• 산업경영시스템학회지
• /
• 제37권4호
• /
• pp.72-81
• /
• 2014

Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site, forestry, farming, and daily life. The objective of this study was to compare one-hand lowering activity to lifting activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level with two workload 7.5kg and 15.0kg. Eight male subjects with LMM were asked to perform lifting/lowering tasks using both a one-handed (left-hand and right-hand) as well as a two-handed technique. Spinal loading was estimated through an EMG-assisted free-dynamic biomechanical model. The biomechanical stress of one-hand lowering activity was shown to be 43% lower than that of one-hand lifting activity. It was claimed that the biomechanical stress for one-hand lifting/lowering activity is almost twice (194%) of the one for two-hands lifting/lowering activity. It was also found that biomechanical stress by one-hand lowering/lifting activity with the half workload of two-hands lowering/lifting activity was greater than that of the two-hands lowering/lifting activity. Therefore, it might be a risk to consider the RWL of one-hand lowering/lifting activity to simply be a half of the RWL of two-hands lowering/lifting activity recommended by NIOSH.

• 한국전문물리치료학회지
• /
• 제17권4호
• /
• pp.8-15
• /
• 2010

This study was designed to investigate the effect of different hand positions on scapulothorcic muscle activities during push-up plus exercises. Fourteen healthy males performed push-up plus exercises under three conditions (neutral, $90^{\circ}$ internally rotated, and $90^{\circ}$ externally rotated hand positions), during which the activities of the serratus anterior, pectoralis major, and upper trapezius muscles were recorded using surface electromyography. The statistical significance at three different hand positions was tested by repeated one-way ANOVA. The mean activities of the serratus anterior increased and the mean activities of the pectoralis major decreased in the order of neutral hand position, internally rotated hand position, and externally rotated hand position. There was a significant difference during push-up plus between neutral and externally rotated hand positions as well as in the serratus anterior/pectoralis major activity ratio (p<.0.5). However, no significant differences were found in the activity of the upper trapezius muscle or the serratus anterior/upper trapezius activity ratio. We suggest that the push-up plus exercise performed in the externally rotated hand position could a beneficial strategy for selective strengthening of the serratus anterior muscle, while minimizing the activity of the pectoralis major muscle.

• 대한공업교육학회지
• /
• 제39권1호
• /
• pp.66-84
• /
• 2014

이 연구는 중학교 제조기술과 자동화 단원을 위한 STEAM 체험활동 과제를 개발 하는데 있다. 이 연구는 준비, 개발, 개선 단계에 따라 진행되었다. 준비단계에서는 STEAM 체험 활동의 필요성에 대한 요구분석과 준비 단계로서 체험활동 목표를 설정하였다. 개발단계에서는 체험활동 과제를 선정하고 적절한 수업 모형을 이용하여 최종 과 제를 개발하였다. 개선단계에서는 개발된 체험 활동 과제에 대하여 전문가 집단의 타당도 검사와 중 학생을 대상으로 예비시험과 현장시험을 통해 수정 보완하였다. 개발된 STEAM 체험 활동은 스마트폰용 접사&망원경 KIT, 목제품을 이용한 판화 만들기이며, 각 체험 활동의 구성은 설계 개요, 재료, 평가 기준, 수업과정안, 포트폴리오 등으로 구성하였다. 이상의 연구 결과를 바탕으로 개발된 STEAM 체험활동 과제가 중학교 제조기술 단원의 실습은 물론 방과후학교, 발명반, 과학교실, 창의적 체험활동, 동아리 활동 등 에서 널리 활용하기를 바란다.

• 대한인간공학회지
• /
• 제32권5호
• /
• pp.413-420
• /
• 2013

Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.

• 대한인간공학회지
• /
• 제30권5호
• /
• pp.597-603
• /
• 2011

Objective: The objective of this study was to compare one-hand and two-hands lifting activity in terms of biomechanical stress for the range of lifting heights from 10cm above floor level to knuckle height. Background: Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lifting tasks using both a one-handed as well as a two-handed lifting technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lifting tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lifting tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 43%, as the workload was increased twice from 7.5kg to 15.0kg. For the right-hand lifting task, these were increased by the average 34%. For the two-hands lifting tasks, these were increased by the average 25%. The lateral shear forces at L5/S1 of one-hand lifting tasks, notwithstanding the half of the workload of two-hands lifting tasks, were very high in the 300~317% of the one of two-hands lifting tasks. The moments at L5/S1 of one-hand lifting tasks were 126~166% of the one of two-hands lifting tasks. Conclusion: It is concluded that the effect of workload for one-hand lifting is greater than two-hands lifting. It can also be concluded that asymmetrical effect of one-hand lifting is much greater than workload effect. Application: The results of this study can be used to provide guidelines of recommended safe weights for tasks involved in one-hand lifting activity.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.876-881
• /
• 2003

This study focused on to design and toanalysis of a myoelectronic hand. We considered a low frequency factor in human life and to quantify low frequency which a human body responded to using a 1-axis ant a 3-axis accelerometer. The dynamic myoelectronic hand are important for tasks such a continuous prosthetic control and a EMG signal recognition, which have not been successfully mastered by the most neural approached To control myoelectronic hand, classifying myoelectronic patterns are also important. Experimental results of FEM are 110㎫ on Thumb, 200㎫ on Index finger, 220㎫ on Middle finger 260㎫ on Ring finger and 270㎫ on Little finger. Experimental results of accelerometer are 1.4-0.4(m/s2) ,(5-20(〔Hz〕) in Feeding activity and 0.4-0(m/s2) (0-10〔Hz〕) in Lifting activity. Considering these facts, we suggest a new type myoelectronic hand.

• 전기학회논문지
• /
• 제57권12호
• /
• pp.2336-2344
• /
• 2008

In this paper, muscular activity and muscle fatigue of FDI(first dorsal interosseous muscle) and thenar muscle of hand was analyzed with surface EMG signal based on four kinds of attitudes(grip, tip, key and palmar) to measure grip strength and pinch strength after hand operation and rehabilitation treatment. The normative data are needed to interpret evaluation data to assess a patient's ability to return to labor environment. The preceding researchers proposed the standard data only by studying on maximum grip strength and the maximum pinch strength followed by each attitude of subjects' hands. But in this study, the muscle activity and muscle fatigue were considered under the various attitude to propose normative data. As a results, the muscle fatigue may be used only for presentation of normative data in labor environment.

• 대한통합의학회지
• /
• 제3권4호
• /
• pp.1-9
• /
• 2015

Purpose : We described how the training of non-dominant hand that applicates the activity effects on dominant hand. Method : From November 6th to December 2nd 2013, We randomly selected 18 people that don't have a damage of hand function and are in college of K in Busan. (cross stitch training group 9 people, control group 9 people) All participants agreed on the research after fully being aware of training procedures and spontaneously conducted. Each training was practiced for 40 minutes in once every second day. One researcher deals with three participants at silent environment. We used the study measurement, Purdue pegboard, to investigate the sharpness of hand. To investigate the advancement of hand function caused by cross stitch training, we practiced three times estimations of primary one before training, middle one after 2 weeks training, last one after four weeks training and obtained the following results. Result : First of all, We found that the group of hand training appeared to be advanced of dominant hand's sharpness depending on the training period more than the control group. Second, We found that the group of hand training appeared to be advanced of non-dominant hand's sharpness depending on the training period more than the control group. Third, We found that the group of hand training appeared to be advanced of both hand's sharpness depending on the training period more than the control group. Fourth, We found that the group of hand training appeared to be advanced of the assembling function sharpness depending on the training period more than the control group. Conclusion : Put the results of this research together, we found that non-dominant hand training that used the activity was of help to advance the function of dominant hand. So, we thinks that hand training might help the recovery of affected hand function to the person that have a problem of hand function like hemiplegia patient. It will be required to practice the further study targeting the person that have a problem of hand function like hemiplegia patient. We hope that this research will be apply to clinical occupational therapy.

• 대한산업공학회지
• /
• 제42권3호
• /
• pp.165-172
• /
• 2016

The purpose of this study is to investigate the ergonomic verification of suitability of the 4-wheeled hand cart to prevent musculoskeletal problems in the firing test range. Because of the increasing amount of firing test, the needs to develop a projectile transferring device such as 4-wheeled hand cart has been increased. For the 4-wheeled hand cart, the lifting and carrying activity in the manual handling method were transformed to pushing activity. The risk of low back pain for lifting and carrying the projectile by manual was estimated by NLE and 3D SSPP. On the other hand, the risk for pushing the 4-wheeled hand cart was estimated by psychophysical and biomechanical method such as Mital's equation, Snook's table and 3D SSPP. It was shown that the 4-wheeled hand cart reduced the risk of low back pain drastically with higher efficiency and design compatibility.

• 한국산학기술학회논문지
• /
• 제16권2호
• /
• pp.1153-1163
• /
• 2015

본 연구는 수부손상환자를 대상으로 과제 지향적 활동이 손 기능에 미치는 효과를 알아보고자 하였다. 2011년 12월부터 2012년 10월까지 경남 창원에 위치하는 C병원에 내원한 16명의 수부손상환자를 두 그룹으로 무작위 할당한 후 실험군에 과제 지향적 활동을 1일 1회, 주 3회, 4주 동안 적용하고 그룹 간 비교를 실시하였다. 과제 지향적 활동군은 캐나다 작업수행측정(Canadian Occupational Performance Measure; COPM)을 통해 대상자가 선호하는 일상생활활동영역에 대한 과제를 제공하였다. 이때 중재의 효과를 검증하기 위해 손 기능 평가로 장악력 검사, 파악력 검사, 엄지의 맞섬, 손가락의 벌림 범위와, Purdue pegboard test, Disabilities of the Arm, Shoulder, and Hand(DASH)를 사용하였다. 중재 전후 비교에서 과제 지향적활동군은 모든 손 기능 평가에 유의하게 향상되었고(p<.05), 대조군의 손 기능도 유의하게 향상되었다(p<.05). 그룹 간 비교에서 과제 지향적 활동군은 손끝집기, 측면집기, 세점집기, Purdue pegboard test, DASH에서 대조군과 유의한 차이가 있었으나(p<.05), 장악력 검사와 엄지의 맞섬 및 손가락의 벌림 범위는 그룹 간 유의한 차이가 없었다. 본 연구의 결과를 통해 과제지향적 활동이 수부손상환자의 손 기능 향상에 더 효과적임을 알 수 있었다.