• Journal of Korean Neurosurgical Society
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• 제61권6호
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• pp.680-688
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• 2018

Objective : To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods : A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results : Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion : In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

• 한국콘텐츠학회논문지
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• 제19권5호
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• pp.350-362
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• 2019

본 연구에서는 연령에 따른 운수업근로자의 직무특성과 건강이 사고경험에 어떠한 영향을 미치는지를 확인하고, 이를 통해 사고예방과 고령운수업근로자에 대한 다양한 관점을 제시하고자 하였다. 산업안전보건연구원에서 실시한 '제 4차 근로환경조사'의 자료를 활용하였으며, 최종적으로 1,997명의 운수업근로자 자료를 상관분석과 교차분석, 로지스틱 회귀분석을 실시하였다. 연구 결과, 운수업근로자의 연령과 사고경험에는 상관관계가 나타나지 않았다. 운수업근로자의 특성과 사고경험과의 관계에서 고령근로자의 경우, '직무수행 중 실수 시 타인이 다침', '근골격계 문제', '심혈관계 문제', '손이나 팔의 반복동작' 순으로 유의한 영향을 미치는 것으로 나타났으며, 이 변수들에 대한 모델 설명력은 56.9%였다(p<.01). 비고령근로자의 경우에는, '우울 및 불안장애', '직무와 안전과의 관계', '직무수행 중 실수 시 타인이 다침', '노동조합 여부' 순으로 유의한 영향을 미치는 것으로 나타났으며, 모델 설명력은 21.8%였다(p<.01). 따라서 추후 운수업근로자들의 사고예방을 위해서는 연령 이외에도 건강과 직무특성 등 다양한 변수를 고려한 접근이 필요할 것이다.

• 대한인간공학회지
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• 제36권3호
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• pp.183-196
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• 2017

Objective: The purpose of this research was to assess the agreement between job physical risk factor analysis by ergonomists using ergonomic methods and physical examinations made by occupational physicians on the presence of musculoskeletal disorders of the upper extremities. Background: Ergonomics is the systematic application of principles concerned with the design of devices and working conditions for enhancing human capabilities and optimizing working and living conditions. Proper ergonomic design is necessary to prevent injuries and physical and emotional stress. The major types of ergonomic injuries and incidents are cumulative trauma disorders (CTDs), acute strains, sprains, and system failures. Minimization of use of excessive force and awkward postures can help to prevent such injuries Method: Initial data were collected as part of a larger study by the University of Utah Ergonomics and Safety program field data collection teams and medical data collection teams from the Rocky Mountain Center for Occupational and Environmental Health (RMCOEH). Subjects included 173 male and female workers, 83 at Beehive Clothing (a clothing plant), 74 at Autoliv (a plant making air bags for vehicles), and 16 at Deseret Meat (a meat-processing plant). Posture and effort levels were analyzed using a software program developed at the University of Utah (Utah Ergonomic Analysis Tool). The Ergonomic Epicondylitis Model (EEM) was developed to assess the risk of epicondylitis from observable job physical factors. The model considers five job risk factors: (1) intensity of exertion, (2) forearm rotation, (3) wrist posture, (4) elbow compression, and (5) speed of work. Qualitative ratings of these physical factors were determined during video analysis. Personal variables were also investigated to study their relationship with epicondylitis. Logistic regression models were used to determine the association between risk factors and symptoms of epicondyle pain. Results: Results of this study indicate that gender, smoking status, and BMI do have an effect on the risk of epicondylitis but there is not a statistically significant relationship between EEM and epicondylitis. Conclusion: This research studied the relationship between an Ergonomic Epicondylitis Model (EEM) and the occurrence of epicondylitis. The model was not predictive for epicondylitis. However, it is clear that epicondylitis was associated with some individual risk factors such as smoking status, gender, and BMI. Based on the results, future research may discover risk factors that seem to increase the risk of epicondylitis. Application: Although this research used a combination of questionnaire, ergonomic job analysis, and medical job analysis to specifically verify risk factors related to epicondylitis, there are limitations. This research did not have a very large sample size because only 173 subjects were available for this study. Also, it was conducted in only 3 facilities, a plant making air bags for vehicles, a meat-processing plant, and a clothing plant in Utah. If working conditions in other kinds of facilities are considered, results may improve. Therefore, future research should perform analysis with additional subjects in different kinds of facilities. Repetition and duration of a task were not considered as risk factors in this research. These two factors could be associated with epicondylitis so it could be important to include these factors in future research. Psychosocial data and workplace conditions (e.g., low temperature) were also noted during data collection, and could be used to further study the prevalence of epicondylitis. Univariate analysis methods could be used for each variable of EEM. This research was performed using multivariate analysis. Therefore, it was difficult to recognize the different effect of each variable. Basically, the difference between univariate and multivariate analysis is that univariate analysis deals with one predictor variable at a time, whereas multivariate analysis deals with multiple predictor variables combined in a predetermined manner. The univariate analysis could show how each variable is associated with epicondyle pain. This may allow more appropriate weighting factors to be determined and therefore improve the performance of the EEM.

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4629-4635
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• 2012

본 연구의 목적은 중량물 들기 작업시 비대칭 무게중심과 상체 옆으로 기울임 여부가 어떻게 L5/S1 주변 허리 근육의 Peak EMG 진폭에 영향을 미치는지를 알아보는 것이다. 요통을 포함한 근골격계질환은 무겁지 않은 물체의 지속적인 반복 취급뿐만 아니라, 일회성의 커다란 부하도 신체 조직의 부담으로 작용하여 발생할 수 있다. 11명의 20대 대학생 남성은 15.8kg의 물체를 들어올리는 Task를 3회 실행하였다. 이 때 대칭 무게중심의 물체를 상체를 기울이지 않고 들어 올리는 경우, 비대칭 무게중심의 물체를 상체를 기울이지 않고 들어 올리는 조건, 그리고 비대칭 무게중심의 물체를 상체를 기울여서 들어 올리는 경우에 따라 6개의 L5/S1 주변의 근육들로부터 Peak EMG 진폭이 수집되어 분석되었다. 결과는 비대칭 무게중심을 지닌 물체 취급시 무게중심에서 먼 쪽의 허리 근육에서 Peak EMG 진폭이 발생하고, 그 진폭의 크기는 대칭 무게중심 물체를 취급하는 경우보다 크게 나타났다. 또한, 비대칭 무게중심의 물체를 취급할 경우 물체나 상체를 물체의 무게중심 방향으로 기울이는 것은 기울이지 않을 때보다 대측성 등근육에서 Peak EMG 진폭 증가시켰다. 이러한 연구 결과는 비대칭 무게중심의 중량물을 들어 올리는 작업에서 요통 발생을 예방하기 위한 행정적인 조치로써 가능하면 상체를 전두면 기준으로 기울이지 않는 작업자 자세 조언이 필요함을 말해준다.

• Physical Therapy Rehabilitation Science
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• 제5권4호
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• pp.210-214
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• 2016

Objective: The aim of this study was to measure the muscle architectural parameters of abdominal muscles in healthy individuals by rehabilitative ultrasound imaging (RUSI) and to investigate their changes after bridging exercise in various environments. Design: Cross-sectional study. Methods: The study included 40 healthy participants (19 men, 21 women). Subjects were randomly allocated to a stable surface group (SG, n=20) or an unstable surface group (UG, n=20). The participants assumed three positions in rest, bridging exercise with knee flexion $60^{\circ}$, and bridging exercise with knee flexion $90^{\circ}$ for the measurement of abdominal muscle thickness by RUSI. For the resting position, the participants held the head neutral in a hook-lying position and the dominant side was measured. For contraction, the participants performed the bridging exercise with the knee joint in $60^{\circ}$ and $90^{\circ}$ of flexion for 10 seconds each. Results: For transversus abdominis, external oblique muscle thickness, within the stable surface group and the unstable surface group, no significant contraction difference was observed in both the $60^{\circ}$ and $90^{\circ}$ bridge exercise conditions. Contraction difference of internal oblique muscle was significantly larger at $90^{\circ}$ than at $60^{\circ}$ within the SG (p<0.05). But within the UG, no significant contraction difference was shown. There was no significant contraction difference between the surface group and the unstable SG at $60^{\circ}$ condition and at $90^{\circ}$ condition in all measured muscles. Conclusions: The contraction difference is different for each muscle during bridge exercise with knee flexion $60^{\circ}$ and bridging exercise with knee flexion $90^{\circ}$. Muscle contraction difference is generally large when exercised on an unstable surface than a stable surface, but these are not statistically significant when bridging exercise is performed using dynamic air cushion for unstable surface.

• 한국자원식물학회지
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• 제30권2호
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• pp.240-264
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• 2017

한국산 초롱꽃과 식물의 전통지식을 확인하고, 이들의 화학성분, 약리효과에 관한 자료와의 비교 분석을 통해 종합적인 고찰을 수행하였다. 그 결과, 민속식물은 총 18분류군으로 식용, 약용, 관상용 등으로 이용되고 있으며, 이 중 약용으로는 도라지, 잔대, 더덕 등 총 12분류군이 확인되었다. 약용 전통지식은 감기, 천식, 산후조리 등 49개의 질병 및 질환을 치료하기 위해 이용된 것으로 조사되었다. 지금까지 한국산 초롱꽃과 잔대속, 더덕속, 도라지속, 초롱꽃속, 영아자속에서 총 211개의 화학성분이 선행 연구자들에 의해 밝혀졌으며, 이들은 triterpenes 109종류, sterols 8종류, polyacetylens 4종류, alkaloids 21종류, flavonoids 14종류, phenolic acids 14종류, phenolic glycosides 11종류, phenylpropanoids 8종류, 그 밖의 성분으로 organic acid 계열 등 22종류이다. 약리효과로는 면역활성, 항염증, 항천식 및 점액분비촉진, 항알레르기, 항산화, 에스트로겐 활성, 항당뇨, 간 보호, 신경 보호, 항종양, 항진통, 순환계, 항비만 등에 효과가 있는 것으로 조사되었다. 조사된 전통지식과 화학성분, 약리효과에 대한 자료를 종합해 본 결과, 한국산 초롱꽃과 식물을 호흡기 계통, 임신 출산 산후조리, 생식 배설 계통, 순환 계통, 근골격계 계통 등의 질병 및 질환에 사용된 전통지식은 해당 식물체 조추출물 및 화학성분을 이용한 약리 실험을 통해 그 효과가 입증되었다고 판단된다.

• 한국운동역학회지
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• 제25권2호
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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.

• Journal of Preventive Medicine and Public Health
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• 제26권4호
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• pp.574-586
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• 1993

산업장 근로자들의 결근실태와 요인을 알아보기 위해 대전시내에 위치한 제조업에 종사하는 근로자 1,184명을 대상으로 1992년 6월에서 8월 사이의 3개월간 결근양상에 대한 조사에서 다음과 같은 결과를 얻었다. 1. 조사대상자의 총결근자율은 20.1%, 질병결근자율은 6.9% 였으며 총결근율은 1.2%, 질병 결근율은 0.5%로 나타났다. 2. 결근자의 평균결근일수는 2.8일이었으며 이중 질병으로 인한 경우가 4.4일, 질병이 아닌 원인으로 인한 경우는 1.4일로 나타났다. 원인별 질병결근의 평균결근일수는 두부, 사지, 체간의 상해로 인한 경우가 $13.2{\sim}18.6$일로 다른 원인에 비해 높았으며, 총 결근일수는 사지상해, 체간상해, 몸살, 두부상해, 근골격계 증상의 순으로 높게 나타났다. 3. 결근여부에 관련있는 변수로서 총결근여부에는 고용구분, 교육정도, 유해요인 노출여부, 1일 근무시간, 직종의 변수였으며, 질병결근여부에는 고용구분, 교육정도, 직종 변수였다. 4. 결근자군에서 결근율에 영향있는 변수로서 총결근율에 작업분위기, 비만지수, 작업환경, 1일 작업시간이었으며 이들 변수의 총결근율에 대한 설명력은 13.1 % 였다. 질병 결근율에는 1일 작업시간, 교육정도, 작업분위기의 순이었으며, 이들 변수의 질병결근율에 대한 설명력은 25.4% 였다.

• 대한골관절종양학회지
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• 제14권2호
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• pp.157-162
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• 2008

악성 골종양의 사지 구제술이 보편화 되었으나 슬관절 주위의 골육종환자 중 예상되는 하지부동이 5 cm 이상 되는 경우의 재건 술식의 선택은 아직 논란이 많다. 양측 골단판 중 하나를 희생하는 것이 불가피한 미성숙 소아의 슬관절 주위 악성골종양에서 가장 이상적인 재건술은; 1)인접 골 단판을 손상하지 않고, 2)가동관절을 유지할 수 있으며, 3) 일차술식이 추후 하지 연장술에 방해가 되지 않아야 할 것으로 생각된다. 저자들은 4세 원위 대퇴골 간부 골육종을 분절절제술 후 저온 열처리 자가골 재삽입술로 재건하였다. 술 후 6개월에 대퇴골 과 열처리 자가골 근위부의 불유합, 열처리 자가골의 흡수 및 파괴 와 내고정물의 해리가 발생하여 환자의 근위 대퇴골을 동종골 간단부에 안착시키는 술식을 이용하여 3개월 만에 근위부 골유합을 얻었으며 기능적 결과도 양호하여 보고하고자 한다.

• 대한의용생체공학회:의공학회지
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• 제29권4호
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• pp.316-322
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• 2008

The purpose of this study was to investigate muscle activation of lower extremity such as rectus femoris, tibialis anterior and soleus according to 0cm(bare foot), 4cm and 7cm heel height of shoe on the rocking surface in older women. 20 older women who did not have any lower musculoskeletal and neurological disorders in the past were participated in this study. Each subject was standing for 15 seconds on the level 8 of Biodex Stability System (BSS) while wearing 4cm and 7cm heel height shoes including bare foot. Electromyography was used to measure muscle activation of lower extremity, and the muscle activation was expressed as a percentage of maximal voluntary isometric contraction (% MVIC). We measured % MVIC of three muscles during 5 seconds except for the first 5 seconds and last 5 seconds. SPSS 12.0 program was used for this study. Repeated one-way analysis of variance(ANOVA) was performed to compare the significant difference among the muscles of lower extremities according to heel heights of shoe on the rocking plate. % MVIC of each muscle such as rectus femoris, tibialis anterior and soleus regarding heel heights of shoe had statistically significant differences (p<0.05). The results of contrast test were as follows; 1) % MVIC of rectus femoris had significant differences between barefoot and 4cm, and barefoot and 7cm. 2) % MVIC of tibialis anterior had significant differences between barefoot and 4cm, barefoot and 7cm, and 4cm and 7cm. 3) % MVIC of soleus had significant differences between barefoot and 7cm, 4cm and 7cm. The results indicate that all commonly responsive muscle on the conditions of barefoot, 4cm, and 7cm shoe height on the rcoking surface is tibialis anterior muscle. We found out that the more heels of shoe high, the more muscle activation increases. High-heeled shoes above 7cm remarkably increase the muscle activation of lower extremity and may result in muscle fatigue. Thus, these shoes may summate risk factors of falls in older women. We can acknowledge that the heels above 4 cm affect each muscle activation in lower extremity on the rocking surface.