• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.143-157
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• 2002

This study was to analyze the kinematic variables when the subjects performing Uchi-mata(inner thigh reaping throw) by Kumi-kata types((How to grasp A or B?) and two different opponent's height in Judo. Kinematic variables were temporal, posture. Data analysis was collective comparison of two-way ANOVA, t-test by type A&B and two different opponent's height. There were significant difference of Kumi-kata types(p<.05) in the time elapsed on Kake phase(KP : throwing phase) and hip, knee, ankle-angle of the attacking foot in the 1st stage of KP and knee, ankle-angle of the attacking foot and hip, knee ankle-angle of the supporting foot in the 2nd stage of KP. There were significant difference of two opponent's(p<.05) in the time elapsed on KP and hip-angle of the supporting foot in 1st stage of KP. Therefore, the interaction effect(p<.05) were in the time elapsed on KP and hip-angle of the supporting foot in the 2nd stage of KP. So, It could be suggested that Judoka hold on the part-behind neck lapel(type A) at the sleeve with the other of Judogi jacked when opponent's height was short. Because the time elapsed on KP of type B was not so fast as type A(p<.05) during performed Uchi-mata, and also the bigger hip-angle of the supporting foot in the 2nd stage of KP grew, the faster the time elapsed on KP became.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.467-479
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• 2009

The purpose of this study was to present the quantitative data which riders can utilize teaching field by comparison analysis of kinematics according to skill level of rider during 2 strides rising trot with the JeJu's-Horse. Participated subjects was consisted of total 10 riders(unskilled: n=5, skilled: n=5). The method of experiment & analysis was based on 3D cinematography. Variables were consisted of temporal, linear & angular kinematics by each event & phase. The skilled assigned more ratio of elapsed time in air than support phase, had the less range of motion in up-down direction and more consistent velocity in lateral & forward direction and performed periodic up-down movement with alignment in vertical direction according to elapsing of phases. The skilled more flexed at elbow and extended backwardly according to elapsing of phases, while more flexed forwardly at hip & knee and plantarflexion at ankle. The skilled postured backward extension but the unskilled do forward flexion. That is, It was considered that the unskilled continued more unstable posture than the skilled during 2 strides in rising trot.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.95-104
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• 2005

To know the proper setup posture for the various clubs, changes of setup variables according to the change of golf club length was investigated. Swing motions of three male low handicappers including a professional were taken using two high-speed videocameras. Four clubs iron 7, iron 5, iron 3 and driver (wood 1) were selected for this experiment. Three dimensional motion analysis techniques were used to get the kinematical variables. Mathcad and Kwon3D motion analysis program were used to analyze the position, distance and angle data in three dimensions. The variables divided into three categories 1) position and width of anterior-posterior direction 2) position and width of lateral direction 3) angles and evaluated based on the theories of many good golf teachers. Major findings of this study were as follows. 1.The stance (distance between ankle joints) was increased as the length of the club increased but the increasing width was not large. It ranges from 5cm to 10cm and professional player showed small changes. 2. Forward lean angle of trunk was decreased (more erected) as the length of the club increased. It ranges from 30 degrees for iron7 to 25 degrees for driver. 3. Angle between horizontal and right shoulder were increased as the length of the club increased. It ranges from 10 degrees to 20 degrees and professional player showed small changes. 4. Anterior-posterior position of the shoulders were located in front of the foot for all clubs and the difference between the shoulder and knee position was decreased as the length of the club increased. 5. Anterior-posterior position of grip (hand) was located almost beneath the shoulders (2.5cm front) for iron7, but it increased to 10cm for the driver. This grip adjustment makes the height of the posture increased only 5cm from iron7 to driver. 6. Lateral position of grip located at 5cm left for the face of iron7, but it located at the right side (behind) for the face of driver. 7. Lateral position of the ball located at the 40%(15cm) of stance from left ankle for iron7 and located at the 10% (5cm) of stance for driver. 8. Head always located at the right side of the stance and the midpoint of the eyes located at the 37% of stance from the right ankle for all clubs. This means that the axis of swing always maintained consistently for all clubs. 9. Left foot opened to the target for all subject and clubs. The maximum open angle was 25 degrees. Overall result shows that the changes of the setup variables vary only small ranges from iron7 to driver. Paradoxically it could be concluded that the failure of swing result from the excessive changes of setup not from the incorrect changes. These findings will be useful for evaluating the setup motion of golf swing and helpful to most golfers.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.532-542
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• 2021

The purpose of this study was to investigate the body's strategy through kinematic variables of the lower extremities and ground reaction forces to maintain the club-head speed and ball accuracy despite the three stances during the golf swing. Ten male golfers who official handicap two were participate in the experiment. All subjects performed swing after maintaining the address posture according to stance conditions(square; SS, open: OS, closed: CS). Using a 3D motion analysis system and force plateform, the results were calculated with the 7-iron full swing each stance. In result, there was no difference in center of displacement, and left and right hip and knee joint angle displacement. Left ankle joint was largely plantar-flexed in OS, and right ankle joint was largely performed in CS from the address to the downswing. From address to take-back, right foot had a large left direction and the left foot had a right direction were greater in OS than in CS. Therefore, despite various stances, maintaining the same posture at impact is thought to have a positive effect on club head speed and ball direction.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.135-142
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• 2008

The primary innovation in the new footwear is a heel lift of $20^{\circ}$ which is proposed to improve posture and balance as well as increase shock absorption. The purpose of this research was to compare the movement, forces and muscle activity between the new shoes and standard athletic footwear during standing and walking. Nine healthy subjects participated in this study. Data were collected at two times: 1) when the subjects first wore the new walking shoes and 2) after the subjects wore the shoes for 6 hours a day for two weeks. 1. During standing. the movement of the center of pressure is increased approximately 60% when wearing the new walking shoes compared to a control shoe. 2. During walking. the ankle is approximately $14^{\circ}$ more dorsiflexed during landing due to the 200heel lift in the new walking shoes. The knee compensates slightly by flexing approximately $2^{\circ}$ more. 3. As a result of the changes in the walking movement, the ground reaction forces are applied more quickly, although the peak magnitudes do rut change. 4. The resultant joint moments at the ankle and knee joints decrease from 21-60% with the largest reductions occurring during landing. In conclusion, the new footwear change the movement, showing a more upright stance. Also, the new footwear reduce joint loading at the joint during the landing and weight acceptance phase of walking. However, the influence of the new footwear is immediate and does rut change after wearing the shoes for two weeks.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.129-138
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• 2020

Due to the nature of the Rosenberg Method, the patient needs to maintain posture for a certain period of time, and the joint space is observed in various forms depending on the angle of knee flexion, which causes difficulties in examination. In order to solve these problems, Image quality was evaluated in order to evaluate the usefulness of the assistive device by making the assistive device itself. SNR and CNR analysis about the presence or absence of an assistive device using the extremity phantom and the angle of the assistive device itself were not statistically significant(p < 0.05). As a result of measuring the distance between the right and left edges of the medial condyle based on the presence or absence of an assist device, and the absence of assist device (96.00±40.6 mm) and presence of an assist device (134.86±17.68 mm) were statistically significant (p <0.05). To find the aLDFA relationship about the femur and tibia, we measured the right and left aLDFA based on the presence or absence of assist device. As a result, the absence of the right-side aLDFA assist device (74.63°±4.87) and the presence of assist device (79.64°±3.65) were statistically significant (p <0.05). The absence of the left-side aLDFA assist device (76.39°±4.62) and the presence of assist device (79.64°±3.65) were statistically significant (p < 0.05). but, As a result of measuring the distance of the overlapping parts of the right and left proximal tibiofibular joint and the lateral condyle, There were no statistically significant differences between the right and left sides. In conclusion, we confirmed that we can obtain Diagnostically valuable images with a constant knee-to-knee spacing using an assist device we self-created. In addition, we could learn through aLDFA relationship between femur and tibial that the smaller the angle, the more medial condyle overlaps with JSW, We also confirmed the significance by deriving similar values on the normal range values of aLDFA using assist devices. However, it is considered necessary to pay attention to internal and external rotations in order to obtain good quality images by evaluating the distance of overlapping parts between proximal tibiofibular joint and lateral condyle.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.328-335
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• 1999

This study was designed to investigate the effects of exercise therapy on joint mobility, daily activity. pain and depression of patients with ankylosing spondylitis. 25 persons with the experimental group and 25 persons with the control group were conveniently sampled among out-patients diagnosed with ankylosing spondylitis at the rheumatism center of H University Medical Center. The control patients were matched to the experimental group and they were selected considering sex and age. The exercise therapy was developed by the author with the assistance of exercise specialists. The program includes muscle relaxation, flexibility, muscle strengths, breathing strengths and straight posture exercises. The 20-minute exercise therapy was carried out to the experimental group once a day for eight weeks from October. 1997 to February, 1998. Before and after the experiments, joint mobility, daily activity, pain and depression were measured respectively. Data were analyzed by $\chi$$^2$-test. t-test, paired t-test and unpaired t-test. The results were as follows : Joint mobility(cervical flexion, extension, shoulder flexion, abduction, hip abduction, knee flexion and fingertip to floor distance) and daily activity in the experimental group after the exercise were significantly increased than that in the control group. The pain and depression score in the experimental group after the exercise were significantly decreased than that in the control group. These findings may indicate that the exercise therapy is effective in increasing the joint mobility and daily activity, and also effective in decreasing pain and depression in patients with ankylosing spondylitis, Accordingly, the exercise therapy can be adopted as an effective nursing intervention for ankylosing spondylitis.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.29-37
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• 2015

Objective : The purpose of this study was to investigate the biomechanical properties of shock absorption strategy and postural stability during the drop landing for each types. Methods : The motions were captured with Vicon Motion Capture System, with the fourteen infra-red cameras (100Hz) and synchronized with GRF(ground reaction force) data(1000Hz). Ten male soccer players performed a drop landing with single-leg and bi-legs on the 30cm height box. Dependent variables were the CoM trajectory and the Joint Moment. Statistical computations were performed using the paired t-test and ANOVA with Turkey HSD as post-hoc. Results : The dominant leg was confirmed to show a significant difference between the left leg and right leg as the inverted pendulum model during Drop Landing(Phase 1 & Phase 2). One-leg drop landing type had the higher CoM displacement, the peak of joint moment with the shock absorption than Bi-leg landing type. As a lower extremity joint kinetics analysis, the knee joint showed a function of shock absorption in the anterior-posterior, and the hip joint showed a function of the stability and shock absorption in the medial-lateral directions. Conclusion : These findings indicate that the instant equilibrium of posture balance(phase 1) was assessed by the passive phase as Class 1 leverage on the effect of the stability of shock absorption(phase 2) assessed by the active phase on the effect of Class 2 leverage. Application : This study shows that the cause of musculo-skeletal injuries estimated to be focused on the passive phase of landing and this findings could help the prevention of lower damage from loads involving landing related to the game of sports.

• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.199-206
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• 2015

Objective : The purpose of this study was to conduct a biomechanical analysis of a one-legged jump in a traditional Korean dance (Wae Bal Ddwigi) according to breathing method. Method : Participants for this study were 10 dancers with experience for at least 10 years in traditional Korean dance. Independent variables for this test were two different types of breathing methods. Dependent variables were ground reaction force and lower extremity kinematic variables. The jumping movement was divided into three separate stages, take off, flight, and landing. The subjects were asked a questionnaire regarding the degree of impact force and stability of landing posture after the experiment. The Kistler Force Plate (9281B, Switzerland) was used to measure ground reaction force. A digital camera was used to look into angles of each joint of the lower part of body. SPSS was used for statistical analysis via the dependent t-test(p<.05). Results : There were significant differences in jumping according to breathing method. The inhalation & exhalation method yielded significantly longer flight times combined with greater ground reaction force. The breath-holding method required more core flexion during landing, increasing movement at the hips and shoulders. Conclusion : Consequently, there was more flexion at the knee to compensate for this movement. As a result, landing time was significantly higher for breath-holding.

• Fashion & Textile Research Journal
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• v.22 no.5
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• pp.650-659
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• 2020

The present study provides reference data required for the design of clothing for the elderly by analyzing the body surface area during fitness motion based on 3D scan data of Korean elderly women. This study was conducted with the procedures of (1) survey of motions and main muscles for fitness, (2) acquisition of 3D scan data, and (3) analysis of rate of change for body surface area during fitness motion. Acquisition of 3D body scan data was obtained from seven elderly females (age: 64-77). We selected 66 anatomical landmarks (40 upper body and 22 lower body) by referring to previous studies. Body surface was segmented by connecting the landmarks marked on the 3D scan data acquired. Analysis of body surface area was conducted in terms of the change rate of surface area in 9 postures of elbow 0°, 90° and 180° for flexion, shoulder 90°, 180° for flexion, shoulder 0°, 180° for abduction, hip 90° for flexion, and knee 90° for flexion compared to the those in the standing posture. The amount of changes in body surface area were 12%-62% in the upper body, 15%-77% in the arm, and 10%-51% in the lower body. A future study on the rate of change of body surface length is needed; in addition, a study on how to apply the results of body surface area and body surface length analysis to clothing pattern design is also necessary.