• 한국정밀공학회지
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• 제27권2호
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• pp.130-136
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• 2010

For stability analysis of the lumbar spine, the hypothesis presented is that the disc has stress sensors driving feedback mechanism, which could react to the imposed loads by adjusting the contraction of the muscles. Fusion in the motion segment of the lumbar spinal column is believed to alter the stability of the spinal column. To identify this effect finite element (FE) models combined with optimization technique was applied and quantify the role of each muscle and reaction forces in the spinal column with respect to the fusion level. The musculoskeletal FE model was consisted with detailed whole lumbar spine, pelvis, sacrum, coccyx and simplified trunk model. Vertebral body and pelvis were modeled as a rigid body and the rib cage was constructed with rigid truss element for the computational efficiency. Spinal fusion model was applied to L3-L4, L4-L5, L5-S1 (single level) and L3-L5 (two levels) segments. Muscle architecture with 46 local muscles was used as acting directions. Minimization of the nucleus pressure deviation and annulus fiber average axial stress deviation was selected for cost function. As a result, spinal fusion produced reaction changes at each motion segment as well as contribution of each muscle. Longissimus thoracis and psoas major muscle showed dramatic changes for the cases of L5-S1 and L3-L5 level fusion. Muscle force change at each muscle also generated relatively high nucleus pressure not only at the adjacent level but at another level, which can explain disc degeneration pattern observed in clinical study.

• 디지털융복합연구
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• 제11권11호
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• pp.613-620
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• 2013

본 연구는 MRI를 사용하여 급성 및 만성 요통환자들의 척추주변근육에 나타나는 변화를 정량적으로 측정 및 분석하고 이를 토대로 요통에 대한 진단 및 치료에 임상적 기초자료를 제공하고자 2012년 8월부터 2013년 1월까지 내원한 환자로 요통이 발생한지 12주 이내의 급성요통환자 20명과 요통이 발생한지 12주 이상 경과된 만성 요통 환자 20명을 대상자로 선정하여 MRI를 촬영한 후 측정하여 비교하였다. 왼쪽과 오른쪽의 지방변성율에서는 척추세움근과 뭇갈래근에서 유의한 차이가 있었고(p<.001), 전체 집단 간 지방변성율 비교에서도 급성요통군과 만성요통군간의 큰허리근, 척추세움근, 뭇갈래근에서 유의한 차이가 있었다(p<.001). 사후검정에서는 급성요통군과 만성요통군에서 각각 다열근과 척추세움근의 지방변성율이 가장 높은 것으로 나타났다. 만성 요통군에서 다열근과 척추기립근의 심한 지방율의 변성은 척추의 안정성을 유지하는 근육의 근력 약화로 나타나는데 본 연구결과를 토대로 급성 만성요통환자들의 재활운동과정에 있어서 뭇갈래근, 급성 요통군은 뭇갈래근과 큰허리근에 더 주의를 기울이고 재활운동 선정 과정에서 중요한 자료와 근거를 제시 할 수 있으라고 사료된다.

• 한국정밀공학회지
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• 제28권1호
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• pp.115-122
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• 2011

Recently, we have proposed a hypothesis that spinal structures have a stress sensor driving feedback mechanism, In the human spine, spinal structure could react to modify muscular action in such a way so as to equalize stress at the disc, therefore reduce the risk of injury, In this analysis, abdominal muscle and abdominal pressure, which were not included in the previous study, were added to identify those effects in spine stability during upright stance posture for the case where the intervertebral disc plays the role of mechanoreceptor, The musculoskeletal FE model was consisted with detailed whole lumbar spine, pelvis, sacrum, coccyx and simplified trunk model. Muscle architecture with 46 local muscles containing paraspinal muscle and 6 rectus abdominal muscles were assigned according to the acting directions. The magnitude of 4kPa was considered for abdominal pressure. Minimization of the nucleus pressure deviation and annulus fiber average tension stress deviation was chosen for cost function. Developed model provide nice coincidence with in-vivo measurement (nucleus pressure). Analysis was conducted according to existence of co-activation of abdominal muscle and abdominal pressure. Antagonistic activity of abdominal muscle produced stability of spinal column with relatively small amount of total muscle force. In contrast to the abdominal muscle, effect of abdominal pressure was not clear that was partly depending on the assumption of constant abdominal pressure.