate kinematic difference between flexed and extended type of knee during Jigeo-Cha-Gi in Taekwon-Do. For this subjects participated were consisted of weights of fin (1), bantam (1) and welter class(1) of male 3 national representative level skilled in two type(flexed and extended type) of Jigeo-Cha-Gi. 3D cinematography analysis was performed for motion analysis and Kwon 3D ver. 3.1) was used for 3D coordinates & analysis variables calculation. In Temporal variable there was no significant difference statistically in all phases & total elapsed time between flexed and extended type, but flexed type was delayed more 0.016 sec than extended type. In displacement of COG there was significant difference in level of p<.05 showing longer mean 6.13 cm in case of flexed type than extended type in displacement of COG during all phase and too significant difference in level of p<.01 showing longer mean 4.4 cm in case of flexed type than extended type in displacement of COG in follow through phase. In velocity of COG there was significant difference in level of p<.001 showing higher mean 15.53cm/s in case of flexed type than extended type in velocity of COG(Y direction) during targeting phase and peak velocity(Y) was more fast 8.74 cm/s in extended type than flexed type. In velocity of leading leg in forward direction(Y) there was significant difference in level of p<.05 showing higher thigh mean value in case of flexed type than extended type but showing higher foot mean value in extended type at level of p<.001 than flexed type in velocity of COG(Y direction). In velocity of leading leg in vertical direction(Z) there was no significant difference in the second & third phase in case of vertical velocity level, but momentum transferred efficiently form proximal to distal endpoint. In front-back & right-left orientation angle of trunk there was possibility of more stable Jigeo-Cha-Gi in extended than flexed type by decreasing in right-left orientation angle of trunk. In relative angle of lower leg(hip, knee, ankle) there was significant difference in level of p<.001 showing longer mean 32.74 deg. in case of flexed type than extended type in hip joint during the second phase but maintained insufficient extended knee of mean 168 deg. in targeting phase.