• Korean Journal of Applied Biomechanics
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• v.25 no.2
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• pp.191-198
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• 2015

Objective : The purpose of this study was to conduct biomechanical analysis of varying backpack loads on the lower limb movements during downhill walking over $-20^{\circ}$ ramp. Method : Thirteen male university students (age: $23.5{\pm}2.1yrs$, height: $175.7{\pm}4.6cm$, weight: $651.9{\pm}55.5N$) who have no musculoskeletal disorder were recruited as the subjects. Each subject walked over $20^{\circ}$ ramp with four different backpack weights (0%, 10%, 20% and 30% of body weight) in random order at a speed of $1.0{\pm}0.1m/s$. Five digital camcorders and two force plates were used to obtain 3-d data and kinetics of the lower extremity. For each trial being analyzed, five critical instants were identified from the video recordings. Ground reaction force, loading rate, decay rate, and resultant joint moment of the ankle and the knee were determined by the inverse dynamics analysis. For each dependent variable, one-way ANOVA with repeated measures was used to determine whether there were significant differences among four different backpack weight conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results : The results of this study showed that the medio-lateral GRFs at RHC in 20% and 30% body weight were significantly greater than the corresponding value in 0% of body weight. A consistent increase in the vertical GRFs as backpack loads increased was observed. The valgus joint movement of the knee at RTO in 30% body weight was significantly greater than the corresponding values in 0% and 10% body weight. The increased valgus moment of 30% body weight observed in this phase was associated with decelerating and stabilizing effects on the knee joint. The results also showed that the extension and valgus joint moments of the knee were systematically affected by the backpack load during downhill walking. Conclusion : Since downhill walking while carrying heavy external loads in a backpack may lead to excessive knee joint moment, damage can occur to the joint structures such as joint capsule and ligaments. Therefore, excessive repetitions of downhill walking should be avoided if the lower extremity is subjected to abnormally high levels of load over an extended period of time.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.2
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• pp.82-87
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• 2000

Tumoral calcinosis is a disease of unclear etiology which presents with periarticular and intramuscular calcification without the disorder of calcium and phosphorus metabolism. The incidence is very rare but the rate is higher among the blacks than whites. There has been no report on the recurrent occurrence on the asian race. We report a case that recurred several times with tumoral calcinosis of both knee and thigh. A 21-year-old woman visited to our department with masses in both right thigh and knee. She had a history of local excisions and biopsies(4 times at other hospital) and showed prompt recurrences. The complete marginal excision was performed for the treatment. The histological examination showed the findings that are compatible with tumoral calcinosis. There has been a free of recurrence over the past two years.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.1
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• pp.41-46
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• 2000

We experienced the case of familiar hypercholesterolemia with multiple xanthomas which was treated by combined surgical and medical therapy. He was 26-year-old male patient of familiar hypercholesterolemia with multiple xanthomas in 22 sites on whole body, and was treated by 17 surgical excisions of the xanthomas and by medical therapy of the hypercholesterolemia. There was a normal healing process of the surgical wounds. Continual postoperative medical therapy of the hypercholesterolemia was done. There was no recurrence of the symptoms during more than 13 months of follow-up. But the serum level of the cholesterol was not lowered significantly, so we are treating him with drug therapy. Familial hypercholesterolemia is caused by a specific disorder of lipid metabolism, and is characterized by increased LDL cholesterol, tendon xanthomas, coronary disease associated with autosomal dominant transmission. Xanthomas usually appear in the second decade of life with familiar hypercholesterolemia which may have high risk for premature coronary atherosclerosis, which might be prevented with early diagnosis and medical treatment. So, orthopedic surgeons do not only excise the xanthomatosis surgically but also can diagnose the underlying hypercholesterolemia.

• Journal of Oral Medicine and Pain
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• v.41 no.4
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• pp.161-168
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• 2016

Purpose: Patients who suffer from rheumatic arthritis, fibromyalgia, other various inflammatory diseases and musculoskeletal disorders, which are all similar to temporomandibular disorders (TMD), have been complaining about changes in the level and type of pain in response to changes in weather conditions for a long time. Through an investigation about pain perception in TMD patients in response to weather conditions, our primary objective was to develop base materials for future studies on change in pain in response to meteorological factors. Methods: Among patients who presented with TMD to Department of Oral Medicine, Pusan National University Dental Hospital from August to October 2016, one hundred consecutive TMD patients diagnosed with TMDs according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were recruited for the study and 28 patients were excluded according to exclusion criteria. Survey was done with the questionnaire and investigated whether there was any difference in incidence and level of pain in TMD patients between non-rainy and rainy days. Results: Among a total of 72 samples, 4 patients reported change in pain on rainy days rather than non-rainy days. Two patients from chronic group (joint and complex subgroup) reported increased pain on rainy days rather than non-rainy days but it was not statistically significant (p>0.05). One patient from chronic/muscle group reported the change in pain characteristics while pain intensity remained unchanged. One patient from acute/complex group reported decreased pain intensity. In comparison of the patients who reported increased pain on rainy days between acute and chronic groups, there were two reported cases and were both from chronic group only. There was a significantly higher chance of reporting increased pain on rainy days in chronic group than acute group (p<0.001). Conclusions: It is considered that TMD patients couldn't perceive the change in pain well in response to weather change on rainy days but some chronic patients could perceive the increase in pain in rainy days.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.4
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• pp.117-128
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• 2013

Objectives The purpose of this study is analyzing internal research trends of abnormal postures and providing problems of researches forward. Methods 6 Korean databases were searched for articles of abnormal postures, irrespective of publication year and 30 research were systematically reviewed. An analytical method such as descriptive statistics and an acutal number and percentage was used. Results We collected 30 studies. 16 studies were published within the last four years. 2012 saw 7 studies, the highest number of studies. Clinical research is the major research method. 26 studies were clinical research. The studies can be categorized according to the characteristic of the research content such as research of related factors or physical characteristics, research of treatment or programs, etc. 16 studies were about research of treatment or programs, the most number of studies. 11 studies were about research of related factors or physical characteristics, and 3 studies were about other issues. Conclusions Since the connection among postural abnormality, pain, and musculoskeletal system disorder has been raising, it is important to conduct a continued, methodical study.

• Journal of Korean Biological Nursing Science
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• v.4 no.2
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• pp.93-112
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• 2002

Recently, the number of the elderly has increased according to the improvement of socioeconomic status and the efficient medical care system. In spite of the development of medicine, the elderly suffers from the various health problems caused by weakness of musculoskeletal system, cardiopulmonary function and immunologic dysfunction. Regular rhythmic exercise program is known to be one of the effective tools to enhance the health condition in the elderly. However, there has been few studies to evaluate the comprehensive effects of rhythmic movement program on the elderly. This study was focused to evaluate the indices of cardiopulmonary function, life satisfaction, calcium, phosphorous, osteocalcin and deoxypyridinoline which are the essential factors of health problems in the elderly women. Twenty six subjects, aged between 68 and 72, who can do the ordinary activities and do not have cardiovascular dysfunction and mental disorder, participated in this study. They were divided into two groups: 13 in the experimental group and 13 in the control group. The experimental group participated in the rhythmic movement program at the welfare center located in G-city. The program were consisted of three sessions a week during 10 weeks. Each session had three parts: warming up(10 minutes), main exercise(40 minutes), finishing(10 minutes). Heart rate, blood pressure and peripheral arterial oxygen saturation were measured for the evaluation of cardiopulmonary function. Serum calcium, phosphorous, osteocalcin and urine deoxypyridinoline were measured as the indices of bony metabolism. Data were analyzed with mean, standard deviation, $x^2$-test, t-test, paired t-test using SPSS PC+ program. The results of this study were as follows. 1) Heart rate of the experimental group showed significant decrease following the rhythmic movement program. Peripheral arterial oxygen saturation of the experimental group showed significant increase following the program. 2) The degree of life satisfaction of the experimental group showed significant increase following the program. 3) Calcium showed significant decrease following the program but remained within normal range. There was no significant difference of phosphorous between two groups. 4) Osteocalcin, the index of bone formation, showed no significant change following the program, but significant increase in the experimental group comparing with the control group. 5) Deoxypyridinoline, the index of bone resorption, in urine of the experimental group showed significant decrease following the program. In conclusion, the rhythmic exercise program in the elderly showed the improvement of physiologic function and favorable effects on life satisfaction and bony metabolism. According to the above results, the regular rhythmic movement program can be strongly recommended for the improvement of health in the elderly women.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.399-406
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• 2009

The purpose of this study was to compare the effect of wearing roller shoes and jogging shoes on kinematic characteristics in lower extremity during walking. Eight male middle school students(age: $15.0{\pm}0.0^{\circ}$ yrs, height $175.9{\pm}6.6cm$, weight: $616.3{\pm}84.9$ N) who have no musculoskeletal disorder were recruited as the subjects. Temporal parameters, step length, stride length, center of mass, velocity of CM, angle of segment, angular velocity and range of motion were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions(p < .05). The results showed that stride length and velocity of CM in wearing roller shoes were significantly less than those found in wearing jogging shoes. These indicated that walking patterns may be changed by different shoe conditions and unstable braking condition because of wheel. Angle of ankle joint at LHC1 and LHC2 in wearing roller shoes was greater than the corresponding value for wearing jogging shoes. It seems that the ankle joints are locked in an awkward fashion at the heel contact to compensate for imbalance. Otherwise, dorsi flexion was not produced at the heel contact point in wearing roller shoes.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.139-149
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• 2014

The purpose of this study was to evaluate the effect of angle change of forefoot's adhesive outsole on the electromyographic activity (EMG) of the erector spinae and selected lower limbs muscle during downhill walking over $-20^{\circ}$ ramp. Thirteen male university students (age: $25.4{\pm}3.9$ yrs, height: $176.2{\pm}5.1$ cm, weight: $717.4{\pm}105.0$ N) who have no musculoskeletal disorder were recruited as the subjects. To assess the myoelectric activities of selected muscles, six of surface EMG electrodes with on-site pre-amplification circuitry were attached to erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), lateral gastrocnemius (LG), and medial gastrocnemius (MG). To obtain maximum EMG levels of the selected muscles for normalization, five maximum effort isometric contraction were performed before the experimental trials. Each subject walked over $0^{\circ}$ and $20^{\circ}$ ramp with three different forefeet's EVA outsole (0, 10, $20^{\circ}$) in random order at a speed of $1.2{\pm}0.1$ m/s. For each trial being analyzed, five critical instants and four phases were identified from the recording. The results of this study showed that the average muscle activities of MG and LG decreased in $20^{\circ}$ shoes compared to $0^{\circ}$ and $10^{\circ}$ ones in the initial double limb stance (IDLS). In initial single limb stance (ISLS) phase, the average muscle activities of ES increased with the angle of forefoot's adhesive outsole, indicating that the increment of shoes' angle induce upper body to flex anteriorly in order to maintain balance of trunk. In terminal double limb stance (TDLS) phase, average muscle activities of TA significantly increased in $20^{\circ}$ outsole compared to $0^{\circ}$ and $10^{\circ}$ ones. There was no external forces acting on the right foot other than the gravity during terminal single limb stance (TSLS) phase, all muscles maintained moderate levels of activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.380-386
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• 2019

Shoulder joint pain is a very common musculoskeletal disorder, in which about 20 percent of adults experience it more than once in their lives. In this study, an objective assessment was made that subacromial space was increased by pectoralis minor stretching exercise, which has a positive effect on impingement syndrome and shoulder pain. Also, This study examined the effects on pectoralis minor length(PML) and acromio-humeral distance(AHD) following pectoralis minor self-stretching exercise in normal adults. In this study, a total of 30 subjects were recruited and randomly divided into a self-stretching exercise group(n=15) and manual stretching exercise group(n=15) to compare the immediate effects of treatment. Studies have shown that both groups have significantly increased both PML and AHD within the group(p<.05). There was no statistically significant difference in the comparison between the groups(p>.05). The results suggest that self-stretching exercise can be recommended as a treatment method for impingement syndrome and prevention of shoulder disease.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.350-362
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• 2019

The purpose of this study was to examine the effects of job characteristics and health on accident experience by analyzing the data of transportation workers according to age. The analysis used data from 'the fourth Korean Working Conditions Survey(KWCS)'. A total of 1,997 transport workers data were finally analyzed, and correlation analysis, crossover analysis and logistic regression analysis were performed. It was confirmed that there was no correlation between the age of the transport workers and the accident experience. In the relationship between the characteristics of transportation workers and the experience of the accident, it was found that, in the case of older workers, there was a significant effect in the order of 'at mistake someone else hurt', 'musculoskeletal problem', 'cardiovascular problem' and 'repetitive movements of hands or arms', the model explaining power was 56.9%(p <.01). In the case of non-older workers, it was found that 'depression and anxiety disorder', 'relationship between job and safety', 'at mistake someone else hurt' and 'labor union', the model explaining power was 21.8%(p <.01). Therefore, in order to promote prevent accidents of transportation workers in future, it is necessary to consider various variables such as health and job characteristics besides age.