• The Journal of the Korean bone and joint tumor society
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• v.18 no.1
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• pp.32-36
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• 2012

A 56 year-old female presented with dysphagia 8 weeks ago and newly developed dysphonia 2 weeks ago. The radiology study and swallowing difficulty evaluation study revealed the esophagus and the posterior wall of the laryngopharynx to be severely compressed by the mass of the anterior $4^{th}$ and $5^{th}$ vertebral body of cervical spine. En bloc excisional biopsy of the bony mass was performed, which completely resolved the clinical symptoms. We report a rare case of osteochondroma occurring at the anterior portion of cervical spine leading to dysphasia and dysphonia with a review of relevant literature.

• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1140-1147
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• 2003

We have examined the effect on neck-muscle activation of altering whole body posture. A Rhesus monkey (Macaca mulatta) was trained to produce sinusoidal (0.25 Hz) head tracking movements in the sagittal plane when seated with trunk and head vertical or while standing in the quadrupedal position. Video-fluoroscopic images of cervical vertebral motion, and electromyographic (EMG) responses were recorded simultaneously. Results demonstrated that vertebral motion varied with body posture, occurring synchronously between all joints in the upright position and primarily at skull-$C_1$ when in the quadrupedal position. Muscle EMG activation was significantly greater (P<0.001) in the quadrupedal position than when upright for all muscles except semispinalis cervicis. Peak activation of all the muscles occurred prior to peak head extension in the quadrupedal position, suggesting synchronous activity between muscles. Data suggest that, when upright, muscles were activated in functional groupings defined by their anatomical arrangement. In the quadrupedal position, gravity acting on the horizontally oriented head produced greater activation and a collective response of the muscles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.244-247
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• 2005

Although several artificial disc designs have been developed for the treatment of discogenic low back pain and used clinically, biomechanical change with its implantation seldom studied. To evaluate the effect of artificial disc implantation on the biomechanics of lumbar spinal unit, nonlinear three-dimensional finite element model of L1-L5, S1 was developed and strain and stress of vertebral body and surrounding spinal ligaments were predicted. Intact osteoligamentous L1-L5, S1 model was created with 1-mm CT scan of a volunteer and known material property of each element were applied. This model also includes the effect of local muscles which was modeled with pre-strained spring elements. The intact model was validated with reported biomechanical data. Two models implanted with artificial discs, SB Charite or Prodisc, at L4/5 via anterior approach were also developed. The implanted model predictions were compared with that of intact model. Angular motion of vertebral body, force on spinal ligaments, facet joint contact force with $2\sim12$ Nm flexion-extension moment.

• Progress in Medical Physics
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• v.21 no.1
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• pp.52-59
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• 2010

To examine among patients with vertebral compression fracture the extent to which signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values at the lumbar vertebral compression fracture site vary on diffusion-weighted MR images according to varying b values on the 1.5T MR device. Diffusion-weighted MR images of 30 patients with compression fracture due to chronic osteoporosis who underwent vertebral MRI from Jan. 2008 to Nov. 2009 were respectively obtained using a 1.5-T MR scanner with the b values increased from 400, 600, 800, 1,000 to $1,200\;s/mm^2$. For diffusion-weighted MR images with different b values, the signal-to-noise ratio (SNR) was assessed at three sites: the site of compression fracture of the lumbar vertebral body at L1 to L5, and both the upper and lower discs of the said fracture site, while for ADC map images with different b values, the SNR and ADC were respectively assessed at those three sites. As a quantitative analysis, diffusion-weighted MR images and ADC map images with b value of $400\;s/mm^2$ (the base b values) were respectively compared with the corresponding images with each different b value. As far as qualitative analysis is concerned, for both diffusion-weighted MR and ADC map images with b value of $400\;s/mm^2$, the extent to which signal intensity values obtained at the site of compression fracture of the lumbar vertebral body at L1 to L5 vary according to the increasing b values were examined. The quantitative analysis found that for both diffusion-weighted MR and ADC map images, as the b values increased, the SNR were relatively lowered at all the three sites, compared to the base b value. Also, it was found that as the b values increased, ADC valueswere relatively lowered at all the three sites on ADC map images. On the other hand, the qualitative analysis found that as the b values increased to more than $400\;s/mm^2$, the signal intensity gradually decreased at all the sites, while at the levels of more than $1,000\;s/mm^2$, severe image noises appeared at all of the three sites. In addition, higher signal intensity was found at the site of compression fracture of the lumbar vertebral body than at the discs. Findings showed that with the b value being increased, both the signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values gradually decreased at all the sites of the lumbar vertebral compression fracture and both the upper and lower discs of the fracture site, suggesting that there is a possibility of a wider range of applications to assessment of various vertebral pathologies by utilizing multi b values in the diffusion-weighted MRI examination.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.59-69
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• 1996

Effects of dietary calcium(Ca), protein, and phosphorus(P) intake on bone mineral density (BMD) were investigated in 129 Korean premenopausal women(age 31-54 years) without diagnosed disease. BMD was measured at the spine(vertebrae L2-4) and femur(neck, Ward's triangle and trochanter). By stepwise multiple regression analysis it was shown that protein, Ca, and P intakes affected most significantly on BMD at the vertebrae L2-4, protein and P intakes affected most significantly on BMD at the femoral neck and Ward's triangle, and body mass index(BMI) affected most significantly on BMD at the trochanteric region. When ate-matched BMD % at the vertebrae L2-4 and all femoral sites was grouped by three levels(<90%, 90-99%, >=100%), only at the vertebrae L2-4>=100% and 90-99% groups had higher Ca intakes than <90% groups. When Ca, protein and P intakes of the recommended level for Korean(RDA) were grouped by three levels (Ca or P ; <=650mg/d, 650-750mg/d, >=750mg/d, Protein ; <=55g/d, 55-60g/d, >=65g/d), only at the vertebrae L2-4>55g/d of protein intake had higher age-matched BMD % than <=55g/d intake, >=750mg/d of Ca and P intakes, age-matched BMD % than <=650mg/d. In RDA range of Ca, protein, and P intakes, age-matched BMD % of the vertebrae L2-4 and all femoral sites was greater than 90%. Correlation between Ca intake and vertebral BMD was examined closer. There was more significant linear correlation between vertebral BMD and Ca intake below 800mg/d(r=0.346, p<0.0001)than above(r=0.376, p<0.019), implying a threshold effect and vertebral BMD was better expressed as a function of the logarithm of calcium intake(r=0.3881, p<0.0001). These results suggest that Ca, protein, and P intakes greater than RDA help to maintain proper BMD in middle-aged prementopausal women. Especially dietary Ca have important role in increasing the vertebral BMD and 800mg/d of Ca intake is optimum amount.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.3
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• pp.13-20
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• 2019

PURPOSE: Sitting with crossed legs may have an effect on maintaining a healthy body posture and proper functioning of the respiratory system. Thus, this study's objective was to identify whether or not sitting with crossed legs affects the vertebral angle, chest wall mobility, the pulmonary function, and the activity of the respiratory muscles. METHODS: Thirty healthy subjects were recruited for this study (16 males and 14 females). The vertebral angle, chest wall mobility, pulmonary function, and the activity of the respiratory muscle were measured while the subjects sat in the correct posture and these factors were again measured with the subjects seated with their legs crossed. Three-dimensional motion analysis was used to determine the trunk and lumbar vertebral angles. Surface electromyography was employed to measure the sternocleidomastoid, the rectus abdominis, and the external and internal oblique abdominis muscles. A tapeline was utilized to evaluate the subjects' chest wall mobility. Spirometry was assessed to determine the forced vital capacity and forced expiratory volume in one second. Paired t-tests were then performed (p<.05). RESULTS: There were significant differences in the trunk and lumbar flexion angles, the chest wall mobility, the activity of the right external oblique muscle, and the left internal oblique abdominis muscle. However, the difference in pulmonary function did not reach statistical significance. CONCLUSION: A crossed leg posture caused slight thoracic extension and lumbar flexion, which may lead to a decrease of the chest wall mobility and also to an imbalance of the abdominal muscles. Therefore, sitting with a crossed leg posture should be avoided. Yet a crossed leg posture did not have any clinical effect on the pulmonary function of healthy people. It may be necessary to study the effects of sitting with crossed legs over an extended period of time for patients suffering with impaired respiratory function.

• Journal of Biomedical Engineering Research
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• v.21 no.6
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• pp.559-566
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• 2000

Methodology for finite element analysis of vertebral column and pedicle screw system, which circumvents the tremendous difficulties in geometric, material, and structural modeling, is proposed. The simplification is focused on the modeling of the cancellous bone in vertebral body the intervertebral disc. and the instrumented internal fixation devices. Each proposed modeling technique is justified to result in reasonable accuracy. These methods are believed to be suitable for the development of pedicle screw systems, not only because modeling itself is much simpler. but also because reliable empirical data for disc stiffness may be incorporated with little additional effort, and presumably frequent design change may be easily reflected on the analysis.

• The Korean Journal of Pain
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• v.23 no.4
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• pp.262-265
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• 2010

Histologically, Schmorl's nodes are defined as the loss of nuclear material through the cartilage plate, growth plate, and end plate into the vertebral body. Most Schmorl's nodes are asymptomatic, although there are some reports of symptomatic Schmorl's nodes, which should be treated similarly to vertebral compression fractures, with conservative treatment as the first choice. We report the case that we reduced the pain by blocking the ramus communicans nerve in a patient with Schmorl's node.

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.436-439
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• 2002

Discospondylitis is an infection of an intervertebral disk with concurrent osteomyelitis of contiguous vertebrae. Clinical signs are variable and include pain, fever, anorexia, weight loss, depression, stilted gait and paresis or paralysis. A seven-year-old, intact female Yurkshire terrier dog was refered to the Vfterinary Medicine Teaching Hospital of Seoul National University because of intermitent pain of unknown cause for 2 weeks. On physical examination, pain was evident when spines were manipulated, especially thoracolumbar junction part. No neurologic deficits were deteced in the general neurologic test. Spinal radiography demonstrated the bony lysis of the vertebral end plates and sclerosis of the $T_{12-13}$ vertebral body. Based on the results of examinations, the dog was diagnosed as discospondylitis and recoverd following antibiotic therapy.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.171-182
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• 2004

This study investigates the biomechanical efficacies of vertebroplasty which is used to treat vertebral body fracture with bone cement augmentation for osteoporotic patients using image and finite element analysis. Simulated models were divided into two groups: (a) a vertebral body, (b) a functional spinal unit(FSU). For a vertebral body model, the maximum axial displacement was investigated under axial compression to evaluate the effect of structural integrity. The stiffness of each FE model simulated was normalized by the stiffness of intact model. In the case of FSU model, 3 types of compression fractures were formulated to assess the influence on spinal curvature changes. The FSU models were loaded under compressive pressure to calculate the change of spinal curvature. The results according to the various factors suggest that vertebroplasty has the biomechanical efficacy of the increment of structural reinforcement in a patient who has relatively high level of BMD and a patient with the amount of 15％, PMMA injection of the cancellous bone volume. The spinal curvatures after compression fracture simulation vary from 9$^{\circ}$ to 17$^{\circ}$ of kyphosis compared to that the spinal curvature of normal model was -2.8$^{\circ}$ of lordosis. These spinal curvature changes cause the severe spinal deformity under the same loading. As the degree of compressive fracture increases the spinal deformity also increases. The results indicate that vertebroplasty has the increasing effect of the structural integrity regardless of the amount of PMMA or BMD and the restoration of decreased vertebral body height may be an important factor when the compressive fracture caused the significant height loss of vertebral body.