THE EFFECTS OF GOLF STANCE ON THE PEAK KNEE ADDUCTION MOMENT DURING THE GOLF SWING

INTRODUCTION: The knee joint is one of the most frequently injured structures in the game of golf. The loads experienced by the knee during the golf swing are typically greater than those experienced during walking. In particular, a heightened lead limb peak external knee adduction moment has been linked to the progression of medial compartment knee osteoarthritis (OA). Altering movement patterns is a common strategy that can be used to reduce loading on the knee joint but has received little attention during the golf swing. Also, while such manipulations may be beneficial from an injury prevention perspective, they may have implications on golf performance. The purpose of this study was to analyze the effects altering stance has on the peak knee adduction moment and swing speed during the golf swing. METHODS: Twenty healthy subjects were recruited for a 3-dimensional biomechanical analysis wherein participants hit three golf shots using different stance positions in which either foot angle or stance width was altered. The following stance conditions were used: self-selected, 0º foot angle (perpendicular to target line), 30º foot angle (externally rotated), wide stance width, and narrow stance width RESULTS: Both the 30º foot angle and the wide stance width significantly decreased (p \u3c 0.001) the lead limb peak external knee adduction moment compared to the self-selected golf stance. In contrast, the narrow stance width significantly increased (p = 0.023) the peak knee adduction moment when compared to the self-selected stance. No significant differences were found in the peak knee adduction moment between the 0º foot angle and self-selected stance. Lastly, no significant differences (p = 0.109) were found in swing speed between any of the stance conditions. CONCLUSION: The externally rotated foot position and wider stance width decreased the lead limb peak knee adduction moment without hindering performance. Considering the prevalence of injury to the lead limb knee joint, modifying a golfer’s stance could potentially be used to increase the longevity of their playing career

Services provided by district school library media supervisors

District school library media supervisors have been shown to be an asset to school library programs. Research has shown that school libraries can be more productive and successful, when they are coordinated by a supervisor holding advanced qualifications. The services offered by a district school library media supervisor can directly affect the role of the school library media specialists he/she supervises. Two groups of school library media specialists were surveyed to determine what services their district supervisor provided and how the presence or absence of this position affected the availability and quality of library services offered. Group A were respondents with district supervision and Group B were respondents without district supervision. The results showed that Group A received more administration, communication, teaching, facilitating, and leadership services on a regular basis than Group B. Both group perceptions differed greatly. Based on Group A responses, district supervisors played a major role in supporting the school library media specialist through services they provided. Based on the results of Group B services received and perceptions of district supervisors, they did not receive the same level of services as Group A

Rating of sports teams via least squares and mean absolute deviation techniques : an empirical study of three NCAA sports

This is a decade-long study of rating sports teams using Least Squares and Mean Absolute Deviation methods. Three NCAA sports are studied: College Football, Men\u27s Basketball, and Women\u27s Basketball. Least Squares outperformed Mean Absolute Deviation in all three sports in terms of accuracy [number of correct games predicted]. The accuracy of the best Least Squares model is: 72.74% for Football, 74.61% for Men\u27s Basketball, and 78.90% for Women\u27s Basketball. This is the first study to consider Women\u27s Basketball and first to use more than one year data set for the Mean Absolute Deviation model. Four types of enhancements are applied to the basic models: Home Edge, Scaling of Differences, Start-of-Season Ratings, and Time Discounting. In three of these four, new ways of modeling these enhancements are introduced: Adjusted Average Home Edge (Home Edge), quasi-Bayesian (Start-of-Season Ratings), and the Time Discounting enhancements. The Adjusted Average Home Edge is the most effective Home Edge term. Start-of-Season ratings are used in all most accurate models. Five out of these six also have their start-of-season ratings regressed to the mean

Relative Pathogenicity of Pythium Species Attacking Seedling Com

Several species of Pythium have been isolated and identified as inciting a root rot and blight of seedling corn. In view of the overall importance of this group of fungi, a comparative study of the relative pathogenicity of a selected number of Pythium species is justified

SeaWiFS technical report series. Volume 5: Ocean optics protocols for SeaWiFS validation

Protocols are presented for measuring optical properties, and other environmental variables, to validate the radiometric performance of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), and to develop and validate bio-optical algorithms for use with SeaWiFS data. The protocols are intended to establish foundations for a measurement strategy to verify the challenging SeaWiFS accuracy goals of 5 percent in water-leaving radiances and 35 percent in chlorophyll alpha concentration. The protocols first specify the variables which must be measured, and briefly review rationale. Subsequent chapters cover detailed protocols for instrument performance specifications, characterizing and calibration instruments, methods of making measurements in the field, and methods of data analysis. These protocols were developed at a workshop sponsored by the SeaWiFS Project Office (SPO) and held at the Naval Postgraduate School in Monterey, California (9-12 April, 1991). This report is the proceedings of that workshop, as interpreted and expanded by the authors and reviewed by workshop participants and other members of the bio-optical research community. The protocols are a first prescription to approach unprecedented measurement accuracies implied by the SeaWiFS goals, and research and development are needed to improve the state-of-the-art in specific areas. The protocols should be periodically revised to reflect technical advances during the SeaWiFS Project cycle

The Future of Conventional Deterrence

The 1990\u27s will see the emergence of a new and qualitatively different world order that will require United States to recast its traditional approaches to foreign policy and national security. For four decades national security policy in the United States, largely defined by the superpower rivalry, was heavily dependent upon strategic nuclear deterrence. Today, as the era of bipolarity recedes, we may confidently expect new and different challenges to our important interest abroad

Multi-Pulse Laser Wakefield Acceleration: A New Route to Efficient, High-Repetition-Rate Plasma Accelerators and High Flux Radiation Sources

Laser-driven plasma accelerators can generate accelerating gradients three orders of magnitude larger than radio-frequency accelerators and have achieved beam energies above 1 GeV in centimetre long stages. However, the pulse repetition rate and wall-plug efficiency of plasma accelerators is limited by the driving laser to less than approximately 1 Hz and 0.1% respectively. Here we investigate the prospects for exciting the plasma wave with trains of low-energy laser pulses rather than a single high-energy pulse. Resonantly exciting the wakefield in this way would enable the use of different technologies, such as fibre or thin-disc lasers, which are able to operate at multi-kilohertz pulse repetition rates and with wall-plug efficiencies two orders of magnitude higher than current laser systems. We outline the parameters of efficient, GeV-scale, 10-kHz plasma accelerators and show that they could drive compact X-ray sources with average photon fluxes comparable to those of third-generation light source but with significantly improved temporal resolution. Likewise FEL operation could be driven with comparable peak power but with significantly larger repetition rates than extant FELs

Introducing physician assistants into new roles: International experiences

Conference report: The development of physician assistants (PAs) is a phenomenon that has accelerated since the new century and many countries are involved (1). We report on countries that have recently introduced PAs to identify opportunities for improving the transition. The 35th Annual Physician Assistant Conference of the American Academy of Physician Assistant (AAPA) held in Philadelphia, US, May 26-31, 2007 was attended by almost 8,000 delegates including PAs, students, academics and policy makers. The main purposes of this conference were to promote professional development, develop ideas and provide education. It also featured an international forum focusing on global developments

Experimental philosophy leading to a small scale digital data base of the conterminous United States for designing experiments with remotely sensed data

Research using satellite remotely sensed data, even within any single scientific discipline, often lacked a unifying principle or strategy with which to plan or integrate studies conducted over an area so large that exhaustive examination is infeasible, e.g., the U.S.A. However, such a series of studies would seem to be at the heart of what makes satellite remote sensing unique, that is the ability to select for study from among remotely sensed data sets distributed widely over the U.S., over time, where the resources do not exist to examine all of them. Using this philosophical underpinning and the concept of a unifying principle, an operational procedure for developing a sampling strategy and formal testable hypotheses was constructed. The procedure is applicable across disciplines, when the investigator restates the research question in symbolic form, i.e., quantifies it. The procedure is set within the statistical framework of general linear models. The dependent variable is any arbitrary function of remotely sensed data and the independent variables are values or levels of factors which represent regional climatic conditions and/or properties of the Earth's surface. These factors are operationally defined as maps from the U.S. National Atlas (U.S.G.S., 1970). Eighty-five maps from the National Atlas, representing climatic and surface attributes, were automated by point counting at an effective resolution of one observation every 17.6 km (11 miles) yielding 22,505 observations per map. The maps were registered to one another in a two step procedure producing a coarse, then fine scale registration. After registration, the maps were iteratively checked for errors using manual and automated procedures. The error free maps were annotated with identification and legend information and then stored as card images, one map to a file. A sampling design will be accomplished through a regionalization analysis of the National Atlas data base (presently being conducted). From this analysis a map of homogeneous regions of the U.S.A. will be created and samples (LANDSAT scenes) assigned by region