• Korean Journal of Applied Biomechanics
• /
• v.16 no.4
• /
• pp.21-30
• /
• 2006

The purpose of the study is to search for the possibility of the application of kinematics analysis to physical education at schools and expand its scope of application. This study chose 9 college students majoring in physical education and classified them into type A group who can make the straight, vertical handstand, type B group whose waist is bent, type C group who cannot handstand completely. The center of mass, distance between hand and leg, and the angle and angular velocity of each joint were obtained. The result of this study is this. 1. The time for CM showed 6:4 for A group and 5:5 for B and C groups. The distance between hand and foot in the event 3 was 44% of the height for A group, and 41% for B and C groups. A Group showed the higher CM positional significant difference, it was vertically direction below the hip joint at front. For significant difference of the B Group showed horizontal and vertical velocity of the CM, the highest vertical was obtained in phase 3. The difference of angle of shoulder join in the flexion/extension was showed gradually extension event 2 and the height angular velocity was at phase 3 in the A group. 2 The analysis of the handstand motion revealed that the phase 3, but the maintenance of posture start part the handstand is also very important. Through these results, this study confirmed that the time for phase of the CM, horizontal and vertical positions, velocity, the distance between hands and foot, and the difference of the angle and angular velocity of hip joint and shoulder joint can be set as the variables of analysis. It was also definite cause that the handstand motions of college students majoring in physical education had many difference in performance.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.4
• /
• pp.105-115
• /
• 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, close, and square 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 LabVIEW 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. In conclusion, the first hypothesis, "In three dimensional maximum linear velocity of racket head would be significant difference among the stance patterns during forehand stroke in tennis" was rejected. The second hypothesis, "In three dimensional anatomical angular displacement of trunk would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that the internal-external rotation showed most important role among the three dimensional anatomical angular displacement of trunk The third hypothesis, "In three dimensional anatomical angular displacement of upperlimb would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. Flexion-extension and internal-external rotation the open stance showed the largest angular displacement and is follwed by square stance and closed stance. The fourth hypothesis, "In three dimensional anatomical angular velocity of upperlimb would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that X-axis angular velocity and Z-axis angular velocity the square stance showed the largest angular velocity of the trunk and X-axis angular velocity and Y-axis angular velocity the closed stance showed the largest angular velocity of the shoulder joint.

• Journal of the Korean Society of Physical Medicine
• /
• v.8 no.2
• /
• pp.193-200
• /
• 2013

PURPOSE: The purpose of this study was to find out variations in body posture by using the baby carrier at the front side and back side. METHODS: Thirty two healthy and young female who will bring up infants and had no musculoskeletal disorders of neck, lumbar and low limb were recruited for this study. They were each marked about ears of tragus, cervical 7th, acromion anterior end, anterior superior iliac spine, posterior superior iliac spine, greater trochanter and lateral malleolus as landmarks to measure variations of body posture when they carry infants at the front side and back side. Landmarks were regarded as the creteria in order to measure NeckFlexion angle(NF), Foreward shoulder angle(FSA), Pelvic tilt(PT), Sway angle(SA), Head displacement(HD) and Scapular displacement(SD). Variations in body posture were measured from the neutral position to the front and back side by using Image J. RESULTS: There were significance level (p<.05) in NF, PT, SA, HD and SD except for FSA in two different side. CONCLUSION: The results of this study indicate that each of the using ways of baby carrier for baby care was influenced postural responses of young women. therefore, it could be considered to apply to women who have abnormal body posture in order to minimize musculoskeletal disorders.

• The Journal of the Korea Contents Association
• /
• v.13 no.2
• /
• pp.348-358
• /
• 2013

This study aimed to investigate the effect of a lap board that was developed to prevent musculoskeletal disorders caused by the use of a computer mouse. Study participants were 10 college students in their 20s who did not have any musculoskeletal symptoms. We analyzed the difference in upper limb movements, electromyographic activity, task performance, and subjective discomfort between 2 conditions: use of a mouse with the lap board and use of a mouse placed on a desk. Results of behavior analysis showed that there was a significant difference between the 2 conditions in terms of the average angle of shoulder flexion, shoulder internal rotation, and forearm pronation(p< 0.05). However, electromyographic activity, task performance, and subjective discomfort showed no significant differences between the 2 conditions. When subjects used the mouse with the lap board, their upper extremity was located much closer to the torso than when they used the mouse placed on the desk. Six of 10 participating students preferred the lap board. We expect that advanced research on prevention of musculoskeletal disorders due to the use of the computer mouse will be conducted in the near future.

• Journal of Industrial Technology
• /
• v.21 no.B
• /
• pp.265-272
• /
• 2001

The human arm is modeled by three rigid bodies(the upper arm, the forearm and the hand)with seven degree of freedom(three in the shoulder, two in the elbow and two in the wrist). The objective of this work is to present a method to determine the three-dimensional kinematics of the human elbow joint using a magnetic tracking device. Euler angle were used to determine the elbow flexion-extension, and the pronation-supination. The elbow motion for the various driving conditions is measured through the driving test using a simulator. Discomfort levels of elbow joint motions were obtained as discomfort functions, which were based on subjects' perceived discomfort level estimated by magnitude estimation. The results showed that the discomfort posture of elbow joint motions occurred in the driving motion.

• Journal of Digital Convergence
• /
• v.15 no.8
• /
• pp.465-476
• /
• 2017

This study attempted to investigate the effects of gold therapy on myofascial pain syndrome(MPS) in the neck, back and shoulder in comparison to stone therapy and verify its availability as an efficient nursing mediator in clinical trials. For this, therapy was given to a total of 20 women in two groups (gold therapy group, stone therapy group: 10 persons each) living in the capital region three times a week (40 min. at a time) for two weeks. In both groups, a statistically significant decrease was found in the following after the treatment: neck circumference, shoulder width, width of the inferior angle of scapula, shoulder thickness and waist circumference (p<0.001). In terms of differences, the gold therapy group was greater than the stone therapy group. In both groups, a statistically significant increase was observed after treatment in the following: cervical lateral bending (right), cervical lateral bending (left), cervical flexion and cervical extension angle (p<0.001). In terms of differences, the gold therapy group was greater than the stone therapy group. In conclusion, this study seems to show that gold therapy is a nursing intervention option having effective fascial relaxation and pain relief for the neck, back and shoulder. Therefore, it would be valuable as safe, non-invasive therapy.

• Journal of the Korean Society of Safety
• /
• v.24 no.2
• /
• pp.83-88
• /
• 2009

The objective of this paper was to evaluate the effectiveness of horizontal, vertical, asymmetric and coupling multipliers for manual material handling. Lifting tasks with 5 different horizontal distances ($30{\sim}70cm$) for 6 vertical distances(ankle, knee, waist, elbow, shoulder and head height) were experimented. The muscle activity and muscle exertion level during asymmetric load handling(without trunk flexion) was experimented. Lifting tasks with and without handle tote box for three postures(straight, bending, right angle posture) were experimented. The degrading tendency did not appeared almost in $60{\sim}70cm$ interval's horizontal distance. As a result of ANOVA, MVC paid attention to horizontal and vertical distance but cross effect was insignificant(p<0.01). The change of the MVC according to the horizontal, vertical distance appeared similar from of RWL. The results of normalized MVC measurement were decreased about 16%, 24%, 34% respectively as the asymmetry angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. RMS EMG values of right erector spinae muscles were decreased as the work posture went to $90^{\circ}$ and those of left erector spinae muscles were increased until the asymmetry angle was $40^{\circ}$ but decreased continually over $40^{\circ}$. 7 subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular. MVC reduced maximum 23% by type of handle. MVC was highest in straight posture, but was lowest in right angle posture. As a result of ANOVA, MVC paid attention to posture, coupling(p<0.01). To all handle types, biceps brachii activity was increased in right angle posture, but reduced in straight posture. Based on the results of this study, it is suggested that the NIOSH guideline should not be directly applied to Korean without reasonable reexamination. In addition, we need to afterward study through an age classification.

• Korean Journal of Applied Biomechanics
• /
• v.12 no.1
• /
• pp.63-87
• /
• 2002

The purpose of this study was to analyze the kinematic variables when Uchi-mata(inner thigh reaping throw) performing by Kumi-kata(engagement position, basic hold) types A, B(A: grasping part-behind neck lapel, B: chest lapel) in Judo with three dimensional analysis technique DLT method by videography. The subjects were four male judokas who have been training in Yong-In University(YIU), on Korean Representative level and Uchi-mata is their tokui-nage(favorite technique), the throwing form was filmed on two S-VHS 16mm video camera( 30frame/sec. Panasonic). Kinematic variables were temporal, posture, and COG. The data collection was performing by Uchi-mata. Six good trials were collected for each condition (type A, B) among over 10 trials. The mean values and the standard deviation for each variable were obtained and used as basic factors for examining characteristics of Uchi-mata by Kumi-kata types. The results of this analysis were as follows : 1) Temporal variables The total time elapsed(TE) by Uchi-mata of types A, B were 1.45, 1.56 sec. respectively. Types A shorter than B. 2) Posture variables In performing of Uchi-mata, the range of flexion in type A, left elbow was $45^{\circ}$ and B was $89^{\circ}$ from Event 2(E2) to Event 6(E6). Type A and B were quite different in right elbow angle in Event1(E1). Left shoulder angle of type A was extended and type B was flexed in E4. Both types right shoulder angles were showed similar pattern. Also both hip angles(right/left) were showed similar pattern. When type A performed Uchi-mata the knee-angle of supporting foot showed $142^{\circ}$in the 1st stage of kake phase[KP], and extended to $147^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $86^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $126^{\circ}$in the 1st stage of KP, and extended to $132^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $106^{\circ}$in the 1st stage of KP, and extended to $121^{\circ}$in the 2nd stage of KP. When type B performed Uchi-mata the knee-angle of supporting foot showed $144^{\circ}$in the 1st stage of KP, and extended to $154^{\circ}$in the 2nd stage of KP. And the foot-ankle angle of supporting foot showed $83^{\circ}$in the 1st stage of KP, and extended to $92^{\circ}$in the 2nd stage of KP. moreover, The knee angle of attacking foot showed $132^{\circ}$in the 1st stage of KP, and extended to $140^{\circ}$in the 2nd stage of KP, and the foot-ankle angle of attacking foot showed $103^{\circ}$in the 1st stage of KP, and extended to $115^{\circ}$in the 2nd stage of KP. During Uchi-mata performing, type A showed pulling pattern and type B showed lift-pulling pattern. As Kumi-kata types, it were different to upper body(elbow, shoulder angle), but mostly similar to lower body(hip, knee, ankle angle) on both types. 3) C. O. G. variables When the subjects performed Uchi-mata, COG of type A, B up and down in vertical aspect was 71cm, 73.8cm in height from the foot in the 2nd stage of KP. As Kumi-kata types, it were different on medial-lateral direction aspect but weren't different in Kuzushi phase on vertical direction aspect.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.24 no.4
• /
• pp.57-72
• /
• 2022

This study categorized and analyzed the body types of adult women in their 20s and 30s using 3D human measurement data from the 8th Size Korea, and intended to construct body shape and dimension data necessary for modeling Korean standard avatars. Data analysis considered data from 1302 adult women in their 20s and 30s, and a total of 49 index values, drop values, and angle items were subjected to factor analysis and one-way ANOVA to categorize the body type, and Duncan test to post-verify significant differences by type. As a result of conducting factor analysis, 13 factors were extracted and were categorized into 4 body types. Type 1 is short in the upper torso, long in the lower torso, long in the arms and legs, and has a upright body shape and sagging shoulder. Type 2 is short in the torso, arms and legs, and has large torso flexion and lower body circumference. Type 3 has abdominal obesity with small torso flexion and lower body circumference. Type 4 is a small body bending forward type. For the distribution of body types by age among those in their 20s and 30s, the highest appearance rate was Type 1 and was therefore selected as the represntative body type. The body type information of this study will be used as basic data for developing standard avatars.

• Korean Journal of Applied Biomechanics
• /
• v.22 no.1
• /
• pp.1-7
• /
• 2012

The purpose of this study was to investigate the pattern change of throwing in baseball after 15 weeks of participation in baseball class, by examining ball speed, trunk and upper body angles. The comparison was with 6 university students that haven't had any experience in baseball. 8 infra red cameras and 2 force platforms were used to collect the data. First, there was an increase in the speed of the ball after the class. Second, there was no significant difference in the allocated phases during the throw before and after class. Third, the release point was lower and more in front. Forth, there was an increase in the knee flexion at the left foot landing and release point. Finally, there was an increase in the maximum shoulder external rotation and pelvis angle. It is recommended that the coordination between the segments should be investigated to improve our understanding of the learning of throwing in future research.