The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Beth A Winkelstein - One of the best experts on this subject based on the ideXlab platform.
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mechanical evidence of cervical facet capsule injury during whiplash a cadaveric study using combined shear compression and extension loading
Spine, 2001Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:Study design A comparison of cervical facet capsule Strain fields in cadaveric motion segments exposed to whiplash-like loads and failure loads. Objectives To compare the maximum principal Strain in the facet capsular ligament under combined shear, bending, and compressive loads with those required to injure the ligament. Summary of background data The cervical facet capsular ligament is thought to be an anatomic site for whiplash injury, although the mechanism of its injury remains unclear. Methods Motion segments from seven female donors were exposed to quasi-static flexibility tests using posterior shear loads of 135 N applied to the superior vertebra under four compressive axial preloads up to 325 N. The right facet joint was then isolated and failed in posterior shear loading. The Lagrangian Strain field in the right facet capsular ligament was calculated from capsular displacements determined by stereophotogrammetry. Statistical analyses examined the effect of axial compression on motion segment flexibility, and compared maximum principal capsular Strain between the flexibility and failure tests. Results Capsular Strain increased with applied shear load but did not vary with axial compressive load. The maximum principal Strain reached during the flexibility tests was 61% +/- 33% of that observed in subcatastrophic failures of the isolated joints. Two specimens reached Strains in their flexibility tests that were larger than their corresponding Strains at subcatastrophic failure in the failure tests. Conclusions The cervical facet capsular ligaments may be injured under whiplash-like loads of combined shear, bending, and compression. The results provide a mechanical basis for injury caused by whiplash loading.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
Gunter P Siegmund - One of the best experts on this subject based on the ideXlab platform.
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mechanical evidence of cervical facet capsule injury during whiplash a cadaveric study using combined shear compression and extension loading
Spine, 2001Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:Study design A comparison of cervical facet capsule Strain fields in cadaveric motion segments exposed to whiplash-like loads and failure loads. Objectives To compare the maximum principal Strain in the facet capsular ligament under combined shear, bending, and compressive loads with those required to injure the ligament. Summary of background data The cervical facet capsular ligament is thought to be an anatomic site for whiplash injury, although the mechanism of its injury remains unclear. Methods Motion segments from seven female donors were exposed to quasi-static flexibility tests using posterior shear loads of 135 N applied to the superior vertebra under four compressive axial preloads up to 325 N. The right facet joint was then isolated and failed in posterior shear loading. The Lagrangian Strain field in the right facet capsular ligament was calculated from capsular displacements determined by stereophotogrammetry. Statistical analyses examined the effect of axial compression on motion segment flexibility, and compared maximum principal capsular Strain between the flexibility and failure tests. Results Capsular Strain increased with applied shear load but did not vary with axial compressive load. The maximum principal Strain reached during the flexibility tests was 61% +/- 33% of that observed in subcatastrophic failures of the isolated joints. Two specimens reached Strains in their flexibility tests that were larger than their corresponding Strains at subcatastrophic failure in the failure tests. Conclusions The cervical facet capsular ligaments may be injured under whiplash-like loads of combined shear, bending, and compression. The results provide a mechanical basis for injury caused by whiplash loading.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
Herbert F Bohnet - One of the best experts on this subject based on the ideXlab platform.
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mechanical evidence of cervical facet capsule injury during whiplash a cadaveric study using combined shear compression and extension loading
Spine, 2001Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:Study design A comparison of cervical facet capsule Strain fields in cadaveric motion segments exposed to whiplash-like loads and failure loads. Objectives To compare the maximum principal Strain in the facet capsular ligament under combined shear, bending, and compressive loads with those required to injure the ligament. Summary of background data The cervical facet capsular ligament is thought to be an anatomic site for whiplash injury, although the mechanism of its injury remains unclear. Methods Motion segments from seven female donors were exposed to quasi-static flexibility tests using posterior shear loads of 135 N applied to the superior vertebra under four compressive axial preloads up to 325 N. The right facet joint was then isolated and failed in posterior shear loading. The Lagrangian Strain field in the right facet capsular ligament was calculated from capsular displacements determined by stereophotogrammetry. Statistical analyses examined the effect of axial compression on motion segment flexibility, and compared maximum principal capsular Strain between the flexibility and failure tests. Results Capsular Strain increased with applied shear load but did not vary with axial compressive load. The maximum principal Strain reached during the flexibility tests was 61% +/- 33% of that observed in subcatastrophic failures of the isolated joints. Two specimens reached Strains in their flexibility tests that were larger than their corresponding Strains at subcatastrophic failure in the failure tests. Conclusions The cervical facet capsular ligaments may be injured under whiplash-like loads of combined shear, bending, and compression. The results provide a mechanical basis for injury caused by whiplash loading.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
Martin B Davis - One of the best experts on this subject based on the ideXlab platform.
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mechanical evidence of cervical facet capsule injury during whiplash a cadaveric study using combined shear compression and extension loading
Spine, 2001Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:Study design A comparison of cervical facet capsule Strain fields in cadaveric motion segments exposed to whiplash-like loads and failure loads. Objectives To compare the maximum principal Strain in the facet capsular ligament under combined shear, bending, and compressive loads with those required to injure the ligament. Summary of background data The cervical facet capsular ligament is thought to be an anatomic site for whiplash injury, although the mechanism of its injury remains unclear. Methods Motion segments from seven female donors were exposed to quasi-static flexibility tests using posterior shear loads of 135 N applied to the superior vertebra under four compressive axial preloads up to 325 N. The right facet joint was then isolated and failed in posterior shear loading. The Lagrangian Strain field in the right facet capsular ligament was calculated from capsular displacements determined by stereophotogrammetry. Statistical analyses examined the effect of axial compression on motion segment flexibility, and compared maximum principal capsular Strain between the flexibility and failure tests. Results Capsular Strain increased with applied shear load but did not vary with axial compressive load. The maximum principal Strain reached during the flexibility tests was 61% +/- 33% of that observed in subcatastrophic failures of the isolated joints. Two specimens reached Strains in their flexibility tests that were larger than their corresponding Strains at subcatastrophic failure in the failure tests. Conclusions The cervical facet capsular ligaments may be injured under whiplash-like loads of combined shear, bending, and compression. The results provide a mechanical basis for injury caused by whiplash loading.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
Barry S Myers - One of the best experts on this subject based on the ideXlab platform.
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mechanical evidence of cervical facet capsule injury during whiplash a cadaveric study using combined shear compression and extension loading
Spine, 2001Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:Study design A comparison of cervical facet capsule Strain fields in cadaveric motion segments exposed to whiplash-like loads and failure loads. Objectives To compare the maximum principal Strain in the facet capsular ligament under combined shear, bending, and compressive loads with those required to injure the ligament. Summary of background data The cervical facet capsular ligament is thought to be an anatomic site for whiplash injury, although the mechanism of its injury remains unclear. Methods Motion segments from seven female donors were exposed to quasi-static flexibility tests using posterior shear loads of 135 N applied to the superior vertebra under four compressive axial preloads up to 325 N. The right facet joint was then isolated and failed in posterior shear loading. The Lagrangian Strain field in the right facet capsular ligament was calculated from capsular displacements determined by stereophotogrammetry. Statistical analyses examined the effect of axial compression on motion segment flexibility, and compared maximum principal capsular Strain between the flexibility and failure tests. Results Capsular Strain increased with applied shear load but did not vary with axial compressive load. The maximum principal Strain reached during the flexibility tests was 61% +/- 33% of that observed in subcatastrophic failures of the isolated joints. Two specimens reached Strains in their flexibility tests that were larger than their corresponding Strains at subcatastrophic failure in the failure tests. Conclusions The cervical facet capsular ligaments may be injured under whiplash-like loads of combined shear, bending, and compression. The results provide a mechanical basis for injury caused by whiplash loading.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
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human cervical motion segment flexibility and facet capsular ligament Strain under combined posterior shear extension and axial compression
Stapp car crash journal, 2000Co-Authors: Gunter P Siegmund, Barry S Myers, Martin B Davis, Herbert F Bohnet, Beth A WinkelsteinAbstract:The purpose of this study was to quantify the intervertebral flexibility and maximum principal Strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 +/- 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian Strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Although significant differences were observed at two axial load levels in the kinematic sequence (197 N and 325 N), neither the regressed flexibility nor the maximum principal Strain in the facet capsular ligament varied significantly with axial compression. Maximum principal Strain during the flexibility tests reached 61 +/- 33 percent of the maximum principal Strain observed in sub-catastrophic failures of the isolated joints. Two of the thirteen specimens reached Strains in their flexibility tests which were larger than their corresponding Strains at sub-catastrophic failure in the failure tests. These results suggest that the cervical facet capsular ligaments may be injured under combined shear, bending and compression load levels that occur in rear-end impacts. For the covering abstract of the conference see ITRD E203843.
