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The article discusses a study to compare energy expenditure and perceived comfort using two modes of carrying a golf bag. the participants completed two trials of walking on a treadmill while carrying a golf bag. Oxygen consumption, heart rate, perceived exertion and comfort were measured during the five-minute walk. The perceived comfort was higher during the double strap trial.

The article presents a study that attempts to determine whether the new design of traditional metal spike golf shoe can reduce golf turf damage. Twenty-four golfers wore three different golf shoe traction designs when performing shots with a driver, 3 iron and 7 iron. Results concluded that a comparison of golf shoe designs highlights greater ground reaction forces with shorter irons.

Braiding is not currently used in the production of golf shafts. The objective of this work was to develop, through a modelling process consisting of altering lamina sequence, a golf shaft, using braided laminas, which would have mass, stiffness and torque comparable to commercially available composite and steel shafts. A 2D conical braided composite model was previously developed and validated to predict elastic constants of braided closed meshed structures. Energy methods were used to calculate the stiffness and torque of shafts using prescribed industry approaches. Shaft mass was calculated based on geometry and density of constitutent materials. Modelled shafts had both braided and unidirectional layers and compared favourably with or were better than commercially available composite and steel shafts in terms of deflection force and twist angle; they had the same weight as composite shafts but were much lighter than steel shafts. If these findings are verified, braided composites would be a viable and effective approach to the design of future golf shafts. [ABSTRACT FROM AUTHOR]

The golf swing has been modelled as a planar movement, but recent findings suggest that the upper limbs and golf club do not move in a single plane. However, the idea that the club alone can be swung in a single inclined plane has not been investigated mathematically. The aims of this study were to determine whether a single plane could be fitted to club motion, and if this plane varied for different clubs. Ten golfers (handicap 1 - 5) performed repeated, consistent swings with three clubs (driver, 5-iron, and pitching wedge). The motion of each club during the downswing was fitted to a single plane. The fit of the plane varied between golfers and clubs (r2 = 0.871 - 0.995, root mean square residual = 44.9 - 166.2 mm). Mean angles of the plane to the reference horizontal Z axis (driver: 125.5°, s = 3.0; 5-iron: 117.1°, s = 3.0; wedge: 113.6°, s = 2.7) and target line axis (driver: -7.8°, s = 5.9; 5-iron: -4.9°, s = 5.7; wedge: -5.9°, s = 6.0) were significantly (P < 0.05) different. Further analysis revealed a single plane was more appropriate for some participants than others, but that it might be neither desirable nor possible in some cases. [ABSTRACT FROM AUTHOR]

The displacement of the golf ball struck by a driving club is affected by several player characteristics and equipment parameters and their interrelationships. Some modelling and simulation studies have shown a relationship between shaft length and clubhead speed, supported by a few experimental studies. The aim of the present study was to examine the relationship between driver length and ball launch conditions in an indoor test facility using a ball launch monitor. Nine males considered to be skilled golfers participated in the study. Four driving clubs of total length 117, 119, 124, and 132 cm were assembled from commercially available components and were used to strike golf shots while initial ball velocity, backspin rate, and launch angles were measured. Statistical analysis identified a significant difference in initial launch speed due to club length, a significant difference between participants, but no difference between the trials for a given golfer. A positive trend was noted between backspin and launch angle for all four clubs, and significant inverse associations between initial launch speed and backspin rate and launch angle. However, the combined launch conditions associated with increasing length were not considered optimal, with uncontrolled swingweight and moment of inertia effects considered to be limiting factors. [ABSTRACT FROM AUTHOR]

Although the golf coaching literature stresses the importance of weight transfer during the swing, research has been conflicting or lacking statistical support. A potential problem with previous studies is that no attempt was made to account for different movement strategies in the golf swing. This study evaluated the relationship between centre of pressure measures and club head velocity within two previously identified swing styles, the "Front Foot" and "Reverse" styles. Thirty-nine Front Foot golfers and 19 Reverse golfers performed swings with a driver while standing on two force plates. From the force plate data, centre of pressure displacement, velocity, range, and timing parameters were calculated. Correlation and regression analysis indicated that a larger range of centre of pressure and a more rapid centre of pressure movement in the downswing was associated with a larger club head velocity at ball contact for the Front Foot group. For the Reverse golfers, positioning the centre of pressure further from the back foot at late backswing and a more rapid centre of pressure transfer towards the back foot at ball contact was associated with a larger club head velocity at ball contact. This study has highlighted the importance of identifying different movement strategies before evaluating performance measures, as different parameters were found to be important for the Front Foot and Reverse styles. [ABSTRACT FROM AUTHOR]

The article reports on a golf pro's decision to develop a glove for golfers that have been disabled due to age or injury that assist them in gripping a golf club correctly and help golfers hold clubs correctly during a golf swing. A discussion of the benefits of a hand exercise machine called the Gripmaster, which is manufactured by DMM products and helps those who suffer from hand problems to improve the strength of their fingers and hands is presented. The plans of the golf pro to continue developing aids and training techniques for golfers with disabilities are discussed.

The oblique impact between a golf ball and a rigid steel target was studied using a high-speed video camera. Video images recorded before and after the impact were used to determine the inbound velocity v i, rebound velocity v r, inbound angle θi, rebound angle θr, and the coefficient of restitution e. The results showed that θr and e decreased as v i increased. The maximum compression ratio ηc, contact time t c, average angular velocity $$\overline{\omega } $$, and tangential velocity $$\overline{v} _{{\text{t}}} $$, along the target were determined from images obtained during the impact. The images demonstrated that ηc increased with v i while t c decreased. In addition, $$\overline{\omega } $$ and $$\overline{v} _{{\text{t}}} $$ increased almost linearly as v i increased. A rigid body model was used to estimate the final angular velocity ω* and tangential velocity νt* at the end of the impact; these results were then compared with experimental data. [ABSTRACT FROM AUTHOR]

Golf shafts are characterized and sold by manufacturers on the basis of their static properties; however, their performance is controlled by their dynamic properties. This paper discusses the relationship between dynamic and static stiffness for a range of carbon fibre composite (CFC) shafts. In particular, the influence of ‘seams’ (specific orientations of the shaft with differing mechanical properties) on static and dynamic stiffness is considered. Vibrational frequency analysis (quasi-static testing) was used to locate the seams, and bend testing was used to determine the static stiffness of the low (seam) stiffness and high (90° to seam) stiffness positions. Dynamic stiffness values were determined by firing a golf ball from a gas cannon at a target attached to the end of the shaft and measuring the resulting deflection for different golf ball speeds. It was found that the dynamic stiffness values over a range of strain rates were similar to the static values for the sheet-laminated shafts indicating that there is no strain rate dependency for these shafts over the strain rates tested. However, for the filament wound shaft, a significant increase in dynamic stiffness, compared with the static value, was seen. This was related to the different CFC microstructure of this shaft. It was also found that the presence of seams resulted in statistically significant differences in static stiffness with respect to shaft orientation for a number of sheet-laminated shafts, whereas there was no difference in dynamic stiffness values. [ABSTRACT FROM AUTHOR]

The purpose of this study was to construct and evaluate the reliability of an apparatus for testing golf putters with respect to distance and direction deviation at different impact points on the clubface. An apparatus was constructed based on the pendulum principle that allowed putter golf clubs to swing at different speeds. The mean speed of the club head before ball impact, and of the ball after impact, was calculated from time measurements with photocells. A pin profile rig was used to determine the directional deviation of the golf ball. Three different putters were used in the study, two that are commercially available (toe-heel weighted and mallet types) and one specially made (wing-type) putter. The points of impact were the sweet spot (as indicated by the manufacturer's aim line), and 1, 2 and 3 cm to the left and right of the sweet spot. Calculation of club head speed before impact, and of ball speed after impact (proportional to distance), showed errors ⩽ 0.5% of interval duration. The variability in ball impacts was tested by measuring time and direction deviations during 50 impacts on the same ball. The mean duration (± s ) after ball impact in the test interval (1.16 m long) was 206 (0.8) ms and the standard deviation in the perpendicular spreading of the balls in relation to the direction of the test interval was 0.005 m. A test - retest of one putter on two consecutive days after remounting of the putter on the test apparatus showed less than 1% difference in distance deviation. We conclude that the test apparatus enables a precise recording of distance and direction deviation in golf putters as well as comparisons between different putters. The apparatus and set-up can be used in the laboratory as well as outdoors on the putting green. [ABSTRACT FROM AUTHOR]

This study examined the information sources that golfers used to purchase golf clubs. Three personal references (family, friends and salespeople) and five non-personal references (television, newspaper, magazine, product catalogue and the internet) were examined from a total of 626 randomly selected golfers in the US. Approximately 85% of the golfers stated that their primary information sources for purchasing golf clubs were personal references. The results suggest that a marketing strategy should place more emphasis on personal sources than non-personal sources. [ABSTRACT FROM AUTHOR]

Measurements are presented of the speed at which six different rods could be swung by four male students. Three of the rods had the same mass but their swing-weight (i.e. moment of inertia) differed by large factors. The other three rods had the same swing-weight but different masses. Our primary objective was to quantify the effects of mass and swing-weight on swing speed. The result has a direct bearing on whether baseball, tennis, cricket and golf participants should choose a heavy or light implement to impart maximum speed to a ball. When swinging with maximum effort, swing speed (V) was found to decrease as swing-weight (Io) increased, according to the relation V = C/Ion, where C is a different constant for each participant and n = 0.27 when Io > 0.03 kg m². Remarkably similar results were obtained previously with softball bats (where n = 0.25) and golf clubs (where n = 0.26). Swing speed remained approximately constant as swing mass increased (when keeping swing-weight fixed). The implications for racket power are discussed. [ABSTRACT FROM AUTHOR]

This paper describes a vision system that recognizes moving targets such as vehicles and pedestrians on public streets. This system can: (1) classify targets {vehicle, pedestrian, others} and, for “vehicles,” discriminate vehicle types and (2) estimate the main colors of targets. According to the input images to the system, the categories of targets are set as {mule (golf cart for workers), sedan, van, truck, pedestrian (single or plural), and other (such as noise)}. Their colors are set as six color groups {red, orange, yellow; green; blue, light blue; white, silver, gray; dark blue, dark gray, black; dark red, dark orange}. In this experiment, we collected images of targets from 9: 00 a.m. to 5: 00 p.m. on sunny and cloudy days as system training samples. The recognition ratio was 91.1% under the condition that both the recognition results of type and color agreed with the operator’s judgment. In addition, the system can detect predefined specific targets such as delivery vans, post office vans, and police cars by combining recognition results for type and color. The recognition ratio for specific targets was 92.9%. For the classification and estimation of targets, we employed a statistical linear discrimination method (linear discriminant analysis, LDA) and a nonlinear decision rule (weighted K-nearest neighbor rule, K-NN). [ABSTRACT FROM AUTHOR]

In the present study, the shape optimization of a golf club head is investigated. The problem of maximizing the release velocity of the ball after impact is treated under the constraint of a specified weight of club head. The thickness distribution of the clubface is chosen as the design variable for optimization. The basis vector method, which is an approximating method for optimization problems in which the sensitivity cannot be derived analytically, is employed. The basis vector represents a fundamental change of shape, and it is preferable to obtaining effective results that the basis vectors be mutually independent. A simple approach to create the basis vectors using eigenmodes is also presented. The theory of impedance matching is confirmed numerically by a two-dimensional example. A three-dimensional example is given to show that this approach is effective for optimal design of the golf club head. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Imparting topspin on a golf ball from putter impact can be achieved either by oblique impact from negative-lofted putter faces or by vertical eccentric impact (commonly referred to as 'vertical gear-effect'). Negative loft gives a small amount of topspin but should preferably be combined with positive putter-head trajectory to give the ball lift at impact. Vertical gear-effect can provide high spin rates for impacts above the sweet spot and desirably gives the ball a small upward lift at impact. This paper outlines the theory of spin generation in putter impact, discusses how high vertical gear-effect can be implemented and considers the effect that such designs have on putt length control, directional accuracy and impact vibration. Ballistic measurement techniques to validate putter designs are described and an unexpected experimental result dependent on shaft coupling is analysed. [ABSTRACT FROM AUTHOR]