• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.72-81
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• 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.

• Physical Therapy Korea
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• v.17 no.4
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• pp.8-15
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• 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
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• v.39 no.1
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• pp.66-84
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• 2014

The purpose of this study is to develop STEAM hand-on activity task for middle school manufacturing & automation unit. This study was conducted following three stages. First of all, I carried out documents research and requirements analysis. And the goals for STEAM hand-on activity were set at this stage. Second, topics for STEAM hand-on activity were selected, and the organized for designing hand-on activity related STEAM in the development step. Finally, pilot and field test were conducted in order to amend and/or complement in improvement step. The theme and/or title of the hand-on activities were 'Making the print using wood', 'Making the close up photography & telephoto lens for smart phone'. The STEAM hand-on activities were designed for ten hours for each subject respectively. Each hand-on activity consists of problem situation, objectives statement, materials and tools, an evaluating criteria, related knowledge, portfolio and so on.

• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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• pp.413-420
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• 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.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.597-603
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• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.876-881
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• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2336-2344
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• 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.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.4
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• pp.1-9
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• 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.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.165-172
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• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1153-1163
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• 2015

The purpose of this study is to investigate the effects of task-oriented activities on hand functions in patients with hand injuries. From December 2011 to October 2012, sixteen patients with hand injuries at C Hospital in Changwon, Gyeongsangnam-do, Korea were randomly divided into two groups. One group was subjected to task-oriented activity and the other to general exercise. Two groups performed each activity once a day, three times a week, for four weeks. The group with the task-oriented activities was provided with the tasks according to subject-preference based on the result of Canadian Occupational Performance Measure (COPM). To verify the effect of intervention, the following hand function measures were used: grip strength, pinch strength, and the range of opposition and abduction, Purdue pegboard test and Disabilities of the Arm, Shoulder and Hand (DASH). Both groups showed significant increase in all of the hand function measures after 4-week activities(p<.05). The task-oriented activity group was significantly different from the control group in powers for tip pinch, lateral pinch and three-jaw chuck pinch, Purdue pegboard test and DASH(p<.05) except in grip strength and the range of opposition and abduction suggesting better improvement in hand functions. This study shows that task-oriented activities improve the hand functions more effectively in patients with hand injuries.