쪼그려 들기와 허리 굽혀 들기 시 하지관절 움직임과 요추전만에 관한 생체역학적 분석

황선홍(Seon hong Hwang),김영은(Young eun Kim),김영호(Young ho Kim) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.11

In this study, lower extremity joint kinematics and kinetics and lumbar lordosis were investigated for two different symmetrical lifting techniques(squat and stoop) using the three-dimensional motion analysis. Twenty-six male volunteers lifted boxes weighing 5, 10 and 15㎏ by both squat and stoop lifting techniques. There were not significant differences in maximum lumbar joint moments between the two techniques. The hip and ankle contributed the most part of the support moment during squat lifting, and the knee flexion moment played an important role in stoop lifting. The hip, ankle and lumbar joints generated power and only the knee joint absorbed power in the squat lifting. The knee and ankle joints absorbed power, the hip and lumbar joints generated power in the stoop lifting. The bi-articular antagonist muscles' co-contraction around the knee joint during the squat lifting and the eccentric co-contraction of the gastrocnemius and semitendinosus were found to be important for straightening up during the stoop lifting. At the time of lordotic curvature appearance in the squat lifting, there were significant correlations in all three lower extremity joint moments with the lumbar joint. Differently, only the hip moment had significant correlation with the lumbar joint in the stoop lifting. In conclusion, the knee extension which is prominent kinematics during the squat lifting was produced by the contributions of the kinetic factors from the hip and ankle joints(extensor moment and power generation) and the lumbar extension which is prominent kinematics during the stoop lifting could be produced by the contributions of the knee joint kinetic factors(flexor moment, power absorption, bi-articular muscle function).

Simplified Structure of Integer Lifting Wavelet Filter Banks for Lossless Image Compression

Yanjuan Li,Dong Chen,Honge Ren 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.7

In this paper, a simplified structure of integer lifting wavelet filter banks for lossless image compression is proposed by shifting and merging the scaling factors of the row and the column wavelet transforms. It is implemented by reducing the numbers of scaling factors and considering the scaling lifting. The numbers of scaling factors of the 2-D wavelet transform can be reduced by shifting and merging operation, and then the computing speed can be improved. Furthermore, the scaling lifting of simplified structure can be used to reduce the computing errors and get more accurate results. Experiments show that the simplified integer lifting structure results in lesser computational steps than the standard integer lifting structure and therefore improves the speed of the image compression. Besides, using the new lossless image compression system based on simplified integer lifting wavelet, the lower bit-rates are obtained.

The Effect of Lifting Speed on Cumulative and Peak Biomechanical Loading for Symmetric Lifting Tasks

Greenland, Kasey O.,Merryweather, Andrew S.,Bloswick, Donald S. Occupational Safety and Health Research Institute 2013 Safety and health at work Vol.4 No.2

Background: To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods: Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results: Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ${\geq}80%$. Conclusion: Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

다단적재 복합들기 작업에 대한 NIOSH 단순들기 수식의 적용 모형 개발

박재희 ( Jae Hee Park ) 한국안전학회 2009 한국안전학회지 Vol.24 No.4

The NIOSH lifting equation has been used as a dominant tool in evaluating the hazard levels of lifting tasks. Although it provides two different ways for each simple and complex lifting task, the NIOSH simple lifting equation is almost used for not only simple tasks but also complex tasks. However, most of lifting tasks in industries are in the form of complex lifting. Therefore some errors occur inevitably in the evaluation of complex lifting tasks. Among complex lifting tasks, a multi-stacking task is the most popular in lifting tasks. To compensate the error in the evaluation of multi-stacking tasks by using the NIOSH simple lifting equation, a set of calculations for finding LIs(Lifting Indices) was performed for the systematically varying multi-stacking tasks. Then a regression model which finds the equivalent height in simple lifting task for multi-stacking task was established. By using this model, multi-stacking tasks can be evaluated with less error. To validate this model, some real multi-stacking tasks were evaluated as examples.

The Effect of Lifting Speed on Cumulative and Peak Biomechanical Loading for Symmetric Lifting Tasks

Kasey O. Greenland,Andrew S. Merryweather,Donald S. Bloswick 한국산업안전보건공단 산업안전보건연구원 2013 Safety and health at work Vol.4 No.2

Background To determine the influence of lifting speed and type on peak and cumulative back compressive force (BCF) and shoulder moment (SM) loads during symmetric lifting. Another aim of the study was to compare static and dynamic lifting models. Methods Ten male participants performed a floor-to-shoulder, floor-to-waist, and waist-to-shoulder lift at three different speeds [slow (0.34 m/s), medium (0.44 m/s), and fast (0.64 m/s)], and with two different loads [light (2.25 kg) and heavy (9 kg)]. Two-dimensional kinematics and kinetics were determined. A three-way repeated measures analysis of variance was used to calculate peak and cumulative loading of BCF and SM for light and heavy loads. Results Peak BCF was significantly different between slow and fast lifting speeds (p < 0.001), with a mean difference of 20% between fast and slow lifts. The cumulative loading of BCF and SM was significantly different between fast and slow lifting speeds (p < 0.001), with mean differences ≥80%. Conclusion Based on peak values, BCF is highest for fast speeds, but the BCF cumulative loading is highest for slow speeds, with the largest difference between fast and slow lifts. This may imply that a slow lifting speed is at least as hazardous as a fast lifting speed. It is important to consider the duration of lift when determining risks for back and shoulder injuries due to lifting and that peak values alone are likely not sufficient.

Comparison of Compressive Forces on Low Back(L5/S1) for One-hand Lifting and Two-hands Lifting Activity

Hong-Ki Kim 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.5

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 10㎝ 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 7.5㎏ to 15.0㎏. 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.

P003 : Nonsurgical powered face lifting with the combination of PDO(absorbable thread) with ulthera and pneumatic radiofrequency

( Kyu Kwang Whang ),( Eun Sun Choi ) 대한피부과학회 2013 대한피부과학회 학술발표대회집 Vol.65 No.2

Background: Nonsurgical modality has been tried for face lift including ulthera combined wiht pneumatic radiofrequency, various cogged thread including APTOS etc. Permanent remained thread can make patient to coimplain because thread remains permanently in the skin. Objectives: Recent developed absorbable thread(polydioxanone, PDO) solve the preexisting problems, and make powerful true face lifting. Our clinic applied this absorbable thread to make the nonsurgical face lifting more effective to previous ulthera lifting. Methods: Patients receive ulthera and pneumatic radiofrequency on whole face. Because jowl area is not completely abolished, we tried to lift up the jowl area and to diminish the mentolabial and nasolabial fold. Results: Whole face of the patients with nonsurgical lifting showed the definite lifting results no less than the surgical face lift procedure. Conclusion: Nonsurgical Powered Face Lifting with the combination of PDO(absorbable thread) with Ulthera and Pneumatic Radiofrequency could provide qualified and visible lifting effects, open new horizon for face lifting, and make additional corrections after preexisting surgical or other face lift surgery.

여러 가지 들기 작업에서의 인체심리학적 · 생리학적 연구

윤훈용,Yun, Hun-Yong 대한인간공학회 2006 大韓人間工學會誌 Vol.25 No.2

The muscular-skeletal disorders(MSDs) that have become a major issue recently in Korean industrial safety area are mainly caused by manual material handling task. The objective of this study is to provide scientific data for the establishment of work safety standard for Korean workers through the experiments of lifting task under various conditions, in order to prevent the muscular-skeletal disorders in the industrial work site. Eight male college students were recruited as participants. Three different lifting frequencies(1, 3, 5 lifts/min) and three twisting angles(including the sagittal plane and two asymmetric angles; i.e., 0°, 45°, 90°) for symmetric and asymmetric tasks, respectively, with three lifting range from floor to knuckle height, knuckle to shoulder, floor to shoulder height for one hour's work shift using free style lifting technique were studied. The maximum acceptable weight of load(MAWL) was determined under the different task conditions, and the oxygen consumption, heart rate, and RPE were measured or recorded while subjects were lifting their MAWLs. The results showed that: (1) The MAWLs were significantly decreased as the task frequency and task angle increased.; (2) The heart rate, oxygen consumption, RPE significantly increased with an increase in lifting frequency although maximum acceptable weight of lift decreased.; (3) The highest heart rate and oxygen consumption was recorded at the lifting range of floor to shoulder, followed by floor to knuckle and knuckle to shoulder.; (4) The RPE value showed that subjects perceived more exertion at the high frequency rate of lifting task and lifting range of floor to shoulder height. (5) The modeling for MAWL using isometric strength, task angle and lifting frequency were developed. It is expected that use of the results provided in this study may prove helpful in reducing MMH hazards, especially from lifting tasks for Korean, and can be used as a basis for pre-employment screening.

골반 경사로 인한 요추부 측만증에서 신발 높이기의 효과

김용민,김동수,최의성,손현철,박경진,김융성 대한척추외과학회 2004 대한척추외과학회지 Vol.11 No.2

실내 생활공간에서 휠체어 리프트 유니트의 사용만족도 및 수행시간에 관한 비교 연구

임호용,이근민 한국지체.중복.건강장애교육학회 2010 지체.중복.건강장애연구 Vol.53 No.4

The present research has placed an emphasis on the comparison of user satisfaction and performance time of the existing wheelchair lifts with that of the wheelchair lifts moving up and down, and horizontally, produced in order to achieve the aim of action performance of physically impaired persons or wheelchair users with paraparesis inferior. The influence of wheelchair lifts on their performance has been excluded depending on the level of impairment; and,in order to increase the consistency of the study, the present research was implemented targeting healthy adults (8 male and 10 female) who had no experience of using a wheelchair. The experimental design of the present study and the production of research wheelchair lifts were completed from January 2009 to October 2009; and, in order for the measurement of user satisfaction and performance time, it was implemented from March1, 2010 to March 31, 2010. As for the experiment tools,a KWL product possessing the wheelchair lifting function, the imported DWL product, and the research wheelchair lifts produced in order for the present experiment were used and the following findings have been obtained by implementing the analysis of the lifting units. Through one-way analysis of variance(one-way ANOVA) based on the satisfaction level of wheelchair lifts, it was found out that there was no statistically significant difference in stability and durability. It was found out that the research wheelchair lifts showed high difference which was statistically significant in the running speed(p<0.001), the lifting speed(p<0.001), functionality (p<0.001), efficiency(p<0.001), convenience(p<0.001), simplicity(p<0.001), and purchase commitments(p<0.001). The research wheelchair lifts showed high average in terms of user satisfaction as well(p<0.001) which was statistically significant; and the results of measuring the performance time showed that there was a statistically significant difference in single measurement(p<0.001), double measurement(p<0.001) and average performance time(p<0.001) which showed that the performance time of the research wheelchair lifts were effective in comparison to other wheelchair lifts. In addition, it was found out that they showed high negative correlation in stability(r=-.476, r=-.352), which is the factor of user satisfaction in terms of weight and height; they showed a high correlation in the running speed(r=.537), the lifting speed(r=.670), functionality(r=.378),efficiency(r=.539), convenience(r=.626), simplicity(r=.529), and purchase commitments (r=.660) in terms of user satisfaction factors based on performance time. In order to predict the explanatory power that user satisfaction factors have on performance time, the relative importance and predictability was found out by implementing the multiple regression analysis. As a result, the explanatory power,that user satisfaction factor an independent variable used to explain the performance time, appeared to be 71.2%. It appeared to show high explanatory power of 24.5% in stability, 22.7% in efficiency, and 37.6% in convenience at performance time. Based on the findings above, the research wheelchair lifts that were produced and developed in this study are regarded to perform the role of assistive equipment so that the physically impaired persons and wheelchair users can perform actions in villages and daily living space. Henceforth, by applying it to physically impaired persons who actually use wheelchairs, it is judged to be applied as a useful foundation for the development of wheelchair lifts through a more accurate prediction of the functionality and stability of the wheelchair lifts applied in this study. Henceforth, it is thought to be applied effectively as a basic material that can contribute to increasing the improvement of wheelchair users’life. 본 연구는 하지마비 장애인 또는 휠체어 사용자들이 일상 생활공간에서 행위 수행을 위한목적을 달성하기 위하여 상하‧ 수평 이동을 할 수 있는 휠체어 리프트 유니트를 제작하여 기존에 사용되고 있는 휠체어 리프트와의 사용만족도 및 수행시간의 비교에 연구 중점을 두었다. 장애 정도에 따라 휠체어 리프트의 수행에 미치는 영향을 배제하고, 연구의 일관성을높이기 위해 휠체어 사용 경험이 없는 건강한 성인 남녀(male=8, female=10)를 대상으로 본연구를 실시하였다. 본 연구의 실험 설계 및 연구용 휠체어 리프트 유니트의 제작은 2009년 1월∼2009년 10월까지 완료하였으며, 사용만족도 및 수행시간 측정을 위해 2010년 3월 1일에서 2010년 3월31일까지 실시하였다. 실험 도구는 휠체어 리프트 기능을 갖춘 KWL 제품과 수입된 DWL 제품을 본 실험을 위해 제작된 연구용 휠체어 리프트 유니트(RWL)와 비교하여 다음과 같은 결과를 얻었다. 휠체어 리프트의 사용만족도에 따른 일원배치분산분석을 통해 안정성과 내구성에서는 통계적으로 유의한 차이가 없는 것으로 나타났으나, 리프트속도(p<0.001), 기능성(p<0.001),효율성(p<0.001), 편리성(p<0.001), 간편성(p<0.001), 구입의사(p<0.001)에서 연구용 휠체어 리프트 유니트에서 통계적으로 유의하게 높은 차이를 보이고 있는 것으로 나타났다. 수행시간을 측정한 결과, 통계적으로 유의한 차이를 보여, 연구용 휠체어 리프트의 수행시간이 휠체어 리프트에 비해 효과적인 것으로 나타났다. 또한 체중과 신장에서 사용만족도 요인인 안정성에서 높은 부적상관(r=-.476, r=-.352)을 보였으며, 수행시간에 따른 사용만족도 요인에서는 주행속도(r=.537), 리프트속도(r=.670), 기능적(r=.378), 효율성(r=.539),편리성(r=.626), 간편성(r=.529), 구입의사(r=.660)에서 높은 상관을 보였다. 사용만족도요인이 수행시간에 미치는 설명력을 예측하기 위해 다중회귀분석을 실시하여 상대적인 중요도 및 예측력을 파악한 결과, 독립변수인 사용만족도가 수행시간을 설명하는 설명력이71.2%로 나타났으며, 안정감에서 24.5%, 효율성에서 22.7%, 편리성에서 수행시간에 37.6%의높은 설명력을 보이고 있는 것으로 나타났다. 위의 결과를 기초로 본 연구에서 제작‧개발된 연구용 휠체어 리프트 유니트는 장애인 및휠체어 사용자들이 도서 및 일상 생활공간에서 행위 수행을 효과적으로 할 수 있는 보조도구로서의 역할을 수행할 것으로 생각되며, 향후 실제 휠체어 사용 장애인에게 기능성과 안전성에 대한 보다 정확한 연구가 필요하며, 이와 같은 연구는 개발에 유용한 지표로 활용될수 있을 것으로 판단된다. 본 연구는 향후 휠체어 사용 장애인의 재활보조기기의 개발과 삶의 질 향상을 위한 기초자료로 사용될 수 있을 것이라 생각된다.