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With advanced motion capture technologies available, the scope and depth of motion analysis now is mainly limited by the capability of the analysis software. Golf swing analysis requires advanced motion analysis methods such as detection of the true impact instant, computation of the impact conditions, definition and use of local reference frames (body and club) in various ways, and determination and use of the functional swing plane. The purpose of this paper was to identify and present solutions for the unique challenges encountered in golf swing motion analysis and to demonstrate the application of such solutions by using Kwon3D, a comprehensive motion analysis program. [ABSTRACT FROM AUTHOR]

The Characteristic Time (CT) and peak vibration frequency of a set of 65 driver heads were measured and correlated (R2=0.83). The Coefficient of Restitution (CoR) of 27 of the heads was determined and the heads were sectioned in order to assess the quality of the weld between the face and crown components by measuring its size as well as inspecting it for signs of oxidation and insufficient heat treatment. In the heads with good welds the CoR was found to depend on the flexibility of both the face and the crown. However, in those with poor welds the CoR was found to have a low dependence on crown stiffness. The ratio of crown vibration/face vibration has been determined and correlated with a visual assessment of the quality of the welds. In order to further understand the effect of the weld geometry and properties on the vibration of the head the first steps towards a predictive vibration model have been taken. The natural frequencies and mode shapes of circular, elliptical, rectangular and square plates have been calculated for a variety of boundary conditions and the frequencies have been experimentally verified for a completely free circular plate. Further work is needed to develop the model to include a weld of variable geometry and material properties. [ABSTRACT FROM AUTHOR]

One of the primary design features of a golf shaft is its bending stiffness which can be characterized by its EI curve (E = modulus of elasticity, I = moment of inertia or second moment of area). Since the golf shaft diameter varies along its length its bending stiffness varies as well. Different shaft designs vary the bending stiffness profile to generate various so-called flex points and relative tip to butt-end stiffness. One way to measure the shaft's EI distribution is by progressively flexing the shaft with a 10 kg load at the center of a series of 250 mm spans. This allows for direct calculation of the average stiffness, EI, via simple beam theory. Because the shaft bending stiffness can vary from 15 to 100N · m² from the tip to the butt-end of the shaft a single load is generally not advisable. In spite of the butt-end being approximately an order of magnitude stiffer in bending than the tip, it is the butt-end loading that needs to be reduced to obtain accurate average EI stiffness. Using a constant 10 kg load can cause up to 27 percent stiffness error due to radial deflection in the butt-end while having less than 3 percent tip stiffness error due to radial deflection. This is because the wall thickness is much less at the butt-end than the tip end of the shaft. Butt-end radial deflection occurs in both steel and composite shafts and alters the stiffness profile of a shaft. In this paper, an experimental method for correcting for radial deflections while measuring shaft bending stiffness is described and results presented. [ABSTRACT FROM AUTHOR]

This paper describes a novel method to measure the loci and attitudes of a high-speed moving object in 3-D space. Here we apply the method to the golf driver head. The employed sensor is a line-CCD camera with high-speed scanning. Because the camera captures only 1-D (line) information in a 2-D image, the scanning speed is very high. During measurement, the line-CCD camera captures the positions of markers located on the driver head. Simple signal processing yields the position at every scan interval and estimates the loci and attitudes of the golf club head. Here we apply the method to golf head motion measurement: however, it can be applied to a variety of high-speed moving objects other than a driver head. [ABSTRACT FROM AUTHOR]

Golf ball launch monitors are among the latest tools available for golf equipment testing and fitting. However, the measurements and information that these systems provide can be confusing and sometimes misinterpreted. Therefore, there is a need for more useful performance indices to help analyze the golfer's game and equipment. In the past, game analysis and club fitting have been based mainly on speed measurements of the club and ball; this is only a small part of the total picture. Today's state of the art equipment can quantify the club path prior to impact as well as the launch conditions of the ball, and use trajectory simulations to predict the flight path of the ball. Taking into account the more complete set of measurements now available, we will introduce new performance indices that have been derived through dimensional analysis and the use of governing equations of motion for golf ball impact and trajectory. In particular, the index of Launch Efficiency has been derived and applied to the analysis of a golfer's game and to club fitting. Test data shows that the performance index of Launch Efficiency provides a more effective way to analyze the golfer's game and equipment. [ABSTRACT FROM AUTHOR]

Golf equipment is more than a four billion dollar industry, making it one of the largest segments within sporting goods. While stagnant in recent years, over the past fifteen years the growth of the golf equipment industry has fueled increased spending in R&D resources, resulting in numerous improvements in the state of the art. However, this still remains a technology-based but marketing-driven industry, where a better mousetrap doesn't guarantee a win. It is an environment where understanding the business of technology is equally important to raising the level of technology. [ABSTRACT FROM AUTHOR]

Nineteen shafts from three batches of commercial golf shafts with different 'flexes' have been characterised in terms of their fundamental bending frequencies. The frequency values show alternating maximum and minimum values at approximately 90° spacings around the circumference of the shaft. Microstructural studies have identified differences in the number of plies around the circumference of the shaft, which, as the wall thickness is constant, leads to fibre volume fraction and Young's modulus variations. The frequency variation has been correlated with the variation in number of plies and the associated mechanical property variations. For the shafts studied the position around the circumference of the shaft at which the number of plies varies has been characterised along the shaft length and related to a 'seam' in properties. [ABSTRACT FROM AUTHOR]

In this paper, I analyze why golf is linked to business and explore the relationship between class structures and the golfing-business environment in Mexico. This work is divided into four parts. The first section explains the theoretical framework utilized in this research, namely Pierre Bourdieu's concepts of capital, habitus, and field. The second part provides a picture of golf in Mexico, showing the specific social meaning of golf in this Latin American country. The third section studies golfers' narratives about the interaction between business and golf; paying particular attention to the structural features of the game and the advice given by golfers about how to carry out business on the golf course. The last part elaborates a more theoretically account of the interaction between business and golf. It examines why the business-golf narrative is deeply connected with notions of ethics and trust, and why these perceptions are profoundly rooted in class ideas. This paper is based on ethnographic research conducted in five golf clubs and 49 interviews carried out with corporate executives and businesspeople in Mexico City. [ABSTRACT FROM AUTHOR]