• Journal of Preventive Medicine and Public Health
• /
• 제32권3호
• /
• pp.361-373
• /
• 1999

ROC곡선의 AUC는 측전도구의 기준 타당도를 나타내는 가장 일반화된 지표다. 본 연구는 ROC분석법을 이용하여 현행의 근로자건강진단에서 업무관련성 근골격계 질환의 고위험군을 변별하는 표준 설문지를 개발하고자 하였다. 컴퓨터를 이용하는 선박 설계업 종사자 89명, 전화번호 안내원 113명, 일반 직업 여성 79명, 주부 89명 등 총 370명의 일차 연구대상군에 대한 재활의 학과 전문의의 최종 진단결과를 기준으로 1996년에 개발된 '근로자의 신체 증상에 관한 설문지'의 응답결과를 비교하였다. 근골격계 질환과의 관련성이 높은 문항조합을 선정하고 문항별 가중치를 산출하기 위해 로짓회귀분석, 상관분석 등을 실시하였으며, 문항조합 및 가중치 산출방법이 서로 다른 4가지 설문모형에 따른 AUC를 비교 하였다. 또한, 국내 모 자동차조립공장 근로자 225명의 설문결과와 산업의학 전문의의 진단결과 자료를 이용하여 4가지 설문모형의 AUC 재현도를 확인하였다. 분석 결과, 통계적으로 유의 한 차이는 없었으나 문항수를 줄여도 문항별 응답수준별 가중치를 부여하면 AUC가 일관되게 증가함을 확인하였다. 증상문항 4개와 신체부위문항 7개를 통합한 11개 문항에 가중치를 부여하는 모형이 변별력, 재현도, 편의성 측면에서 우수한 것으로 나타나, 이를 기준으로 새로운 업무관련성 근골격계 질환 설문지를 설계할 수 있었다. 문항수가 적으면서도 타당도는 높은 설문지를 개발하고, 상대적인 비교평가에 쓰일 수 있는 정량적 가중치를 제시한 것이 본 연구의 주요성과라 할 수 있다. 본 연구는 전문의 사이의 진단기준 차이를 고려하지 못한 점, 다양한 인구집단에 적용할만한 절대적인 참고치를 제시하지 못한 점 등에서 한계가 있다. 그러나, '측정 도구의 정량적 타당도 검증을 통한 질병 감시용 도구 개발'이라는 본 연구의 기본 취지 및 접근방법은 향후 조직적인 질병 예방활동에 활용될 여지가 있을 것이다.

• 한국심리학회지 : 문화 및 사회문제
• /
• 제9권spc호
• /
• pp.107-122
• /
• 2003

본 논문에서는 근골격계질환, 특히 직업성요통에 관련되는 위험요인의 영향을 종합적으로 살펴보고자 하였다. 첫째로 물리적인 요인의 영향을 알아보기 위하여 해석적인 인체역학 모델과 NIOSH(National Institute for Occupational Safety & Health) Guidelines를 이용하여 자동차 조립작업의 직업성 요통관련 위험도를 평가하였다. 총 246 작업자에 대한 분석을 수행하였는데, 분석결과 총 20개의 작업에서 L5/S1에서의 압축력이 300kg이 넘었으며 44개의 작업은 NIOSH Guidelines에 의한 분석결과, 최저허용기준치(ACTION LIMIT)을 넘는 것으로 나타났다. 둘째로 사회심리적 요인과 직업성요통의 관계에 대해 분석하였다. 사회심리적 요인의 영향을 알아보기 위하여 증상과 PWI(Psychosocial Well-being Index)를 토대로 한 설문을 이용하여 246명 작업자 모두에게 설문조사를 실시하였다. 그 결과 207명의 작업자가 직업성 요통증상을 경험한 적이 있으며 특히 27명의 작업자는 유병자로 분류된 바 있는 사람들이었다. PWI 점수를 근거로 하여 나눈 두 집단(저스트레스군, 고 스트레스군)은 증상이나 진단결과에 있어서 통계적으로 유의한 차이를 보이지 않았다. 또한 사회심리적 스트레스와 작업강도와의 관계를 살펴보면 주로 작업자세요인과 사회심리적 스트레스가 유의한 관계를 가지는 것으로 나타났다. 마지막으로 직업성요통의 발생에 대하여 경로분석을 수행하였다. 분석결과 인구학적 요인, 사회심리적 요인, 작업특성 요인이 직업성 요통에 직접적으로 영향을 미쳤으며, 개인특성요인 즉, 작업경험, 흡연, 수면시간 등은 직업성요통에 직접적인 영향을 미치는 않은 것으로 나타났다. 그러나 개인특성요인은 직업성 요통에 유의한 영향을 미치는 사회심리적 요인과는 밀접한 관계를 가졌다. 향후 다양한 직종에서의 이와같은 경험적 연구결과가 축적되어 우리나라의 조직문화적 특성을 고려한 직업성 요통에 대한 위험모델에 구축되어야 한다고 사료된다.

• 대한인간공학회지
• /
• 제30권6호
• /
• pp.695-703
• /
• 2011

Objective: This study was to investigate the effects of coordinated upper-limb body postures on the subjective discomfort rating, heart rate, and muscle activities. Background: Although generally many checklists such as OWAS, RULA, and REBA were applied to evaluate various body postures, the body postures were might be overestimated or underestimated because each body part(i.e., back, shoulder, and elbow etc.) was evaluated separately, and then added all rates of individual body parts to assess an overall risk level for the body posture in these methodologies. Methods: A total of 20 participants maintained 14 postures which were combinations of back, shoulder, and elbow flexion angles and then muscle activities, subjective discomfort, and heart rates were collected every three minute during a sustained 15 minute and 0.5kg weight holding task. Four muscle groups were investigated: erector spine, anterior deltoid, upper trapezius, triceps brachii. Results: Results showed that subjective discomfort was the lowest when the angle of back and shoulder were both $0^{\circ}s$, while the body posture with $45^{\circ}$ of back angle and $45^{\circ}$ shoulder angle was rated as the most subjective discomfort posture. In general, the subjective discomfort ratings increased as back and shoulder flexion angles increased. It was noted that, however, the subjective discomfort of body posture with a $45^{\circ}$ back angle and $45^{\circ}$ shoulder flexion angle was lower than that of body posture with a $0^{\circ}$ back and $45^{\circ}$ shoulder flexion angle. The research findings of heart rates and muscle activities showed similar results for the analyses of subjective discomfort ratings. Conclusions: The possible limitations of the current ergonomics evaluation techniques which assessing a body posture with summing all body part score after individually analyzed in this study. Based on the analyses of subjective discomfort, heart rate, and muscle activities, it was recommended that a use of effects of coordinated upper-limb body postures would be considered when one evaluates work-load for various working postures. Application: These findings can be used for developing a more accurate assessment checklist for working posture as well as preventing musculoskeletal disorders of workers in workplaces.

• 한국산업보건학회지
• /
• 제15권2호
• /
• pp.104-113
• /
• 2005

A variety of ergonomic assessment methods of lifting tasks known as a major cause of work-related lower back pain have been used. But there is a limited information in choosing the most appropriate assessment method for a particular job and in finding out strengths and weakness of the methods. The purpose of this study was to assess and compare the ergonomic risks of lifting tasks in a marine diesel engine production industry by three lifting ergonomic assessment tools widely used: the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE), the Washington Administrative Code 296-62-0517(WAC), and the Snook Tables. Lifting index(weight of load/Recommended Weight Limit) of NLE($LI_{NLE}$) was above 1 at 34 tasks(75.6%) of a total number of 45 lifting tasks. LI of WAC($LI_{WAC}$) was above 1 at 11 tasks(24.4 %). LI of Snook Table($LI_{Snook}$) was above 1 at 29 tasks(64.4%). Thus, LI was high in orders of $LI_{NLE}$ > $LI_{Snook}$ > $LI_{WAC}$. There were significantly high correlations among three Lls(p<0.01). The correlation coefficients between $LI_{NLE}$and the other three Lls($LI_{WAC}$ and $LI_{Snook}$) were r=0.93 and r=0.88, respectively. The linear regression equations were y = 0.444x + 0.11(r=0.93) between $LI_{NLE}$ and $LI_{WAC}$, y = 0.93x + 0.008(r=0.88) between LI(NLE) and $LI_{Snook}$. The LI values by WAC was significantly lower than those by the other tools. The compared features, strength and limitation among these tools were described in this paper.

• 대한인간공학회지
• /
• 제33권6호
• /
• pp.565-575
• /
• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.

• 대한약침학회지
• /
• 제27권1호
• /
• pp.14-20
• /
• 2024

Objectives: Frozen shoulder (FS) is one of the most challenging shoulder disorders for patients and clinicians. Its symptoms mainly include any combination of stiffness, nocturnal pain, and limitation of active and passive glenohumeral joint movement. Conventional treatment options for FS are physical therapy, nonsteroidal anti-inflammatory drugs, injection therapy, and arthroscopic capsular release, but adverse and limited effects continue to present problems. As a result, pharmacoacupuncture (PA) is getting attention as an alternative therapy for patients with FS. PA is a new form of acupuncture treatment in traditional Korean medicine (TKM) that is mainly used for musculoskeletal diseases. It has similarity and specificity compared to corticosteroid injection and hydrodilatation, making it a potential alternative injection therapy for FS. However, no systematic reviews investigating the utilization of PA for FS have been published. Therefore, this review aims to standardize the clinical use of PA for FS and validate its therapeutic effect. Methods: The protocol was registered in Prospero (CRD42023445708) on 18 July 2023. Until Aug. 31, 2023, seven electronic databases will be searched for randomized controlled trials of PA for FS. Authors will be contacted, and manual searches will also be performed. Two reviewers will independently screen and collect data from retrieved articles according to predefined criteria. The primary outcome will be pain intensity, and secondary outcomes will be effective rate, Constant-Murley Score, Shoulder Pain and Disability Index, range of motion, quality of life, and adverse events. Bias and quality of the included trials will be assessed using the Cochrane handbook's risk-of-bias tool for randomized trials. Meta analyses will be conducted using Review Manager V.5.3 software. GRADE will be used to evaluate the level of evidence for each outcome. Results: This systematic review and meta-analysis will be conducted following PRISMA statement. The results will be published in a peer-reviewed journal. Conclusion: This review will provide scientific evidence to support health insurance policy as well as the standardization of PA in clinical practice.

• 한국융합학회논문지
• /
• 제11권9호
• /
• pp.277-285
• /
• 2020

본 연구는 헤드 마운티드 디스플레이(Head-Mounted Display; HMD) 사용이 건강한 젊은 성인들의 목관절가동범위(CROM)와 목 근육 두께 및 통증에 미치는 영향을 분석하였다. HMD 군(남자 16명, 여자 7명)은 HMD를 착용하고 30분 동안 정해진 영상을 시청하도록 하였다. 대조군(남자 15명, 여자 8명)은 HMD군과 동일한 자세로 HMD 착용없이 30분 동안 앉아있게 하였다. 실험 전·후에 목관절가동범위, 위등세모근과 어깨올림근의 두께와 압력통증역치를 측정하고 대응표본 t검정과 독립 t검정으로 분석하였다. HMD 군의 목관절가동범위와 양쪽 위등세모근과 어깨올림근의 압력통증역치는 사전 검사 보다 유의하게 감소하였고(p<.05), 양쪽 위등세모근의 두께는 유의하게 증가하였고(p<.05). 반면에, 대조군은 목관절가동범위, 근육 두께 및 압력통증역치에서 유의한 차이가 없었다(p>.05). 분석 결과, 장시간 HMD 사용은 목관절가동범위와 압력통증역치를 감소시키고 근육을 비대하게 하여 목과 어깨의 근골격계 질환을 야기할 수 있으므로, 본 연구는 올바른 자세를 유지하며 적절한 시간 동안만 HMD를 사용할 것을 권장한다.

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