The purpose of this study was to examine football neck collars and determine their effectiveness at preventing transient brachial plexopathy and other neck injuries due to football impacts. Transient brachial plexopathy, commonly called a stinger or burner, is an injury to the brachial plexus. As many as 65% of collegiate football players will receive suffer such an injury. Accessory neck collars are worn to mitigate the risk of stingers, although little research has been performed to test their effectiveness. In addition to the standard shoulder pad and helmet combination, three collars were tested: the McDavid Cowboy Collar, a collar designed by a Virginia Tech physician called the Bullock Collar, and a prototype device called the Kerr Collar. This study utilized a Hybrid-III 50th percentile male outfitted with a standard collegiate football helmet and shoulder pads, and impacted with a linear pneumatic impactor. Forty eight total impacts were performed; impacts were performed at side, front, and axial loading impact locations, with low and high speed impacts, and normal and raised shoulder pad configurations. Each collar was effective at some positions, but no collar was effective at all impact locations. The Cowboy Collar reduced lower neck bending moments in the front position, but raised upper neck bending moments. It also reduced lower neck bending moments in the side position, but only in the raised configuration. The Bullock Collar was effective at reducing lower neck bending moment in the side position. The Kerr Collar was effective at reducing lower neck bending moments in the side impact location, and provided a larger percent reduction in impactor force in the axial loading position, compared to the shoulder pads alone. Further testing is needed at lower impact velocities that more closely represent injurious impacts in the field. / Master of Science

The syndrome commonly referred to as whiplash injury" resulting from motor vehicle accidents is complex and remains a challenge to clinicians, as is evidenced by the recent report of the Quebec task force on the "whiplash syndrome". The main objective of this prospective randomised study was to evaluate two conservative treatment regimens (early immobilisation-experimental group-1, early active mobilisation experimental group-2) which are based on accepted physiological rationale and then to compare their effectiveness with existing treatment regimens that are commonly practiced (control group) in the management of "whiplash" type of injuries. To this stage, the current study is the only prospective randomised clinical trial of its type conducted with a sufficiently large sample size and over a long study period. The results of the current study clearly demonstrated that the subjects in the immobilised group recovered from their pain-related symptoms and returned to their normal duties sooner than those in the other two treatment groups. In addition to this, those subjects who received the immobilisation regimen did not show adverse effects on either the range of motion or the strength of the neck muscles. Thus, the immobilisation regimen was clearly shown to be the preferred option when compared to the other two treatment methodologies investigated in the current study.Although the primary interest of the current study was to compare the efficacy of three different treatment regimens, a series of statistical analyses were performed to establish the prognostic significance of several factors associated with "whiplash" injury. This showed that factors such as gender, age, speed of the vehicles involved, paraesthesia, intensity of pain at the time of the initial examination, interscapular pain, blurred vision and difficulty in focusing, all had prognostic value. ++ / Similarly, the type of collision, seating position, presence of headache within 24 hours post injury, pre-existing degenerative changes in the cervical spine, loss of lordosis and litigation factors had no prognostic significance. Another major emphasis of the current study has been to concentrate on the pain related symptoms of the neck which are of major concern to "whiplash" subjects and to those clinicians treating them. A paucity of such information is considered to be one of the most notable causes of difficulties encountered in the management of "whiplash" injuries.As an adjunct to the main study, the morphology of the deep pre- and post vertebral muscles of the neck region using embalmed cadavers and fresh post-mortem specimens was investigated, as the literature is deficient in--this regard. Similarly, a longitudinal study of 45 subjects was also performed using Magnetic Resonance Imaging (MRI) technology. The longitudinal nature of the M.R.I. study provided for the first time an account of the details associated with the progressive pathological changes that occurred in some disc lesions, at defined points in time following a MVA. The observations made from the adjunct studies help develop a better understanding of the pathoanatomy associated with the deep muscles of the neck region and the pathological changes that occur following a traumatic disc lesion as evidenced within 2 weeks, after 3 months and 12 months post- injury. On the basis of the observations made in the current study, a classification of the "whiplash" injury has been proposed for the consideration of clinicians. Similarly, the questionnaire used for data collection in the current study, can be readily modified and utilised in a clinical situation for establishing documentation, planning treatment strategies and for evaluation of the treatment outcomes of "whiplash" type of injuries.

Introduction: Little is known about the effect of beliefs on whiplash-associated disorders. Objective: To assess population beliefs regarding whiplash injury, to assess expectation as a predictor of recovery; to explore symptom attribution (Study III); and, assess the relationship between the Whiplash Disability Questionnaire (WDQ) and self-assessed recovery. Materials and Methods: Canadian residents were surveyed about whiplash injury; a whiplash cohort was assessed for association between expectations of recovery and recovery; whiplash patients were examined to correlate auditory symptoms and cerumen occlusion; and, Whiplash patients were asked a global recovery question and results compared to the whiplash Disability Questionnaire (WDQ). Results: Beliefs about whiplash injury were more negative. Expectations of recovery from injury increases the recovery rate. Cerumen explains auditory symptoms in whiplash patients. Patients responding yes to the recovery question had a low WDQ score. Conclusions: Population beliefs, expectations of recovery and symptom attribution are important in whiplash-associated disorders. / Experimental Medicine

Injuries to the head and neck are potentially the most severe injuries in humans, since they may damage the nervous system. In accidents, the cervical musculature stabilizes the neck in order to prevent injury to the spinal column and is also a potential site for acute muscle strain, resulting in neck pain. The musculature is consequently an important factor in the understanding of neck injuries. There is however a lack of data on muscle response and little is known about the dynamics of the individual muscles. In this thesis the numerical method of Finite Elements (FE) is used to examine the importance of musculature in accidental injuries. In order to study the influence of a continuum musculature, a 3D solid element muscle model with continuum mechanical material properties was developed. It was hypothesized that a 3D musculature model would improve the biofidelity of a numerical neck model by accounting for the passive compressive stiffness, mass inertia, and contact interfaces between muscles. A solid element representation would also enable the study of muscle tissue strain injuries. A solid element muscle model representing a 50th percentile male was created, based on the geometry from MRI, and incorporated into an existing FE model of the spine. The passive material response was modeled with nonlinear-elastic and viscoelastic properties derived from experimental tensile tests. The active forces were modeled with discrete Hill elements. In the first version of the model the passive solid element muscles were used together with separate active spring elements. In the second version the active elements were integrated in the solid mesh with coincident nodes. This combined element, called the Super-positioned Muscle Finite Element (SMFE), was evaluated for a single muscle model before it was incorporated in the more complex neck muscle model. The main limitation of the SMFE was that the serial connected Hill-type elements are unstable due to their individual force-length relationship. The instabilities in the SMFE were minimized by the addition of passive compressive stiffness from the solid element and by the decreased gradient of the force-length relation curve.  The solid element musculature stabilized the vertebral column and reduced the predicted ligament strains during simulated impacts. The solid element compressive stiffness added to the passive stiffness of the cervical model. This decreased the need for additional active forces to reproduce the kinematic response of volunteers during impact. The active response of the SMFE improved model biofidelity and reduced buckling of muscles in compression. The solid element model predicted forces, strains, and energies for individual muscles and showed that the muscle response is dependent on impact direction and severity. For each impact direction, the model identified a few muscles as main load carriers that corresponded to muscles generating high EMG signals in volunteers. The single largest contributing factor to neck injury prediction was the muscle active forces. Muscle activation reduced the risk of injury in ligaments in high-energy impacts. The most urgent improvements of the solid element muscle model concerns: the stability of the SMFE; the boundary conditions from surrounding tissues; and more detailed representations of the myotendinous junctions. The model should also be more extensively validated for the kinematical response and for the muscle load predictions. It was concluded that a solid muscle model with continuum mechanical material properties improves the kinematical response and injury prediction of a FE neck model compared to a spring muscle model. The solid muscle model can predict muscle loads and provide insight to how muscle dynamics affect spinal stability as well as muscle acute strain injuries. / QC 20100809

Introduction: Chronic pain after whiplash trauma (chronic WAD) to the neck is still a common clinical problem in terms of pain management, rehabilitation and insurance claims. In contrast to the increased knowledge concerning mechanisms of chronic pain in general, no clinical guidelines exist concerning assessment, pain control and rehabilitation of patients with chronic WAD. Aim: The general aim of this thesis was to use experimental techniques to better understand the complex mechanisms underlying chronic pain after whiplash trauma. The specific aims of papers I and II were mainly to use analgesic drugs with different target mechanisms alone or in combinations to assess their effects on pain intensity (VAS). Experimental pain techniques were used in all studies to assess deep tissue sensitivity (electrical, mechanical and chemical stimuli). Paper IV aimed at assessing deep tissue sensitivity to mechanical and chemical stimulation. The aim in paper III was to investigate if biochemical changes in interstitial muscle tissue (trapezius muscle) could be detected in WAD patients. Materials and Methods: The thesis is based on three different groups of patients with chronic WAD. In paper III and IV two different groups of healthy controls also participated. All patients were initially assessed in the pain and rehabilitation centre. In paper I (30 patients) and II (20 patients) two different techniques of drug challenges were used. In paper I: morphine, ketamine and lidocaine were used as single drugs. In paper II: remifentanil, ketamine and placebo were used in combinations and together with experimental pain assessments. Microdialysis technique was used in paper III (22 patients from study IV and 20 controls). In paper IV (25 patients and 10 controls) a new quantitative method, computerized cuff pressure algometry, was used in combination with intramuscular saline. In all papers, experimental pain techniques for deep tissue assessment (except cutaneous electrical stimulation in paper I) were used in different combinations: intramuscular hypertonic saline infusion, intramuscular electrical stimulation and pressure algometry. Results and Conclusion: There are multiple mechanisms behind chronic whiplash-associated pain, opioid sensitive neurons, NMDA-receptors and even sodium channels might play a part. A significant share of the patients were pharmacological non-responders to analgesic drugs targeting the main afferent mechanisms involved in pain transmission, this implies activation of different pain processing mechanisms (i.e. enhanced facilitation or changes in the cortical and subcortical neuromatrix). Experimental pain assessments and drug challenges together indicate a state of central hyperexcitability. Ongoing peripheral nociception (paper III), central sensitization and dysregulation of pain from higher levels in the nervous system may interact. These findings are likely to be present early after a trauma, however it is not possible to say whether they are trauma-induced or actually represents pre-morbid variations. Clinical trials with early assessments of the somatosensory system (i.e., using experimental pain) and re-evaluations, early intervention (i.e. rehabilitation) and intensified pain management could give further knowledge.

No description available.

This study presents mathematical surrogate models, derived from finite element kinematic response data, to predict car crash-induced occupant head and neck injury risk for a broad range of impact velocities (10 – 45 mph), impact locations, and angles of impact (-45° to 45°). The development of these models allowed for wide-scale injury prediction while significantly reducing the overall required number of impact test cases. From these, increases in both the impact velocity and the impact’s locational proximity to the occupant were determined to result in the greatest head and neck injury risks. Additionally, strong interactions between the impact orientation variables (location and angle) produced significant changes in the head injury risk, while the neck injury risk was relatively insensitive to these interactions; likely due to the uniaxiality of the current standard neck injury risk metrics. Overall, this methodology showed potential for future applications in wide-scale injury prediction or vehicular design optimization.

No description available.