The low back loading to which an individual is exposed has been linked to injury and the reporting of low back pain. Despite extensive research on the spine and workplace loading exposures, statistics indicate that efforts to date have not led to large reductions in the reporting of these injuries. One possible cause for the apparent ineffectiveness of interventions may be a poorly defined understanding of the mechanical exposures of the spine during work related activities. There are sophisticated models that can predict spine loads and are responsive to how an individual moves and uses their muscles, however the models are complex and require extensive data collection to be implemented. This fact has prevented these models from being employed in industrial settings and the simplified surrogate methods that are being employed may not be predicting load exposures well. Therefore, this work focused on examining surrogate methods that can produce estimates of spine loading equal to our most complex laboratory based models. In addition, our understanding of spine tolerance to combined motion and load has been based upon in-vitro work that has not accurately represented coupled physiologic compression and flexion or has not investigated potentially beneficial loading scenarios. The result has been a lack of clear data indicating when motion should be treated as the primary influence in injury development or when load is the likely injury causing exposure. As a result, research was conducted to determine the interplay between load and motion in cumulative injury development, as well as investigating the potential of static rest periods in mitigating the effects of cumulative compression. Study one examined the potential utility of artificial neural networks as a data reduction approach in obtaining estimates of time-varying loads and moments equal in magnitude to those of EMG-assisted and rigid link models. It was found that the neural network approach under predicted peak force and moment exposures, but produced strong predictions of average and cumulative exposures. Therefore this method may be a viable approach to document cumulative loads in industrial settings. Study two compared the load and moment estimates from a currently employed, posture match based ergonomic assessment tool (3DMatch) to those obtained with an EMG-assisted model and those predicted with a rigid link modeling approach. The results indicated that 3DMatch over predicted peak moments and cumulative compression. However, simple correction approaches were developed which can adjust the predictions to obtain more physiologic estimates. Study three employed flexion/extension motion with repetitive compression loading profiles in an in-vitro study, with both load and motion profiles being obtained from measures in study 1. It was found that at loads above 30% of a spine’s compressive tolerance, repetitive flexion/extension would not lead to intervertebral disc injury prior to an endplate or vertebral fracture occurring. However, as loads fall below 30% the likelihood of experiencing a herniation increases, while the overall likelihood of an injury occurring decreases. Comparison to relevant studies indicated that while repetitive flexion did not alter the site of injury it appeared to degrade the ability of the spine to tolerate compression. Finally, study four employed dynamic compression while the spine was maintained in a neutral posture to investigate the effects of ‘rest’, or periods of static low level loading, on altering the amount of load tolerated prior to injury. It was found that there was a non-linear relationship between load magnitude and compressive tolerance, with increasing load magnitude exposures leading to decreasing cumulative load tolerances. Periods of low level static loading did not alter the resistance of the spinal unit to cumulative compression or impact the number of cycles tolerated to failure. In summary, this work has examined methods that may allow for better predictions of spine loading in the workplace without the large data demands of sophisticated laboratory approaches. Where possible, suggestions for optimal implementation of these surrogates have been developed. Additionally, in-vitro work has indicated a load threshold of 30%, above which herniation is not likely to occur during dynamic repetitive loading. Furthermore, the insertion of static rest periods into dynamic loading scenarios did not improve the spine’s failure tolerance to loading, indicating that care should be exercised when determining optimal loading paradigms. In combination, the applied methods that have been developed and the information regarding injury development that has been obtained will help to refine our understanding of the exposures and tolerances that define mechanical injury in the spine.

Limited hip mobility is known to affect the lumbar spine. Much of the previous research has utilized a participant population whose hip mobility is compromised due to arthritic or neurological dysfunctions. Such aetiologies may confound the outcomes, as their effects may not be limited to the hip. The purpose of this thesis was to recruit a healthy young adult population with limited hip mobility to further investigate its effect on the lumbar spine, as well as the role of exercise intervention. Several cascading studies were conducted that were unified around a central theme of links between hip and spine function: Study # 1 investigated the normal distribution of passive hip extension and rotation in a group of 77 males (age 19-30). Data was collected using an infra-red motion capture system and compared to goniometric measurements. The resulting angles represent the 5th – 95th percentiles, including the averages and standard deviations. Study # 2 compared movement patterns between groups of males with limited and excessive hip mobility. Participants were required to perform simple functional activities (lunging, twisting, walking, etc) as well as use the elliptical trainer. Resulting hip and spine angles demonstrated that the men with limited hip mobility stood with a more anteriorly tilted pelvis, and assumed a posture with more lumbar and hip flexion on the elliptical trainer, compared to those with greater mobility. This, in turn, resulted in a greater lumbar compression load due to increased back muscle activity. Study #3 involved recruitment of 24 young adult males with limited hip mobility. Their movement patterns were assessed (as in study #2), then they were assigned to one of four intervention groups: hip stretching, spine stabilizing, hip stretching combined with spine stabilization, and control. Participants in the 3 exercise groups attended supervised exercise sessions once/week for 6 weeks, but were expected to exercise a minimum of 4 times/week on their own. At the end of the 6 weeks, intake parameters were re-assessed, and movement pattern assessment repeated. Despite significant increases in available hip flexibility and/or large increases in trunk muscle endurance and trunk motor control, there were few indications that participants were any more adept at decreasing lumbar motion, or utilizing their newfound hip flexibility during functional activities. Study #4 compared those in the 10th and 90th percentiles of available hip rotation, using a frictionless apparatus to investigate passive stiffness properties of the hip. Participants adopted a posture of upright standing, with one leg supported on a turntable apparatus, and upper body and pelvis secured. A an applied rotational moment resulted in passive hip internal and external rotation. Outcomes demonstrate that those with limited hip mobility stand with the leg more externally rotated and require a larger moment to initiate motion. Passive stiffness curves indicate greater stiffness properties in those with limited hip mobility, and more resistance to an external rotation moment than internal rotation. Study #5 investigated passive hip stiffness in the sagittal plane, comparing those with limited and excessive hip extension. Using a frictionless jig, with the participants lying on their left side, the left hip was pulled into extension with knee position varying. Those with limited hip mobility demonstrated increased passive stiffness compared to the more mobile group, and stiffness was greater when the knee was in extension. The group with limited mobility also showed a trend of increased back extension compared to the more mobile group, when the hip and lumbar spine were both free to react to the applied extension moment. Study #6 summarizes the spine/hip kinematics and muscle activation levels produced when using the elliptical trainer, as well as lumbar compressive and shear forces. It differs significantly from walking in that it produces more lumbar motion in flexion/extension and lumbar twist, but less lateral bend. Participants also tended to adopt a greater mean lumbar flexion angle on the elliptical, which in turn resulted in greater muscle activity in the back extensors. Varying hand position, velocity and stride length were all found to significantly affect the amount of lumbar motion. Highly phasic muscle activity is seen, with the gluteal muscles and internal obliques demonstrating the greatest activation levels.

Cervical Spine injuries are a common occurrence during motor vehicle accidents, and they represent a significant economic cost to society. Numerical Finite Element (FE) models have been formulated to investigate the response of the neck under various loading scenarios and to improve vehicle safety. The Global Human Body Models Consortium (GHBMC) was formed to develop a detailed FE model capable of simulating occupant response and predicting subsequent soft tissue injuries in the cervical spine. The objective of this thesis was to validate the neck region of the GHBMC model at the segment level in flexion and extension, and at rotation rates observed during car crash scenarios. Nine cervical spines, under the age of 50, were procured from post mortem human subjects and they were dissected into segments. A segment consisted of two vertebrae with the ligaments and the intervertebral disc intact, and the muscle, nervous, and cardiovascular tissues removed. A custom built fixture was built to test each specimen three times in flexion and extension at two rotation rates: a low rate (one degree per second) and a high rate (500 degrees per second). To avoid damaging the specimens after the first test, the segments were only rotated up to ten degrees for the segments at the C2-C3 through C5-C6 level, and up to eight degrees for the C6-C7 and C7-T1 level. The segment response was represented by plots of the moment against the angle of rotation in the sagittal plane. The segment models were simulated at the same low and high rotation rates, and the model results were evaluated against the experimental response. The low speed experimental results were compared to existing quasi-static studies, but there was not an elevated rotation rate study at each segment level to compare with the high rate response. The segment response from the existing data was generally weaker than the results of this thesis because the earlier studies tested older specimens, and the exiting studies applied a step-wise loading protocol instead of a continuous one. A statistical analysis was conducted to determine the significance of the difference between the low and high rate experimental response. At the maximum angle of rotation, the analysis found moderate evidence (p < 0.05) of increased segment stiffness at the high rotation rate for the C5-C6 and C6-C7 segments in flexion and extension, and weak evidence of increased stiffness for the C3-C4 and C4-C5 segments in flexion and extension, and for the C2-C3 and C7-T1 segments in extension. Below six degrees of rotation, there was no statistical evidence that the low and high speed responses were significantly different for any segment. In flexion, the model response was within one standard deviation of the experimental mean at the C6-C7 and C7-T1 segment level. For the C2-C3 through C5-C6 segment levels, the model was stiffer than the experimental mean. In extension, the model was within one standard deviation at every segment level except at the C2-C3 and C7-T1 segment levels where the model response was weaker than the experimental response. For the high rate model analysis, the model predicted that the high rate simulations were stiffer than the low rate simulation at every segment level; however the difference was much greater in flexion than in extension. Recommendations for further research included studying the high rate behaviour of the intervertebral discs under compressive and bending loading, and investigating the translational and rotational displacement of the spine during flexion and extension and compare the results with the model. The procurement of more post mortem human subjects would increase the sample size and it could improve the significance of the statistical analysis, and additional spines would permit the analysis of other effects, such as the influence of gender.

Limited hip mobility is known to affect the lumbar spine. Much of the previous research has utilized a participant population whose hip mobility is compromised due to arthritic or neurological dysfunctions. Such aetiologies may confound the outcomes, as their effects may not be limited to the hip. The purpose of this thesis was to recruit a healthy young adult population with limited hip mobility to further investigate its effect on the lumbar spine, as well as the role of exercise intervention. Several cascading studies were conducted that were unified around a central theme of links between hip and spine function: Study # 1 investigated the normal distribution of passive hip extension and rotation in a group of 77 males (age 19-30). Data was collected using an infra-red motion capture system and compared to goniometric measurements. The resulting angles represent the 5th – 95th percentiles, including the averages and standard deviations. Study # 2 compared movement patterns between groups of males with limited and excessive hip mobility. Participants were required to perform simple functional activities (lunging, twisting, walking, etc) as well as use the elliptical trainer. Resulting hip and spine angles demonstrated that the men with limited hip mobility stood with a more anteriorly tilted pelvis, and assumed a posture with more lumbar and hip flexion on the elliptical trainer, compared to those with greater mobility. This, in turn, resulted in a greater lumbar compression load due to increased back muscle activity. Study #3 involved recruitment of 24 young adult males with limited hip mobility. Their movement patterns were assessed (as in study #2), then they were assigned to one of four intervention groups: hip stretching, spine stabilizing, hip stretching combined with spine stabilization, and control. Participants in the 3 exercise groups attended supervised exercise sessions once/week for 6 weeks, but were expected to exercise a minimum of 4 times/week on their own. At the end of the 6 weeks, intake parameters were re-assessed, and movement pattern assessment repeated. Despite significant increases in available hip flexibility and/or large increases in trunk muscle endurance and trunk motor control, there were few indications that participants were any more adept at decreasing lumbar motion, or utilizing their newfound hip flexibility during functional activities. Study #4 compared those in the 10th and 90th percentiles of available hip rotation, using a frictionless apparatus to investigate passive stiffness properties of the hip. Participants adopted a posture of upright standing, with one leg supported on a turntable apparatus, and upper body and pelvis secured. A an applied rotational moment resulted in passive hip internal and external rotation. Outcomes demonstrate that those with limited hip mobility stand with the leg more externally rotated and require a larger moment to initiate motion. Passive stiffness curves indicate greater stiffness properties in those with limited hip mobility, and more resistance to an external rotation moment than internal rotation. Study #5 investigated passive hip stiffness in the sagittal plane, comparing those with limited and excessive hip extension. Using a frictionless jig, with the participants lying on their left side, the left hip was pulled into extension with knee position varying. Those with limited hip mobility demonstrated increased passive stiffness compared to the more mobile group, and stiffness was greater when the knee was in extension. The group with limited mobility also showed a trend of increased back extension compared to the more mobile group, when the hip and lumbar spine were both free to react to the applied extension moment. Study #6 summarizes the spine/hip kinematics and muscle activation levels produced when using the elliptical trainer, as well as lumbar compressive and shear forces. It differs significantly from walking in that it produces more lumbar motion in flexion/extension and lumbar twist, but less lateral bend. Participants also tended to adopt a greater mean lumbar flexion angle on the elliptical, which in turn resulted in greater muscle activity in the back extensors. Varying hand position, velocity and stride length were all found to significantly affect the amount of lumbar motion. Highly phasic muscle activity is seen, with the gluteal muscles and internal obliques demonstrating the greatest activation levels.

Thesis (M.Tech.: Chiropractic) - Dept. of Chiropractic, Durban Institute of Technology, 2004 1 v. (various pagings) / Chiropractors are treating spinal joint dysfunction in infants that present with conditions such as infantile colic. Authors conducting research into spinal joint dysfunction in infants have used static and motion palpation to identify these spinal lesions in the infants. The reliability of static and motion palpation used in infants for the assessment of spinal joint dysfunction has not yet been established. The lack of a reliable assessment tool for spinal joint dysfunction in infants reduces the inferential validity of the research studies assessing the efficacy of chiropractic treatment in infants. It is therefore necessary to establish the interexaminer reliability of static and motion palpation in infants. The purpose of this study was to determine the interexaminer reliability of static and motion palpation for the assessment of spinal joint dysfunction in healthy infants aged two to ten weeks

No description available.

Die demographische Entwicklung mit Zunahme des Anteils der älteren Bevölkerung hat in den vergangenen 20 Jahren zu einem Anstieg operationspflichtiger Wirbelsäulenverletzungen geführt. Neue Operationstechniken wurden entwickelt, um den Herausforderungen, die sich durch den größeren Anteil älterer Patienten ergeben, entgegen zu treten. Neben offen-chirurgischen Verfahren kommen mehr und mehr minimal-invasive Techniken zur Anwendung (Lendemans et al. 2011a). Doch unabhängig von der gewählten Methode birgt jeder operative Eingriff Risiken und die Gefahr intra- und postoperativer Komplikationen. Dazu gehören neben allgemeinen Komplikationen wie Blutungen, Verletzung umliegender Strukturen oder postoperativen neurologischen Ausfällen auch implantatbedingte Komplikationen wie z.B. Lockerung, Dislokation oder Bruch des eingebrachten Materials. Letzt genannte Komplikationsart ist ein gemeinsames Charakteristikum der in dieser Arbeit untersuchten Patienten. Ziel dieser Arbeit war es, die im Zeitraum vom 01.01.2003 bis 31.12.2009 an der Klinik für Unfall-, Wiederherstellungs- und Plastische Chirurgie der Universität Leipzig operierten Patienten, bei denen aufgrund von Hardwarekomplikationen Revisionseingriffe durchgeführt werden mussten, zu analysieren. Von insgesamt 57 Patienten (♂/♀=35/22) wurden u.a. Daten zu Unfallart, Lokalisation und Klassifikation der Verletzung, operative Details (Operationsdatum, Operationsdauer, Art der durchgeführten Operation einschließlich Einzelheiten zu den verwendeten Implantaten, Navigationsverfahren), postoperative Komplikationen, Nebendiagnosen (kardiale Nebenerkrankungen, Diabetes mellitus Typ II, Morbus Bechterew, Osteoporose, Nikotinabusus) und BMI ermittelt. Die statistische Auswertung wurde teilweise getrennt für die von uns festgelegten Gruppen (FRAKTUR – CARCINOM – SPONDYLODISZITIS – SPONDYLOLISTHESIS) vorgenommen. Das von uns untersuchte Patientengut kann als inhomogen beschrieben werden. Das Durchschnittsalter betrug 59 Jahre, die Altersspanne reichte von 21 bis 92 Jahre. Die Mehrheit der Patienten konnte der Frakturgruppe zugeordnet werden. Am häufigsten war der Abschnitt der LWS von Verletzungen bzw. den weiteren Krankheitsbildern betroffen. Die operative Stabilisierung erfolgte überwiegend von dorsal. Alle Eingriffe wurden Bildwandler-kontrolliert durchgeführt. In 4 Fällen kam zusätzlich eine CT-Navigation zum Einsatz. Als instrumentierungsbedingte Komplikationen wurden postoperativ am häufigsten Materialdislokation/-lockerung und Pedikelschraubenfehllage beobachtet. Bei 78,9% der Patienten (n=45) war ein einziger Revisionseingriff ausreichend. 12 Patienten (21,1%) mussten mindestens einer weiteren Revisionsoperation unterzogen werden. Als Nebendiagnosen wurden 28-mal (49,1%) kardiale Erkrankungen, 13-mal Osteoporose (22,8%), 11-mal (19,3%) Diabetes mellitus Typ II, und 3-mal (5,3%) Morbus Bechterew gezählt. Fast die Hälfte der Patienten (45,6%) hatte 2 oder mehr Begleiterkrankungen. Als weiterer Risikofaktor wurde bei 26,3% ein Nikotinabusus angegeben. Mit einem Anteil von 57,8% (n=33) waren mehr als die Hälfte der Patienten übergewichtig (BMI ≥ 25). In Zusammenschau mit den Angaben der Literatur können die von uns untersuchten Nebendiagnosen als Risikofaktoren für implantatbedingte Komplikationen angesehen werden. Der Einsatz computerassistierter Navigation, insbesondere bei der Implantation der Pedikelschrauben, kann dazu beitragen, die Komplikationsrate zu minimieren. Das Auftreten von Hardwarekomplikationen scheint multifaktoriell bedingt zu sein. Diverse Nebenerkrankungen, der Habitus des Patienten, das gewählte Operationsverfahren und nicht zuletzt die Erfahrung des Operateurs beeinflussen das postoperative Ergebnis.

Core exercise is a staple of many physical training regimens with goals ranging from improving athletic performance to rehabilitation of spine and knee injuries. Traditionally, dynamic movements such as flexion, lateral bending and twisting core exercise maneuvers are used in training programs; an approach consistent with training the distal limbs where muscular effort is mostly devoted to creating motion. However, knowledge of the functional anatomy of core musculature and spine injury mechanisms questions the use of these types of exercises. Alternative core exercises make use of isometric postures and static bracing to create muscular activation while minimizing spine loads and injury mechanisms linked with movement. This study aims to quantify the effect of various core training programs on the change of passive and active stiffness properties of the torso. This study was driven by several curiosities: 1) Isometric core exercises are reported to help some people who have low back pain. Is there a short lasting ???enhanced stiffness??? after performing these exercises? 2) Core training regimens use Isometric and Dynamic core exercises to enhance core bracing properties. Is one method superior to the other in terms of enhancing core stiffness? 3) If adaptations to core stiffness can be achieved with core exercise, do these adaptations differ between beginners and trained individuals? Twenty four healthy male subjects (22.9 ?? 2.7 years, 1.79 ?? 0.06 m, 77.5 ?? 10.8 kg) were recruited for short and long term core training. Of the overall population, twelve subjects (21.7 ?? 1.89 years, 1.80 ?? 0.076 m, 78.3 ?? 12.3 kg) were University students with little to no experience in performing regular core exercise. The other twelve subjects (24.2 ?? 2.89 years, 1.79 ?? 0.047 m, 76.8 ?? 9.71 kg) were athletically trained with at least one year of experience performing regular core exercise (minimum three times per week). This study was a repeated measures design examining short and long term core stiffness (active and passive) and range of motion before and after a single fifteen minute bout of isometric core exercise and a six week core training program. The long term training groups were divided evenly into isometric, dynamic and control groups. The Isometric group received a six week training program consisting of core bracing exercises ranging from basic static bodyweight exercises to weighted exercises with additional challenge of distal limb mobility while maintaining a braced core, while dynamic group exercises consisted of movement and speed based core exercises. The Control group received no further training during this period. All subjects were asked to refrain from any extra core demands not given by the researchers. After the training period was complete all subjects were retested for stiffness and range of motion. Passive stiffness tests were performed using a frictionless bending apparatus for flexion, extension, left and right lateral bend and left and right axial twist directions. Active stiffness was assessed via a ???quick release??? mechanism, preloaded with a 16 kg mass and randomly released to assess active extension. Participants were instrumented with unilateral electromyography (EMG) of selected core musculature and electromagnetic signals for motion capture for lumbar kinematics. To determine if training had an effect on dependent variables a series of repeated measures ANOVAs were performed; short term training utilized a 2x2 Repeated Measures ANOVA using the pre/post condition and training experience (na??ve vs. savvy) as factors. Long term training utilized a 3x2x2 Repeated Measures ANOVA using training group (Isometric vs. Dynamic vs. Control), training experience (na??ve vs. savvy) and pre/post condition as factors. In general, short term isometric core training increased core stiffness in all directions for na??ve and savvy subjects. Comparisons between these two subject groups did not yield any significant differences. After long term training stiffness was increased the greatest in the Isometric training group with both na??ve and savvy subjects. Dynamic training yielded significant increases in stiffness but for only one direction in each subject group (right lateral bend in na??ve subjects and left axial twist in savvy subjects). The Control group did not show any significant changes in stiffness. Comparisons between training groups and training experience did not yield any significant differences. Isometric training lead to significant stiffness increases in all test except for passive and active extension in na??ve subjects, and similar results were found for savvy subjects except for right lateral bend not showing any significant changes. Researchers believe reasons for insignificant changes are related to high variances which may be due to inadequate statistical power and a wide variety of responses within each subject group. Though some analyses showed inadequate statistical power due to small sample sizes it should be noted that this research is the first of its kind investigating the trainability of core stiffness in the short and long term, and thus difficult to establish sample sizes without any baseline values. The findings of this study can be directly applied to core training for rehabilitation and athletic function. Enhancements in core stiffness are thought to subsequently enhance traits such as load bearing ability, pain management and athletic function. The results of short term training give insight into how a short training session performed prior to a load bearing task can make the task safer and easier to perform. The results of long term training show that Isometric training performed over a long duration may induce more permanent enhancements to stiffness and core function.

Lacrosse, Canada’s national summer sport, is a sport anchored in first nations’ tradition. Its growing popularity in North America has not been reflected by a similar interest in the scientific literature more specifically on the biomechanics of the lumbar spine with its throwing motion. The aim of this study was to describe the motions, forces and muscle actions of the lumbar spine with the hybrid, overhand and sidearm throw. Twelve subjects were asked to throw at maximal speed while captured by a 3D motion analysis system. Flexion, extension and axial rotation angular velocities as well as positive and negative powers in the two planes were calculated. The first research question pertained to consistency in angular velocities and powers between trials of a given throwing technique. Subjects showed a fairly high variation on all variables but mostly with the angular velocities in extension and the peak positive power in flexion/extension which had high coefficient of variations (CVs). The contralateral rotation velocity and the positive rotation power had the lowest CVs. Overall the CVs for powers exceeded the angular velocities’. The second research question addressed if a difference in variables was present between the three throwing methods. A significant difference was observed in the peak negative power in flexion/extension and the peak positive power in rotation. The contralateral rotation angular velocity also showed a significant difference but the sphericity assumption failed. No other variable showed a significant difference but the observed power for those variables was also quite small. Due to the lack of power and the further need for controlling some unforeseen sources of error, this study can be used as a pilot study to further define and improve future studies in the field of lacrosse biomechanics.

Cervical Spine injuries are a common occurrence during motor vehicle accidents, and they represent a significant economic cost to society. Numerical Finite Element (FE) models have been formulated to investigate the response of the neck under various loading scenarios and to improve vehicle safety. The Global Human Body Models Consortium (GHBMC) was formed to develop a detailed FE model capable of simulating occupant response and predicting subsequent soft tissue injuries in the cervical spine. The objective of this thesis was to validate the neck region of the GHBMC model at the segment level in flexion and extension, and at rotation rates observed during car crash scenarios. Nine cervical spines, under the age of 50, were procured from post mortem human subjects and they were dissected into segments. A segment consisted of two vertebrae with the ligaments and the intervertebral disc intact, and the muscle, nervous, and cardiovascular tissues removed. A custom built fixture was built to test each specimen three times in flexion and extension at two rotation rates: a low rate (one degree per second) and a high rate (500 degrees per second). To avoid damaging the specimens after the first test, the segments were only rotated up to ten degrees for the segments at the C2-C3 through C5-C6 level, and up to eight degrees for the C6-C7 and C7-T1 level. The segment response was represented by plots of the moment against the angle of rotation in the sagittal plane. The segment models were simulated at the same low and high rotation rates, and the model results were evaluated against the experimental response. The low speed experimental results were compared to existing quasi-static studies, but there was not an elevated rotation rate study at each segment level to compare with the high rate response. The segment response from the existing data was generally weaker than the results of this thesis because the earlier studies tested older specimens, and the exiting studies applied a step-wise loading protocol instead of a continuous one. A statistical analysis was conducted to determine the significance of the difference between the low and high rate experimental response. At the maximum angle of rotation, the analysis found moderate evidence (p < 0.05) of increased segment stiffness at the high rotation rate for the C5-C6 and C6-C7 segments in flexion and extension, and weak evidence of increased stiffness for the C3-C4 and C4-C5 segments in flexion and extension, and for the C2-C3 and C7-T1 segments in extension. Below six degrees of rotation, there was no statistical evidence that the low and high speed responses were significantly different for any segment. In flexion, the model response was within one standard deviation of the experimental mean at the C6-C7 and C7-T1 segment level. For the C2-C3 through C5-C6 segment levels, the model was stiffer than the experimental mean. In extension, the model was within one standard deviation at every segment level except at the C2-C3 and C7-T1 segment levels where the model response was weaker than the experimental response. For the high rate model analysis, the model predicted that the high rate simulations were stiffer than the low rate simulation at every segment level; however the difference was much greater in flexion than in extension. Recommendations for further research included studying the high rate behaviour of the intervertebral discs under compressive and bending loading, and investigating the translational and rotational displacement of the spine during flexion and extension and compare the results with the model. The procurement of more post mortem human subjects would increase the sample size and it could improve the significance of the statistical analysis, and additional spines would permit the analysis of other effects, such as the influence of gender.