• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.23 no.2
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• pp.9-16
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• 2017

Background: The purpose of this study was to investigate the relationship between the spine and the flat-foot, the stability and the alignment of the posture of the neck to prevent the alignment of the ankle joint operation and the lower back flexibility of the lumbar region according to the type of treatment using active stretching of the triceps, back pain, and to see how they affect weight bearing differences. Methods: The subjects of this study were 24 chronic low back pain patients. They were randomly divided into experimental group and control group. In the experimental group, ankle joint mobilization and active scraping of triceps were performed three times a week for a total of 6 weeks. The control group was performed in the same way without articulation. The range of flexion and extension motion of the lumbar spine and pain degree and difference of weight-bearing were measured before and after the experiment. Results: The model of ankle joint mobilization and calf muscle elongation of flat foot significantly improved the range of flexion and extension motion of the vertebrae (p<.05) and the VAS and distribution of weight-bearing were decreased in both of two groups (p<.05). In other words, the exercise and mobilization help to recover of the balance of the whole musculoskeletal, the vertebrae. Conclusions: The active exercise of the triceps muscle of the lower leg in this study It affects the flexibility of the lumbar spine, the pain and the difference in the weight support of the lower extremities, when we performed ankle joint mobilization for exercise and cramping, pain and the difference in weight support between the two lower limbs.

• Journal of Korean Neurosurgical Society
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• v.53 no.6
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• pp.331-336
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• 2013

Objective : The offset connector can allow medial and lateral variability and facilitate intralaminar screw incorporation into the construct. The aim of this study was to compare the biomechanical characteristics of C7 intralaminar screw constructs with and without offset connector using a three dimensional finite element model of a C6-7 cervical spine segment. Methods : Finite element models representing C7 intralaminar screw constructs with and without the offset connector were developed. Range of motion (ROM) and maximum von Mises stresses in the vertebra for the two techniques were compared under pure moments in flexion, extension, lateral bending and axial rotation. Results : ROM for intralaminar screw construct with offset connector was less than the construct without the offset connector in the three principal directions. The maximum von Misses stress was observed in the C7 vertebra around the pedicle in both constructs. Maximum von Mises stress in the construct without offset connector was found to be 12-30% higher than the corresponding stresses in the construct with offset connector in the three principal directions. Conclusion : This study demonstrated that the intralaminar screw fixation with offset connector is better than the construct without offset connector in terms of biomechanical stability. Construct with the offset connector reduces the ROM of C6-7 segment more significantly compared to the construct without the offset connector and causes lower stresses around the C7 pedicle-vertebral body complex.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.376-381
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• 2019

Objective : To define optimal method that calculate the safe direction of cervical pedicle screw placement using computed tomography (CT) image based three dimensional (3D) cortical shell model of human cervical spine. Methods : Cortical shell model of cervical spine from C3 to C6 was made after segmentation of in vivo CT image data of 44 volunteers. Three dimensional Cartesian coordinate of all points constituting surface of whole vertebra, bilateral pedicle and posterior wall were acquired. The ideal trajectory of pedicle screw insertion was defined as viewing direction at which the inner area of pedicle become largest when we see through the biconcave tubular pedicle. The ideal trajectory of 352 pedicles (eight pedicles for each of 44 subjects) were calculated using custom made program and were changed from global coordinate to local coordinate according to the three dimensional position of posterior wall of each vertebral body. The transverse and sagittal angle of trajectory were defined as the angle between ideal trajectory line and perpendicular line of posterior wall in the horizontal and sagittal plane. The averages and standard deviations of all measurements were calculated. Results : The average transverse angles were $50.60^{\circ}{\pm}6.22^{\circ}$ at C3, $51.42^{\circ}{\pm}7.44^{\circ}$ at C4, $47.79^{\circ}{\pm}7.61^{\circ}$ at C5, and $41.24^{\circ}{\pm}7.76^{\circ}$ at C6. The transverse angle becomes more steep from C3 to C6. The mean sagittal angles were $9.72^{\circ}{\pm}6.73^{\circ}$ downward at C3, $5.09^{\circ}{\pm}6.39^{\circ}$ downward at C4, $0.08^{\circ}{\pm}6.06^{\circ}$ downward at C5, and $1.67^{\circ}{\pm}6.06^{\circ}$ upward at C6. The sagittal angle changes from caudad to cephalad from C3 to C6. Conclusion : The absolute values of transverse and sagittal angle in our study were not same but the trend of changes were similar to previous studies. Because we know 3D address of all points constituting cortical shell of cervical vertebrae. we can easily reconstruct 3D model and manage it freely using computer program. More creative measurement of morphological characteristics could be carried out than direct inspection of raw bone. Furthermore this concept of measurement could be used for the computing program of automated robotic screw insertion.

• Korean Journal of Radiology
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• v.20 no.4
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• pp.641-648
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• 2019

Objective: The purpose of this study was to investigate whether three-dimensional (3D) magnetic resonance imaging could improve diagnostic accuracy for suspected posterior ligamentous complex (PLC) disruption. Materials and Methods: We used 20 freshly harvested goat spine samples with 60 segments and intact surrounding soft tissue. The animals were aged 1-1.5 years and consisted of 8 males and 12 females, which were sexually mature but had not reached adult weights. We created a paraspinal contusion model by percutaneously injecting 10 mL saline into each side of the interspinous ligament (ISL). All segments underwent T2-weighted sagittal and coronal short inversion time inversion recovery (STIR) scans as well as coronal and sagittal 3D proton density-weighted spectrally selective inversion recovery (3D-PDW-SPIR) scans acquired at 1.5T. Following scanning, some ISLs were cut and then the segments were rescanned using the same magnetic resonance (MR) techniques. Two radiologists independently assessed the MR images, and the reliability of ISL tear interpretation was assessed using the kappa coefficient. The chi-square test was used to compare the diagnostic accuracy of images obtained using the different MR techniques. Results: The interobserver reliability for detecting ISL disruption was high for all imaging techniques (0.776-0.949). The sensitivity, specificity, and diagnostic accuracy of the coronal 3D-PDW-SPIR technique for detecting ISL tears were 100, 96.9, and 97.9%, respectively, which were significantly higher than those of the sagittal STIR (p = 0.000), coronal STIR (p = 0.000), and sagittal 3D-PDW-SPIR (p = 0.001) techniques. Conclusion: Compared to other MR methods, coronal 3D-PDW-SPIR provides a more accurate diagnosis of ISL disruption. Adding coronal 3D-PDW-SPIR to a routine MR protocol may help to identify PLC disruptions in cases with nearby contusion.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.913-920
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• 2005

Compared to previous in-vitro test, FE model showed reliable motion patterns. A finite element model of a 50th percentile male neck was developed to study the mechanics of whiplash injury while the rear impacts. The model was consisted of the whole cervical vertebrae including part of occipital, intervertebral discs. which were modeled using linear viscoelastic materials and posterior elements. The sliding interfaces were defined to simulate contact phenomena in facet joints and in odontoid process. All ligaments and atlanto-occipital membrane were modeled as nonlinear bar elements. Only muscle elements were not considered. Motion of each cervical vertebra was obtained from the dynamic simulation with a MADYMO model for 15 km/h $40\%$ rear end offset impacts. Soft tissue neck injury(STNI) was investigated with a developed FE model. In FE model analysis, the high stress was appeared at C3/C4 disc in offset impact. Further research is still needed in order to improve the developed neck FE model for many different crash patterns.

• Development and Reproduction
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• v.16 no.3
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• pp.169-175
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• 2012

Angelman syndrome (AS) is a neurodevelopmental disorder characterized by intellectual disability and autism. The genetic cause is the absence of UBE3A, an E3 ubiquitin ligase, from the maternal chromosome which can arise from multiple origins. Recently discovered targets of Ube3a are important for activity dependent changes in synaptic transmission and spine morphology. Plasticity studies in an AS mouse model is important for basic plasticity research with regard to understanding protein homeostasis as well as the search for therapeutic targets for the patients. The progress on synaptic plasticity from this unique disorder is reviewed.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.311-320
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• 1997

사회가 발달함에 따라 교통사고 등에 의한 외상 환자는 20 -30 년전에 비해 기하급수적으로 증가 하고 있으며 그러한 외상 중에 경추부 상해의 빈도는 매우 높다. 경추부 상해 원인을 규명하기 위한 임상학적 시도는 한계성을 지니고 있다. 본 논문에서는 실제 경추부 형상을 바탕으로 근육과 인대 등 을 비선형 스프링, 댐퍼 등으로 수치 모델링하여 후면 충돌시 경추부의 거동과 경추부에 미치는 상해를 구현하였다. 이를 이용하여 편타성 상해와 에어백으로 인한 경추부 골절의 생리학적 원인을 분석하고 자 한다.

• Journal of the Ergonomics Society of Korea
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• v.12 no.1
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• pp.57-73
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• 1993

In this paper, methods of human figure representation in computer graphics are described. Many applications of the human figure representation are found in areas including industry, advertisement, and cartoon production and further research for the methods that show the human figure more realistically is ex- pected. Two analytic methods for human model, kinematics and dynamics, are ex- plained and the characteristics of the man-machine interface systems that include human figure representation are presented. Various techniques of the human figure representation based on kinematics or(and) dynamics are discussed and representation methods of human body segments such as hand, face, spine are introduced in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1058-1072
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• 1997

A head-neck complex dummy, for measuring brain pressure and reaction force in the cervical spine was developed for experimental study related in injury mechanism. Dummy comprised aluminium-casted head with water filled cavity for simulating brain and mechanical neck assembled with six motion segments. Several kinds of experiments (compression, bending, cyclic modulus, relaxation and constant velocity profile) for the developed mechanical neck showed that this neck model is biomechanically reliable compared with in-vitro test results. As an application of developed head-neck complex dummy, shock absorbing properties of protective helmet was chosen. The experiments showed that the maximum pressure increment of brain after impact was tolerable compared with the guide line for mild brain injury pressure (25psi). Constrast to this results, the reaction force in the neck was high enough to produce failure in the cervical spine.

• Health Policy and Management
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• v.11 no.3
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• pp.71-88
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• 2001

The purpose of this study is to analyze the cost-effectiveness of four medications for treating and preventing osteoporosis -HRT therapy(conjugated equine estrogen 0.625mg for 25 days and medroxyprogesterone acetate 5mg for 01112 days), Alendronate(10mg and 5mg), Active Vitamin D(Calcitriol), and Calcium. Total costs include the direct medical cost -examination fee, consultation fee, prescription fee, fee for preparing medications, and the price of pharmaceuticals- and the indirect cost of patients such as traffic expenses and time cost. In addition, the costs of monitoring in adverse reactions are added. The effects of four medications are expressed as BMD(Bone Mineral Density) percent change measured by DEXA(Dual Energy X-ray Absorptiometry) in lumbar spine(L2-L4) and femoral neck site. A mixed model based on meta analysis provides the estimates of effectiveness, which are then appled to the hypothetical cohort consisting of postmenopausal women at the age of 50-59. HRT therapy is the most cost-effective medication at 172,433.64 won (lumbar spine site) and 546,328.28 won (femoral neck site) per BMD percent change for osteoporosis. Alendronate 10mg is more cost-effective than Alendronate 5mg as 345,971.23 won and 378,441.63 won per lumbar BMD percent change at 0.991ｇ/$cm^2$, respectively. Alendronate 10mg is more cost-effective than Alendronate 5mg as 1,329,257.89 won and 1,467,291.23 won per femoral neck BMD percent change at 0.834ｇ/$cm^2$, respectively.