• 국제물리치료학회지
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• 제11권4호
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• pp.2203-2211
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• 2020

Background: Backpacks are one of the most widely used accessories in modern society. However, previous studies have shown that carrying a backpack can cause various musculoskeletal problems. Objectives: To investigate the effects of a body-adhesive backpack on craniovertebral angle, sagittal shoulder angle and the muscle fatigue in the upper extremity. Design: Randomized cross-over design. Methods: For this study, 36 healthy university students participated in this study. The experiment was conducted three times using common backpack, and body-adhesive backpack condition. The angles of the cervical spine and shoulder joints of the subjects were calculated without the backpack. Electrodes were placed at upper trapezius, lower trapezius, rectus abdominis and erector spinae to check for muscle fatigue. Subjects carried a backpack and walked on a treadmill for 15 minutes at 4 km/h. The muscle fatigue signal was also measured while walking. After walking, the craniovertebral and sagittal shoulder angles were measured again while subjects carried backpack. Results: As a result of this study, body-adhesive backpack condition showed significant decrease and significant increase in craniovertebral angle and sagittal shoulder angle than common backpack (P<.05). Body-adhesive backpack condition showed significant decrease in upper trapezius, lower trapezius, erector spinae, and rectus abdominis when compared to a common backpack (P<.05). Conclusion: This study suggests that a body-adhesive backpack is more beneficial in correcting body posture than a common backpack.

• Child Health Nursing Research
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• 제14권2호
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• pp.176-185
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• 2008

Purpose: The purposes of this study were to investigate extent of backpack use and incidence of musculoskeletal pain, and to identify the relationship between backpack use and musculoskeletal pain. Method: A descriptive correlational study was conducted in one elementary school and one middle school in D city. Participants were 273 children, aged 12-14, who completed a self-administered questionnaire. Body weight, height, and backpack weight of participants were measured. Results: Mean backpack weight was 3.78 Kg and relative backpack weight (RBW) was 7.42%. Of backpack users, 23.8% carried more than 10% of their RBW and 9.2% carried more than 15%. Only 44.3% organized the contents in their backpack correctly. For more than three fourth of the students (76.2%), the bottom of backpack in the standing position drooped more than 10 cm below the waistline, and 46.3% complained of musculoskeletal pain. Use of a waist belt was significantly related to musculoskeletal pain. Conclusions: A considerable proportion of school children were not following guidelines for safe backpack use. Although the relationship between backpack use and musculoskeletal pain in this study was not significant, the fact that 46.3% of the students experienced musculoskeletal pain is very meaningful information. Further research is required to identify the risk factors of musculoskeletal pain among children.

• 한국전문물리치료학회지
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• 제27권1호
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• pp.45-52
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• 2020

Background: A backpack is available equipment for moving some objects. Most studies have found that the appropriate weight limit of backpack for students is between 10% to 15% of their body weight (BW). However, Some students should carry a backpack heavier than 15% of BW. Therefore, It is associated with abnormal shoulder and neck posture on students. Objects: This study tested the effects that various amounts of weight carried by university students in their backpacks had on their cervical posture and electromyography of neck muscle. Methods: The subjects consisted of 12 students (6 male, 6 female) in university. There were three loading conditions tested: no backpack, a backpack that weighed 10% and 15% of the student's BW. The dependent variables were the craniovertebral angle (tragus to C7) and the neck muscle activities (sternocleidomastoid, upper trapezius). All 12 subjects were asked to walk while wearing a backpack for 5 minutes and were then instructed to rest for 2 minutes. Results: When assessing the craniovertebral angle, the results of this study were significantly decreased in the order of 0%, 10%, and 15%. And then, there were significantly increased electromyography of neck muscles that comparison of the weight of 10% and 15% on 0%. It was found that as the weight of the backpack increased, the craniovertebral angle decreased (p < 0.05) and the muscle activities increased (upper trapezius p = 0.012, sternocleidomastoid p = 0.013). Conclusion: Our study recommended that some students shouldn't carry on over the 15% backpack of own weight, and also they should distribute backpack load to equal on body for optimal posture.

• 대한인간공학회지
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• 제25권4호
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• pp.35-40
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• 2006

The purpose of this study was to investigate the relationships between weights of backpack and back and shoulder pains of elementary school students in Korea. A cross-sectional sample of 278 boys and 233 girls aged between 7 and 12 years were analyzed for this study. 49.1% of the participated children reported their backpacks were felt heavy, and the weights of their backpack were grater than 13.3% of their body weight. About 65.4% of students carried greater than 10% of their body weights. The weight of the backpack showed significant positive relationship with shoulder pain but not with their back pain. The results of this study suggested that overweighed backpack could cause the musculoskeletal pain to the elementary school students. Therefore, an effective backpack safety program for parents and students is necessary to educate them how to prevent possible musculosketal pain related to the weight of backpack within the perspective of the ergonomical approach.

• 대한인간공학회지
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• 제31권6호
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• pp.741-747
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• 2012

Objective: The purpose of this study is to compare the EMG activities of the trunk muscles when carrying a backpack with belts and without belts. Background: This research aimed to explore the influence of carrying a backpack with belts on the trunk muscles activity and to suggest a desirable method of wearing backpacks. Method: Seventy five adolescents participated in this study. The EMG activities of upper trapezious, cervical erector spinae and rectus abdominis were collected. One way ANOVA was used to analyze the collected data. LSD was used for post-hoc test. Results: The EMG data from treadmill walking showed significant differences between carrying a backpack with belts and without belts for the cervical erector spinae and upper trapezious(p<.05) in all group(A Group: no belt, B Group: lumbar belt, C Group: lumbar-chest belt). In descending walking, significant difference were found for the cervical erector spinae and rectus abdominis in all group. In ascending walking, there were no significant differences in all group. LSD showed that the muscle activity of the trunk muscles decreased significantly when the lumbar belt and lumbar-chest belt were worn. Conclusion: The trunk muscles activities were decreased when the subjects were wearing a backpack with belts, comparing with wearing a backpack without belts. Application: These results can be used to provide useful information on how wearing a backpack in adolescent.

• 대한산업공학회지
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• 제26권2호
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• pp.110-116
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• 2000

The soft drink deliveries are made for a broad line of soft drink products by using a hand truck and the backpack mode of carriage. The workers usually deliver the beverages by backpack mode of carriage, because they feel safe with such a carrying method in stairways. In this study, the physiological workload of backpack carrying was investigated, especially focused on the effects of weight of load and carrying by the stairway. A laboratory experiment was conducted to measure heart rate and oxygen uptake during backpack carrying tasks, and an ergonomic guideline was proposed for such type of task based on the results of the experiment. Eight healthy male subjects performed the backpack carrying of 40kg and 60kg, (1) on the level ground, (2) upstairs and (3) downstairs. The result showed that the stairways caused the increased physiological cost, and that a carrying load of 60kg required significantly higher physiological cost as compared to carrying 40kg. Although backpack carrying has some advantages in the biomechanical aspect, it should be advised to carry a load of less than 40kg, since the task requires a very high physiological cost. During backpack carrying, it is also recommended for a delivery person to make more trips with a light load rather than to make less trips with a heavier load at one trip.

• 한국의류산업학회지
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• 제12권3호
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• pp.364-371
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• 2010

The purpose of this study is to weigh the students' backpacks of middle school in daily use and to analyse their physiological responses and subjective senses when carrying backpack in order to promote healthy and comfort school life of girl middle school students. Two female students were subjects who answered the questionnaires on two types of backpack and their metabolism, perspiration and the changes of skin temperature were measured in constant environment chamber, $25{\pm}1$ and $49{\pm}10$% RH. They walked on the treadmill carrying the backpack with the increment of backpack weight, 2 kg, 4 kg to 6 kg. When the backpack increases to 6 kg, the discomfort parameters and responses increases rapidly. Comparing with general type, improved type of backpack showed good results in physiological responses, but not in subjective senses, such as the ease of movement, pain, or total preference, specially in 2 kg and 4 kg. The girl students prefer the general type of backpack which is of fashion and small, when it weighs light such as 2 kg or 4 kg, while they prefer the improved bag which is functional when it is heavy as 6 kg. The longer wearing time of the medium weight, for example, 4 kg without feeling or recognition of any discomfort due to fashion style, might cause the students' posture and health weaker or more vulnerable to the problems.

• 대한물리치료과학회지
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• 제18권4호
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• pp.81-85
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• 2011

Purpose : The purpose of this study was to investigate the changing plantar foot pressure by the backpack load of 0, 10, 15, and 20% of their body weight while level walking in flat foot and so to recommend suitable backpack weight limitations for flat foot subjects. Method : 14 young flat foot subjects($24.29{\pm}2.16yrs$) participated in this study. the subjects were assigned to carry backpack load and there was four level walking modes : (1) unloaded walking(0%), (2) 10% body weight(BW) load, (3) 15% BW load and (4) 20% BW load. Repeated ANOVA was used to compare each region data of foot according to different backpack weight. Results : As backpack load became increased, the contact area of midfoot was significantly increased, and contact area of forefoot and rearfoot were significantly decreased. maximum pressure at each region during walking tended to be greater as the load increased, but a significant difference was found only for the heel medial and lateral regions Conclusion : Based on this data, the weight of backpack could influenced structure and function of the foot in flat foot.

• 대한통합의학회지
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• 제1권1호
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• pp.33-43
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• 2013

Purpose : The study was designed to identify the change of body alignment according to surface during walking with backpack. Methods : Healthy twenty people(10 men & 10 women) participated in this study. The exclusion criteria were orthopedic and neurologic disease. Initial alignment measurements were performed. Results were evaluated by angle and range from earlobe to acromion, acromion to malleolus and earlobe to malleolus in the GPS system. Results : On the hard surface, the distance and angle from malleolus to earlobe increased after walking with backpack which is 20 % of weight(p<.05). In addition the distance from malleolus to acromion and the angle from earlobe to acromion increased(p<.05). On the soft surface, on the other hand, the distance and angle from malleolus to earlobe decreased after walking with backpack which is 20 % of weight(p<.05). There was no relationship between the change of the surface and the body's alignment(p>.05). Conclusion : Consequently, the body alignment was changed by backpack which is 20 % of weight, but body alignment wasn't changed by the surface. So more study need to be surveyed regard of this.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.418-424
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• 2019

백팩은 한쪽 어깨에 매는 가방에 비해 척추에 대칭적으로 무게분산이 가능하지만, 무게중심이 뒤쪽으로 이동하게 하여, 체간이 전방굴곡되는 자세 변형을 야기한다. 본 연구는 모멘트팔의 길이차이에 따른 가방 착용 시 균형과 보행에 미치는 영향에 대해 확인하였다. 정형외과적 손상 및 신경학적 손상이 없는 정상 성인 30명을 대상으로 하였다. 대상자는 1) 백팩 미 착용, 2) 일반적인 백팩, 3) 모멘트 길이를 감소시킨 백팩의 3가지 조건에서 각각 균형 및 보행을 측정하였다. 자세동요면적과 속도에서 백팩 미착용과, 일반적인 백팩, 특수 백팩의 3가지 조건에 따른 유의한 차이가 있었으나, 백팩의 모멘트팔의 길이에 따른 유의한 차이는 없었다. 양하지 지지기와 보행속도는 백팩 미착용과, 일반적인 백팩, 특수 백팩의 3가지 조건에서 유의한 차이가 있었으며, 양하지 지지기에서만 백팩의 모멘트팔의 길이에 따른 유의한 차이가 있었다. 본 연구의 결과를 통해 백팩 착용시 모멘트팔의 길이 변화가 보행에 도움이 될 수 있었다.