• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.304-310
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• 1997

연세대학교 영동세브란스 병원에서 94년 요통환자 2천4백10명을 직업별로 분류한 결과, 주부가 56%, 학생이 13.4%를 차지했다고 발표했다. 특히 주부환자비율은 85-90년에 38.9%로 조사된 것에 비하면 주목할만한 증가세를 보였다. 이러한 주부요통증가의 원인 중 임상적으로 이미 확인된 것이 하이힐에 의한 것이다. 하이힐을 신을 경우 허리에 부담을 주고 요통을 유발할 수 있다는 것이다. 그러나, 이러한 임상적 가설에 대한 구체적인 연구나 검증이 이루어진 바 없어 하이힐이 허리에 어떤 영향을 주는지에 대해 확인할 수 없었다. 따라서, 본 연구에서는 하이힐이 허리에 미치는 영향에 대한 임상적 가설을 검증하고 영향 정도에 대한 구체적 수치를 제시하고자 한다. 이를 위해 5명의 신체 건강한 20대 초반의 여성들이 모집되었고, 하이힐의 굽높이를 독립변수로, 허리 근육 피로도를 종속 변수로 설정하여 하이힐의 굽높이가 허리 근육에 미치는 영향에 대해 조사하였다. 허리 근육 피로도는 Spectral EMG를 통해 분석하였고 정량화되었다. 측정된 자료를 통계 분석한 결과, 하이힐의 굽높이가 여성의 허리 근육에 유의하게 영향을 미침이 발견되었고, 우리 나라 여성에게 적합한 하이힐의 굽높이는 3-5cm 정도임이 밝혀졌다. 본 연구 결과는 하이힐의 디자인에 있어서 굽높이에 대한 추천치로 제안될 수 있으며 여성들의 하이힐로 인한 요통을 어느 정도 예방할 수 있어 여성 근로 손실을 줄이는 데 기여할 수 있다. 본 연구를 하이힐 굽형태나 충격흡수 등의 독립변수 요인을 추가하여 확대하면 하이힐 디자인에 응용하는데 더욱 유용하리라 생각된다. 없었다. 전신쾌적감은 약간 쾌적하게 나타났고 전신온냉감은 약간 따뜻하다라고 나타났으며 손가락끝의 동통감은 약간 아프다고쪽으로 나타났다.때문에 이를 디자인에 곧바로 적용시키기 어려운 점이 있다. 이에 본 연구는 기존의 바용성 평가를 위한 분석도구들이 갖는 문제 점들 해결하여 제품의 사용자 인터페이스 디자인 개발과정에서 활용할 수 있는 평가 분석도구를 개발하는 것을 목표로 한다. 이를 위해 첫째, 다양한 유형의 정보를 포함하는 비디오 정보를 선정하였따. 둘째, 데이터를 다양한 측면에서 추출할 수 있는 Data logger를 개발하였다. 셋째, 데이터를 시각적으로 정리하고 분석할 수 있는 도구를 제안한다. 마지막으로 인터페이스 디자인에서 여러 가지 디자인안을 도출해 내는 작업에 이용할 수 있는 종합화과정을 개발한다. 이러한 일련의 과정이 통합된 컴퓨터 시스템 안에서 이루어지도록 프로그램을 개발하여 정보의 유용성을 높일 수 있도록 한다.at the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtai

• 대한인간공학회지
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• 제33권2호
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• pp.143-153
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• 2014

Objective: The aim of this study is to investigate the effects of trunk-forearm supported sitting on trunk flexion angle, trunk extensor fatigue and seat contact pressure. Background: The relationship between sitting posture and musculoskeletal disorders of the trunk extensor fatigue and seat contact pressure has been documented. The trunk-forearm support type ergonomic chair was devised from the fact that trunk-forearm support has been reported to reduce trunk extensor activity and discomfort. Method: Using three different sitting postures, upright ($P_1$), trunk-forearm supported ($P_2$) and normal sitting ($P_3$), six healthy subjects participated in the study. Motion capture system was used to collect head and trunk flexion angle, and surface electromyography (sEMG) was used to collect myoelectric signal of upper trapezius, lower trapezius, erector spinae, multifidus, and pressure mat system was used to measure seat contact pressure. Results: When trunk and forearm were supported by the ergonomic chair, higher head flexion angle showed upright > trunk-forearm supported > normal in order, and muscle fatigue showed less than upright and normal sitting. Mean seat contact pressure decreased 19% than upright sitting. But muscle fatigue was not affected by each condition. Conclusion: Trunk-forearm supported sitting of the ergonomic chair showed positive effect in respect of trunk and head flexion angle, trunk extensor fatigue, seat contact pressure. To acquire comprehensive understanding of the effectiveness of the ergonomic chair, further studies such as anatomical effects from measurement of external applied loading effect to the body from interface pressure analysis are required. Application: The results of the publishing trend analysis might help physiological effects of trunk-forearm support type chair.

• 대한물리의학회지
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• 제7권2호
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• pp.173-182
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• 2012

Purpose : This study was investigated the effect of lower extremity muscle activity during open kinetic chain exercise (OKC) and closed kinetic exercise (CKC) in normal young adults. Methods : The participants were consisted of forty-one. All subjects were randomly assigned to two groups of open kinetic chain exercise group (n=21) and closed kinetic chain exercise group(n=20). It was perform 3 sets, 3 times per week for 6 weeks both open kinetic chain exercise group and closed kinetic chain exercise group. Subjects were assessed for each subject took pre-test, post-test in 2 weeks, post-test in 4 weeks, post-test in 6 weeks measurement the surface EMG data for vastus medialis and lateralis, lateral and medial hamstring, lateral and medial gastrocnemius, tibialis anterior. Results : The vastus medialis and lateralis muscle activity was significantly increased within the intervention period both group(p<.05). The lateral and medial part of hamstring muscle activity was significantly increased with in the intervention period(p<.05). The tibialis anterior muscle activity of open kinetic chain exercise group and closed kinetic chain exercise group was significantly increased in the intervention period(p<.05). The lateral and medial part of gastrocnemius muscle activity of open kinetic chain exercise group and closed kinetic chain exercise group was significantly increased with in the intervention period(p<.05). Conclusion : It was found that both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed. these exercises can be selectively adapted not only as treatment exercise for patients but also as preventive exercise for normal person to improve balancing ability by conducting proper amount of exercise for each individual's condition and stage.

• 대한물리의학회지
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• 제15권2호
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• pp.75-81
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• 2020

PURPOSE: The purpose of this study was to investigate the effect of taping method using elastic tape and non-elastic tape on pain, grip strength and muscle activity in middle-aged female patients with lateral epicondylitis. METHODS: The subjects were 40- to 50-year-old female patients with lateral epicondylitis. A total of 22 subjects were divided into two groups, and each group had 11 patients. The intervention was carried out three times a week for 4 weeks. One group applied tape using elastic tape (ETG) while the other group applied tape using non-elastic tape (NETG). The measurement factors were pain, grip strength, and muscle activity. Pain was measured using VAS. Grip strength was measured using a grip dynamometer, and muscle activity was measured using EMG in the affected extensor carpi radialis brevis. Changes in interventions were compared among the groups using a paired t-test. The comparison between groups compared delta values (Changed values) between pre- and post-intervention using an independent t-test. RESULTS: In both groups, there was a statistically significant decrease in VAS. However, there was no statistically significant decrease in the delta value of VAS between ETG and NETG. In both groups, grip strength and muscle activity increased after intervention. There were statistically significant differences in delta values between ETG and NETG. CONCLUSION: Taping is a good intervention method for patients with lateral epicondylitis. Both elastic tape and non-elastic tape were effective. In particular, taping using elastic tape is an effective method for improving muscle function with pain reduction.

• 대한통합의학회지
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• 제4권3호
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• pp.17-25
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• 2016

Purpose : This study attempts to examine the effect of the balance exercise on the unstable surfaces for the vital capacity in healthy adults. Methods : A total of 13 subjects was randomly divided into a breathing exercise training group (n=7) and a breathing and balance exercise training group (n=6). Changes in vital capacity and respiratory muscle activity were measured before and after the intervention. The intervention was performed three times a week for four weeks. Forced vital capacity (FVC), forced expiratory volume at one second (FEV1) and maximal voluntary ventilation (MVV) were used as measurement tools for the vital capacity test. Electromyography (EMG) was also used to examine respiratory muscle activity. Result : The breathing exercise training group showed significant improvement in terms of FVC, FEV1 and external oblique (EO), and transverse abdominis/internal oblique (TrA/IO) of MVV. The breathing and balance exercise training group showed significant improvement in terms of FVC, MVV and EO, TrA/IO of FVC and rectus abdominis (RA), EO, and TrA/IO of MVV. However, in comparing changes in vital capacity and respiratory muscle activity before and after the training, the breathing exercise training group and the breathing and balance exercise training group showed a significant difference in terms of MVV. Conclusion : This study is as a preliminary study to find out the relation between a balance exercise and a vital capacity, it is considered to require a further study with several revisions of subjects, duration and time for an intervention.

• 한국전문물리치료학회지
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• 제25권4호
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• pp.46-52
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• 2018

Background: The hamstring muscles in the lower extremity are highly important for knee joint stability and can be classified into medial and lateral hamstrings according to the anatomical position, which have some different functions. To measure the strength of the individual hamstring muscles, manual muscle testing is clinically performed by dividing rotation postures into internal and external postures. However, this has no sufficient scientific background. Objects: This study aimed to test the difference that the tibial rotation would cause in the muscle activity of the medial and lateral hamstrings. Methods: The muscle activities of the biceps femoris, semitendinosus, and semimembranosus were measured in a total of three different postures (neutral position and internal and external rotations) with 3 replications. During the maximal isometric contraction, resistance was constantly provided by the string attached to the strap, not by manual resistance of the examiner. Before and after electromyography measurements, the participants underwent hamstring flexibility measurement using the active knee extension test in the supine position on the treatment table. Results: The semitendinosus had a 12.56% reduction in muscle activity in external rotation as compared with that in neutral position. The biceps femoris and semimembranosus showed reduced muscle activities in both external and internal rotations as compared with those in neutral position. Only the women showed significant decreases in the comparison between pre and post-active knee extension. Conclusion: Only the semitendinosus muscle was consistent with the anatomical speculation. However, the reduction in the muscle activity of the semitendinosus as compared with that in neutral position was only 12.56%, the clinical value of which may be difficult to justify.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.939-947
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• 2010

With the rising numbers of elderly and disabled people, the demand for welfare services using a robotic system and not involving human effort is likewise increasing. This study deals with a mobile-robot system combined with a BWS (Body Weight Support) system for gait rehabilitation. The BWS system is designed via the kinematic analysis of the robot's body-lifting characteristics and of the walking guide system that controls the total rehabilitation system integrated in the mobile robot. This mobile platform is operated by utilizing the AGV (Autonomous Guided Vehicle) driving algorithm. Especially, the method that integrates geometric path tracking and obstacle avoidance for a nonholonomic mobile robot is applied so that the system can be operated in an area where the elderly users are expected to be situated, such as in a public hospital or a rehabilitation center. The mobile robot follows the path by moving through the turning radius supplied by the pure-pursuit method which is one of the existing geometric path-tracking methods. The effectiveness of the proposed method is verified through the real experiments those are conducted for path tracking with static- and dynamic-obstacle avoidance. Finally, through the EMG (Electromyography) signal measurement of the subject, the performance of the proposed system in a real operation condition is evaluated.

• 한국운동역학회지
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• 제17권4호
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• pp.181-190
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• 2007

The purpose of this study was to analyze the muscle fatigue for lower limbs during the level and downhill running. The subjects were 6 males of twenties who have no experience to get the injury in the lower limbs and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. EMG signal was gained by ME3000P8 Measurement Unit and computed the Median Frequency(MF) with the power spectrum analysis in the Megawin software. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps Femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Tibialis anterior(TA) were selected. The result of this study were as follows: The MF of RF decreased in the downhill running than level running in length of time but, the MF of VL was opposite. The MF of BF decreased in the level and downhill running, but, the MF of BF decreased much in the level than downhill running. The MF of GLU decreased much in the downhill running but, almost no change in the level running. The MF of TA decreased in the level running than downhill running. The MF of GL decreased in the level running but, the MF of GM decreased in the downhill running in length of time. This study analyzed the muscle fatigue of the lower limbs with the median frequency on the basis of an assumption that the impact force for the flexion and extension of the joint and the body mass may be much in the eccentric contraction such as the downhill running than level running. RF and GM showed the muscle fatigue in the downhill running than level running. BF and GL showed the muscle fatigue in the level running than downhill running.

• 대한통합의학회지
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• 제4권4호
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• pp.67-75
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• 2016

Purpose: The purpose of this study was to compare Hip-Knee-Ankle(HKA) angle and muscle activation ratio between vastus medialis(VM), rectus femoris(RF), and vastus lateralis (VL), and by this, to examine their relationship. It is aimed to explore how the activation ratio among the muscles involved in patellofemoral kinetics would vary in relation with the frontal alignment of the lower extremity. Subjects and Methods: 26 healthy subjects were recruited for the study. The HKA angles were measured with radiograph. The VM, RF, VL muscle activation level were measured by surface electromyography while each participant performed 4 different types of movement (isometric knee extension, squat, ambulation, step-up) and VM/RF, VM/VL, RF/VL ratios were calculated. Pearson correlation was used to estimate the relationship between the HKA angle and the muscle ratio. Results: There was significant moderate correlation between HKA angle and VM: RF on the left side during ambulation (p<0.05). Moderate correlations were also observed during step-up and squat with less significance (p<0.1). Conclusion: The frontal alignment of the knee measured by the HKA angle was conditionally associated with muscle activation ratio between VM and RF (VM:RF); On the left, during ambulation, step-up, and squat, the more valgus knee tended to correlate with the more VM muscle activation ratio, which is expected to induce more stabilizing effect to the patella and its tracking. It suggests that the frontal alignement measured by the HKA-angle can affect PF kinetics. It also indicates a possibility that increase in valgus alignment of the knee, by the HKA measurement, may not act unfavorably to generate PFP.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.406-413
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• 1997

근전도(EMG:Electromyogram)를 사용하여 국부 근육 피로(Localized Muscle Fatigue)를 정량화으로 분석 하기 위해 널리 이용되고 있는 AR(Autoregressive)모델의 1차 계수, RMS(Root Mean Square), ZCR(Zero Crossing Rate), MPF(Mean Power Frequency), MF(Median Frequency)를 선택하여, 근육이 발휘하는 힘과 시간의 흐름에 따라 근육 피로의 정도를 민감하게 나타내는 매개변수를 규명하였다. 피실험자 10명의 좌우 척추세움근(Erector Spinae Muscle)을 대상으로 등장수축(Sustained Isometric Contraction)조건에서 허리의 신전(Extension)운동을 실시하였다. 이때 발휘해야 하는 힘의 수준은 15%, 30%, 45%, 60%, 75% MVC 로 정하였고 각 수준마다 20초 동안 근전도를 측정하 였다. 데이터 분석은 총20초 구간의 근전도를 0.5초 간격으로 나누어 매개변수들을 각각 구하고 분석을 실시하였다. 시간의 흐름에 대한 피로도 분석 결과, AR 모델의 1차 계수와 MPF가 유의한 차이를 보였으며, 낮은 수준의 %MVC에서는 AR 계수가, 높은 수준에서는 MPF가 민감한 반응 결과를 나타냈다. 그리고 근육이 발휘하는 힘의 정도를 분석하기 위해 주로 사용되고 있는 RMS 보다는 더 AR 계수가 모든 수준에서 뚜렷하게 차이를 보인 것이 확인되었다. 따라서 AR 모델의 1차 계수가 근육의 피로 정도와 힘의 수준을 다른 매개변수에 비해 더욱 민감하게 구별함이 입증되었다. 이러한 결과는 다른 분야에서도 근육 피로를 정량적으로 측정하는데 사용될 수 있을 것으로 생각되며, 개인적 변이도를 고려한 확률 기법을 사용한다면 보다 정확한 근전도 분석이 이루어질 것으로 기대된다.있음을 알 수 있었다. 사료된다.의 결과는 자전거 에르고노미터의 결과가 트레드밀의 결과에 87.60%정도 나타났다.음을 관찰하였다. 특히 vitamin C와 E의 병용투여는 상승적으로 적용하여 간세포손상을 더욱 억제시킴을 알 수 있었다.mance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are signif