• Title/Summary/Keyword: body rotation

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Design of high stiffness and lightweight body for stiffness distribution ratio (강성 배분비를 괴려한 고강성 경량화 차체 설계)

  • Yang, Hee-Jong;Kim, Ki-Chang;Yim, Hong-Jae;Kim, Chan-Mook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.562-566
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    • 2006
  • Lightweight body can cause a low stiffness due to the decrease of panel thickness and reinforcing member. The other way, high stiffness body demands an increase of mass. Front pillar section area is decreased due to driver's visual field. Global vehicle stiffness is affected by stiffness distribution ratio between upper part and lower part at side body structure. This paper will describe a process used to evaluate the stiffness distribution ratio based on research of strain energy analysis of the tip rotation method. In addition, optimum design schemes are presented for high stiffness and lightweight body structure considering the investigated stiffness distribution ratio. In this way the designer will be aided by a defined design guide and a set of supporting tool to help him work towards a good design

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Characteristics and Classification of Lower Body of Unmarried Adult Female aged Twenties (20대 미혼여성의 하반신 체형분류 및 특성)

  • 성화경;최경미
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.4
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    • pp.727-739
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    • 1997
  • The purpose of this study was to classify and analyze the lower body of adult female and to provide it'stotal data for clothing construction. The subjects were 82 Korean adult females and their age range is from 19 to 24 years old. 42 variables (10 variables from the direct anthropometric data, 2 variables from the multiplication method and 30 variables from the indirect anthropometric data) in total were applies to analyze(means, standard deviations, factor analysis, cluster analysis) The result of factor analysis indicated that 10 factors were extract'cd through factor analysis and orthogonal rotation by the method of varimax and those factors comprise 82. 5 percent of total variance. The obesity of lower body was closely related to hip angle indicated the degree of drooping hip was extracted a independent factor, not influenced by other variance. And somatotype of lower body is classified by cluster analysis, using the FASTCLUS of SAS. To classify the lower body, two kinds of silhouette, front- back and side were applied to analize. The front- back silhouette was subdivided into five groups and the side silhouette four.

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Evaluation of Biomechanical Movements and Injury Risk Factors in Weight Lifting (Snatch)

  • Moon, YoungJin
    • Korean Journal of Applied Biomechanics
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    • v.26 no.4
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    • pp.369-375
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    • 2016
  • Objective: The purpose of this study was to investigate the possibility of injuries and the types of movement related to damage by body parts, and to prepare for prevention of injuries and development of a training program. Method: For this study, the experiment was conducted according to levels of 60 percentages (ST) and 85 percentages (MA) and 10 subjects from the Korean elite national weightlifting team were included. Furthermore, we analyzed joint moment and muscle activation pattern with three-dimensional video analysis. Ground reaction force and EMG analyses were performed to measure the factors related to injuries and motion. Results: Knee reinjuries such as anterior cruciate ligament damage caused by deterioration of the control ability for the forward movement function of the tibia based on the movement of the biceps femoris when the rectus femoris is activated with the powerful last-pull movement. In particular, athletes with previous or current injuries should perceive a careful contiguity of the ratio of the biceps femoris to the rectus femoris. This shows that athletes can exert five times greater force than the injury threshold in contrast to the inversion moment of the ankle, which is actively performed for a powerful last pull motion and is positively considered in terms of intentional motion. It is activated by excessive adduction and internal rotation moment to avoid excessive abduction and external rotation of the knee at lockout motion. It is an injury risk to muscles and ligaments, causing large adduction moment and internal rotation moment at the knee. Adduction moment in the elbow joint increased to higher than the injury threshold at ST (60% level) in the lockout phase. Hence, all athletes are indicated to be at a high risk of injury of the elbow adductor muscle. Lockout motion is similar to the "high five" posture, and repetitive training in this motion increases the likelihood of injuries because of occurrence of strong internal rotation and adduction of the shoulder. Training volume of lockout motion has to be considered when developing a training program. Conclusion: The important factors related to injury at snatch include B/R rate, muscles to activate the adduction moment and internal rotation moment at the elbow joint in the lockout phase, and muscles to activate the internal rotation moment at the shoulder joint in the lockout phase.

The Effect of Novel Stretching on the Range of Motion and Acromio-Humeral Distance in Patients with Glenohumeral Internal Rotation Deficits with Posterior Shoulder Tightness (노벨 스트레칭과 관절가동술이 어깨 후방 뻣뻣함으로 인한 어깨관절 안쪽돌림 결핍 환자의 관절가동범위와 봉우리-위팔뼈 거리에 미치는 영향)

  • Yong-Tae, Kim;Sang-Bin, Lee
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.28 no.3
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    • pp.33-40
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    • 2022
  • Background: The cross-body and the sleeper stretches have been used to improve posterior shoulder tightness (PST). However, such stretching techniques may not always help achieve scapular stability and may even aggravate patient's symptoms. Therefore, a new stretching technique (passive glenohumeral internal rotation with bridging) was developed as a more effective method that may allow for greater scapular stability without aggravating the symptoms. Thus, this study aimed to examine and compare this novel stretching technique to determine its effect on the range of motion (ROM) and acromio-humeral distance (AHD) in patients with glenohumeral internal rotation deficits (GIRD) with posterior shoulder tightness. Methods: A total of 30 symptomatic patients with asymmetrical GIRD were randomly assigned to two groups: the novel stretching group (n=15) and the joint mobilization group (n=15). The intervention was conducted twice a week for a total of four weeks. The ROM of shoulder internal rotation was measured by a goniometer and the AHD was evaluated by an X-ray before and after the intervention. Results: Both the treatments improved ROM and AHD in patients with GIRD (p<.05). However, the improvements in internal rotation ROM and AHD in the novel stretching group were significantly greater than that of the subjects in the mobilization group. There was a significant difference between the two groups (p<.05). Conclusion: These results show that both novel stretching and joint mobilization improved ROM and AHD in patients with GIRD with PST. However, novel stretching was more effective than joint mobilization.

A Study on the Consumer's Purchasing Motives toward Casual Hanbok - in the areas of Pusan - (생활한복의 구매동기에 관한 연구 -부산지역을 중심으로-)

  • 최은경
    • Journal of the Korean Society of Costume
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    • v.45
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    • pp.71-84
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    • 1999
  • This study was to identify the dimensions of consumer's purchasing motives and purchasing delay reasons toward casual hanbok. Other objective was to examine relationship between these variables and future purchasing intention. Th 22 purchasing motive questions and 19 purchasing delay reasons were selected through the result of self-questionnaire analysis. 302 purchaser and 297 consumers who delay for particular reasons in Pusan responsed to the second questionnaire of purchasing motives and purchasing delay reasons toward casual Hanbok. The results as follows: 1. For factor analysis 22 purchasing motive questions were subjected to the principle component analysis with orthogonal rotation after extraction of 6 major factors. Six dimensions are consciousness of nation goodness of design conformity with fashion charming apperance relaxation fo body and mind nation goodness of design conformity with fashion charming appearance relaxation of body and mind and pursuit of individuality. These factors explained 62.0% of total variables. 2. Consumer's purchasing motives such as consciousness of nation goodness of design charming appearance and relaxation of body and mind has predicting power to the re-purchasing intention of casual hanbok 3. For factor analysis 19 delay reason question were subjected to the principle component analysis with orthogonal rotation after extraction of 5 major factors. Five dimensions are non-fitness for occasion and body shape unsatisfaction with design unsatisfaction with price need of information search for better product and preference for traditional hangok. These factors explained 60.4% of total variables. 4. Delay reasons of unsatisfaction with design and price were positively related to the future purchasing intention. This delay reason is caused by forces external to the consumer and the consumer has engaged in information search. This result explained this type of consumer has the strong future purchasing intention.

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The Effect of Genu Valgum on the Body Mass Index, Moment of Lower Limb Joints, Ground Reaction Force (신체질량지수, 하지관절의 모멘트, 지면반발력이 무릎외반슬에 미치는 영향)

  • Lee, Yong-Seon
    • Korean Journal of Applied Biomechanics
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    • v.25 no.3
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    • pp.257-263
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    • 2015
  • Objective : The purpose of this study was to investigate the effect of genu valgum on the body mass index, movement of lower limb joints, and ground reaction force. Methods : Gait patterns of 30 college students with genu valgum were analyzed and the static Q angle of the femur was measured for selecting genu valgum of the subjects. To analyze the kinetic changes during walking, the six-camera Vicon MX motion analysis system was used. The subjects were asked to walk 12 meters using the more comfortable walking method for walking. After they walked 12 meters more than 10 times, their most natural walking patterns were chosen three times and analyzed. Results : As a result of measuring a relationship between genu valgum and Q-angle, as the Q-angle increases, it showed a genu valgum also increased. Body Mass Index showed a significant difference between the groups was higher in the genu valgum group.(p<.001). The analysis result showed that genu valgum had a significant effect on the internal rotation moment in the hip joint(p<.05). Also, genu valgum had a significant effect on the internal rotation moment of the knee joint(p<.05). The comparative analysis of the Medial-Lateral ground reaction force in the genu valgum group showed a tendency to increase the medial ground reaction force(p<.05). The vertical ground reaction forces of the middle of the stance phase(Fz0) showed a significant increase in genu valgum group(p<.05), in particular the results showed a decrease in the early stance phase(p<.001). Conclusion : In conclusion, the change in body mass is considered to be made by proactive regular exercise for improvement of the genu valgum. In addition, the prevention of the deformation caused by secondary of the genu valgum in this study may be used as an indicator of the position alignment rehabilitation for structural and functional improvements. Applying a therapeutic exercise program for the next lap will require changes in posture alignment.

The study of batting characteristics in elite baseball players (엘리트 야구 선수의 타격 특성 연구)

  • Lee, Young-Suk
    • Korean Journal of Applied Biomechanics
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    • v.13 no.1
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    • pp.173-184
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    • 2003
  • The purpose of this study was to investigate the batting characteristics in elite baseball players. Seven skilled collegiate players hit the ball which was thrown by a pitching machine linearly and strongly to the center of the field. Time, velocity, angle and pound reaction force variables were measured by using high-speed video cameras and pound reaction force analyzer. The results were as follows: 1. The elite players finished their stride performance in a short time and they stayed longer in a swing phase. The increases in the range of trunk rotation were associated with the delay of the swing phase. 2. The 'take-back' phenomenon in the trunk was showed after the stride phase. 3. The down swing demonstrated powerful line drives. 4. Equivalent body weights were placed on both feet during the ready phase. 95% of the body weights were moved to the rear foot during the stride phase, whereas the body weights were driven to the front foot during the swing phase. 95% of the body weights were placed on the front foot at impact.

3D Animation Authoring Tool Based On Whole Body IK and Motion Editing

  • Ju, Woo-Suk;Im, Choong-Jae
    • Journal of Korea Multimedia Society
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    • v.11 no.6
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    • pp.869-874
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    • 2008
  • The work of creating character motion needs the higher professional technology and sense and the creating work of realistic and natural motion possess the most part of production term. In this paper we introduce the easy and convenient 3D animation authoring tool which makes the motion based on whole-body inverse kinematics and motion editing function. The proposed 3D animation authoring tool uses the forward kinematics using quaternion and whole-body inverse kinematics to determine the rotation and displacement of skeleton. Also, it provides the motion editing function using multi-level B-spline with quasi-interpolant. By using the proposed tool, we can make 3D animation easily and conveniently.

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Effect of Gym-ball Exercise Program to Pelvis and Spine of the 20's Woman

  • Oh, Seung-Hyean;Yoo, Kyung-Tae
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.4
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    • pp.339-345
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    • 2014
  • PURPOSE: This study is to investigate the effect of 4 weeks of gym ball exercise on the pelvis and spine of women in 20s. METHODS: Randomly selected 10 of 20 subjects are allocated to experimental group who will practice gym-ball exercise while the rest 10 subjects are allocated to control group. Values for pelvic obliquity DL-DR, pelvic torsion DL-DR, pelvic rotation, kyphotic angle ICT-ITL (max), and lordotic angle ITL-ILS (max) were measured through recording using 3-dimensional image analyzer as a preliminary inspection. Gym-ball exercise was implemented 3 sessions a week for 4 weeks. Each session consisted of 10 minutes of warm up exercise, 30 minutes of main exercise, and 10 minutes of cool down exercise totaling 50 minutes. Post inspections were measured after exercise. RESULTS: Experimental group showed statistically significant difference in pelvic obliquity DL-DR, pelvic torsion DL-DR, and kyphotic angle ICT-ITL (max) (p<.05) and values of pelvic obliquity DL-DR showed statistically significant difference between two groups (p<.05). However pelvic rotation, lordotic angle ITL-ILS (max) did not show a significant difference. CONCLUSION: These results showed that gym-ball exercise has positive effect in the pelvic obliquity, torsion and spine kyphotic angle and expected to have positive effect on the body balance, body lineup, and coordination.

The Biomechanical Correlation Analysis of Upper Body according to Forward Head Posture (머리전방자세에 따른 상체의 생체역학적 상관분석)

  • Jung, Yeon-Woo;Gong, Won-Tae;Kwon, Hyeok-Soo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.19 no.2
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    • pp.1-9
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    • 2013
  • Background: The purpose of this study is to analysis of correlation upper body according to forward head posture. Methods: The subjects of this study were 40 female university students who were equally and randomly allocated to a forward head posture group, normal group. Using general posture system, electromyograph, visual analogue scale, tape measurement, neck disability index were evaluated. Results: There was positive correlation between posture analysis and Sternocleidomastoid, neck flexion (p<.05). There was positive correlation between Craniovertebral angle (CVA) and trapezius upper, VAS (p<.05). There was negative correlation between posture analysis and CVA (p<.05). There was negative correlation between Cranial rotation angle and CVA (p<.05). Conclusion: Increased forward head posture lead to increase of pain, muscles activity, so it suggests to be necessary on the prevention of dysfunction and limited activities daily living.

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