• 한국운동역학회지
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• 제23권4호
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• pp.369-376
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• 2013

The purposes of this study were to assess dynamic stability toward pelvis-spine column distortion during running and to compare the typical three-dimensional angular kinematics of the trunk motion; cervical, thoracic, lumbar segment spine and the pelvis from the multi-segmental spine model between exercise group and non-exercise group. Subjects were recruited as exercise healthy women on regular basis (group A, n=10) and non-exercise idiopathic scoliosis women (group B, n=10). Data was collected by using a vicon motion capture system (MX-T40, UK). The pelvis, spine segments column and lower limbs analysiaed through the 3D kinematic angular ROM pattern. There were significant differences in the time-space variables, the rotation motion of knee joint in lower limbs and the pelvis variables; obliquity in side bending, inter/outer rotation in twisting during running leg movement. There were significant differences in the spinal column that is lower-lumbar, upper-lumbar, upper-thoracic, mid-upper thoracic, mid-lower thoracic, lower thoracic and cervical spine at inclination, lateral bending and twist rotation between group A and group B (<.05, <.01 and <.001). As a results, group B had more restrictive motion than group A in the spinal column and leg movement behaved like a 'shock absorber". And the number of asymmetry index (AI) showed that group B was much lager unbalance than group A. In conclusion, non-exercise group was known to much more influence the dynamic stability of equilibrium for bilateral balance. These finding suggested that dynamic stability aimed at increasing balance of the trunk ROM must involve methods and strategies intended to reduce left/right asymmetry and the exercise injury.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.341-348
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• 2017

본 연구에서는 척추측만증 환자의 척추 만곡 위치와 방향이 자세 균형에 미치는 영향을 평가하였다. 총 15명의 실험대상자를 흉추 만곡 그룹, 요추 만곡 그룹, 이중 만곡 그룹으로 분류하여 연구를 진행하였다. 초음파 기반 동작 분석 시스템과 압력 분포 시스템을 사용하여 환자의 동적 체간 움직임(요추, 흉요추, 하흉추, 상흉추에서의 각도 변화)과 족저 압력 분포(최대힘, 최대압력)을 측정하였다. 측정 결과를 통해, 특발성 척추측만증 환자의 동적 체간 움직임과 족저 압력 분포 모두 척추 만곡의 발생 부위와 방향에 따라 비대칭적으로 각도와 압력이 증가하면서 자세 불균형이 발생하는 것을 알 수 있었다. 또한, 단일 만곡과 이중 만곡을 가진 그룹 간의 자세 균형 패턴에서의 차이를 확인할 수 있었다. 추후 연구에서는 본 연구에서의 결과를 기반으로 척추측만증 환자의 자세 조절 능력과 체간 균형을 향상시키고 척추측만을 치료하는데 도움을 줄 수 있는 재활 훈련 장치를 개발하고자 한다.

• 대한인간공학회지
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• 제28권3호
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• pp.41-47
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• 2009

The purpose of this study, during the lifting task was researching the difference and a relationship between the ground reaction force and the grip strength by change of position. After grip strength has measured in symmetry position and asymmetry position at 45cm and 75cm of height of hand, ground reaction force was measured by same attitude lifting wooden box. We analyzed the difference of grip strength and ground reaction force in each position change. The results of grip strength, the grip strength of both hand were significant difference that in study subject symmetry and asymmetry position (p<0.01). The results of symmetry lifting task, the study subjects was significant difference of the ground reaction force difference by height (p<0.05). Asymmetry lifting task was significant difference of ground reaction force difference by direction of rotation was changed (p<0.01). The result of it will rotate with non-dominant hand side of lifting tasks from height 75cm where it easily maintains a balance possibility and decreasing the load of the hand. Therefore, from the workshop in the work people, it will be between the height 75cm and non-dominant hand side of trunk rotatory direction in the lifting tasks. Future study is necessary researched about the change of grip strength when the height of the hand is higher, and the difference of the ground reaction force when the change of weight.

• 한국전문물리치료학회지
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• 제25권4호
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• pp.9-18
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• 2018

Background: Leg length discrepancy (LLD) leads to many musculoskeletal disorders and affects daily activities such as walking. In the majority of the population, mild LLD is a common condition. Nevertheless, it is still controversy among researchers and clinicians on the effects of mild LLD during gait, and available studies have largely overlooked this issue. Objects: The purpose of the present study is to investigate the effects of mild LLD on the gait parameters and trunk acceleration. Methods: A total of 15 female and male participants with no evidence of LLD of >.5 ㎝ participated in the present study. All participants walked under the following two conditions: (1) The non-LLD condition, where the participants walked in shoes of the same heel height; (2) A mild LLD condition induced by wearing a 1.5 ㎝ higher heel on the right shoe. The GAITRite system and tri-axial accelerometer were used to measure gait parameters and trunk acceleration. To compare the variation of each variable, a paired t-test was performed. Results: Compared to the non-LLD condition, step time and swing phase were significantly increased in the mild LLD condition, while stance phase, single support phase, and double support phase significantly decreased in the short limb (p<.05). In the long limb of the mild LLD condition, single support phase significantly increased, while swing phase significantly decreased (p<.05). Furthermore, significant decrease in the gait velocity and cadence in the mild LLD condition were observed (p<.05). In the comparison between both limbs in the mild LLD condition, the step time and swing phase of the short limb significantly increased compared with the long limb, while step length, stance phase, and single support phase of the long limb significantly increased compared with the short limb (p<.05). Additionally, trunk acceleration of all directions (anterior-posterior, medial-lateral, vertical) significantly increased in the mild LLD condition (p<.05). Conclusion: The results of the present study demonstrate that mild LLD causes altered and asymmetrical gait patterns and affects the trunk, resulting in inefficient gait. Therefore, mild LLD should not be overlooked and requires adequate treatment.

• 대한인간공학회지
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• 제29권3호
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• pp.279-286
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• 2010

The purpose of this study was to compare the electromyographic(EMG) activities of trunk and hip muscles between right and left sides while subjects performed prolonged manual task in asymmetric and symmetric weight-bearing posture. Fifteen healthy male college students were recruited for this study. The subjects were asked to perform bimanual upper extremity task for 6 minutes in two different standing postures. In the symmetric weight-bearing posture, the subjects were standing with evenly distributed body weights to both legs. In the asymmetric weight-bearing posture, the subjects distributed about 90% of their body weight onto their preferred(supporting) leg and 10% of their body weight onto the opposite leg while they were standing. EMG activities of the right and left internal oblique, erector spinae, gluteus maximus, and gluteus medius were measured and normalized as % MVIC. Then the EMG data were statistically analyzed using paired t-tests. The EMG activities of all measured muscles were not significantly different between the right and left side in the symmetrical weight-bearing posture(p>0.05). However, the EMG of the supporting side internal oblique was significantly lower than the opposite side(p<0.05), and the EMG of the erector spinae, gluteus maximus, and gluteus medius were significantly greater on the supporting side(p<0.05). The results of this study support that unbalanced use of right and left muscle possibly causes the changes in muscle length which results in asymmetry of trunk and hip muscles. Furthermore, the uneven weight support onto right and left legs will cause a distortion of viscoelastic ligaments around hip and sacroiliac joints in the long run. Further studies to determine the effect of various manual tasks on the trunk and hip muscles as well as the effect of asymmetrical weight-bearing standing posture on hip and back muscle fatigue may be required.

• 한국안전학회지
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• 제24권2호
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• pp.83-88
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• 2009

The objective of this paper was to evaluate the effectiveness of horizontal, vertical, asymmetric and coupling multipliers for manual material handling. Lifting tasks with 5 different horizontal distances ($30{\sim}70cm$) for 6 vertical distances(ankle, knee, waist, elbow, shoulder and head height) were experimented. The muscle activity and muscle exertion level during asymmetric load handling(without trunk flexion) was experimented. Lifting tasks with and without handle tote box for three postures(straight, bending, right angle posture) were experimented. The degrading tendency did not appeared almost in $60{\sim}70cm$ interval's horizontal distance. As a result of ANOVA, MVC paid attention to horizontal and vertical distance but cross effect was insignificant(p<0.01). The change of the MVC according to the horizontal, vertical distance appeared similar from of RWL. The results of normalized MVC measurement were decreased about 16%, 24%, 34% respectively as the asymmetry angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. RMS EMG values of right erector spinae muscles were decreased as the work posture went to $90^{\circ}$ and those of left erector spinae muscles were increased until the asymmetry angle was $40^{\circ}$ but decreased continually over $40^{\circ}$. 7 subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular. MVC reduced maximum 23% by type of handle. MVC was highest in straight posture, but was lowest in right angle posture. As a result of ANOVA, MVC paid attention to posture, coupling(p<0.01). To all handle types, biceps brachii activity was increased in right angle posture, but reduced in straight posture. Based on the results of this study, it is suggested that the NIOSH guideline should not be directly applied to Korean without reasonable reexamination. In addition, we need to afterward study through an age classification.

• 한국전문물리치료학회지
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• 제24권2호
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• pp.66-75
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• 2017

Background: After a stroke, the control of the trunk muscle may be severely impaired. Due to the importance of trunk control in complex daily postures, the ability to adopt a correct sitting posture is considered a determinant of the recovery of independent function after a stroke. Objects: The purposes of this study were to compare differences in buttock pressure between the left and right sides of hemiplegic patients and differences in their pelvic tilting angles (sagittal and coronal planes) after sitting training with visual biofeedback (VBF) in real time. Methods: Twenty-two individuals with unilateral strokes (11 left-side and 11 right-side hemiplegic stroke patients) participated in this study. Buttock pressure was measured using a pressure mat, and pelvic angles were measured using a palpation meter. Results: The asymmetry of pressure between the right and left (first and third chamber) sides was significantly decreased after the VBF training. The measurements obtained using the palpation meter revealed a significant decrease in the pelvic angles pre- versus post-intervention. Conclusion: VBF training may be distribute a patient's buttock pressure equally while in a sitting posture and increase the length of time a stroke patient can maintain a symmetrical sitting posture. It can also improve pelvic control while sitting in a neutral position.

• Safety and Health at Work
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• 제13권4호
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• pp.440-447
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• 2022

Background: Agricultural handle equipment is present on all production areas' farms. They are handy and portable; however, excessive use can lead to acute traumas or accidental injuries. Repetitive movements, awkward postures, and hand-arm vibrations predispose them to pain and work-related musculoskeletal disorders. The purpose of this study was to observe the interaction of handle equipment in terms of electromyographic activity and analyze the postural work-related alterations. Materials and methods: Twenty male agricultural operators, mean age 24±1.54 years, underwent the electromyographic analysis testing their muscular activities with a brushcutter, electric saw, and hedge trimmer in four different test conditions. Results: The brushcutter proved to be the agricultural handle equipment with the higher mean frequency (3.37±0.38 Hz) and root mean square (5.25±1.24 ms^-2). Furthermore, the digital postural analysis showed a general asymmetry of the main arm and the respective side of the trunk. The head resulted right inclined in the anterior frontal plane by 5.7°±1.2°; the right scapula lower than the left in the posterior frontal plane (8.5°±1.8°), and a working trunk inclination of 34.15°±5.7°. Conclusions: Vibrations of handle equipment and awkward working postures represent a risk for agricultural operators. Preventive measures are required to avoid young operators from experiencing musculoskeletal disorders all lifelong.

• 대한추나의학회지
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• 제4권1호
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• pp.1-16
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• 2003

Objectives : The purpose of this study is researching for possibility that Moire topography be applied in group school screening for scoliosis known school health problem, and find acceptable method of early detection and early treatment for scoliosis Methods : The authors practiced Moire topography for primary & middle school 1,895 students[male 976, female 919] in Jeonju, korea in 2001. After we distinguished students who had abnormal finding in Moire topography and then re-examined spinal X-ray analysis. The data was analysed and evaluated statistically Results : According to this research, the abnormal finding in Moire topography was 53.7% (1,018 students), and students needed X-ray re-examination were 11.2% (213 students). Students diagnosed scoliosis by X-ray re-examination were 1.8%. According to statistical analysis, interval between vertical base line of pelvis and vertical base line of neck, gap between left distance and right distance to the vertical base line of pelvis and difference of contour lines have strong correlations with deformity degree of the body surface examined by Moire. Conclusions : Following this research, throughout early detection for scoliosis by Moire topography could reduce exposure from scoliosis radiographs, and could detect trunk asymmetry that couldn't be found existing X-ray examination, so it made selecting students under observation who have bad posture possible.

• 대한한의학회지
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• 제21권4호
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• pp.148-158
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• 2000

Objective : The purpose of this study was to investigate the back shape of school children using the phase-shifting scanning grating projection moire interferometer, which was developed by the Korea Advanced Institute of Science and Technology and is useful in evaluating three dimensional back shape. Methods : In this study the subjects consisted of 1,358 pupils [711 boys(52.36%), 647 girls(47.64%)] attending elementary and middle schools in Seoul. Their ages ranged from nine to fifteen and the average age was 12.2. With the phase-shifting scanning grating projection moire interferometer, the posterior view of the body were taken to see if there are correlations of moire fringe number, width difference between left and right, and correlation between differences in moire fringe number and width on both sides in the scapular, lumbar and gluteal regions. Results : The results were as follows : I. More frequent findings of fringe were observed on the right in all regions : in the scapular region, 309 boys(43.4%) and 156 girls(24.2%) had more fringe numbers on the right side; in the lumbar region, 68 boys(9.5%) and 11 girls(1.7%); and in the gluteal region, 160 boys(22.4%) and 63 girls(9.8%). Such tendency was striking especially in the scapular and lumbar regions, and in boys rather than in girls. In the scapula, 661 subjects(48.7%) with one moire fringe on either side need further attention and 110 subjects(8.I %) with two or more are required to do follow-up radiography for scoliosis. 2. In an analysis of width difference in the trunk, the left side is wider in all regions except for the gluteal region in boys : in the scapular region 21 boys(3.0%) and 103 girls(15.9%); in the lumbar region, 87 boys(12.2%) and 250 girls(38.6%); and in the gluteal region 197 girls(30.4%) had a wider left side and 45 boys(6.3%) showed a wider right side. 3. In correlation analysis of the number of moire fringe and width difference in each region, the side where more moire fringes were observed was significantly wider in the lumbar and gluteal regions, but not in the scapular region.(p<0.01) Conclusions : From these results, it is concluded that the back shape of elementary and middle school students in Seoul shows that the right side had more moire fringes; the left side was wider; and especially in the lumbar and gluteal regions the side where more moire fringes were observed was wider.