Byung-Hoon Woo

Kinematical Analysis of Up-Down Motion in Ski Simulator

This study was to investigate the kinematical analysis using ski simulator. Twelve people(six skilled, six unskilled) participated in the experiment. Each phase of motion time was slight differences between the skilled group and the unskilled group but not significant difference in statistics. In displacement of vertical on COG(Center of Gravity), left and right down motion showed significant difference between group. In velocity of horizontal on COG, both left and right down motion showed significant difference between group, and up motion of between down motion showed significant difference. In displacement of angle on ankle, knee, hip joint almost showed significant difference between group. Almost in body position was lower skilled group than unskilled group.

Development of Wearing of Musculo-Skeletal Functional Garment for Adolescents` Idiopathic Scoliosis -With the Principle of Sports Taping Applied-

We aimed to analyze the muscle activity of adolescent patients with idiopathic scoliosis during gait and develop the wearing of musculo-skeletal functional garment by applying the principle of sports taping based on the result of the analysis. We selected 20 male students between the ages of 13 and 18 and divided them into 2 groups: one group consisted of 10 patients with idiopathic scoliosis

The Effects of Accuracy on Skill Level and Eye-Tracking Type in Golf Putting

The purpose of this study was to analyze the impact accuracy and kinematic parameters of skill level and eye-tracking type during putting strokes. For comparison, five elite golfers and five novice golfers participated in this study. Three-dimensional kinematic data were collected for each subject while 10 putting trials were performed for each skill level and eye-tracking type. The APAS system was used to compute the impact accuracy and kinematic parameters of putter heads. The putting stroke was divided into three phases: back swing, downswing, and follow-through. The findings indicated that significant differences were found in skill level as it affected the rate of success. For impact accuracy and the displacement of putter heads, a significant difference was found for the skill level, particularly in backs-wing and follow-through. In addition, the displacement of the putter head had a greater influence on stroke accuracy than on velocity.

Characteristics for Gait of the Induced Equinus in Normal Subjects

The purposes of this study was to investigate the physical compensation for gait on induced equinus in normal subjects. Ten subjects were participate in the experiment (age: 23.8±2.8 yrs, height: 177.3±4.3 cm, weight: 70.8±4.6 kg). The study method adopted 3D analysis with six cameras and ground reaction force with two force-plate. Induced equinus were classify as gait pattern on unilateral and bilateral equinus. The results were as follows; In displacement of COM, medio-lateral and anterior-posterior COM were no significant, but in vertical COM, unilateral equinus gait was higher than bilateral equinus gait. In displacement hip joint, left hip joint was more extended in FC1 and FC2 during unilateral equinus gait. In displacement knee joint, left knee joint was more extended in FC2, right knee joint was more extended in all event during unilateral equinus gait. In trunk tilt, unilateral equinus gait was more forward tilt in TO1 and TO2. ROM of each joint was no significant. In Displacement of pelvic tilt angle, X axis of unilateral equinus gait was more increase than bilateral equinus gait at FC2, TO2 and MS2. Y axis of unilateral equinus gait was more increase than bilateral equinus gait at MS1, FC2 and MS2. Z axis was no significant in both equinus gait. In GRF, right Fx and Fy were no significant in both equinus gait, Fz was more bigger vertical force in bilateral equinus gait. Left Fx was more bigger internal force in unilateral equinus gait, Fy and Fz were no significant in both equinus gait.

Biomechanical Analysis on Kinematic Chains Type of Trunk

The purpose of this study was to investigate the trunk rotation type by wheel and axle. In order to analysis, 3D-motion analysis and electromyography were conducted on kinematic variables, impulse, average-EMG and integrated-EMG. Twelve healthy (age: yrs, height: , weight: ) participated in the experiment. The results were as follows; in hand`s velocity and acceleration, wheel and axial rotating movement using kinematic chain(type 3) were much faster. In impulse, type 3 was much stronger. In average-EMG, right and left, latissimus dorsi muscles was much stronger. In integrated-EMG, left erector spinae, right/left latissimus dorsi, and left external oblique muscles was much stronger. These results considered that, in the trunk rotation utilizing the kinematic chains action, latissimus dorsi muscles highly contribute to the muscle utilization that makes the rotating movement maximally effective.

Characteristics of the Compensation for Gait of the Induced Knee Stiffness in Normal Subjects

The purposes of this study were investigated physical compensation for gait on induced knee stiffness in normal subjects. Ten subjects were participated in the experiment(age: 26.0±6.3 yrs, height: 175.5±5.3 cm, weight: 69.1±6.1 kg). The study method adopted 3D analysis with five cameras and ground reaction force with two force-plate. Induced knee stiffness level were classified as gait pattern on ROM of knee(free level, 30° restriction level, fix level). The results were as follows; In angular displacement of hip joint, left hip joint was the more extended in mid-stance on induced right knee stiffness. In angular displacement of knee joint, there was no physical compensation on induced right knee stiffness, but free knee level gait was more flexed in swing phase of right knee joint. In angular displacement of ankle joint, right ankle joint was the more dorsiflexed on induced right knee stiff- ness, and 30° restriction level and fix level gait were less plantarflexed in TO2. In trunk tilt, free and 30° restriction level gait was more backward tilt on induced right knee stiffness. In ROM of each joint, right knee joint was more larger and trunk tilt was more lower on induced right knee stiffness. In GRF, Fx was more bigger lateral force in free and 30° restriction level gait, and was more bigger medial force in fix level gait. Fy was more bigger propulsion force in free level gait, and was was more bigger braking force in 30° restriction level gait. Left braking force in 30° restriction level gait was more bigger. Fz was no significant.

Effect Verification of Wearable Assisting Wear for Increasing Golf Carry Distance

The purpose of this study was to verify the effects of developed assisting wear which maximize trunk(back) muscles stretch-shortening effect during backswing and downswing for increasing golf ball carrying distance. Design and fabrication of assistive wear were performed based on the results of analyzed data of trunk EMG activity from the golf drive swings of elite professional male golfers during back swing and downswing phases. After the prototype of wear was produced, surface EMG and Flight scope tests were conducted to verify the effectiveness of the wear for increasing distance to the professional golfers. Results indicated that wearing trial showed significant longer carry distance than the non-wearing trial(p

Kinematic Analysis of T-Stop Motion by Inline Skate Rolling Speed

The purpose of this study was to investigate the kinematical analysis of T-stop motion by inline skate rolling speed. Six subjects were participated in the experiment(age: yrs, weight: , height: , career: yrs). The study method adopted 3-dimensional analysis and 2 cameras for filming to analyze the required displacement of center of mass, displacement of right and left hip joint, displacement of right and left knee joint, displacement of trunk tilt using by APAS. The results were as follows; In anterior-posterior displacement of COM, the faster rolling speed, the longer displacement at phase 2. In vertical displacement of COM, the faster rolling speed, the lower displacement. In medial-lateral displacement of COM, there was no significant on rolling speed. In angular displacement of right thigh segment, the faster rolling speed, the bigger displacement in X and Z axis. In angular displacement of left thigh segment, the faster rolling speed, the lower displacement in X axis. In angular displacement of right shank segment, the faster rolling speed, the bigger displacement in Z axis. In angular displacement of left shank segment, the faster rolling speed, the bigger displacement in X and Y axis. In angular displacement of trunk segment, the faster rolling speed, the bigger displacement in Z axis.

The Effects of Age and Walkway Type on Lower Extremities Kinematics in Elderly Women

Objective : The purposes of this study was to perform a kinematical analysis on age and walkway types in elderly women subjects. Method : Forty subjects participated in the experiment (A1 group - age: , height: , weight: , A2 group - age: , height: , weight: , A3 group - age: , height: , weight: , A4 group - age: , height: , weight: ). The study method adopted was the 3D analysis with six cameras. Ground type were classifed as gait pattern on flat, ascent and descent ramp. For the statistical analysis, the SPSS 21.0 was used to perform Repeated measured Two-way ANOVA. Results : In velocity of CM, there was faster movement on flat ground. When it came to the velocity of right toe, there was no significance in early mid-swing of right foot, but A4 was the slowest in late mid-swing of right foot on flat ground. In joint angle in left foot strike, the left hip joint and knee joint were more flexed in descent ramp, In addition left and right ankle joints were more plantarflexed in descent ramp, and left ankle joint was more plantarflexed in the over 75 yrs age groups. Conclusion : The higher age group were more flexed in lower body joints during descent ramp.

Kinematical Analysis of Fastball and Longtoss during Baseball Throwing

The purpose of this study was to investigate relation between fastball motion and longtoss motion, and the kinematical analysis using APAS(Ariel Performance Analysis System). Eight people(age: , height: , weight ) participated in the experiment. Followings are the conclusion. In displacement of fore-aft on COG(Center of Gravity), fastball motion moved more forward than longtoss motion. In displacement of vertical on COG(Center of Gravity), fastball motion was lower than longtoss motion In velocity of right hand, greater release velocity was measured for fastball motion than for longtoss motion. In displacement of elbow and shoulder joint, more extended displacement was exhibited in fastball motion than longtoss motion. In displacement of trunk tilt, fastball motion showed foreward tilt, longtoss motion showed backward tilt. In stride, fastball showed longer than longtoss.