Trunk muscle geometry and centroid location when twisting
| Autor: | O. D. Schipplein, G. J. Novak, J. H. Trafimow, Gunnar B. Andersson, Y.H. Tsuang, A. Hafezi |
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| Rok vydání: | 1993 |
| Předmět: |
Adult
Male Rotation Coordinate system Posture Biomedical Engineering Biophysics Lumbar medicine Supine Position Humans Orthopedics and Sports Medicine Displacement (orthopedic surgery) Abdominal Muscles Psoas Muscles Physics Lumbar Vertebrae medicine.diagnostic_test Muscles Rehabilitation Biomechanics Lumbosacral Region Centroid Magnetic resonance imaging Anatomy Thorax Magnetic Resonance Imaging Transverse plane Computer-Aided Design Stress Mechanical Trunk muscle Muscle Contraction |
| Zdroj: | Journal of biomechanics. 26(4-5) |
| ISSN: | 0021-9290 |
| Popis: | The trunk muscles of the lumbar region were studied using magnetic resonance imaging (MRI) in five male volunteers placed in neutral and in two twisted postures. Using a CAD digitizing system, the positions of trunk muscle centroids and the cross-sectional areas of these muscles were measured from the transverse scans at 1 cm intervals from L2 to S1. Muscle lines of action were created by connecting the muscle centroids from the successive sections. Changes in cross-sectional areas and displacements of centroids in a three-dimensional coordinate system and the local two-dimensional coordinate system were estimated at each disc level. In the three-dimensional coordinate system, all muscle centroids were displaced when twisting. Thus, the locations and orientations of all muscle lines of action changed. In the local two-dimensional coordinate system, only the muscle centroids of four abdominal muscles were displaced. Most of these displacements occurred in the first 25° of twisting. Higher up in the lumbar spine, the displacement was greater. The changes in moment arms were sometimes as great as twofold. Only the abdominal oblique muscle (AOM) changed their cross-sectional area significantly; the area of the right AOM ipsilateral to the side of twisting increased, while that of the left AOM was decreased. |
| Databáze: | OpenAIRE |
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