Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 537-546 |
| Number of pages | 10 |
| Journal | Journal of Biomechanics |
| Volume | 26 |
| Issue number | 4-5 |
| DOIs | |
| Publication status | Published - 1993 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Orthopedics and Sports Medicine
Cite this
Trunk muscle geometry and centroid location when twisting. / Tsuang, Y. H.; Novak, G. J.; Schipplein, O. D.; Hafezi, A.; Trafimow, J. H.; Andersson, G. B J.
In: Journal of Biomechanics, Vol. 26, No. 4-5, 1993, p. 537-546.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Trunk muscle geometry and centroid location when twisting
AU - Tsuang, Y. H.
AU - Novak, G. J.
AU - Schipplein, O. D.
AU - Hafezi, A.
AU - Trafimow, J. H.
AU - Andersson, G. B J
PY - 1993
Y1 - 1993
N2 - 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.
AB - 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.
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UR - http://www.scopus.com/inward/citedby.url?scp=0027577568&partnerID=8YFLogxK
U2 - 10.1016/0021-9290(93)90015-7
DO - 10.1016/0021-9290(93)90015-7
M3 - Article
VL - 26
SP - 537
EP - 546
JO - Journal of Biomechanics
JF - Journal of Biomechanics
SN - 0021-9290
IS - 4-5
ER -