• Journal of Life Science
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• v.24 no.10
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• pp.1125-1131
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• 2014

The purpose of this study was to investigate the relationship between quadriceps composition and its functional contractility in obese and nonobese elderly individuals. Thirty-four ($70{\pm}2yr$) individuals (obese, n=21; nonobese, n=13) participated in the study. The thigh composition was assessed with a CT scan, and its functional contractility was measured with an isotonic dynamometer. Variables were analyzed with a $2{\times}2$ two-way ANOVA and a contrast test (p<0.05). There were no between-group differences in the subjects' ages and heights, but individuals in the obese group were approximately 23% heavier and had 18% more fat than those in the nonobese group, regardless of gender. The total thigh volume of the obese elderly was greater (~29%) than that of the nonobese elderly, regardless of gender, and the fat volume (~39%) of the obese elderly was greater than that of the nonobese elderly, regardless of gender (p<0.05). Interestingly, the obese elderly tended to have a greater thigh muscle volume (~17% for males [p<0.05] and ~10% for females) than the nonobese. Despite the greater muscle volume, the peak knee extensor torque of the two groups was comparable or slightly greater in the obese individuals. However, when this was normalized by the total thigh volume, the nonobese males showed significantly greater peak torque (~26% for right and ~20% for left; p<0.05) compared to the obese males. The nonobese females also showed greater peak torque (~8% for both legs) than the obese females after normalization, but the result was not statistically significant. In conclusion, although the obese elderly individuals had greater quadriceps muscle mass than the nonobese, the normalized peak torque of the obese was significantly lower than that of the nonobese, implying a lower degree of muscle contractility.

• Journal of the Korean Arthroscopy Society
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• v.3 no.1
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• pp.9-16
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• 1999

Purpose : We have evaluated the outcome of the operative treatment of PCL rupture using the achilles tendon allograft. Materials and Methods : A retrospective study was completed for 30-PCL reconstruction cases, using the achilles tendon allograft from september 1996 to march 1998. There was an average follow up of 24 months, with range of 12 to 50 months. Results : The active range of motion was improved postoperatively. The Lysholm Knee Score was improved from a mean of 54 points preoperatively to 87 points postoerative 18 months. The "Cybex 340 isometric test" revealed satisfactory results compared with autograft. Conclusions : Use of allograft for recostruction of the PCL is an attractive option because it precludes the harvesting of autogenous tissue in a knee that is already at risk for patellofemoral and tibiofemoral osteoarthrosis.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.2
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• pp.129-134
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• 2006

Purpose: In the professional soccer team, we performed pre-seasonal physical examination and analyzed the results to establish a standardization data in relation to their position. Materials and Methods: We performed physical examination to the professional soccer team, consisted 34 player's average age 24.9 years. The examination performed were questionnaire on history, musculoskeletal examination, muscle power test, physiologic test, functional test. Results: According to the relationship between player position and injury pattern,. Knee injuries are most frequent on history. Physical examination outcome was that forward were prone to flexor hallucis longus tendinitis, midfielder for chronic ankle instability, defender for achilles tendinitis. Isokinetic test was done at dominant side, Peak torque to body weight ratio was 55.1%. Physiologic test checked body fat percentage was midfielder was superior as 19.8 (SD 2.9). Functional test out-come was that back strength 125 N. sergeant jump 59.6 cm, reaction time 208.5 sec, flexibility 19.2 m/s, side step 39.9 cm. Conclusion: Pre-seasonal physical examination gave us the standardization data and preventive measurement could be advocated from this results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.628-634
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• 2016

Many pitchers suffer from various types of injury (distortion, sprain and so on). The rate of injury is increased if there are differences in strength between the extensor and flexor muscles when a joint movement is performed with maximum speed. However, there has been insufficient research into the injury caused by strength differences between the extensor and flexor muscles. Thus, the purpose of the study was to examine the effects of elbow ulnar collateral ligament injury on the maximal isometric strength in young baseball pitchers. The data collection was conducted for 2 weeks. The subjects (n=36) who participated in this study were placed into either the injury group (n = 18, IG) or normal group (n = 18, NG). The maximal isometric strength for the pectoralis major (PM), infraspintus (I), biceps brachii (BB), triceps brachii (TB), flexor carpi radialis (ECR) and extensor carpi radialis (FCR) muscles were determined by an isometric strength machine (K-DFX) and then the differences in strength were calculated by muscle group. All of the data were analyzed by SPSS 18.0 with the independent t-test. In the results, the maximal isometric strengths in the IG for the I (p=0.035), BB (p=0.031) and TB (p=0.041) were significantly lower than those in the NG, while that for the ECR (p=0.047) was significantly greater. In addition, the differences of the maximal isometric strength between the PM and I (p = 0.008), BB and TB (p = 0.002), and FCR and ECR (p = 0.032) in the IG were significantly greater than those in the NG. In conclusion, the differences in muscle strengths of the subjects in the IG were greater than those in the NG, which suggests that they might have a higher injury rate in the future. However, they might be able to recover from their injury and achieve better performance if the differences in strength were reduced by training.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.295-306
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• 2002

The purpose of this study was analysis inter relative the ball velocity and isotonic torque of shoulder joint. The subject were twelve overthrow pitcher of professional baseball player. The measurement was used Cybex 6000. The results of this study were as follows : 1. As the siting position of maximal adduction torque of dominant, A group was higher than B group. As the non-dominant, B group was higher than A group for improved angular velocity. There is no significance difference between group. 2. As the siting position of maximal abduction torque of dominant and non-dominant, B group was higher than A group for all measurement. There is no significance difference between group. 3. As the layed position of maximal internal torque of dominant, A group was higher than B group. As the non-dominant was just higher at $180_{\circ}$/sec than B group, B group was higher at $60_{\circ}$/sec and $300_{\circ}$/sec than A group. There is no significance difference between group. 4. As the layed position of maximal external torque of dominant and non-dominant, A group was more higher than B group for all measurement. There is no significance difference between group. 5. As the standing position of maximal internal torque of dominant, A group was just higher at $60_{\circ}$/sec than B group, B group was higher at $180_{\circ}$/sec and $300_{\circ}$/sec than A group. As the non-dominant, B group was higher than A group. There is no significance difference between group. 6. As the standing position of maximal external torque of dominant, A group was higher $60_{\circ}$/sec and $180_{\circ}$/sec than B group. But B group was higher $300_{\circ}$/sec than A group. As the non-dominant, B group was higher than A group. There is no significance difference between group.

• Exercise Science
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• v.21 no.3
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• pp.373-384
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• 2012

The effects of inspiratory muscle training in conjunction with aerobic exercise on inspiratory muscle strength, pulmonary function, and maximal oxygen uptake(VO₂max) were examined. Twenty four healthy collegiate men were divided into three groups; respiratory muscle training group(RTG; n=8), running exercise group(REG; n=8), and both respiratory muscle training and running group(BTG; n=8). Their pulmonary function, maximal inspiratory pressures(PImax), and VO₂max were assessed before and after intervention. RTG underwent inspiratory muscle training(IMT) with load set to 50 % of PImax, 30 times per session, twice a day, 4 days a week REG ran on a treadmill at 70-75 % of VO₂max for 30 min a day, 4 days a week. BTG participated both IMT and the running exercise. Participant's anthropometric parameters and pulmonary function were not changed. VO₂max increased by 6.1±3.3 %, 5.9±6.6 %, and 10.0±8.3 % in RTG, REG, and BTG, respectively(p< .05), and PImax also increased by 21.7±14.3 %, 19.7±12.0 %, and 27.0±12.1 % in RTG, REG, and BTG, respectively, but no group differences were found. Based on the study, although statistically insignificant, BTG showed the biggest increase of VO₂max and PImax indicating a possible synergic effect of inspiratory muscle training and aerobic exercise on respiratory responses.

• Journal of Life Science
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• v.20 no.11
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• pp.1704-1710
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• 2010

The purpose of this study was to describe the biomechanical characteristics of stroke patients. These characteristics were obtained during walking on a Zebris system, cinematography system and EMG system. Seven female stroke patients participated in this study. The magnitude of the profiles (joint peak angle, joint peak moments, foot pressure COP, EMG data) correlated with rehabilitation training duration using t-test. The significance level selected for this study was p<0.05, t-test. Joint analysis identified significant differences in hip joint peak angle and hip joint peak moment. Foot pressure verified significant differences in gait line length of COP. The EMG signal proved significant differences in rectus femoris and vastus lateralis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.46-51
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• 2019

As the industry develops and quality of life increases, the concept of leisure is also changing. Bicycling is a healthy sport for exercising while enjoying nature, facilitating the enjoyment of a healthy life. As a result, the awareness surrounding bicycles has increased, and so has the interest in lighter and more luxurious carbon bikes. The number of domestic companies producing carbon bicycles frames is nil. In this study, we analyze the frames of existing foreign brands and analyze the deformation and stress concentration area according to the load of the frame, using the finite element analysis. In addition, we set up the range of stiffness based on the content of the structural analysis, to localize the carbon bicycle frame and famous foreign products, and compare the prototype with the stiffness by using bicycle molds for track races.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.17-27
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• 2020

The purpose of this study is to confirm the effects of a 6-week high-intensity combined training program on canoe athletes' cardiorespiratory function, isokinetic trunk strength, and anaerobic power. For the purpose of this study, the high-intensity combined training program was applied to 9 high-school canoe athletes. The high-intensity combined training program consists of aerobic exercise performed 2 times a week (Tuesday and Thursday), anaerobic exercise performed 3 times a week (Monday, Wednesday, and Friday), and flexibility exercise performed 5 times a week. The core of the high-intensity combined training program was the anaerobic training program performed with 100% weight for repetition; otherwise, the existing training method was divided into the percentage (%) of the 1RM. The aerobic exercise and the gym ball exercise are performed subsidiarily. Results showed that there was a statistically significant difference in height and muscle mass, whereas there was no statistically significant difference in weight, body fat percentage, and BMI followed by the high-intensity combined training program. There were statistically significant differences in maximum oxygen uptake and total exercise time. The angular velocity of 30°/sec showed a statistically significant difference in the peak torque item of flexors only. Also, the angular velocity of 120°/sec showed a statistically significant difference in the total work item of extensors only; however, there was no statistically significant difference in all the items of peak power, average power, and peak drop. In conclusion, it seems that the high-intensity combined training program may be applied as a training program for enhancing canoe athletes' performance. For further studies, more than 6 weeks training program with more participants would show improved results of isokinetic strength and anaerobic power in athlets.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.371-376
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• 2002

자동화된 생산시설에도 불구하고, 아직도 여러 현장에는 사람이 직접 bag, box, carton 등을 들고, 내리고, 옮기는 등의 인력운반 (Manual Materials Handling, MMH) 작업으로 생산활동이 이루어지고 있다. 상자 운반 작업에서 있어서 손잡이는 최대허용무게에 영향을 미친다는 연구 결과들이 많이 나왔지만, 자세에 따른 손잡이 형태의 영향에 관한 연구들은 미흡한 실정이다. 따라서 본 연구에서는 MMH 작업시 흔히 사용되는 3가지 자세(구부린 자세, 팔을 편 자세, 팔을 90$^{\circ}$로 굽혔을 때 자세)에서 손잡이 형태에 따라 tote box를 들 때, 작업자세와 손잡이 형태에 따른 Maximum Voluntary Contraction (이하 MVC)를 측정하고 MVC에 대한 작업자세와 손잡이 형태의 상관관계의 통계적 분석, 주관적 평가방법(Borg법)과 MVC와의 유의성을 검증하였다.