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J F Cusick

Publications and source records attributed to J F Cusick.

At least 19 recordsLinked to original sources
PubMed2001

Whiplash injury determination with conventional spine imaging and cryomicrotomy.

STUDY DESIGN: Soft tissue-related injuries to the cervical spine structures were produced by use of intact entire human cadavers undergoing rear-end impacts. Radiography, computed tomography, and cryomicrotomy techniques were used to evaluate the injury. OBJECTIVES: To replicate soft tissue injuries resulting from single input of whiplash acceleration to whole human cadavers simulating vehicular rear impacts, and to assess the ability of different modes of imaging to visualize soft tissue cervical lesions. SUMMARY OF BACKGROUND DATA: Whiplash-associated disorders such as headache and neck pain are implicated with soft tissue abnormalities to structures of the cervical spine. To the authors' best knowledge, no previous studies have been conducted to determine whether single cycle whiplash acceleration input to intact entire human cadavers can result in these soft tissue alterations. There is also a scarcity of data on the efficacy of radiography and computed tomography in assessing these injuries. METHODS: Four intact entire human cadavers underwent single whiplash acceleration (3.3 g or 4.5 g) loading by use of a whole-body sled. Pretest and posttest radiographs, computed tomography images, and sequential anatomic sections using a cryomicrotome were obtained to determine the extent of trauma to the cervical spine structures. RESULTS: Routine radiography identified the least number of lesions (one lesion in two specimens). Although computed tomography was more effective (three lesions in two specimens), trauma was not readily apparent to all soft tissues of the cervical spine. Cryomicrotome sections identified structural alterations in all four specimens to lower cervical spine components that included stretch and tear of the ligamentum flavum, anulus disruption, anterior longitudinal ligament rupture, and zygopophysial joint compromise with tear of the capsular ligaments. CONCLUSIONS: These results clearly indicate that a single application of whiplash acceleration pulse can induce soft tissue-related and ligament-related alterations to cervical spine structures. The pathologic changes identified in this study support previous observations from human volunteers observations with regard to the location of whiplash injury and may assist in the explanation of pain arising from this injury. Although computed tomography is a better imaging modality than radiography, subtle but clinically relevant injuries may be left undiagnosed with this technique. The cryomicrotome technique offers a unique procedure to understand and compare soft tissue-related injuries to the cervical anatomy caused by whiplash loading. Recognition of these injuries may advance the general knowledge of the whiplash disorder.

Aged↗
PubMed2001

Whiplash syndrome: kinematic factors influencing pain patterns.

STUDY DESIGN: The overall, local, and segmental kinematic responses of intact human cadaver head-neck complexes undergoing an inertia-type rear-end impact were quantified. High-speed, high-resolution digital video data of individual facet joint motions during the event were statistically evaluated. OBJECTIVES: To deduce the potential for various vertebral column components to be exposed to adverse strains that could result in their participation as pain generators, and to evaluate the abnormal motions that occur during this traumatic event. SUMMARY OF BACKGROUND DATA: The vertebral column is known to incur a nonphysiologic curvature during the application of an inertial-type rear-end impact. No previous studies, however, have quantified the local component motions (facet joint compression and sliding) that occur as a result of rear-impact loading. METHODS: Intact human cadaver head-neck complexes underwent inertia-type rear-end impact with predominant moments in the sagittal plane. High-resolution digital video was used to track the motions of individual facet joints during the event. Localized angular motion changes at each vertebral segment were analyzed to quantify the abnormal curvature changes. Facet joint motions were analyzed statistically to obtain differences between anterior and posterior strains. RESULTS: The spine initially assumed an S-curve, with the upper spinal levels in flexion and the lower spinal levels in extension. The upper C-spine flexion occurred early in the event (approximately 60 ms) during the time the head maintained its static inertia. The lower cervical spine facet joints demonstrated statistically greater compressive motions in the dorsal aspect than in the ventral aspect, whereas the sliding anteroposterior motions were the same. CONCLUSIONS: The nonphysiologic kinematic responses during a whiplash impact may induce stresses in certain upper cervical neural structures or lower facet joints, resulting in possible compromise sufficient to elicit either neuropathic or nociceptive pain. These dynamic alterations of the upper level (occiput to C2) could impart potentially adverse forces to related neural structures, with subsequent development of a neuropathic pain process. The pinching of the lower facet joints may lead to potential for local tissue injury and nociceptive pain.

Aged↗
PubMed2000

Morphology of young and old cervical spine intervertebral disc tissues.

The intervertebral disc of the cervical spine undergoes degenerative changes during the aging process. Although many studies have reported the qualitative changes in the disc, methodology to quantify these changes is lacking. The present study was designed to quantify the geometrical variations of the nucleus pulposus, annulus fibrosus and uncovertebral joints. The age groups of specimens were classified as juvenile, adult and aged. Fresh intervertebral discs with adjacent vertebral bodies of the lower cervical spine of primates were isolated. The specimens were sectioned sequentially in a coronal plane. Sections were stained with Hematoxylin and Eosin, Verhoeff's, Safranin O, and Trichrome methods to distinguish the nucleus, annulus and uncovertebral joints. Histological images were examined using light microscopy and processed using a computer imaging program to trace the boundaries of the disc components. Dorsal-to-ventral depth and medial-to-lateral width of the nucleus pulposus, and its relative location to the annulus pulposus were also obtained. In the juvenile and adult discs, the nucleus appeared as a light opaque region with scattered notochordal cells with a clear distinction from the annulus region. In contrast, in the aged discs, the nucleus appeared as a dense region of amorphous, irregular collagen materials with less distinction from the annulus region. With the progression of aging, the dorsal-to-ventral depth of the nucleus decreased considerably compared to medial-to-lateral width. The uncovertebral joints were clear in the adult discs. The joints were less distinct in the aged discs and their size decreased. Quantification of three-dimensional geometrical variations will assist in better defining the disc tissue in the mathematical models.

Aging↗
PubMed1999

Evaluation of cervical laminectomy and laminoplasty. A longitudinal study in the goat model.

STUDY DESIGN: An evaluation of the longitudinal radiologic changes up to 6 months induced by multilevel laminectomy and laminoplasty and the biomechanical responses in the goat model, complemented by biomechanical studies of intact specimens. OBJECTIVES: To determine the long-term radiographic differences and biomechanical responses of laminectomy and laminoplasty in an in vivo animal model. SUMMARY OF BACKGROUND DATA: Previous clinical and laboratory studies have indicated that multilevel laminectomy can cause increased flexibility in the cervical spinal column. Although the potential for laminoplasty to resolve these changes has been suggested, other evaluations have not supported this contention. Clarification of this controversy with long-term in vivo studies has not been performed. METHODS: Ten adult goats were divided into two groups, one undergoing C3-C5 laminectomy and the other open-door laminoplasty. Lateral cervical spine radiographs were obtained at 4-week intervals for a 6-month period. After the goats were killed, biomechanical testing was performed using pure moment loading on the surgically treated specimens and on three intact (without surgery) cervical spinal columns. RESULTS: In the laminectomy preparations, the cervical curvature index was noted to decrease by 59% at 16 weeks (P < 0.028) and by 70% at 24 weeks (P < 0.002), whereas the decrease in laminoplasty was not significantly different. Biomechanical testing indicated a significantly increased sagittal-plane slack motion in the laminectomy group (55 degrees) compared with that in intact specimens (39 degrees), but no significant difference between the laminoplasty and intact groups with respect to this motion. Laminectomy was found to be significantly stiffer (36%) in flexion than in extension, whereas the contrary was true for laminoplasty (37%). CONCLUSIONS: Radiographic and biomechanical results in the goat model suggest that laminoplasty is superior to laminectomy in maintaining cervical alignment and preventing postoperative spinal deformities.

Animals↗
PubMed1998

Single-voxel proton MR spectroscopy of nonneoplastic brain lesions suggestive of a neoplasm.

BACKGROUND AND PURPOSE: MR spectroscopy is used to characterize biochemical components of normal and abnormal brain tissue. We sought to evaluate common histologic findings in a diverse group of nonneoplastic diseases in patients with in vivo MR spectroscopic profiles suggestive of a CNS neoplasm. METHODS: During a 2-year period, 241 patients with suspected neoplastic CNS lesions detected on MR images were studied with MR spectroscopy. Of these, five patients with a nonneoplastic diagnosis were identified retrospectively; a sixth patient without tissue diagnosis was added. MR spectroscopic findings consistent with a neoplasm included elevated choline and decreased N-acetylaspartate and creatine, with or without detectable mobile lipid and lactate peaks. RESULTS: The histologic specimens in all five patients for whom tissue diagnoses were available showed significant WBC infiltrates, with both interstitial and perivascular accumulations of lymphocytes, macrophages, histiocytes, and (in one case) plasma cells. Reactive astrogliosis was also prominent in most tissue samples. This cellular immune response was an integral component of the underlying disorder in these patients, including fulminant demyelination in two patients, human herpesvirus 6 encephalitis in one patient, organizing hematoma from a small arteriovenous malformation in one patient, and inflammatory pseudotumor in one patient. Although no histologic data were available in the sixth patient, neoplasm was considered unlikely on the basis of ongoing clinical and neuroradiologic improvement without specific therapy. CONCLUSION: Nonneoplastic disease processes in the CNS may elicit a reactive proliferation of cellular elements of the immune system and of glial tissue that is associated with MR spectroscopic profiles indistinguishable from CNS neoplasms with current in vivo MR spectroscopic techniques. Such false-positive findings substantiate the need for histologic examination of tissue as the standard of reference for the diagnosis of intracranial mass lesions.

Adolescent↗
PubMed1997

Finite element analysis of cervical facetectomy.

STUDY DESIGN: Moment-rotation responses and disc anulus stresses of intact and facetectomized C4-C6 cervical spinal units were analyzed using detailed, three-dimensional, finite element models. OBJECTIVES: To evaluate biomechanical effects of progressive unilateral and bilateral facet resections on cervical spine segmental mobility (external response) and disc anulus stress (internal response). SUMMARY OF BACKGROUND DATA: Experimental studies have demonstrated that facetectomy significantly increases segmental mobility of the cervical spine. The biomechanical effects of facetectomy on the internal response, however, have not been investigated. METHODS: Moment-rotation responses of C4 with respect to C6 and von Mises stress in the disc anulus were examined using finite element models of a 0% (intact), 25%, 50%, 75%, and 100% unilaterally and bilaterally facetectomized cervical spinal unit. The model simulations were conducted under the pure-moment loading of 1.8 Nm in flexion, extension, lateral bending, and axial torsion. The intact model also was validated experimentally under the same conditions. RESULTS: The moment-rotation responses of the intact unit were within the ranges of experimental data. Cervical rotations increased with the increased degree of facet resection. The greatest change occurred between 50% and 75% facet resections in bilateral facetectomy. Similar patterns were found for disc anulus stresses, but to a greater extent. The maximum increase in rotation (11%) and in anulus stress (30%) occurred in lateral bending. Torsion was the least affected loading mode. The effects of unilateral facetectomy were considerably less than those of 75% bilateral facetectomy. CONCLUSIONS: Facetectomy has a greater effect on anulus stress than on intervertebral joint stiffness. Significant increase in anulus stresses and segmental mobility may occur when bilateral facet resection exceeds 50%.

Adult↗
PubMed1997

Wire fixation techniques of the cervical facets.

STUDY DESIGN: The changes in the biomechanical responses of the cervical spine altered by multilevel laminectomy to various facet wiring techniques were evaluated. OBJECTIVE: To determine the effectiveness of various proposed techniques of cervical facet wiring used to offer rigid internal fixation after multilevel laminectomy. METHODS: Eight human cadaveric spine segments from C2-11 underwent combined flexion-compression loading. After testing intact and three-level laminectomy (C4-C6) preparations, two techniques of facet wiring fixation were evaluated in an identical manner. Force, displacement, and kinematics data at every level of the column were obtained. RESULTS: The mean stiffness of the intact column was significantly greater than the mean stiffness for laminectomized specimens. Individual facet wiring to the bone graft and through the spinous process below the laminectomy failed to restore stiffness to the laminectomized preparations, whereas the Luque rectangle method restored the stiffness to that found in the intact column. The increases in segmental and overall sagittal rotations resulting from multilevel laminectomy were not decreased significantly by the individual facet wiring technique, but the Luque rectangle technique demonstrated a reduction of sagittal rotations compared with laminectomy without fixation. CONCLUSIONS: The significant increases in total column flexibility and segmental flexural rotations after multilevel laminectomy were not corrected by techniques that depend on individual facet wires secured to an overlying strut, including wiring to the inferior intact segment. Crosslinking of the facet wire fixation above and below the laminectomized segments, as exemplified by the Luque rectangle technique, restored column stiffness and reduced segmental sagittal rotations.

Biomechanical Phenomena↗
PubMed1997

Finite element modeling of cervical laminectomy with graded facetectomy.

In this study, an anatomically accurate three-dimensional finite element model of the human lower cervical spine (C4-C6) was used to study the biomechanical effects of cervical laminectomy with and without graded facetectomy. The intact finite element model was validated under flexion, extension, lateral bending, and axial torsion load vectors of 1.8 Nm magnitude. The moment rotation response of the finite element model matched well with experimental data. The gross external (angular motion) and the internal (superior and inferior intervertebral disc stress) responses were delineated under the four physiological loading modes for these iatrogenic changes. Results indicated that laminectomy markedly altered the cervical angular motion and the disc stress under flexion compared with all other loading modes. Facetectomy increased the angular motion and the inferior disc stress notably under flexion but did not affect the adjacent superior disc stress. Facet resection of > 50% caused pronounced increases in angular rotation and intervertebral disc stresses. These findings suggest that the resection of more than one-half of this structure may require additional procedures to restore the strength of the cervical column. Although gross external motion response can be obtained by experimental studies, the internal stress response can only be determined using mathematical models such as the finite element model used in the present study. The accentuated changes in the disc stress compared with the changes in the external rotation may be clinically relevant because increased internal load/stress can result in disc degeneration. The present three-dimensional finite element model offers additional information to better understand the extrinsic and intrinsic responses of the iatrogenically altered cervical spine.

Biomechanical Phenomena↗
PubMed1996

Human head-neck biomechanics under axial tension.

A significant majority of cervical spine biomechanics studies has applied the external loading in the form of compressive force vectors. In contrast, there is a paucity of data on the tensile loading of the neck structure. These data are important as the human neck not only resists compression but also has to withstand distraction due to factors such as the anatomical characteristics and loading asymmetry. Furthermore, evidence exists implicating tensile stresses to be a mechanism of cervical spinal cord injury. Recent advancements in vehicular restraint systems such as air bags may induce tension to the neck in adverse circumstances. Consequently, this study was designed to develop experimental methodologies to determine the biomechanics of the human cervical spinal structures under distractive forces. A part-to-whole approach was used in the study. Four experimental models from 15 unembalmed human cadavers were used to demonstrate the feasibility of the methodology. Structures included isolated cervical spinal cords, intervertebral disc units, skull to T3 preparations, and intact unembalmed human cadavers. Axial tensile forces were applied, and the failure load and distraction were recorded. Stiffness and energy absorbing characteristics were computed. Maximum forces for the spinal cord specimens were the lowest (278 N +/- 90). The forces increased for the intervertebral disc (569 N +/- 54). skull to T3 (1555 N +/- 459), and intact human cadaver (3373 N +/- 464) preparations, indicating the load-carrying capacities when additional components are included to the experimental model. The experimental methodologies outlined in the present study provide a basis for further investigation into the mechanism of injury and the clinical applicability of biomechanical parameters.

Adult↗
PubMed1996

Cervical spine injuries from high-velocity forces: a pathoanatomic and radiologic study.

The detailed analysis of the radiologic and pathoanatomic data from 10 human cadaver head-neck complexes defined the type and extent of expected cervical spine injuries after high-velocity flexion-compression loads to the cranium. All specimens demonstrated multiple injuries with both contiguous and noncontiguous patterns. Although all preparations showed evidence of axial compression, a multiplicity of other force vectors, including noncontiguous occurrences of flexion, extension, and shear, were documented. These findings indicate that the injury pattern is not a sequential process but a reaction to changes in the segmental interrelations of the various vertebral column components, including varying vector applications of injurious forces at the segmental level. The presence of moderate or severe spondylotic alterations restricted the distal transmission of injury forces with the principal injury patterns occurring at or proximal to the initial level of severe spondylotic involvement. These data emphasize the need for increased awareness of the presence of multiple cervical spine injuries, both contiguous and noncontiguous, and that separate levels of compromise may not share similar mechanisms of injury.

Aged↗
PubMed1995

Biomechanical alterations induced by multilevel cervical laminectomy.

STUDY DESIGN: The biomechanical responses of the cervical spine undergoing a combined loading vector within the physiologic range and after multilevel laminectomy were evaluated. The experimental conditions were designed to more closely replicate the typical clinical situation than accomplished by previous studies. OBJECTIVE: To determine the biomechanical alterations induced by multilevel cervical spine laminectomy using an in vitro model. SUMMARY OF BACKGROUND DATA: The few previous laboratory studies concerned with the effects of cervical laminectomy have generally indicated a lack of significant change in strength or flexibility induced by the procedure. These studies have been limited by a variety of factors, including the use of pure loads under low physiologic loading conditions, restriction of the laminectomy to one or two segments, and the evaluation of a small number of specimens. METHODS: Twelve fresh human cadaver cervical spine segments from C2-T1 were used. A custom-designed fixture was attached to the proximal end of the specimen to apply a flexion-compression load. Retroreflective targets were positioned in bony landmarks for localized temporal kinematics of the entire cervical column. Testing was performed before (intact) and after a three-level (C4-C6) laminectomy, and data regarding the force, displacement, and kinematics at every level of the column were obtained. RESULTS: The mean stiffness of the intact cervical column was significantly greater (P < 0.05) than the mean stiffness for the laminectomized specimen. Sagittal rotation angle had significant (P < 0.05) differences between intact (3.6 degrees) and laminectomy (8.0 degrees). Laminectomized specimens consistently responded with higher rotations compared with the intact specimen at every cervical spine level. CONCLUSION: Multilevel cervical laminectomy induces significant increases in total column flexibility associated with increased segmental flexural sagittal rotations. These motion changes were generalized with a tendency to show the greatest change at the lower level of laminectomy. Such biomechanical changes may constitute part of the underlying basis for failure of laminectomy to offer sustained good therapeutic results of the myelopathy associated with cervical stenosis and cervical spondyloarthropathy.

Adult↗
PubMed1995

Syringomyelia after removal of benign spinal extramedullary neoplasms.

STUDY DESIGN: This is a case report. OBJECTIVES: Two patients with noncommunicating syringomyelia manifesting symptoms years after the uneventful excision of a benign intradural extramedullary neoplasms are presented. SUMMARY OF BACKGROUND DATA: The association of noncommunicating syringomyelia with benign extramedullary neoplasms as a coexistent or delayed process is a rare event. The pathogenesis of such spinal cord cavitation after tumor removal and the relationship with therapeutic intervention is not well defined. METHODS: The delayed occurrence of neurologic impairment emphasizes the need for considering development of syringomyelia rather than tumor recurrence. RESULTS: The effects of chronic spinal cord compression in the thoracic region may be accelerated by adverse stresses acting on the spinal cord associated with tethering of the spinal cord. CONCLUSION: In defining the pathogenesis of this form of spinal cord cavitation, these cases suggest that therapeutic approaches directed at resolving the process should not only include lyses of adhesions, but shunting procedures, which appear to be most efficacious when these procedures are performed at or cephalad to the level of original tumor removal.

Aged↗
PubMed1995

Cervical vertebral strain measurements under axial and eccentric loading.

The mid to lower cervical spine is a common site for compression related injury. In the present study, we determined the patterns of localized strain distribution in the anterior aspect of the vertebral body and in the lateral masses of lower cervical three-segment units. Miniature strain gages were mounted to human cadaveric vertebrae. Each preparation was line-loaded using a knife-edge oriented in the coronal plane that was moved incrementally from anterior to posterior to induce compression-flexion or compression-extension loading. Uniform compressive loading and failure runs were also conducted. Failure tests indicated strain shifting to "restabilize" the preparation after failure of a component. Under these various compressive loading vectors, the location which resulted in the least amount of deformation for a given force application (i.e., stiffest axis) was quantified to be in the region between 0.5- 1.0 cm anterior to the posterior longitudinal ligament. The location in which line-loading produced no rotation (i.e., balance point) was in this region; it was also close to where the vertebral body strains change from compressive to tensile. Strain values from line loading in this region produced similar strains as recorded under uniform compressive loading, and this was also the region of minimum strain. The region of minimum strain was also more pronounced under higher magnitudes of loading, suggesting that as the maximum load carrying capacity is reached the stiffest axis becomes more well defined.

Aged↗
PubMed1995

Vascular effects of spinal cord stimulation in the monkey.

Because of clinical reports suggesting beneficial effects of electrical stimulation in peripheral vascular disease, studies have been conducted in the monkey. Regional blood flow was measured prior to, during and following the application of electrical currents to the spinal cord. The flow measurements were made using radioactive microspheres. In addition, tissue temperatures and venous and arterial concentrations of epinephrine and norepinephrine were measured. The results show that electrical stimulation increases blood flow to the skin and muscle. It is hypothesized that the effect is due to sympathetic inactivation secondary to the application of electrical currents.

Animals↗
PubMed1995

An experimental technique to induce and quantify complex cyclic forces to the lumbar spine.

The human spine is a complex, heterogeneous nonlinear and viscoelastic structure. In addition, in vivo loading is not uniaxial. Although many studies on the mechanical behavior of the spine under "pure" forces and single cycle load applications exist, little research is conducted with complex cyclic loads. In this study, we developed a technique to induce and quantify controlled complex physiological loads to the lumbar spinal column under cyclic (chronic) conditions. The methods described include specimen preparation and mounting to induce controlled complex loading (cyclic compression-flexion vector was chosen as an example), instrumentation, and biomechanical data to achieve the objectives. The results indicated that the specimen sustained the external load in a combined compression-flexion mechanism without considerable off-axis forces (lateral shears) and moments (lateral bending and torsion). By mounting the anchoring bolt in appropriate places (such as an anterolateral placement to induce compression-flexion-lateral bending), this technique can be used to apply and continuously quantify complex physiological acute or cyclic loads to describe the biomechanics of the spine. This procedure of inducing complex loads eliminates the difficulty in applying the principles of superposition, using the response from individual "pure" forces to account for the nonlinearity and viscoelasticity of the human lumbar spinal column.

Biomechanical Phenomena↗
PubMed1994

Cyclic compression-flexion loading of the human lumbar spine.

STUDY DESIGN: The present study was designed to investigate the biomechanical behavior of the lumbar spine under controlled complex physiologic situations with chronic input. OBJECTIVE: The objective was to determine the response of the human cadaver lumbar spinal column under repetitive compression-flexion forces. SUMMARY OF BACKGROUND DATA: Studies have been conducted in the past to determine the biomechanical response of the spine under uniaxial or pure forces. There is no methodology that can be used to apply and continuously quantify the fatigue response of the lumbar spinal column under controlled combined complex loading vectors (e.g., compression flexion). METHODS: Intact cadaver lumbar columns (L1-L5) were mounted with the superior end in contact with a ball-transfer mount, inducing a flexion load to the spine while allowing multiple degrees of freedom. The distal portion of the specimen was attached to a six-axis load cell to quantify the force sustained by the specimen during the entire loading cycle. The applied load and piston deformation and the generalized six-axis force histories were gathered as a function of time using a digital data acquisition system. RESULTS: The stiffness versus number of cycles (K-N) response exhibited nonlinear characteristics. The stiffness increased initially and then stabilized after 1,000-2,000 cycles of loading, delineating the viscoelastic characteristics of the spine. The initial stiffness increase before stabilization was found to be significantly different (P < 0.025) compared to the stiffness beyond 2,000 cycles. CONCLUSIONS: The data suggest that the fatigue response can be understood by cyclically loading the ligamentous lumbar spine preparation to approximately 2,000 cycles.

Aged↗
PubMed1994

Continuous motion analysis of the head-neck complex under impact.

The objective of the present study was to analyze the localized kinematic biodynamics of the human head-neck complex under impact loading. Unembalmed human cadaveric head-neck complexes were subjected to axial compressive forces delivered using an electrohydraulic testing device. The head-neck complex was aligned along the stiffest-axis; musculature was simulated using preloaded springs and cables; and retroreflective targets were inserted into the vertebral body, the facet joint articulation, and the spinous process at every level of the cervical column. At dynamic loading rates (1.8-5.1 m/min), mid to lower cervical spine injuries consistently occurred in these preparations. Continuous motion analysis of the components (vertebral body, intervertebral disk, facet joint, and the spinous process) at all levels of the cervical spine showed the temporal order of the transfer of the external load. Injuries documented by computed tomography and cryomicrotomy techniques correlated with the kinematics of the structure. The application of dynamic loading to the head-neck complex coupled with high-speed, continuous-motion analysis of the intervertebral components of the entire cervical column makes possible the definition of the temporal kinematic mechanics that are fundamental to the understanding of the biodynamics of cervical spine trauma. Using these procedures, we have correlated the kinematics with the onset and pattern of neck injury secondary to impact forces.

Aged↗