• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.43-53
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• 2005

This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.75-83
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• 2008

The purpose of this study was to evaluate the correlation between joint moment and joint position angle according to the different walking speeds. According to the different walking speeds(1.5m/s, 1.8m/s, 2.1m/s), experiments were terminated by 8 male subjects. In conclusion, 1. The peak extensor moment of knee joint increased by increasing walking speed, however, walking speed didn't have an effect on peak flexor and abductor moment of knee joint. 2. The position angle of knee joint increased movement of flexion, but other position angles of knee joint didn't have difference when the peak extensor moment generated. 3. The peak joint moment of hip significantly increased in extension, flexion and abduction by increased walking speed. 4. The hip position angle showed more flexible at the hip peak flexor/extensor moment generated. 5. The co-ordination pattern between peak knee joint moment and knee position angle were mathematically modeled by using a least square method. We could get the high level value of R2. We expect to apply this results for evaluating the physical faculty of knee joint.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.637-645
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• 2009

The purpose of this study was to investigate the biomechanical alterations in the punching motion of 10 elderly women after 12 weeks of taekwonaerobics training. Seven infrared cameras(Qualisys MCU-240) and 2 force platforms(Kistler-9286AA) were used to acquire raw data. The results were as follows. First, the minimum joint angles of the lower limbs had a statistically significant difference between both the dorsiflexion/plantar flexion(1eft, $p=0.001^*$) and the inversion/eversion(both, $p=0.009^*$, $p=0.04^*$) from the ankle angle. There were differences in abduction/adduction(left, $p=0.04^*$) from the knee angle, as well as internal/external rotation(both, $p=0.07^*$, $p=0.02^*$) from the hip angle. Second, the maximum resultant joint moments of the lower limbs had statistically significant differences in the inversion/eversion moment from the ankle joint(both, $p=0.05^*$, $p=0.05^*$), the abduction/adduction moment(left, $p=0.08^*$) from the knee joint, and the internal/external rotation moment(right, $p=0.09^*$) from the hip joint. Third, the maximum resultant joint powers of the lower limbs had a statistically significant difference both in flexion/extension joint powers(both, $p=0.05^*$, $p=0.01^*$) and in abduction/adduction(both, $p=0.02^*$, $p=0.00^*$) from the hip joint, as well as abduction/adduction(left, $p=0.00^*$) from the knee joint, In conclusion, the elderly women were somewhat changed after 12 weeks of taekwonaerobics training.

• Journal of Community Nutrition
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• v.1 no.2
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• pp.98-107
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• 1999

The purpose of this study was to investigate Bone Mineral Density(BMD) and affecting factors on BMD of college women in Seoul. The subjects were 47 healthy college women aged 18-25 years. Antrophometric and body fat measurements were performed by Bioelectrical Impedance Fatness Analyzer(Tanita TVF 202). Blood pressure and pulse frequency were measured. Dietary intakes and general living habits were examined through questionnaires and nutrient intakes were analyzed by Computer Aided Nutritional Analysis(CAN) program for professional. Serum total cholesterol, TG(triglyceride), HDL-cholesterol, total protein, albumin, GOT, calcium were measured by Spotchem(SP-4410). Serum osteocalcin and alkaline phosphatase(ALP) were measured to monitor bone formation. BMD of lumbar spine(L2-L4), right hip(neck, ward's triangle, trochanter) and right forearm were measured by Dual Energy X-ray Absorptiometry(DEXA). Muscle strength was measured by examining leg flexion strength(right and left), leg extension power(right and left), handgrip power(right and left) and back strength. All data were statistically analyzed by the SAS PC package program. BMD of college women was normal(by WHO, 1994). Their muscle strength was bad(by national fitness guidebook, 1995). Only a mall number of them exercised (32.6% of subjects). There was no significant difference among BMD, muscle strength and % body fat(p<0.05). There were significant differences between BMD and total cholesterol as well as TG and VLDL-cholesterol(p<0.05). Total cholesterol was associated with decreasing BMD of the right forearm(p<0.05). TG and VLDL-cholesterol are associated with increasing BMD of right hip ward's triangle(p<0.05). There were significant differences among BMD, ALP and serum total protein. ALP was associated with decreasing BMD of the right forearm(p<0.05). There were significant differences between BMD and Ca as well as between Na and K intakes (p<0.05). Intakes of Na and K were associated with decreasing BMD of the right forearm (UD)(p<0.05). There were significant differences between in BMD and pulse frequently and serum albumin (p<0.05). Serum albumin is associated with increasing BMD of L3-L4(p<0.05), right hip neck(p<0.05). %Body fat, TG, VLDL-C, Ca intake, pulse frequency and serum albumin were associated with increasing BMD(p<0.05). Intakes of Na and K, ALP, total cholesterol, total cholesterol, total protein and height are associated with decreasing BMD(p<0.05). Overall results indicate that Ca intake but to be moderate in protein and Na intakes in order to increase BMD. Body exercise was recommended to increase BMD as well.

• 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.

• The Research Journal of the Costume Culture
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• v.23 no.4
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• pp.616-627
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• 2015

The purpose of this study was to develop slacks patterns for obese-schoolgirls aged 10~12 by using a 3D virtual garment simulation system. The criteria for subjects in this study were girls who had a BMI of over $25kg/m^2$. A total of 155 schoolgirls who met these criteria were enrolled. The results were as follows: First, by using 3D virtual garment simulation, a new slacks pattern considerate of obese-schoolgirls was developed. The basic numerical formulae were as follows: Front and back hip girth of H/4-0.5+1 and H/4+0.5+1.5, front waist girth of W/4+1+0.5, back waist girth of W/4+2+0.5, front crotch extension of H/16-0.5, back crotch extension of H/8-0.5, front dart amount of 1, and back dart amount of 2. Second, according to the new slacks pattern appearance evaluation, the new slacks pattern scored more highly than the existing pattern for silhouette and ease amount, confirming that the new slacks pattern is appropriate for obese-schoolgirls. Additionally, the new slacks pattern was evaluated allowing for the proper space length of the waist, abdomen and hips. This study is expected to serve as important basic data for ensuing studies that may utilize a 3D virtual garment simulation system with 2D patterns and for future 3D pattern production program development.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.99-116
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• 2003

The purpose of this study was to kinematics factors on during round-off at end of beam-salto backward stretched with step-out to cross on balance beam. Four elite female gymnastics players participated as subject of this study. The methods of this study was analyzed using three dimentional analysis. The results and conclusion of this paper is obtained as follows ; 1. The phase of time was the most short time in board touch down phase and board take-off phase. Also, it was shown a more long time in total time compared to previous study. 2. The horizontal displacement of each phase was shown the most high levels in balance beam landing. The vertical displacement was display a non-linearity increase in board take-of phase, and it was shown the most high levels in vertical displacement during landing of balance beam. 3. The horizontal velocity of each phase was shown the most high levels in board touch down, and it was display a gradually decreased levels because flight during board take-of. The resultant velocity of CG on each phase was shown the most high levels in board touch down and board take-off. 4. The angle of hip joint was shown the most high levels as performed a motion in extension state during board take-off, and the angle of knee joint was display a increased levels because of flight cause body extension in board take-off. Also the angle of ankle joint was shown a increasing levels during board take-off. Considering to this results, it is suggest that the change of kinematics factors in board touch down and board take-off is key role on the effective board control.

• 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.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.27-36
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• 2002

The purpose of this study was to examine the effects of graded low back exercise program with patient education about low back pain care on abdominal strength, endurance and flexibility of waist of chronic low back pain patents. For this study 13 patients aged 40 to 60 were selected as subjects, who suffered from low back pain and got diagnosed by physician. The exercise program and the education were executed for total 6 weeks, posture education were executed with physical exercises over first 1 to 4 weeks period and over 5 to 6 weeks the exercises were executed. The effect of the exercises and the education were evaluated through weights, WHR, fat(%), flexibility by sit-and-reach and trunk extension test, strength by sit-up test and back sit-up test. Weights were, decreased after physical exercise and education, but there was no statistical significance. Wasit hip ratio(WHR) and fat(%) were decreased after physical exercise and education, but there were no statistical significances. Sit-and-reach was significantly increased from $13.68{\pm}5.59cm$ to $19.45{\pm}3.81cm$ after education and physical exercise(P<0.05). Trunk extension was significantly increased from $30.31{\pm}11.34cm$ to $40.88{\pm}6.16cm$ after education and physical exercise(P<0.05). Sit-up and Back sit-up were increased after physical exercise and education, but there were no statistical significances. These results suggest that graded low back exercise program with patient education about low back pain care increase the abdominal strength, endurance and the flexibility of waist in low back pain patients.

• Physical Therapy Korea
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• v.27 no.3
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• pp.171-177
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• 2020

Background: The flexion-relaxation phenomenon (FRP) refers to a sudden onset of activity in the erector spinae muscles that recedes or fades during full forward flexion of the trunk. Lumbar spine and hip flexion are associated with many daily physical activities that also impact trunk flexion. Shorter hamstring muscles result in a reduction of pelvic mobility that eventually culminates in low back pain (LBP). Many studies have explored the FRP in relation to LBP. However, few studies have investigated the influence of hamstring muscle length on the FRP in relation to the erector spinae muscles during trunk flexion. Objects: This study aimed to investigate the influence of hamstring muscle length on the FRP in relation to the erector spinae muscles during trunk flexion. Methods: Thirty subjects were divided into three groups according to hamstring length measured through an active knee extension test. The 30 participants consisted of 10 subjects who had a popliteal angle of 20° or less (Group 1), 10 subjects who had a popliteal angle of 21°-39° (Group 2), and 10 subjects who had a popliteal angle of 40° or more (Group 3). A one-way analysis of variance was used to compare the difference in muscle activity of the erector spinae muscles during trunk flexion. Results: The subjects with a shorter hamstring length had significantly higher muscle activity in their erector spinae muscles during trunk flexion and full trunk flexion (p < 0.05). The subjects with a shorter hamstring length also had a significantly higher flexion-relaxation ratio (p < 0.05). Conclusion: The results of this study demonstrate that differences in hamstring muscle length can influence the FRP in relation to the erector spinae muscles. This finding suggests that the shortening of the hamstring might be associated with LBP.