• Title/Summary/Keyword: 어깨 높이

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The Investigation of the Changes of Visual Problems in VDT Workers (VDT 작업 전·후 시기능 변화)

  • Gang, Myoung Jin;Choe, Oh Mok
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.2
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    • pp.33-39
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    • 2002
  • The purpose of this study is to evaluate the effects of continuing work on VDT(video display terminal). Therefore, we examined visual fatigue by a questionnaire and measured frequency of blinking, tear film break-up time(BUT), height of palpebral fissure, visual acuity, refraction with retinoscopy and accommodation before and after two hour long VDT work. For the ocular symptoms, the greatest number was tired eyes accounting for 34%. In the visual symptoms, blurred vision was the highest rate of 83% and in case of systemic symptoms, shoulder pain was 38% marked top ranking but other symptoms were also distributed similar rate. The frequency of blinking during VDT work decreased significantly comparing with the one at rest. The average frequency of blinking is 8/min during VDT work and 22/min at rest. The BUT measured immediately after VDT work decreased much more than in the resting state. The average BUT was 7sec immediately after VDT work and 12sec at rest. The height of palpebral fissure during VDT work increased significantly comparing with the value at rest. The average height of palpebral fissure was 7.69mm at rest and 9.04mm during VDT work. The average visual acuity decreased almost 9.5% from 0.63 to 0.57, but refraction with retinoscopy increased about 0.28D to the direction of myopic shift. The amplitude of accommodation decreased approximately 1.49D from 7.98D to 6.49D and this resulted from the prolongation of near point of accommodation. Near point of convergence also was prolongated from 9.45cm to 10.30cm after VDT work.

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A Kinematical Analysis of Mae-ukemi (forward breakfall) in Judo (유도전방낙법의 운동학적 특성 분석[I])

  • Kim, Eui-Hwan;Kim, Ji-Tae
    • Korean Journal of Applied Biomechanics
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    • v.12 no.2
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    • pp.131-142
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    • 2002
  • The purpose of this study was to analyze kinematic variables of a Mae-ukemi (forward breakfall :MU) in Judo through 3-D image analysis with five Judoka with over 2 years' career (2nd dan, 3rd dan). The kinematic variables include posture, and distance variables; the mean values and the standard deviations for each variable were obtained to analyze kinematic variables of a MU in Judo. From the data analysis and discussion, the following conclusions were drawn : 1) Posture variables : The angles of wrists during right before Mae-ukemi (RBU) were extended from the just MU position(MUP) and flexed from in the right after MU(RAU), and there was a difference in the displacement between the angles of the right and left wrists. The angles of elbows were flexed in the ready position from in the RAU. The angles of ankles were flexed from the ready position to that down position, extended from the down position to that transition, and flexed from the transition positiont to that RAU. 2) Distance variables : The distance height between the mat and shoulders in the RBU(32.2cm) to in the MUP(18.3cm) and in the RAU(20.5cm). during that height between the mat and hips in the RBU(48.0cm) to in the MUP(23.4cm), and in the RAU(30.6cm).

The Comparative Kinematic Analysis of a Volleyball Spike Serve (배구 스파이크 서브 동작의 운동학적 비교 분석)

  • Park, Jong-Chul;Back, Jin-Ho;Lee, Jin-Taek
    • Korean Journal of Applied Biomechanics
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    • v.19 no.4
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    • pp.671-680
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    • 2009
  • We performed a study to obtain kinematic data on the characteristics of spike serving techniques used by volleyball players, including other basic data that will be useful for in-field applications. We used three-dimensional videography to compare good tough serves and serve errors. The subjects were 3 left attackers whose spike serves were videographed (60 fileds/s). The three-dimensional coordinates were calculated using the direct linear transformation method and then analyzed using the Kwon 3D software program version 3.1. There was no difference in time elapsed. However, the vertical displacement of the center of body mass(CM) differed between the 2 types of serves: in successful serves, the CM tended to be lower, as did the maximum ball height at the time of hitting. Further, the higher the level of the hitting hand was at the moment of impact, the higher was the likelihood of scoring points. In good serves, the players tended to accelerate their CM movement just before jumping to hit the ball and descend rapidly at the moment of hitting. The hand speed along with ball velocity during the impact was proven to be higher in successful serves. Moreover, in successful serves, the shoulder angles increased to a greater extent while the elbow angles were maintained constant. This possibly resulted in faster and more precise serves. An important observation was that the angle of trunk inclination during the jump did not increase with the swing of the shoulders, muscle tendon complex.

The Kinematical Analysis of Straddle Jump to Push up Motion on Sports Aerobics (스포츠 에어로빅스 Straddle Jump to Push up 동작의 운동학적 분석)

  • Kim, Cha-Nam
    • Korean Journal of Applied Biomechanics
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    • v.12 no.2
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    • pp.77-90
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    • 2002
  • This study serves the purpose of understanding about correct jump and landing motion through Kinematical Analysis of Straddle Jump to Push up Motion at target by four elite sports aerobics athletes have more than four years career. And further more that make good assistance for coaches effective guidance through an offer basic data and correct diagnosis, evaluate of motions. It was picture-taked by two-video camera for Straddle Jump to Push up Motions. Camera speeds are 60 frame/sec. There are Kinematical Variation elements for analysis, the displacement of COG, each angle displacement left/right of shoulder-joint, each angle displacement left/right of knee-joint and each speed left/right of tip of the toes. Every each person accomplished severaly 3 times and we have acquired this conclusion. The conclusions were as follows; 1. Each situation for displacement of COG showed low height of COG by phase 1, 4, 5(79.05${\pm}9.07,\;46.41{\pm}3.65,\;18.66{\pm}0.54cm$) and It showed high height of COG by phase 2, 3($120.80{\pm}6.13,\;148.12{\pm}9.19cm$). 2. Each displacement left, right of shoulder-joint flexion by phase 1($91.07{\pm}8.30,\;90.77{\pm}5.72$deg/sec)and It showed maximal extension angles by phase 2($102.48{\pm}10.00,\;102.39{\pm}10.51$deg/sec). in part of phase 3, left of shoulder-joint angle($94.43{\pm}4.12$deg/sec) showed flexion phase 1, the other right shoulder-joint angle(88.38${\pm}$4.98deg/sec) showed more a little lower than phase 1, in last phase that showed most low by phase 4($70.58{\pm}13.72,\;54.24{\pm}11.58$deg/sec). 3. Each displacement left, right of hip joint showed maximal extent conditions by phase 2, 3($160.35{\pm}22.68,\;1534.77{\pm}5.40$deg/sec, $150.04{\pm}12.79,\;145.54{\pm}13.00$deg/sec) beside, ankle-joint showed minimal angle by phase 1, 4($93.59{\pm}18.92,\;85.37{\pm}13.23$deg/sec, $66.60{\pm}15.77,\;80.60{\pm}16.57$deg/sec). 4. Each displacement left, right of hip joint showed maximal extent conditions by phase 2($157.15{\pm}9.13,\;163.52{\pm}8.18$deg/sec), and right of hip joint showed minimal angle by phase 3($110.87{\pm}13.81,\;77.53{\pm}8.95$deg/sec) It showed alike condition of low angle by phase 1, 4($91.04{\pm}2.31,\;96.26{\pm}2.20$deg/sec). 5. Each displacement left, right of knee-joint showed maximal extent conditions by phase 1, 3, 4($173.46{\pm}2.95,\;171.51{\pm}5.44$deg/sec, $172.24{\pm}4.49,\;171.26{\pm}0.65$deg/sec, $162.78{\pm}2.13,\;164.10{\pm}5.97$deg/sec) but It showed flexion only left of knee-joint by phase 2($164.45{\pm}7.51,\;159.38{\pm}3.48$deg/sec). 6. Each speed left, right of the tip of the toes showed most fastest when someone jumped with lift up leges by phase 1, 2($321.32{\pm}67.91,\;316.90{\pm}41.97$cm/sec, $410.06{\pm}153.06,\;399.77{\pm}189.34$cm/sec), It showed more less speed than phase 1,2 by phase 3($169.74{\pm}67.17,\;150.00{\pm}63.80$cm/sec) and It showed most slow speed than phase 1,2,3 by phase 4($87.22{\pm}34.90,\;85.72{\pm}52.23$cm/sec).

Effects of Teratainment Taping and Footpad Exercise on the Improvement of Flat Foot in a University Student (테라테인먼트 테이핑과 발바닥 운동이 대학생의 평발 개선에 미치는 영향)

  • Lee, Jeong-Uk;Yoon, Young-Jeoi;Ko, Sun-Kun
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.4
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    • pp.369-375
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    • 2019
  • This study looked at the effects of teratainment taping and footpad exercise on the improvement of flat foot in a university student. We divided it into flexible flat foot taping group(n=13), flexible flat foot exercise group(n=14), rigid flat foot taping group(n=12), rigid flat foot exercise group(n=13) through a navicular drop test. After one hour's application of teratainment taping and footpad exercise, the height change of navicular, balancing ability and postural stability were evaluated. Change in the height of the navicular was measured before and after intervention, and the balancing ability was measured timed up & go test, and the postural stability ability was evaluated for stability limits in shoulder-width double leg stance, narrow base double leg stance, tandem stance. According to result, there was a statistically significant difference in the left and right foot of the flexible tapping group, right foot of the flexible tapping group, right foot of the rigid tapping group in the change in the height of the navicular in comparison pre- and post- intervention(p<0.5). There were no statistically significant differences in pre- and post- intervention comparisons intragroup and intergroup in balancing ability. There was a statistically significant difference in flexible flat foot exercise group and rigid flat foot taping group in tandem stance in comparison pre- and postintervention in the postural stability(p<0.5). And there was a statistically significant difference in tendem stance of the flexible flat foot exercise group compared to the rigid flat foot exercise group(p<0.5). The results of this study show that teratainment taping and footpad exercise have a significant effect on the improvement of flat foot in adults. Therefore, it is recommended to apply teratainment taping and footpad exercise to improve flat foot.

Analysis Characteristic the Using Surface Electromyography of Head Neck and Around of Shoulder Muscles Express Scaling Working of the Dental Hygienist (치과위생사의 스켈링 작업 시 발현되는 두경부 및 견부 주위 근육들의 표면 근전도를 이용한 특성 분석)

  • Jeon, Eun-Suk;Nam, Kun-Woo;Ha, Mi-Sook
    • Journal of dental hygiene science
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    • v.12 no.4
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    • pp.437-442
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    • 2012
  • The current research examines the aching part and the muscle activity that happens during scaling practice subject to 20 dental hygienic students and therefore propose a basic data according to the working attitude of the Dental Hygienist. During the scaling we used the free EMG (BTS Inc., Milan, Italy) to measure the muscle activity, and in order to check the musculoskeletal pain area we used the Nordic-style questionnaire, and the measured research results are as following: At the moment of scaling according to posture the occurrence of the pain showed no difference among the groups elbow, back, leg, knee, ankle/foot but in the neck, shoulder, wrist/hand, waist showed a high difference in the degree of pain according to posture. Results from measuring the muscular activity according to posture, in the group that had a good posture, the trapezius and brachial muscles showed a change according to time, and in the group that had a bad posture a high muscle activity was shown in larynx, trapezius and brachial muscles. In the muscle activity, the changing aspect between the two parts, the group that fulfilled a scaling in a good posture showed a low muscle activity, but in the group that fulfilled the scaling in a bad posture the muscle activity increased excessively. Therefore we examined that when fulfilling a scaling maintaining a bad posture can help in using more effectively the activity of the muscle, in the future I think there is a need to raise the office efficiency by subjecting to dental hyginiest that are in the clinics and performing experiments.

A study on conceptual evaluation of structural stability of room-and-pillar underground space (주방식 지하공간의 구조적 안정성 평가개념 정립에 관한 연구)

  • Lee, Chulho;Chang, Soo-Ho;Shin, Hyu-Soung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.6
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    • pp.585-597
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    • 2013
  • In this study, in order to evaluate stability of the room-and-pillar underground structure, a series of preliminary numerical analyses were performed. Design concept and procedure of an underground structure for obtaining a space are proposed, which should be different from structural design for the room-and-pillar in mine. With assumed material properties, a series of numerical analyses were performed by varying size ratios of room and pillar and then the failure modes and location at yielding initiation were investigated. From the results, relationship between the ratio of pillar width to the roof span (w/s) and overburden pressure at failure initiation shows a relatively linear relation, and the effect of w/s on structural stability is much more critical than the ratio of pillar width and height (w/H) which is a crucial parameter in design of the room-and-pillar mining. It means that roof tensile failure and shear failure at shoulder and pillar are necessary to be considered together for confirming overall structural stability of the room-and-pillar structure, rather than considering the pillar stability only in mining. Failure modes and location at failure initiation were varied with respect to the ratio of room and pillar widths. Therefore, it is necessary to simultaneously consider stability of both roof span and pillar for design of underground structure by the room-and-pillar method.

Comparison of 3D Scanned Anthropometric Data between Korean and American Adults by using Ratios and Indices (지수치를 활용한 한국과 매국 성인 3차원 인체치수 비교)

  • Yi, Kyong-Hwa;Istook, Cynthia
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.6
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    • pp.959-967
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    • 2008
  • The body measurement ratios and indices used in this study are all 3D female measurement data of the two countries were obtained from Size Korea Project and SizeUSA Project. The purpose of the study is to compare and analyze body measurement data between two countries. The results of this research are helpful for the clothing manufacturer and company to trade with America. The samples were 1,988 Korean and 6,306 American females. Thirty-five body measurement ratios and indices were chosen as the principal measurements in making garments. The conclusion of this research was as follow; First, U.S. females have measurements that exceed Korean women, except for crotch length total and shoulder slope. Second, the correlation coefficients of height and weight are relatively higher than other measurements in the two countries' body measurements. Finally, American women's height ratios are significantly bigger than Korean women's in most height ratios. On the other hand, Korean are significantly bigger than American in weight ratios. The drop values of Korean females are also smaller than those of American. It was recognized that American women are much bigger, wider and more obese than Korean according to the results by utilizing the girth ratios. BMI, Rohrer and Vervaeck index.

Kinetic Analysis of the Salto Side-Ward Tucked on the Balance Beam (평균대 옆공중돌기 동작의 운동역학적 분석)

  • Yeo, Hong-Chal;Chang, Jae-Kwan
    • Korean Journal of Applied Biomechanics
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    • v.18 no.3
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    • pp.61-69
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    • 2008
  • The purpose of this study is to examine the success or failure on the balance beam in element group requirements posture which is bending salto side-ward tucked through kinetic analysis. The national team players were participated. The goal was to present training methods to coaches and athletes so as to provide scientifically useful information. The results from this study were summarized as below. When the performance was successful, the features of the body's center of gravity during the side somersault motion showed to spread from the center of the balance beam and the center of the gravity moved to the direction of the body's rotation. In the spring sections - event2 and 3, when the performance was successful, up/down fluctuation became more wider and increased air time. It supported the result that the projecting variable was higher than in failure trial. In addition, the right side hip joint angles and speed, and angular velocity as jumping up for a leap were larger than in failure trial. Those variables showed the optimal conditions for a leap. By increasing the speed of the upper limb from the shoulder and the speed of the shoulder joint angular velocity, the momentum was increased. Especially the right side shoulder joint angular velocity increased dramatically because the right leg was held. As to the side somersault motion, the angular momentum of successful trial with respect to x-axis was bigger than failed trial. It indicated that the increasing angular momentum with respect to x-axis was an important factor in flying motion. Besides, as to side somersault, the appropriate proportion of angular momentum with respect to y-axis and z-axis was a key to successful trails.

The effects of 8-week spinal stabilization exercise program on NDI, postural balance and body shape change in patients with chronic neck pain (8주간의 척추 안정화 운동 프로그램이 만성 경부통 환자의 NDI, 균형 능력 및 자세 변화에 미치는 영향)

  • Kim, Ju Eun;Ha, Sung;Kim, Won Moon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.43-51
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    • 2020
  • This study examined how the eight-week spinal stabilization exercise program affects the cervical disability index, postural balance ability, and body shape change. The exercise program performed 60 minutes of spinal stabilization exercise three times a week for eight weeks. Sixteen patients with chronic neck pain, who complained of neck pain for six months, were classified into exercise group (n=8 patients) and control group (n=8 patients). The results before and after the eight-week exercise program were observed. Significant differences were observed in the time, group, and interaction of the neck disability index (p<.05). The balance ability showed significant interaction effects between the groups and periods (p<.05). Significant differences were noted in the timing and interaction in the pelvic inclination angle in posture change (p<.05), and there were significant differences in the group, timing, group, and interaction in the cervical and shoulder position angles (p<.05). The above results showed that the spinal stabilization exercise significantly improved the cervical disability index, balance ability change, and body shape change in patients with chronic neck pain. Future studies will analyze the specific changes in spinal structure through radiographic imaging to increase the validity of spinal stabilization exercise.