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 studies presented in this dissertation investigated biomechanical factors associated with sports-related brain injuries on the field and in the laboratory. In the first study, head impact exposure in youth football was observed using a helmet mounted accelerometer system to measure head kinematics. The results suggest that restriction on contact in practice at the youth level can translate into reduced head impact exposure over the course of a season. A second study investigated the effect of measurement error in the head impact kinematic data collected by the helmet mounted system have on subsequent analyses. The objective of this study was to characterize the propagation of random measurement error through data analyses by quantifying descriptive statistic uncertainties and biases for biomechanical datasets with random measurement error. For distribution analyses, uncertainties tend to decrease as sample sizes grow such that for a typical player, the uncertainties would be around 5% for peak linear acceleration and 10% for peak angular (rotational) acceleration. The third and fourth studies looked at comparisons between two headforms commonly used in athletic helmet testing, the Hybrid III and NOCSAE headforms. One study compared the headform shape, particularly looking at regions that are likely to affect helmet fit. Major differences were found at the nape of the neck and in the check/jaw regions that may contribute to difficulty with fitting a helmet to the Hybrid III headform. For the final study, the impact responses of the two headforms were compared. Both headforms were mounted on a Hybrid III neck and impacted at various magnitudes and locations that are representative of impacts observed on the football field. Some condition-specific differences in kinematic parameters were found between the two headforms though they tended to be small. Both headforms showed reasonable repeatability. / Ph. D.

The research presented in this thesis aims to improve the knowledge of head impact biomechanics in youth football players by analyzing head impact exposure of youth football players and the performance of youth football helmets. The results of the studies presented provide a foundation for researchers, football leagues, and helmet manufactures to implement changes and modifications that aim to reduce concussion risk in youth athletes. The first study presented in this thesis aims to quantify the head impact exposure of 7 to 8 year old football players and determine the cause of variation in player exposure. To conduct this study, 19 players were instrumented with helmet mounted accelerometers that measured real-time acceleration data on the field. This data was analyzed to determine the magnitude, frequency, and location of each impact sustained by players in the 2011 and 2012 football season. From these data, it was determined that the average 7 to 8 year old player experienced 161 impacts per season, 60% of which were in practice and 40% were in games. The median impact for 7 to 8 year old players was 16 g and 686 rad/s². The magnitude of the 95th percentile impact was 38 g and 2052 rad/s². A total of 125 impacts above 40 g were recorded, 67% of which occurred in practices and 33% occurred in games. It was determined that returning players experienced significantly more impacts per season than first time players and practices had significantly higher magnitude impacts than games. These data can be used to further develop practice modifications that aim to reduce total impacts and high magnitude impacts experienced by youth football players. The second study presented in this thesis aims to quantify differences in youth football helmet performance before and after a football season. Currently, the only requirement regarding helmet recertification and reconditioning states that no helmet older than 10 years will be recertified or reconditioned. Quantitative data is needed to either support or refute this guideline and provide data describing how often youth football helmets should be recertified and reconditioned. To conduct this study, 6 youth Riddell Revolution football helmets, 3 that were new and 3 that had been used for one season, were tested on a drop tower from various heights and impact locations before and after the 2013 football season. It was determined that there was no significant difference in helmet performance before and after a season for new helmets or helmets that had been used for one season. In addition, there was no significant correlation between the frequency of impacts, the 95th percentile impact magnitude, or the product of the frequency and 95th percentile impact magnitude with the change in helmet performance. Future studies should be conducted that analyze the performance of youth football helmets over the course of multiple seasons. / Master of Science

Youth and varsity football helmets are currently designed similarly and tested to the same impact standards from the National Operating Committee on Standards for Athletic Equipment (NOCSAE). Youth players have differences in anthropometry, physiology, impact exposure, and potentially injury tolerance that should be considered in future youth-specific helmets and standards. This thesis begins by investigating the current standards and relating them to on-field data. The standard drop tests represented the most severe on-field impacts, and the performance of the youth and varsity helmet did not differ. There likely is not a need for a youth-specific standard as the current standard has essentially eliminated the catastrophic head injuries it tests for. As more is known about concussion, standards specific to the youth population can be developed. The second portion of this thesis compares the impact performance between 8 matched youth and varsity helmet models, using linear acceleration, rotational acceleration, and concussion correlate. It was found that helmet performance did not differ between the youth and varsity helmets, likely attributed to testing to the same standard. The final portion of this feature is aimed at advancing STAR for youth and varsity football helmets by including linear and rotational head kinematics. For varsity helmets, an adult surrogate is used for impact tests which are weighted based on on-field data collected from collegiate football players. For youth helmets, a youth surrogate is used and tests are weighted based on data collected from youth players. / Master of Science

Scholars in many fields have long studied the patterns of employment and promotions in industries and occupations. However, the area of sport has been largely omitted from studies of this type. This study explored the possibility of an internal labor market for head coaches of the National Football League (NFL). Subjects were those people who were the head coaches of NFL teams for the years 1970 to 1975 and 1980 to 1985. Following theoretical guidelines, the subjects were tested for evidence of industrial, occupational, and/or pure internal labor markets. Statistical treatment of the data utilized chi square tests. The results of this study provided evidence of industrial and occupational internal labor markets, but there was no support for a pure internal labor market. The tests showed an intertwining of the industrial and occupational internal labor markets over the course of the subjects' careers. There also were significant findings in the areas of mentor and position played by the subjects. This study can serve as a foundation for further studies. / Master of Science

In recent years, concussions and the effect this injury has on the human brain has been an area of concern for many people involved in sports. And perhaps rightfully so, as between 1.6 and 3.8 million people each year sustain a sports-related concussion in the United States. In the past, concussions have been solely linked to transient symptoms; however, recent research suggests that the injury can also result in long term neurocognitive impairment. Thus, there is much needed research to better understand concussions and assist in the development of safety techniques that will reduce the occurrence of such injury. Participants of youth football are at an extreme disadvantage as very little research has been conducted on this population. The research presented in this dissertation attempts to characterize head impact exposure of a variable subgroup of youth football, middle school football, in order to better understand concussions in youth. In addition to better understanding concussions, it is imperative that correct laboratory techniques are developed to accurately simulate realistic head impacts. This dissertation also presents results from the evaluation of current testing procedures that can be used for laboratory testing of sports equipment and simulation of actual field impacts. Evaluation of these techniques will further validate their ability to act as methods for both safety and research in sports injury. Thus, the overall goal of this dissertation is to provide results that will both further understanding of concussions and evaluate the realistic performance of laboratory techniques, influencing informed decisions to reduce the risk of concussions. / Ph. D.

The effects of two different noise sources upon their surrounding communities were investigated with both quantitative and qualitative measures. A high school football game, which presents continuous noise over a relatively short duration on a predictable schedule was found to have a slight annoyance on its surrounding community. In contrast, a train horn blow at a residential intersection was investigated. This sound was unpredictable and could occur at any time. Residents in this community were found to have a moderate level of annoyance. It was found that each of the noises studied violated suggested noise levels for common household activities, in addition to many local, state, and federal noise regulations. It is recommended that both of the sounds studied herein be reduced or eliminated altogether. Limiting the level of sound produced by the PA system at the football game and using a noise reducing barrier would help in the case of the football game. Converting the railroad intersection into one with sufficient safety features, especially a crossing quad-gate that no longer requires trains to blow their horns would be the optimal solution, with the added benefit of precluding vehicles from entering the crossing when a train is present. / Master of Science

Shoulder-to-helmet (STH) impacts have been shown to cause approximately twenty percent of concussions in football, yet little research has investigated shoulder pad design and STH impacts. While shoulder pads are designed to protect the player wearing them, they have the potential to better protect the struck player in STH collisions. This study aimed to characterize STH impacts and identify the effect of shoulder pad stiffness on the struck head kinematics. Additional padding was added to a shoulder pad as means to reduce the overall stiffness of the system, and an unmodified shoulder pad acted as the control. Participants performed a series of impact tests with two shoulder pad variations to identify if additional padding in the shoulder pads could reduce head kinematics. Participants struck a helmeted Hybrid III dummy with a National Operating Committee on Standards for Athletic Equipment (NOCSAE) on the side, replicating a lateral STH impact. Linear and rotational kinematics of the struck head were recorded for each impact, and impact speed was derived from high-speed video. Peak kinematics were compared between shoulder pad configurations to identify differences in pad performance. Impact response corridors were developed from this study that could be used to inform future controlled laboratory test setups that replicate STH impacts. A controlled test setup would allow for future testing at higher impacts speeds to evaluate concussive level impacts. Overall, this study aimed to identify if shoulder pad design can affect the struck head kinematics in STH impacts, which would open a new avenue of player safety research and development. / Master of Science / Shoulder-to-helmet (STH) impacts have been shown to cause approximately twenty percent of concussions in football, yet little research has investigated shoulder pad design and STH impacts. While shoulder pads are designed to protect the player wearing them, they have the potential to better protect the struck player in STH collisions. This study aimed to characterize STH impacts and identify the effect of shoulder pad stiffness on the struck head kinematics. Participants performed a series of impact tests with two shoulder pad variations to identify if additional padding in the shoulder pads could reduce head kinematics. Participants struck the side of a crash test dummy head with their shoulder to replicate a STH impact. Linear and rotational kinematics were recorded for each impact, and impact speed was derived from high-speed video. Values that are used to quantify head injury were compared between shoulder pad configurations to identify differences in pad performance. This study defined impact response corridors that could be used to inform future controlled lab test setups that replicate STH impacts. A controlled test setup would allow for future testing at higher impacts speeds to evaluate concussive level impacts. Overall, this study aimed to identify if shoulder pad design can affect the struck head kinematics in STH impacts, which would open a new avenue of player safety research and development.

Yes / We employ unconditional quantile regression with region of origin fixed effects, whereby we find that attending live football matches significantly increases expenditures by inbound tourist in the UK, and surprisingly we find that such effects are strongest for those who overall spend the least. Higher spending individuals spend significantly more than those who do not attend football matches, even when such individuals are otherwise similar. We analyse the impact of football attendance across the tourism expenditure distribution which is a relatively neglected aspect within previous research.

Yes / The inbound tourist expenditure generating role of football (soccer), particularly the English Premier League 15 (EPL) is evaluated. An enhanced economic and management understanding of the role of regular sporting fixtures emerges, as well as quantification of their impact. Expenditure on football tickets is isolated to identify local economic spillovers outside the stadium walls. Using the UK International Passenger Survey, unconditional quantile regressions (UQR) is used to evaluate the distributional impact of football attendance on tourist expenditures. Both total expenditure and a new measure which adjusts expenditures for football ticket prices are considered. UQR is a novel technique which is as yet underexploited within sport economics and confers important methodological advantages over both OLS and quantile regressions. Significant cross quantile variation is found. High spending football fans spend more, even after ticket prices are excluded. Surprisingly, spending effects owing to attendance are strongest for those who overall spend the least, confirming the role of sport as a generator of tourist expenditure unlike most others. Though the attendance effect is smaller for higher aggregate spenders, there is nevertheless a significant impact across the distribution. Distributional expenditure impacts highlight clear differentials between attendance by high and low spenders. Similar analysis is applicable to other global brands such as the National Football League (NFL) in the United States (American football) and the Indian Premier (cricket) League. The EPL’s global popularity can be leveraged for achieving enhanced tourist expenditure.