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- Andersson, Eva A, et al.
(författare)
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Diverging intramuscular activity patterns in back and abdominal muscles during trunk rotation.
- 2002
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 1528-1159 .- 0362-2436. ; 27:6, s. E152-60
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: An intramuscular electromyographic study was performed on trunk rotations during sitting and standing. OBJECTIVE: The aim was to provide new information on activation levels for deep trunk muscles in various unresisted and resisted trunk rotations. SUMMARY AND BACKGROUND DATA: Frequent daily trunk twisting and decreased maximal strength during trunk rotation have been associated with low back pain or sciatic pain. However, the involvement of deep trunk muscles during different trunk rotations is relatively unknown. METHODS: Ten healthy subjects participated. Fine-wire electrodes were inserted, under ultrasound guidance, into psoas, quadratus lumborum, the superficial medial lumbar erector spinae (ES-s, multifidus) and its deep lateral portion (ES-d, iliocostalis), iliacus, rectus abdominis, obliquus externus, and obliquus internus. RESULTS: The highest involvement for all muscles was observed on the ipsilateral side, in maximal trunk twists with shoulder resistance, except obliquus externus, which showed a dominant contralateral side, and rectus abdominis, which was little activated in all rotations. In contrast, maximal trunk twist without shoulder resistance, i.e., freely performed, resulted generally in lower levels for all muscles involved and in a shift of side dominance for the lumbar muscles quadratus lumborum, psoas, and ES-s. CONCLUSIONS: During trunk rotations the activity patterns for various trunk muscles could drastically change, and even be the opposite, between the two body sides, within the same type of task, depending on several factors such as initial position, effort level, sitting or standing, and external shoulder resistance.
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| 2. |
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| 3. |
- Bauer, H
(författare)
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Surgical strategy for spinal metastases
- 2002
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 1528-1159 .- 0362-2436. ; 27:10, s. 1124-1125
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Brolin, Karin, et al.
(författare)
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Development of a finite element model of the upper cervical spine and a parameter study of ligament characteristics
- 2004
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Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 29:4, s. 376-385
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Numeric techniques were used to study the upper cervical spine. Objectives. To develop and validate an anatomic detailed finite element model of the ligamentous upper cervical spine and to analyze the effect of material properties of the ligaments on spinal kinematics. Summary of Background Data. Cervical spinal injuries may be prevented with an increased knowledge of spinal behavior and injury mechanisms. The finite element method is tempting to use because stresses and strains in the different tissues can be studied during the course of loading. The authors know of no published results so far of validated finite element models that implement the complex geometry of the upper cervical spine. Methods. The finite element model was developed with anatomic detail from computed tomographic images of the occiput to the C3. The ligaments were modeled with nonlinear spring elements. The model was validated for axial rotation, flexion, extension, lateral bending, and tension for 1.5 Nm, 10 Nm, and 1500 N. A material property sensitivity study was conducted for the ligaments. Results. The model correlated with experimental data for all load cases. Moments of 1.5 Nm produced joint rotations of 3degrees to 23degrees depending on loading direction. The parameter study confirmed that the mechanical properties of the upper cervical ligaments play an important role in spinal kinematics. The capsular ligaments had the largest impact on spinal kinematics (40% change). Conclusions. The anatomic detailed finite element model of the upper cervical spine realistically simulates the complex kinematics of the craniocervical region. An injury that changes the material characteristics of any spinal ligament will influence the structural behavior of the upper cervical spine.
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| 8. |
- Cornefjord, M., et al.
(författare)
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Cerebrospinal fluid biomarkers in experimental spinal nerve root injury
- 2004
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Ingår i: Spine. - 1528-1159. ; 29:17, s. 1862-8
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Cerebrospinal fluid biomarkers were evaluated in a setup using established pig models to mimic clinical disc herniation. OBJECTIVES: To investigate biomarkers for nerve tissue injury, inflammation, and pain in cerebrospinal fluid after mechanical compression and/or nucleus pulposus application to spinal nerve roots. SUMMARY OF BACKGROUND DATA: The association between mechanical compression, biochemical effects of nucleus pulposus, and nerve root injury in degenerative disc disorders is incompletely investigated. METHODS: The unilateral S1 nerve root was exposed in 20 pigs. The animals were divided into four groups (n = 5 each): 1) slow-onset mechanical compression with an ameroid constrictor; 2) autologous nucleus pulposus application; 3) mechanical compression plus nucleus pulposus; and 4) sham operation. After 1 week, 6 mL of cerebrospinal fluid was collected, and four structural nerve proteins, neurofilaments, S-100, glial fibrillary acidic protein, neuron-specific enolase, the proinflammatory cytokine interleukin-8, the neurotransmitter nociceptin, and substance P endopeptidase activity were analyzed using immunoassays. RESULTS: The concentration of neurofilament was increased in the mechanical compression group (17.0 microg/L +/- 5.0) and in the mechanical compression plus nucleus pulposus group (19.8 +/- 12.1 microg/L) compared with the sham group (0.9 +/- 0.9 microg/L) and the nucleus pulposus group (0.4 +/- 0.1 microg/L) (P < 0.01 for both). The concentration of nociceptin was increased significantly in the mechanical compression group (24.0 +/- 8.6 fm/mL) and in the mechanical compression plus nucleus pulposus group (31.2 +/- 6.6 fm/mL) compared with the sham group (7.0 +/- 1.3 fm/mL) (P < 0.05 and P < 0.01, respectively). A correlation was found between concentrations of neurofilament and nociceptin (r = 0.50, P < 0.05). There were no intergroup differences regarding glial fibrillary acidic protein, neuron-specific enolase, S-100, interleukin-8, or substance P endopeptidase activity. CONCLUSIONS: The present study demonstrates increased concentrations of neurofilament and nociceptin in cerebrospinal fluid after nerve root compression. A simultaneous application of nucleus pulposus did not increase the response.
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| 10. |
- Daggfeldt, Karl, et al.
(författare)
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The visible human anatomy of the lumbar erector spinae.
- 2000
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Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436 .- 1528-1159. ; 25:21, s. 2719-25
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Image data of the male and female cadavers from the Visible Human Project were visualized and quantified. OBJECTIVE: To clarify the anatomy of the lumbar part of the human lumbar erector spinae muscles. SUMMARY OF BACKGROUND DATA: Recent studies have shown discrepancies in the description of the anatomy of the lumbar part of the lumbar erector spinae. The main differences concern whether lumbar fascicles of iliocostalis lumborum exist and whether the lumbar fascicles have direct attachments to the ilium or attach via the erector spinae aponeurosis. With the Visible Human Project from the U.S. National Library of Medicine, a new powerful basis for anatomic investigation has become available. METHODS: Software was produced to visualize sections oriented in any direction and with maximum resolution of the Visible Human male and female. Three-dimensional coordinates of anatomic structures in the image space could be marked in the cross-sectional images. The geometry and the physiologic cross-sectional areas of the erector spinae fascicles of lumbar origin were thus derived. RESULTS AND CONCLUSIONS: The study supports a classification of the lateral fascicles of the lumbar part of the lumbar erector spinae as part of iliocostalis lumborum. In both the male and the female, a large part of the erector spinae fibers of lumbar origin attached to the erector spinae aponeurosis. These results are of importance for biomechanical analysis of force transmission in the lumbar spine.
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