• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.55-61
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• 2018

The purpose of this study was to analyze the biomechanical differences of lower extremity joints of the frontal plane during sidestep cutting in male and female Judo athletes. In the knee and hip joint, the female group showed a smaller angle than the male group at the time of IC(initial contact). But peak knee joint adduction moment of female group was greater than male group(p<.05). Therefore, female Judo athletes were more likely to injure their knees at the point where their initial foot contacted the ground than male athletes during sidestep cutting.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.325-332
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• 2012

This study aimed to analyze the effects of external load between male and female on angular velocity, moment, and absorbed energy of the lower-extremity joints during drop landing. The study subjects were 9 male($mass=70.82{\pm}4.64kg$, $height=1.71{\pm}0.04m$, $age=24.5{\pm}1.84years$), 9 female($mass=50.14{\pm}4.09kg$, $height=1.61{\pm}0.03m$, $age=23.6{\pm}2.62years$), without any serious musculoskeletal, coordination, balance, or joint/ligament problems for 1 year before the study. The angular velocity, flexion/extension and abduction/adduction moments, and absorbed energy of the lower-extremity joints were compared between the men and women during drop landing under 4 different conditions of external load(0%, 8%, 16%, and 24%) by using two-way repeated ANOVA(p < .05). The women landed with a greater peak angular velocity of the ankle joint, greater peak inversion moment, and lower peak hip-extension moment than the men did, under all 4 conditions. Additionally, the landing characteristics of the women were distinct from those of the men; the women showed a greater peak knee-adduction moment and greater absorbed energy of the knee joint. These differences indicate that anterior cruciate ligament(ACL) strain was greater in the women than in the men and therefore, women may be at a higher potential risk for noncontact injuries of the ACL with an increase in external load.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.161-173
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• 2005

Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance. The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle according to open stance patterns during forehand stroke in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVlEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head angle were defined 1. In three dimensional maximum linear velocity of racket head the X axis showed $11.41{\pm}5.27m/s$ at impact, not the Y axis(horizontal direction) and the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. the stance distance between right foot and left foot was mean $74.2{\pm}11.2m$. 2. The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. and is followed by wrist joints, in addition the movement of elbow joints showed least to the stroke. The three dimensional anatomical angular displacement of racket increased flexion/abduction angle until the impact. after impact, The angular displacement of racket changed motion direction as extension/adduction. 3. The three dimensional anatomical angular displacement of trunk in flexion-extension showed extension all around the forehand stroke. The angular displacement of trunk in adduction-abduction showed abduction at the backswing top and adduction around impact. while there is no significant internal-external rotation 4. The three dimensional anatomical angular displacement of hip joint and knee joint increased extension angle after minimum of knee joint angle in the forehand stroke, The three dimensional anatomical angular displacement of ankle joint showed plantar flexion, internal rotation and eversion in forehand stroke. it could be suggest that the plantar pressure of open stance during forehand stroke would be distributed more largely to the fore foot. and lateral side.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.67-75
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• 2002

The purpose of this study is to know the average of hip joint range of motion and difference according to the aging for the elderly. This study consisted of elder male(n=75) and elder female(n=109). The result of assessment and analysis in hip pint range of motion are as follows : 1) The average hip flexion(knee flexed) joint range of motion in 60-69(from sixty to sixty-nine)years old are $104.26^{\circ}$(Left-Male), $101.00^{\circ}$(Right-Male), $107.05^{\circ}$(Left-Female), $107.05^{\circ}$(Right-Female). 70-79years old are $104.59^{\circ}$(L-M), $102.05^{\circ}$(R-M), $105.73^{\circ}$(L-F), $108.75^{\circ}$(R-F). 80-89years old are $101.53^{\circ}$(L-M), $101.13^{\circ}$(R-M), $96.83^{\circ}$(L-F), $97.67^{\circ}$(R-F). There was significant difference in hip flexion(knee flexed) among female group(p<.01). The average hip flexion(knee extended) joint range of motion in 60-69(from sixty to sixty-nine)years old are $73.13^{\circ}$(Left-Male), $72.04^{\circ}$(Right-Male), $77.29^{\circ}$(Left-Female), $75.97^{\circ}$(Right-Female). 70-79years old are $74.95^{\circ}$(L-M), $72.19^{\circ}$(R-M), $76.73^{\circ}$(L-F), $76.65^{\circ}$(R-F). 80-89years old are $70.83^{\circ}$(L-M), $70.37^{\circ}$(R-M), $69.00^{\circ}$(L-F), $69.00^{\circ}$(R-F). There was significant difference in left hip flexion(knee extended) among female group(p<.05). 2) The average hip extension joint range of motion in 60-69years old are $13.09^{\circ}$(L-M), $12.78^{\circ}$(R-M), $10.97^{\circ}$(L-F), $10.68^{\circ}$(R-F). 70-79years old are $8.95^{\circ}$(L-M), $8.48^{\circ}$(R-M), $11.24^{\circ}$(L-F), $10.90^{\circ}$(R-F). 80-89 years old are $8.40^{\circ}$(L-M), $8.23^{\circ}$(R-M), $7.33^{\circ}$(L-F), $7.33^{\circ}$(R-F). There was significant difference in left(p<.01) and right(p<.05) hip extension among male group(p<.05). 3) The average hip abduction joint range of motion in 60-69 years old are $33.04^{\circ}$(L-M), $33.17^{\circ}$(R-M), $33.16^{\circ}$(L-F), $33.37^{\circ}$(R-F). 70-79 years old are $31.00^{\circ}$(L-M), $30.05^{\circ}$(R-M), $32.44^{\circ}$(L-F), $32.68^{\circ}$(R-F). 80-89 years old are $29.07^{\circ}$(L-M), $27.90^{\circ}$(R-M), $28.17^{\circ}$(L-F), $28.67^{\circ}$(R-F). There was no significant difference among group. 4) The average hip adduction pint range, of motion in 60-69years old are $29.57^{\circ}$(L-M), $29.35^{\circ}$(R-M), $31.87^{\circ}$(L-F), $31.89^{\circ}$(R-F). 70-79, years old are $27.41^{\circ}$(L-M), 27.00(R-M) $30.85^{\circ}$(L-F), $31.28^{\circ}$(R-F). 80-89 years old are $26.87^{\circ}$(L-M), $26.63^{\circ}$(R-M), $24.67^{\circ}$(L-F), $24.83^{\circ}$(R-F). There was significant difference in hip abduction among female group(p<01). 5) The average hip external rotation pint range of motion in 60-69years old are $32.26^{\circ}$(L-M), $31.17^{\circ}$(R-M), $33.53^{\circ}$(L-F), $34.42^{\circ}$(R-F). 70-79 years old are $31.64^{\circ}$(L-M), $28.62^{\circ}$(R-M) $31.29^{\circ}$(L-F), $31.45^{\circ}$(R-F). 80-89 years old are $26.40^{\circ}$(L-M), $26.07^{\circ}$(R-M), $24.77^{\circ}$(L-F), $24.27^{\circ}$(R-F). There was significant difference in left(male, female p<.01) and right(female p<.0l) hip external rotation among group. 6) The average hip internal rotation joint range of motion in 60-69years old are $30.30^{\circ}$(L-M), $28.13^{\circ}$(R-M), $34.27^{\circ}$(L-F), $36.03^{\circ}$(R-F). 70-79years old are $31.24^{\circ}$(L-M), $29.57^{\circ}$(R-M), $28.51^{\circ}$(L-F), $29.10^{\circ}$(R-F). 80-89 years old are $24.63^{\circ}$(L-M), $24.40^{\circ}$(R-M), $24.27^{\circ}$(L-F), $24.27^{\circ}$(R-F). There was significant difference in left(male p<.05, female p<.01) and right(female p<.01) hip internal rotation among group.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.33-39
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• 2010

The purpose of this study was to investigate the changes in walking pattern of the elderly during inclined walkway with uneven surfaces and level walking. 10 young($26.3{\pm}1.3$ years, $174.3{\pm}5.3\;cm$, $69.5{\pm}9.5\;kg$) and 13 elderly($72.4{\pm}5.2$ years, $164.5{\pm}5.4\;cm$, $66.1{\pm}9.6\;kg$) male subjects were participated in the experiment. Experiment consisted of 2 walking conditions: horizontal and inclined walkway with uneven surfaces. 3D motion capturing system were used to acquire and analyze walking motion data with sampling frequency of 120 Hz. To compare differences between conditions, kinematic variables(walking speed, stance-swing ratio, hip joint angle, knee joint angle, ankle joint angle, pelvic rotation angle) were used. Results showed that there were some changes of elderly walking pattern in inclined walkway with uneven surfaces: hip joint(adduction and rotation) and pelvic movement pattern. These changes by inclination and surface may affect gait pattern of young subjects as well as elderly subjects. However, in case of elderly it revealed more unstable gait than the young. Further study is necessary to clarify changes in walking pattern for elderly by considering various gait variables including head movement and various walkway conditions.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.363-370
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• 2015

Objective : The purpose of this study was to give the basic data for the cutting movement with the various angels on the poly urethane. Method : Ten healthy men voluntarily participated in this study. A three-dimensional motion analysis system (VICON) and force plates were used to analyze the movements of the joints for the lower extremities. For the statistical analysis the IBM SPSS 21.0 was used to perform repeated measured ANOVA and post-hoc comparison result was used to perform the Scheffe and the level of significance was set up at ${\alpha}=.05$. Results : There were significant differences for the time required for the increasing angles of the cutting movement(p<.05). In addition, there were significant differences for the maximum dorsiflexion, plantarflexion of ankle joint, maximum flexion of knee joint and hip joint with the increasing the angles of cutting movement(p<.05). Also, there were significant differences for the maximum adduction and abduction angle of the hip joint with the increasing of the angles of cutting movement. There was signigicant difference for the resultant utilized coefficient of friction(RuCOF) for the increasing angles of cutting movement(p<.05). Conclusion : There was a pattern to increase the coefficient friction with the angle of cutting direction. Also, it would be possible to use the poly urethane for the outdoor floor with the results of this study.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.373-380
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• 2015

This study which was conducted on male tennis player on one hand(OH) & two hand(TH) backhand stroke and how both motion differed on low extremity movement with each feature analyzed in detail, the result as follow. The motion of TH based on resultant velocity, appeared to be a higher than OH, which was important variable in determining the ball speed. Contrary to TH where the player minimized the motion in the lower body and finalized a stroke through the turn of the trunk as if sticking the ball closed to the body, OH was carried out such that the player appeared to chase the ball. Whereas in OH, the knee joint extension moment was not found to be larger than TH, the opposite result came out for abduction moment and internal rotation moment. In the case of hip joint, consisted of extension, abduction and internal rotation moment, the outcome emerged to be greater for TH with conspicuous difference in abduction moment. Flection moment for TH overwhelmed in TH though both adduction and external rotation moment brought about similar outcome for both strokes.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.33-42
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• 2008

The purpose of this study was to analyze kinematic variables during Side kick motion in Taekwon Aerobics. The subjects of this study were the 7 skilled and 7 unskilled female college students. A QTM and an Auto Track were used to acquire raw data. The sampling rates camera was 100 Hz. The parameters were calculated and analyzed with Visual3D and SPSS 12.0. The results were as following; 1. In the elapsed time, there was no significance difference statically between a skilled and unskilled group. 2. In the cases of knee angle, there was significant difference statically at Maximum Knee Flexion2(p=0.046, F=4.925). 3. In the cases of knee angular velocity, there was significant difference statically at Maximum Knee Flexion1(p=0.031, F=5.940). 4. In the flexion/extension of hip angle, there was significant difference statically at Maximum Knee Flexion2(p=0.012, F=8.668). 5. In the abduction/adduction of hip angular velocity, there was significant difference statically at Minimum Knee Flexion (p=0.019, F=7.324). 6. In the external rotation/internal rotation of hip angular velocity, there was significant difference statically Minimum Knee Flexion(p=0.005, F=11.87).

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.33-42
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• 2006

It is important to analyze the characteristics of normal gait in clinical and biomechanical aspects. Although gait characteristics can be varied by anthropometric, racial and cultural factors, normal gait studies have been performed mostly for Western people. The present study conducted a gait analysis for Korean young adults and compared the gait characteristics with those of Western people for the establishment of Korean normal gait data. A total of thirty-two adults in twenties(20 males and 12 females) were participated in the gait experiment and their spatio-temporal and kinematic/kinetic gait characteristics were analyzed. The comparison of the gait characteristics between Korean and Western people, revealed that the stride length and walking speed of Korean were significantly smaller than those of Western people by 0.1~0.3m and 0.15~0.40m/s respectively. And the knee abduction moment of Korean was larger than that of Western people, while the other moments(such as hip flexion/extension moments, abduction/adduction moments, and knee flexion/extension moments) were smaller than those of Western people. The ranges of joint angles between the gait studies were largely different with each other, but most of motion patterns and excursions were similar.

• Physical Therapy Korea
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• v.18 no.2
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• pp.1-8
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• 2011

The purpose of this study was to investigate the effect of high heeled shoes with the total contact insert (TCI) on the frontal plane of the joints for the lower extremity during the gait. Ten healthy females voluntarily participated in this study and the height of the high heeled shoes was 7 cm. A three-dimensional motion analysis system (VICON) and force plates were used to analyze the movements of the joints for the lower extremities. The results were as follows: There were no significant differences for the angle value on the event of the gait cycle in the maximum eversion and inversion of the ankle joint, the varus and valgus of the knee joint, and the adduction and abduction of the hip joint (p>.05). But, there was a significant difference or the range of motion in the ankle joint (p<.05). The value of ankle and knee moment with a TCI was less than the value for no TCI. And there were significant differences for the moment value of the maximum inversion and eversion on the ankle joint and for the maximum varus and valgus on the knee joint (p<.05). Therefore, a TCI would be effective in stabilizing the joints of the lower extremities and increasing the balance of a body to reduce the injure from a fall during the gait.