• 한국운동역학회지
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• 제25권1호
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• pp.95-101
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• 2015

Objective : The purpose of this study was to analyze the effects of multisensory exercise on foot pressure sensitivity and balance for the elderly. Method : The subjects were 17 elderly women (11 for the experimental group and 6 for the control group) with a mean age of 83. The subjects all lived in senior residence centers in Seoul. Multisensory exercise was done twice a week for 40 minutes during a 12 week period. Exercise programs were changed every 3 weeks according to the principal of gradual progress of the exercise. In order to train the vision system subjects were asked to open and close their eyes during exercise. When it came to training the vestibular system, subjects stood and walked on high elastic mats with their bare feet. For the somatasensory system subjects always stood and walked with their bare feet. The sub-Metatarsal Pad Elasticity Acquisition Instrument (MPEAI) was used to measure foot pressure sensitivity. MFT Balance test (V1.7) was used to measure anterior / posterior and medial / lateral directional balance. For the statistical analysis the IBM SPSS 21.0 was used to perform Repeatde measured ANOVA and Wilcoxon ranked test. Results : For the multisensory exercise group Hallux (after 6 weeks, 12 weeks), heel (after 6 weeks) and 2nd Metartarsal $40^{\circ}$ (after 6 weeks) pressure sensitivity increased statistically, but the control group didn't change. Also, balance didn't change for the experimental and control group statistically. Conclusion : Exercise with bare feet on a high elastic mat had a partially positive effect on foot sensitivity.

• Physical Therapy Rehabilitation Science
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• 제6권4호
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• pp.182-188
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• 2017

Objective: The purpose of this study was to compare ankle function between adults with and without Down syndrome (DS). Design: Cross-sectional study. Methods: Ten adults with DS and 18 without participated in this study and underwent manual muscle test (MMT), range of motion (ROM) assessment, star excursion balance test (SEBT), and functional movement screen (FMS). The tests were demonstrated to increase their accuracy and the actual measurements were assessed after one or two demonstrations. To minimize the standby time and fatigue, the travelled distance and measuring order were adjusted. To remove the influence of shoes on the measurements, the shoes were taken off and only socks were worn. Results: Dorsal and plantar flexion MMTs of both ankles were significantly weaker and plantar flexion ROM of both ankles were significantly lower in adults with DS compared with those without (p<0.05). However, dorsal flexion ROM of both ankles were not significantly different between them. There were significant differences in distances measured in all the directions (anterior, anterolateral, lateral, posterolateral, posterior, posteromedial, medial, and anteromedial directions) of SEBT (p<0.05). Significant differences were also demonstrated in the scores of hurdle step, inline lunge, shoulder mobility, and rotary stability among the seven items of FMS (p<0.05). Conclusions: To enhance the dynamic stability of adults with DS, it is necessary to improve ankle stability by strengthening the ankle dorsal and plantar flexors.

• 한국운동역학회지
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• 제20권1호
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• pp.41-47
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• 2010

The purpose of this study was to evaluate the kinematic effect of upper extremity usage for the scoccer instep kick motion. Ten male university students were recruited as the subjects. Temporal parameters, ball velocity, velocity of CG, angle of segment, angular velocity, and trunk orientation angle were determined for each trial. The results showed that temporal parameters in WU and WORU were significantly less than those found in WOU during pre impact phase. These indicated that no usage of upper extremity may increase excessive setup time in order to improve the accuracy of instep kick. Angle of right knee in WOU at LC was significantly greater than corresponding value for WU since angular momentum contributions of the lower limb were not effectively balanced by contributions of the upper limb. We found that the lower extremity movement was controlled by lateral movement in the trunk as a result of no usage of the upper extremity, resulting in the relatively greater trunk rotation in WOU.

• 한국운동역학회지
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• 제21권2호
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• pp.215-222
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• 2011

The purpose of this study was to analyze the effects of the use of the lower extremity supporter to ground reaction force(GRF) & EMG in women. Five women participated in the experiment conducted in the study(age: $46.7{\pm}3.5$ yrs, weight: $52.3{\pm}2.2$ kg, lower extremity height: $74.1{\pm}0.9$ cm, knee height: $40.7{\pm}1.4$ cm). The Ground reaction force was measured by AMTI ORG-6 and the Muscle activity of the lower extremity was measured by an 8-channel surface EMG system(Noraxon Myoresearch, USA, 1000Hz). We statistically compared muscle activity and ground reaction force with and without the lower-extremity supporter by one-way repeated ANOVA. The results were as follows. First, the use of the lower extremity supporter affects the ground reaction force along the anterior-posterior axis(Y). Second, the vertical(Z-axis) reaction force on the upper part of the lower extremity supporter increase because of the difference between the interval of vertical movement. Third, the muscle activity of the lateral gastrocnemius and rectus femoris was higher in the upper part of the lower extremity supporter. Further research for example, on a comparative analysis of joint moments, the effects of direct stressor on joints. and the relationship between muscle activity and joint movement, is necessary for a better understanding of the effects of the lower-extremity supporter.

• 항공우주시스템공학회지
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• 제14권1호
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• pp.16-20
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• 2020

차량이 주행 중에 그리고 항공기가 활주로에 착륙하는 순간과 활주 중에 발생하는 피로는 착륙장치, 기체와 차량의 현가장치 등에 수명 주기와 밀접한 관련이 있다. 휠에 작용하는 하중들은 종축 힘, 횡력, 수직력과 제동력이다. 차량의 동특성과 내구성을 연구하기 위해 본 논문의 시뮬레이터는 시험실에서 실제 노면 형상을 재현에 사용된다. 그러므로 제품 개발 시간과 비용을 절감할 수 있다. 하드웨어적으로 유압 피로 시뮬레이터 구조의 중요한 요소는 각 축을 분리하고 여러 하중과 진동을 견뎌내는 것이다. 본 논문의 역기구학적 해석 방법은 Dummy wheel 중심에서 축 방향으로 최대 동작 변위를 준 후 커플링에 의한 유압 서보 작동기의 작동 크기를 도출한다. 해석의 결과는 실제 노면 형상을 정확하게 재현하기 위해 축 간의 커플링이 미약함을 확인하는 것이다.

• 한국광학회지
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• 제21권6호
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• pp.241-246
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• 2010

본 논문에서는 근접장 패턴의 깊이와 종횡비(aspect ratio) 향상을 위해 전기장이 적용된 노광후굽기(electric field enhanced postexposure baking) 공정을 제안하였다. 전기장이 적용된 노광후굽기 공정 중 광산(photoacid) 분포를 기술하기 위하여 픽(Fick)의 확산 제 2법칙에 기반을 둔 지배방정식을 구성하였다. 수치해석(numerical calculation)을 통해 전기장의 세기가 0 에서 $8.0{\times}10^6\;V/m$ 로 증가함에 따라 광산의 수직적 이동거리가 늘어나는 것에 반해 수평적 이동거리는 거의 변화가 없음을 확인하였고, 이 때 근접장 패턴 형상을 얻었다. 이를 통해 근접장 패턴의 깊이, 종횡비, 패턴의 측벽 각(sidewall angle)이 향상됨을 알 수 있었다.

• 구강회복응용과학지
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• 제21권1호
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• pp.43-57
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• 2005

Temporomandibular disorders have been defined as a collective term embracing a number of clinical problems that involve the temporomandibular joint, the masticatory nuscles, and associated structures. There have been many different contributing factors of TMDs which were traumatic, occlusal, pathophysiological and psychosocial. Among there factors, the effect of occlusion on TMDs have been a controversy for a long time. The purpose of this study was to investigate the effect of occlusal factors and oral habits on TMDs. In this study, 140 subjects with signs and symptoms of TMDs and diagnosed of TMD in the Orofacial Pain clinic of Yonsei University Dental Hospital though March to July 2004 were selected for the TMDs group and 50 subjects without any signs and symptoms of TMDs as the control group. The subjects were evaluated clinically in TMDs' Occlusal and Prosthodontic Restoration examinations. TMDs' examination was composed of the TMJ pain, sound, locking, temporal or masseter muscle palpation, mandibular movement, oral habits and headache. Occlusal examination was made of overjet, overbite, lost teeth number, nonfunctional interference, midline shift, then pattern of lateral movement and attrition. prosthodontic restoration examination had the existence of restoration, placement, then number of crown or bridge and Satisfiable index which estimated the quality of occlusal state of prosthodontic restorations. Following results were obtained : 1. The prevalence of TMDs was higher in their 20s & 30s, female of the TMD patients group. 2. The clenching frequency in the TMDs group(40.71%) was higher than those in the control group(18.00%), and there was a significant statistical difference(p<0.05). 3. The frequency of Nonfunctional interference in the TMDs group(10.00%) was higher than those in then Control group(2.00%), and there was a significant statistical difference(p<0.05). The result of this study indicated TMDs prevalence was higher in their 20s, 30s, female group of TMDs patients similar to the previous studies. Clenching and nonfunctional interference were estimated as the contributing factors of TMDs.

• The Journal of Korean Physical Therapy
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• 제25권4호
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• pp.210-216
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• 2013

Purpose: A cost effective tool for the clinical measurement of trunk reposition sense is clearly needed. This study was to analyze intrarater and interrater Reliability of trunk repositioning error (TRE) test which assesses trunk position sense using a portable digital inclinometer. Methods: Twenty four normal healthy subjects were recruited. TRE was measured using a portable digital inclinometer. A digital inclinometer (Acumar-ACU360; Lafayetter Instrument) with precision to $1^{\circ}$ was placed on skin over the spinous process from first to second thoracic vertebra (T1-T2) and secured with double-sided tape. TRE test during sitting forward and lateral flexion movement was assessed. When they reached a point approximately 50% of full trunk flexion range, the examiner instructed the subjects to stop and told them. This was the target position that they should try to reproduce exactly. Each subject performed six trials. Results: ICC (2,1) for intrarater reliability (with-day and between-day) of TRE test in sagittal and frontal plane of movement was 0.75 and 0.78 (excellent reliability). Interrater reliability was 0.66 in sagittal and 0.64, frontal plane (fair to good reliability). However, there were poor correlations between an average of TRE test in sagittal and frontal plane. Conclusion: TRE test using a portable digital inclinometer demonstrated good to excellent reliability. The device may be a cost effective clinical measurement for trunk reposition sense measurement.

• 한국운동역학회지
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• 제23권4호
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• pp.369-376
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• 2013

The purposes of this study were to assess dynamic stability toward pelvis-spine column distortion during running and to compare the typical three-dimensional angular kinematics of the trunk motion; cervical, thoracic, lumbar segment spine and the pelvis from the multi-segmental spine model between exercise group and non-exercise group. Subjects were recruited as exercise healthy women on regular basis (group A, n=10) and non-exercise idiopathic scoliosis women (group B, n=10). Data was collected by using a vicon motion capture system (MX-T40, UK). The pelvis, spine segments column and lower limbs analysiaed through the 3D kinematic angular ROM pattern. There were significant differences in the time-space variables, the rotation motion of knee joint in lower limbs and the pelvis variables; obliquity in side bending, inter/outer rotation in twisting during running leg movement. There were significant differences in the spinal column that is lower-lumbar, upper-lumbar, upper-thoracic, mid-upper thoracic, mid-lower thoracic, lower thoracic and cervical spine at inclination, lateral bending and twist rotation between group A and group B (<.05, <.01 and <.001). As a results, group B had more restrictive motion than group A in the spinal column and leg movement behaved like a 'shock absorber". And the number of asymmetry index (AI) showed that group B was much lager unbalance than group A. In conclusion, non-exercise group was known to much more influence the dynamic stability of equilibrium for bilateral balance. These finding suggested that dynamic stability aimed at increasing balance of the trunk ROM must involve methods and strategies intended to reduce left/right asymmetry and the exercise injury.

• 한국운동역학회지
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• 제24권3호
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• pp.189-199
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• 2014

The purpose of this study was to compare pflugbogen's biomechanical characteristics between on the ski simulator and snowed ski slope to develop interactive ski simulator. Nine ski instructors(sex: male, age: $29.6{\pm}5.4yrs$, height: $176.0{\pm}5.6cm$, body mass: $76.0{\pm}14.0kg$) belong to Korean Ski Instructors Association participated in this research. 24 Infrared cameras for snowed ski slope experiment and 13 infrared camera for ski simulator experiment were installed near by path of pflugbogen. The participants did pflugbogen on the snowed ski slope and the ski simulator both. During the experiment, the participants weared motion capture suit with infrared reflective makers on it, and plantar pressure sensors in ski boots, so that ski motion and plantar pressure data were collected together. Displacement of COG(center of gravity) movements, trunk flexion/extension angle, adduction/abduction angle, and plantar pressure data were significantly different between on the simulator and ski slope. However, percentage of time of COG movement in the phases during medial/lateral and anterior/posterior movement were not significantly different. Findings indicate that the difference between two groups occurred because the ski simulator's drive mechanism is different from ski motion on the slope. In order to develop the ski simulator more interactively for pflugbogen, the ski simulator's drive mechanism need to be reflected 3D motion data of pflugbogen on the slope that were purposed in this research.