• 대한산업공학회지
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• 제24권2호
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• pp.167-173
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• 1998

Many workers like welders work in squatting postures with the object on the ground during an entire work shift. It is suspected that such prolonged squatting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to examine the physical stress caused by the prolonged squatting and to recommend a safe work/rest schedule for a welding task with squatting posture based on the lab experiments. In this study, 8 healthy student subjects participated in the experiment. They maintained a squatting work posture for 16 minutes with 4 different stool height conditions: no stool; 10cm height; 15cm height; and 20cm height. Every 2 minutes, the discomfort was subjectively assessed with the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort ratings, we found that a 10cm height stool relieved the workload most. Discomfort rating results also indicated that a 20cm height stool showed the highest workload, and the there were no difference in workload between a 15cm height stool and no stool. We recommend to use low height stools and to maintain such working postures no longer than 6 minutes for prolonged squatting tasks.

• 한국의류학회지
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• 제31권11호
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• pp.1530-1541
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• 2007

The purpose of this study is to establish a standard sizing system for Taekwondo uniforms. The sample utilized in the study consisted of 5,679 male and female subjects, obtained from Size Korea Project. Twenty three measurements were identified and selected as critical in the design and construction of Taekwondo uniforms. The results were as follows: First, it was determined that all brands used "height" as a key dimension of size designation. Two of brands added "chest girth" or "numeric numbers" to designate size in addition to "height". For example: 1) height/chest girth, 2) height/numeric number. The size pitches of all current Taekwondo uniforms in the market were 10cm of height for all brands. Second, the study showed male measurements were larger and longer than females, establishing that independent sizing specifications by sexes are needed. Third, in case of Taekwondo shirts, height and chest girth were selected as control dimensions. In case of pants, height and waist girth were selected as control dimensions. For selecting optimal sizing pitch, 2 different pitches of chest girth and waist girth(4cm pitch by KS and 8cm pitch by researchers) were compared, while height pitch was fixed at 10cm. Fourth, based on the analysis of the measurements(coverages and coverage efficiency rates), it was determined that 8cm pitches of chest and waist girth were efficient in both upper and lower Taekwondo uniforms. Fifth, subjects distribution counts and percentages were shown after analyzing coverage efficiency rates. Separate results are noted for the upper and lower Taekwondo uniforms. As previously mentioned, height pitches were 10cm and chest and waist pitches were 8cm. Finally, as a result of this research, key and referable measurements relevant to making Taekwondo uniforms were identified for male and female uniform. In case of Taekwondo shirts, 18 sizes were established for men, 16 sizes for women. Twenty five sizes for men and 20 sizes for women were presented in size tables for pants.

• 대한물리의학회지
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• 제10권2호
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• pp.9-16
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• 2015

PURPOSE: The objective of this study was to identify the effects of shoulder abduction strength and EMG activities of the selected scapular and shoulder muscles during isometric shoulder abduction. METHODS: Thirty-four healthy young females were recruited for this study. Surface EMG equipment with inline force sensor was used to determine the shoulder abductor strength and the activity of the serratus anterior (SA), upper trapezius (UT), lower trapezius (LT), and middle deltoid (MD) during three shoe heel height conditions: (1) barefoot, (2) 3-cm shoe heel height, and (3) 7-cm shoe heel height. RESULTS: Isometric shoulder strength showed statistically significant difference among the conditions (p<0.05), and post-hoc test showed lower strength during the 7-cm condition ($49.98{\pm}17.56kg$) than during the barefoot ($44.97{\pm}20.15kg$) and 3-cm conditions ($36.59{\pm}17.07kg$). Furthermore, EMG activities of the SA, UT, and MD appeared to be statistically significantly different among the conditions, with lower values in the 7-cm condition compared to the barefoot condition (p<0.05). EMG ratios (MD/UT and SA/UT) were lower during the 7-cm condition than during the barefoot condition (p<0.05). CONCLUSION: These findings suggest that isometric shoulder abduction strength and EMG activities of scapular and shoulder muscles may be adversely changed with increasing shoe heel height.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1265-1272
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• 2016

The present study evaluated the effects of different cutting height on nutritive value, fermentation quality, in vitro and in vivo digestibility of whole crop barley silage. Whole crop barley forage (Yuyeon hybrid) was harvested at height of 5, 10, and 15 cm from the ground level. Each cutting height was rolled to make round bale and ensiled for 100 days. After 100 days of ensiling, pH of silage was lower (p<0.05) in 5 cm, but no difference between 10 and 15 cm of cutting height. The content of lactate and lactate to acetate ratio were increased (p<0.05) in 5 cm of cutting height, whereas the acetate content was higher (p<0.05) in 10 and 15 cm than that of 5 cm cutting height. Aerobic stability was greater (p<0.05) in silages of 10 and 15 cm of cutting height. Three total mixed rations (TMR) were formulated with silages from the three different cutting heights (TMR5, TMR10, and TMR15) incorporated as forage at 70:30 ratio with concentrate (dry matter [DM] basis). In vitro dry matter digestibility was higher (p<0.05) in the TMR5 and TMR10 than that in TMR15, whereas in vitro neutral detergent fiber digestibility was higher (p<0.05) in the TMR10 and TMR15 than that in TMR5. Concentration of $NH_3-N$ was highest (p<0.05) in the TMR10 followed by TMR15 and TMR5. Total volatile fatty acid was decreased (p<0.05) with increased cutting height. The digestibility of DM and neutral detergent fiber were highest (p<0.05) in TMR15, than those in TMR5 and TMR10, whereas acid detergent fiber digestibility was higher (p<0.05) in TMR5 than that in TMR10. The results showed that increasing cutting height, at least up to 10 to 15 cm, of whole crop barley forage at harvest (Yuyeon) may be beneficial for making silage for TMR formulation and increasing digestibility of DM and NDF.

• 산업공학
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• 제18권3호
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• pp.288-296
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• 2005

Many jobs and activities in our daily lives require squatting postures. The fore part includes housekeepers, farmers, and welders and the latter includes a wide variety of activities such as housekeeping; planting, cultivating and harvesting various agricultural products; grinding, welding, etc. It is speculated that prolonged squatting postures without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is conducted to examine the proper height of stools according to the position of the working materials and to develop wearable stools for workers with squatting posture. Forty male and female subjects participated in the experiment to find the proper height of stools according to the position of the working materials. Subjects were asked to squat and work with 3 different working positions: floor level; ankle level; shank level of 3 different stool height conditions: 10cm height; 15cm height; and 20cm height. After 5 minutes of maintaining a squatting work posture while sitting on the different height stools, Likert summated rating method as well as pairwise ranking test was applied to evaluate the user preferences for provided stools under the conditions of different working positions. The results of statistical analysis show that the subjects preferred 10cm height stool for floor level, 15cm height stool for ankle level, 20cm height stool for knee level. We thus strongly recommend to use appropriate height stools in accordance with the different working positions. Moreover, a prototype wearable stool was designed such that workers with squatting posture do not need to move the stool while they are moving about. The purpose of developing wearable stool was to decrease the physical stress and hence promote worker's health who work with squatting posture.

• 한국운동역학회지
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• 제21권2호
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• pp.197-205
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• 2011

Various jumping and landing motions are shown during sports event. But most previous studies have not considered landing height and distance simultaneously. The purpose of this study was to identify the effects of landing height and distance on knee injury mechanism. Fourteen male(age: $28.86{\pm}1.99$ yrs, height: $177.00{\pm}4.69$ cm, weight: $76.50{\pm}6.41$ kg) participated in this study. The subjects attempted drop landing task onto the ground from 30 cm to 45 cm heights and to 20 cm to 40 cm distances. The results were as follows. First, higher drop landing height and longer distance showed greater degree of maximal knee flexion and valgus. Second, higher drop landing height and longer distance showed greater maximal knee extension moment and varus moment. Third, higher drop landing height and longer distance showed larger maximal knee absorption power. Lastly, higher drop landing height showed increased Peak GRF. Landing height was more related to the cause of injury, which was indicated by increased maximal knee extension moment, peak GRF and maximal knee absorption power. Landing distance was also associated with increased knee valgus moment and absorption power during landing. These results suggest that landing height and distance may be the cause of injury.

• 한국초지조사료학회지
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• 제22권1호
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• pp.15-22
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• 2002

제주지역에서 예취높이에 따른 (2, 4, 6, 8 및 l0cm)에 따른 양마의 생육특성, 수량성 및 사료가치를 구명하기 위하여 2001년 4월 13일부터 10월 8일까지 시험한 결과는 다음과 같다. 초장은 2cm 예취에서 157.7cm였던 것이 예취높이가 높아짐에 따라 점차적으로 커져서 10cm 예취에서는 180.2cm로 커졌다. 엽수, 분지수, 경직경 및 주당 무게는 초장반응과 비슷한 경향이었다. 생초, 건물, 단백질 및 TDN 수량은 2cm 예취에서 각각 85.5MT/ha, 11.97MT/ha, 1.63MT/ha, 4.95MT/ha로 감수되었으나 예취높이가 높아짐에 따라 점차적으로 증가되어 10cm 예취에서 생초수량 113.7MT/ha, 건물수량 15.63MT/ha, 단백질수량 2.72MT/ha, TDN수량은 7.54MT/ha 증수되었다. 예취높이가 2cm에서 l0cm로 높아짐에 따라 조단백질 함량은 14.2%에서 17.6%로, 조지방 함량은 2.9%에서 3.9%로, NFE 함량은 24.2%에서 25.8%로, TDN 함량 35.5%에서 30.4%로, 조회분 함량은 9.9%에서 8.1%로 낮아졌다.

• 한국약용작물학회지
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• 제28권2호
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• pp.136-141
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• 2020

Background: The leaves of the goji berry (Lycium chinense Mill.) are used as raw materials in processing and by replace fruits to some extent. The reason is that the leaves are cheaper, however, betaine content is higher than in the fruits. These experiments were conducted to determine the planting density and cutting height for producing a large number of leaves. Methods and Results: The cultivar 'Myeongan' with many branches was used. When the shoot height reached 50 cm - 70 cm, harvesting was possible four times a year. The time to next harvest was approximately 38 days after regeneration of new shoots. Leaf quantity was in the order of 1st > 2nd > 4th > 3rd harvest. Insect damage occurred during the third harvest in late July and early August, therefore, eco-friendly control was necessary. The total yield was higher at the planting density 60 cm × 30 cm than that of 60 cm × 20 cm or 60 cm × 40 cm. The yield at cutting for shoot height of 60 cm was increased by 6.3 percent compared to that of 50 cm, At the cutting height of 70 cm, harvest was difficult owing to hardening of stems and thorns. Betaine content, an indicator component of goji berry, was not significantly different according to planting densities and cutting height. Conclusions: The ideal cutting period to produce leaves of goji berry for processing is when the shoots grow to approximately 60 cm, and the leaves can be harvested 4 times a year. The dried-leaf yield was highest at the planting density of 60 cm × 30 cm.

• 한국엔터테인먼트산업학회논문지
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• 제13권1호
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• pp.207-215
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• 2019

본 연구는 뇌졸중 편마비 환자 12명을 대상으로 지팡이 높이에 따라 선 자세 시 양측 발의 압력, 보행 시 보행 속도의 변화를 알아보고자 하였다. 선 자세 시 발의 압력은 풋스캔(Foot scan system, 한국)을 사용하여 측정하였다. 보행 시 보행 속도 차이는 Optogait를 사용하여 측정하였다. 본 연구의 결과는 비 마비 측 발의 압력에서 넙다리뼈 큰 돌기 높이, 넙다리뼈 큰 돌기 위 5cm, 넙다리뼈 큰 돌기 위 10cm 순으로 큰 값을 나타내었으며 유의한 차이가 있었다. 마비 측 발의 압력은 넙다리뼈 큰 돌기 위 10cm, 넙다리뼈 큰 돌기 위 5cm, 넙다리뼈 큰 돌기 순으로 큰 값을 나타내었으며 유의한 차이가 있었다. 이는 지팡이 높이가 높을수록 마비측으로 무게중심이 이동하여 체중지지율이 높아진 것을 알 수 있었다. 보행 속도는 넙다리뼈 큰 돌기 위 5cm, 넙다리뼈 큰 돌기 10cm, 넙다리뼈 큰 돌기 높이에서 미세한 차이는 보였으나 통계학적으로 유의한 차이가 나타나지 않았다. 이는 지팡이 높이가 보행 속도 능력을 변화시킬 만큼 크지 않았다는 것을 볼 수 있었다. 본 논문은 지팡이 높이가 뇌졸중 편마비 환자의 선 자세 시 체중지지율과 보행 시 보행 속도에 대해 알아보고자 하였으며, 차후 임상에서 뇌졸중 편마비 환자들의 지팡이를 적용한 선 자세 또는 보행을 위한 치료에서 지팡이 높이를 설정할 때 기초자료를 제공할 수 있을 것으로 생각된다.

• 한국전문물리치료학회지
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• 제20권3호
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• pp.36-44
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• 2013

This study aimed to investigate the influence of shoe heel height and muscle fatigue on static and dynamic balance in young women. Thirty women who were used to wearing high heels volunteered to participate in this study. The shoe heel heights were 0 cm and 7 cm. And ankle plantar flexor fatigue was experimentally induced. Static and dynamic balance were measured using the one leg standing test (OLST) and the star excursion balance test (SEBT) in anterior, posteromedial, and posterolateral directions, respectively. Values in the OLST (shoe heel height 0 cm, $28.83{\pm}3.24$ sec to $26.12{\pm}6.13$ sec; and 7 cm, $24.75{\pm}7.09$ sec to $16.86{\pm}9.32$ sec) and the SEBT in anterior (shoe heel height 0 cm, $71.02{\pm}4.57%$ to $69.50{\pm}3.66%$; and 7 cm, $64.17{\pm}3.53%$ to $59.61{\pm}4.06%$) and posteromedial (shoe heel height 0 cm, $92.01{\pm}5.61%$ to $90.38{\pm}7.10%$; and 7 cm, $83.09{\pm}7.29%$ to $76.83{\pm}9.28%$) directions were significantly reduced when fatigue-inducing exercise was performed (p<.05). Furthermore, within these parameters, there were significant interaction effects between shoe heel height and fatigue condition (p<.05). These findings suggest that shoe heel height and muscle fatigue contribute to some changes in static and dynamic balance in young women, probably leading to negative effects on physical function during a variety of activities of daily living.