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The internal pressure in a tennis ball controls its rebound characteristics but it is known that there can be a pressure loss from the ball resulting in them becoming unusable. This is annoying to many players who are thus continuously sustaining the costs of ball replacement. This paper describes a series of experiments conducted to evaluate this pressure loss. These included taken samples of balls from long-term storage, from actual use in tennis and also subjecting balls to short-term high frequency bouncing. A standard rebound test was used to evaluate the characteristics of the balls. It was concluded that the period of storage is probably the major factor in causing pressure loss. It is assumed the loss is a result of the permeability of the rubber used for the shell of the ball. An experimental pressure vessel was constructed that would enable balls to be externally pressurised for varying periods of time at varying levels of pressure to recover their internal pressure. The paper describes the results of these tests and sets out conclusions that can be used for the design of a player friendly device to rejuvenate tennis balls. [ABSTRACT FROM AUTHOR]

Teams of employees at firms innovate. Scientists and engineers at universities and research institutions innovate. Inventors at private labs innovate. Regular people consume. Wrong! Regular people innovate, too. Users have been the source of many large and small innovations across a wide range of product classes, industries, and even scientific disciplines. In this paper I describe the contributions made by user innovators in the windsurfing, skateboarding, and snowboarding industries. [ABSTRACT FROM AUTHOR]

Design of sports equipment is primarily performance driven. As a consequence of this approach the sports equipment industry has eagerly adopted new materials and processes over the years that provide the competitive edge but which have unintentionally placed additional burdens on the environment. With the introduction of more rigorous environmental regulations in the developed countries there has been a further shift of manufacturing operations to areas of the world where such policies are more relaxed. There is much evidence that such practices have caused further global environmental degradation. With around 80% of the environmental burden of a product determined during the design stage it is clear that new design practices and tools are required in order to address this problem in a more sustainable way. Environmental concerns need to become a design objective rather than a constraint. This paper discusses the principles and strategies for environmentally sound design of sports equipment and in particular the eco-design approach based on life cycle assessment (LCA). A case study is presented involving comparative environmental life cycle assessment of carbon fibre and glass fibre composite tennis racquets using software EcoScan. [ABSTRACT FROM AUTHOR]

In this paper the authors describe the first stages of developing a genetic algorithm for optimising hockey stick design. The final iteration of this algorithm optimises the mass distribution and total mass of the hockey stick, and ranks the performance of each design based on its modelled ability in hitting and perceived performance in dribbling. The fitness function used draws on player performance testing results, validated models and implied human perception data. [ABSTRACT FROM AUTHOR]

Science and football are two different worlds that nevertheless deal with each other in an increasing manner. Decisions about the effective and efficient use of football΄s most important human capital, the players, are taken not any more solely on the base of intuition and common sense, but are supported by advanced computer systems. These systems allow the club management to measure and analyze the effectivity of the decisions in a more objective and sound way, resulting in a decrease of wasted money, such as `bad buys and transfers΄. Indeed, football is arrived in the process of professionalization, although – like in all sports – emotion and work of man will never be excluded! In this paper two computer support systems are introduced, namely Coach&ScoutAssistant and EffectivityInAction. The first system is used to track and trace the development of (youth) players and to calculate the value-added and best position in the team of a scouted player. The second system is used on-line during the match and generates graphs that reflect the effectivity of the competing teams. Both systems are answers to the intriguing question about the discrepancy between individual and team performance: what is the relation between the performance of an individual player and the performance of his team as a whole? [ABSTRACT FROM AUTHOR]

System analysis and design is an engineering technique which is widely used in industrial projects to ensure a solution is reached which fulfills the requirements of the user. The same technique has been used in this research for the design and implementation of a cricket bowling system which has been designed with both existing technology and the requirements of players and coaches in mind. The structured analysis and design methodology has been teamed with an object oriented approach to provide a component based solution which includes a bowling machine able to recreate any common bowling delivery, a visualization to provide temporal and spatial information about the delivery and an independent user interface to ensure robustness. This papers looks in more detail at the design and analysis methodologies used to create this solution. [ABSTRACT FROM AUTHOR]

The consumer sports electronic (CSE) market has been growing at an unprecedented rate, largely due to the advances made in microelectronics, communication technologies, high-level software, optoelectrics, micro-optics, bioengineering, and new materials. This paper proposes a structured process to enter this business sector for innovative, high-technology companies. [ABSTRACT FROM AUTHOR]

In the design and development of measuring units in elite sport the request for high objectivity, reliability and validity of the results creates high requirements for the construction of the specific devices which usually are not covered by comemercially available systems. But only a sufficiently exact simulation of the competition conditions enables the researcher to evaluate the results with respect to the performance prerequisites of the sport in question and the actual training state resp. athletic shape of the athlete. This refers to the sport specific movement patterns as well as to the robustness caused by the interaction between athlete and measuring unit. The paper presents solutions of selected measuring units. [ABSTRACT FROM AUTHOR]

Four problems has been solved: the design engineering of ski, finding several parameters in underdetermined problem of mechanics, optimal flight control of ski-jumper and making a strategic, plan for a factory of bicycles. All are solved in the frames of one approach called Pareto-optimisation. Pareto-optimisation is a relatively new method of multi-objective optimisation that makes the job of experts making final decision much more transparent than in other multi-objective approaches involving the dialogue with operator. The problems solved are typical problems when multi-objective optimisation arises in engineering. Method demonstrated in this paper gives a powerful tool of multi-objective optimisation and enables statement and successful solution of such problems in practice of sports engineering. [ABSTRACT FROM AUTHOR]

The last 20 years has witnessed an explosion of professional sporting and leisure activities, driven by consumers having more disposable income to spend, economic globalization, multi-channel 24 hour TV, the WWWeb and mobile telecommunications all hungry for content and information. It comes as no surprise then, that science and engineering have already embraced these opportunities with the advent of new disciplines like sports nutrition, sports psychology and the latest one onto the scene, sports engineering. This paper analyses some of the recent and likely future developments, and on this basis puts forward the view that sports engineering will be a transforming agent for the Sports & Leisure Industry well into the 21st Century. The yardstick for these developments will be considerations of sustainability, briefly introduced here in analytical categories, and their resulting innovation potentials. [ABSTRACT FROM AUTHOR]

Shock-absorbing layers perform vital roles in the user comfort, safety and ball interaction characteristics of synthetic sports pitches. The layer typically comprises a porous composite of granulated recycled rubber bound in a polyurethane resin, compacted to form a flat continuous pad upon which the carpet is laid. A lack of published information regarding sports shockpads has prompted research at Loughborough University that aims to investigate the fundamental aspects of shockpad layers, namely their design, construction, characteristic behavior, and test methods. This paper outlines the findings of a detailed study investigating the effect of mix design variables on shockpad properties. Primary mix design variables, binder content, bulk density and rubber size distribution, were varied individually in industry standard shockpads produced using a reproducible hand-construction method. A comparison of tensile strength, ball rebound measurements and Clegg Hammer impact behaivior, showed marked influence of these variables over shockpad performance. The dominance of smaller sized rubber particles in a 2–6mm rubber size produced a softer shockpad (lower Clegg Impact Values), higher tensile strength and slightly decreased ball rebound resilience (more energy absorbed). Higher binder contents increased shockpad strength but had no effect on ball rebound or Clegg Impact Values. Increasing the bulk density of shockpads increased the shockpad tensile strength and decreased Clegg Impact Values (i.e. softer). Further work is ongoing to assess the effect of other design and construction variables. Testing to assess the effect of various carpets placed above the shockpad is also ongoing to assess the whole pitch system΄s performance. [ABSTRACT FROM AUTHOR]

Bobsleigh runners are a critical factor for success in bobsleigh races. It is very important to use runners which generate a minimum frictional loss in contact with ice. As other studies show, the pressure greatly influences the coefficient of friction between steel and ice. In literature, there are indications for a decreasing coefficient of friction with increasing pressure as well as for an increasing coefficient of friction. This paper presents a method to measure the coefficient of friction μ between steel and ice. The normal pressure p on the sample was increased continuously. It was shown, that there is a minimum coefficient of friction for an optimum pressure value popt. Results were transferred to bobsleigh engineering. A molding method was developed to examine the surface of the ice, in particular the trace a runner generates in the bobsleigh track. A highly precise impression material was used and impressions were analyzed by scanning electron microscopy (SEM). The actual pressure between runner and ice was estimated according to SEM analysis. Comparing the actual pressure with laboratory results, design recommendations for a new bobsleigh runner were determined. [ABSTRACT FROM AUTHOR]

The sports and leisure area is an extensive field of application for fiber reinforced plastics (FRP). The remarkable material and manufacturing properties like high stiffness and strength at low density, corrosion and chemical resistance as well as the possibility to realize complex geometrical shapes exceed the possibilities of conventional structural materials, like metals. While a few decades ago steel was substituted by aluminum as chassis material for racing bikes primarily due to the considerably lower density, nowadays, FRP, and therein especially carbon fiber reinforced plastics (CFRP), appear to be the trend setting material nowadays. The application of FRP in load bearing structures, such as bike chassis, is more complex and demands a very close interaction between all disciplines involved in the development process such as material science, design, manufacturing and testing. This paper intends to highlight the potential of CFRP for ultra-light chassis applications in an adequate structural design by considering the Canyon Carbon Ultimate F10 racing bike chassis as one of today΄s lightest and stiffest racing bike chassis worldwide. After a brief introduction into FRP and CFRP a comparison of the anisotropic CFRP with conventional isotropic metals is shown. An overview of the requirements for road and racing bike chassis is given and results of finite element design analyses are presented to show the influence of the lay-up configuration on the frame stiffness. Finally, a comparison with the leading aluminum and CFRP racing bike chassis shows an outstanding lightweight quality of the developed frame which proves the ultra-light weight potential of CFRP in the racing bike chassis sector. [ABSTRACT FROM AUTHOR]

Sandvik Nanoflex® is a revolutionary metal alloy developed by Sandvik Materials Technology, Sweden. Exploiting the latest advances in nanotechnology, Sandvik Nanoflex® offers an exceptional strength-to-weight ratio for the most demanding conditions in high-performance sports. By combining ductility with an extremely high tensile strength and excellent joining and forming properties, Sandvik Nanoflex® opens for very interesting new design solutions in sports equipment. The paper outlines the characteristics of the material and describes cases of application within different fields of sports, each item optimized for low-weight and robustness. It is demonstrated that traditional light-weight materials, such as aluminum and titanium, are regularly outperformed by Sandvik Nanoflex®. [ABSTRACT FROM AUTHOR]

InnoBay is a project sponsored by the Bayerische Forschungsstiftung (a none-profit sponsor for research and development). Goal is the invention of a new bobsled. Involved in the project team are faculties of mechanical engineering and sport science of the Technische Universitaet Muenchen, industrial partners and the Bavarian Bobsled Association. The partners analyse different topics like the interaction between athletes and sports equipment, the aero dynamical behaviour of crew and bobsled as well as problems concerning production. The Institute of Machine Tools and Industrial Management (iwb) is responsible for the manufacturing of the runners. They are important parts of the bobsled, because they significantly determine the runtime. Due to their slender and complex geometry they are difficult to manufacture. During the project various criteria like the choice and order of the production processes or necessary clamping systems will be evaluated regarding their influence on the runtime. In combination with the results of other subprojects, dealing with material selection and geometry optimisation, new bobsled runners will be designed, manufactured and tested. This paper highlights the planned activities and presents first results. [ABSTRACT FROM AUTHOR]

The use of helmets has been proposed as a means of reducing the incidence of fatality in skiing and snowboarding. This paper presents results that suggest that while helmets may be effective at preventing minor injuries, they have not been shown to reduce the overall incidence of fatality in skiing and snowboarding even though as many as 40% of the population at risk are currently using helmets. The results indicate that the use of a helmet will indeed influence the primary cause of death, but perhaps not the ultimate outcome. [ABSTRACT FROM AUTHOR]

Cricket bowling is a complex skill which cannot easily be re-created using machines. Bowling machines are used by players of all standards to provide an unlimited number of deliveries, launched towards the batsman in a repeatable manner for training purposes. However they have a number of limitations which results in them not being used as extensively or as productively as they could be if they were more realistic. The purpose of this paper is to explore the requirements of players and coaches when considering the ideal bowling machine and the use of the systems engineering approach of Quality Function Deployment (QFD) to ensure a novel bowing system fully caters for these needs. A state of the art bowling system is being designed at Loughborough University using this methodology; a prototype machine has been built and tested at the England and Wales Cricket Board΄s National Cricket Centre. [ABSTRACT FROM AUTHOR]

The paper gives an overview of the history of the application of computers in sports and of current research activites in this field. Consequences for university education in sports related disciplines are discussed. [ABSTRACT FROM AUTHOR]

The paper describes the results of ethnographic studies of fitness and sports activities, and introduces a framework for developing concepts and solutions in this area. [ABSTRACT FROM AUTHOR]

Recent trends in information and communication technologies (ICT) and sensor electronics offer new and fascinating options for computer-supported training (CST). Particularly miniaturization and integration of several functions within one device (e. g., smartphone or PDA) offer new options for the documentation and analysis of training data in sport. In order to plan, document and analyze outdoor endurance training procedures many parameters can be assessed, e. g., stress and strain indicators like velocity, acceleration, work, power, rate of perceived exertion (RPE), heart rate (HR), and lactate. The purpose of this paper is to describe the procedure of developing and testing a prototype that integrates assessment and further analysis of GPS data, performance data, HR, and RPE. The available products are analyzed and a first step to a solution is presented using the following components: Garmin GSMMAP 60 CS, Polar HR monitor S720i (with special supplements for biking), and HP iPAQ h2210. First test with representative subjects are promising. [ABSTRACT FROM AUTHOR]

In this paper the potentials of increasing the attractiveness of fitness workout by integrating information technologies into fitness equipment will be discussed. User needs will be identified, existing solutions will be examined, and the development of an innovative computer-supported fitness device will be presented as an example. [ABSTRACT FROM AUTHOR]

Over the past decade, the United Kingdom has experienced a decline in the proportion of young people continuing with their education in the physical sciences through to university level. In general, young people believe these subjects to be `boring΄ and irrelevant to their everyday lives. The image of the physical sciences is a serious concern to the UK Government since in order to maintain the UK΄s position as a technological leader in the world economy, a continual flow of high calibre graduates is essential. Numerous initiatives have been undertaken to encourage young people to study the physical sciences with varying degrees of success. This paper discusses one successful initiative coordinated and delivered by the Sports Engineering Research Group from the University of Sheffield. A series of interactive lectures and workshops were devised to explore how modern science and technology plays an ever increasing role in sport. In just two years, more than 13,000 young people took part in the initiative during 120 events across the UK. The impact of the initiative was monitored and evaluated throughout its duration by collating questionnaire data. Responses from the questionnaires, as well as other forms of feedback, showed the use of sport to be highly effective in terms of engaging young people΄s interest. The project demonstrated that the physical sciences need not be taught in a manner that disengages young people; by using examples and demonstrations from the world of sport, its perception can be one of interest and fascination. [ABSTRACT FROM AUTHOR]

Arguably the performance of elite athletes today has almost as much to do with science, as it does with training. Traditionally the measurement of elite athlete performance is commonly done in a laboratory environment where rigorous testing of biomechanics and physiology can take place. Laboratory testing however places limits on how the athlete performs, as the environment is sufficiently different to the training environment. In addition, performance characteristics are further augmented during competition when compared to regular training. By better understanding athlete performance during the competition and training environment coaches can more effectively work with athletes to improve their performance. The testing and monitoring of elite athletes in their natural training environment is a relatively new area of development that has been facilitated by advancements in microelectronics and other micro technologies. Whilst it is a logical progression to take laboratory equipment and miniaturize it for the training and competition environment, it introduces a number of considerations that need to be addressed. In this paper the use and application of inertial devices for elite and sub-elite sporting activities are discussed. The capacity of accelerometers and gyroscopes to measure human motion thousands of times per second in multiple axis and at multiple points on the body is well established. However interpretation of this data into well-known metrics suitable for use by sport scientists, coaches and athletes is something of a challenge. Traditional brute force techniques such as achieving dead reckoning position and velocity by multiple integration are generally regarded as an almost impossible task. However novel derivative measures of performance such as energy expenditure, pattern recognition of specific activities and characterisation of activities into specific phases of motion have achieved greater success interpreting sensor data. [ABSTRACT FROM AUTHOR]

As launch and flight monitors become more prevalent in retail and research locations the need for fitting golf equipment has increased. In this paper, the fitting of golf clubs is discussed using a calibration club from which performance of other clubs is predicted. In order to do this, extensive testing, both robot and player, was completed building a database of club responses as a function of ball speed, backspin, and launch angle. From the trajectory data the best fit club for a player was determined. For drivers, the fitting simply consists of maximizing the length of the ball΄s flight and roll. [ABSTRACT FROM AUTHOR]

This paper proposes an evaluation method of long and short shaft of golf club by real swing. Head speed of the club, stability of direction of a ball, reliability of impact at the sweet spot and feeling of the club under the swing are used for the evaluation. First the swing is analysed by four link model and head speed and torque under the swing are calculated by Newton-Euler΄s method. Then difference of swing by short and long shaft club is discussed for high and middle level golfer. Next stability of direction and reliability of impact at the sweet spot are measured and these mean values and distributions are obtained. Questionnaire of feeling of the club of swing are performed and these data are statistically analyzed and obtained principal component and coefficient of correlation of each item. From these data, the long and short shafts of golf club are evaluated by evaluation function which would be decided by players requirement. [ABSTRACT FROM AUTHOR]

This paper presents the results of the research carried out during the expedition of the Polytechnic University of Valencia (UPV) in the south face of the Mount Everest. The objective of the study was to evaluate the modification of the thermal properties of two mountain boots worn during the expedition. Both boots were tested before and after the expedition using the laboratory Textile Transmission Test (TTT). This test provides information about the global thermal isolation of the footwear, the global water vapour resistance of the footwear, and the water absorption capability. A breathable/waterproof sock is used to study the transport of water. Two different models of boot were worn by the subjects (One of them developed with a high thermal isolation and the other commercial). The hours of use were 175 (60 estimated kilometers) and the mean environmental conditions were, temperature 5°C and humidity 36% RH. The results of the study showed statistically significant differences in the dry thermal insulation and the wet heat exchange, but not in the global water transfer and absorption of the boots. The results of this study show that actually there is a relevant degradation of the thermal properties with use of sport equipment for high altitudes, which can increase injury risk for sportsmen. This highlights the need to advance in the control of performance during the whole life cycle of the equipments for extreme conditions in order to reduce injury risk of on high altitude climbers. [ABSTRACT FROM AUTHOR]

Contact sports such as rugby demand high performance apparel capable of withstanding large stresses during game-play. In order to ensure that failures are minimised the fabric requires testing. Current British standards detail methods of tensile testing fabrics from bulk stock as opposed to fully manufactured garments. It is important for the sporting goods industry that tensile strength data is tested from panels of the made-up garment instead of material from bulk stock. Generally manufacturers are interested in the minimum force required for a garment to fail. This paper describes a protocol for tensile testing of made-up rugby shirts and their critical components. Summarised are findings from one full protocol test which illustrate typical strengths, and design weaknesses for a modern rugby shirt. [ABSTRACT FROM AUTHOR]

Intermittent pneumatic compression (IPC) technologies are widely used in clinical populations to aid the reduction of limb oedema and for the prophylaxis of deep vein thromboses (DVT). IPC application within athletic populations is not however widespread. The main mechanism for the effectiveness of IPC is that it augments venous and arterial blood flow via the periodic inflation of external cuffs. We believe that this may be beneficial to the warmdown activities of athletes. The removal of waste products may help to reduce injury risk and the phenomenon of delayed onset muscle soreness (DOMS). A new implementation of the technology has been developed to test the extent of any potential warm-down effects induced by IPC treatment in athletes. This paper presents a pilot study in which male participants were exposed to IPC following intensive exercise. The specific treatment comprised 60sec inflation and 60sec deflation of a calf-thigh three compartment sequential compression garment (ratio 70:65:60mmHg) on each leg. This cycle was implemented by an electric pump with the participants in the partially supine position. The recovery protocol was designed to assess the ability of IPC to reduce the symptoms of delayed onset muscle soreness (DOMS) elicited by a high intensity repeated shuttle run. A 1 hour IPC treatment was implemented in this case. Vertical jump was used to identify any change in performance pre and post trial. Visual analogue scales were used +1, +24 and +48 hours after the tests to assess the presence of DOMS. During these tests, heart rate and blood pressure measurements were recorded. [ABSTRACT FROM AUTHOR]

Objective: This paper investigates the influence of footwear geometry on ground reaction forces (GRF) and perception of stability during locomotion. Method: 12 subjects walked on a treadmill ergometer ADAL wearing 5 different shoes models. A barefoot situation was added to the protocol, according to the literature as the best condition of stability. 3 data sets were recorded: GRF (Fx, Fy, Fz) were recorded at constant speed (CS) of 2, 4 and 6 km.h−1, and during transition phases (0 to 2, 0 to 4, 0 to 6 km.h−1). Transition phases (TP) were studied because gait transitions are characterized by a loss of stability. Two running conditions (8 km.h−1 at CS and 0 to 8 km.h−1 at transition) have completed this protocol. At CS, forces were recorded on 10 steps. In TP, maximal force peaks were retained. Then, the subjects filled in a questionnaire to evaluate, for each shoe, their sensations of: 1) stability during running and walking, 2) foot support, 3) heightening of the rearfoot, 4) width of the shoe at the heel, 5) general comfort, 6) cushioning. Geometrical parameters of the shoe were measured: heel counter dimensions, different widths of the sole, sole slopes, heights of upper on external malleolus… These 3 data groups were crossed with correlation matrix. Results: GRF exhibited significant differences between shoes: medial force peaks were more important in barefoot condition and with the shoe which was considered by the subjects as stable in the walking condition. When we added the running condition, there were significant differences between this shoe and all the other conditions (with shoes and barefoot). These results could suggest that a better stability could be associated with more important medial force peaks. Correlations between GRF data, perception of the subjects and shoe measurements brought to the conclusion that there are different parameters of the shoe which could influence the stability: the sole slope, the height of upper on external malleolus and the inside width of the sole at the heel. These results show that stability sensations and biomechanical measurements are bound. Further investigations will be suggested to correlate these preliminary results with center of pressure path in order to validate that GRF could be useful to evaluate stability of the shoe or not. [ABSTRACT FROM AUTHOR]

Materials are not only in technical application a very important aspect but also in designing functional sports equipment. In high performance as well as in mass sports the materials for equipment, sports wear and supports are responsible for the function and the quality. More and more the advertising uses the developments in designing materials for the marketing of sports products, to convince of buying or to restore the athletes for new sportive options. [ABSTRACT FROM AUTHOR]

Safety in Sports Engineering is a broad and diverse topic. The papers in this section reflect that diversity. Historically safety in sport has been a stated goal, but often was secondary to performance. As we become more sophisticated in our ability to analyze and anticipate problems, we also become more proficient in the application of analytical tools such as qualitative analysis, simulation, application of new materials to old problems, statistical analysis, experimental field and lab studies, as well as epidemiological data to determine the degree to which a product might work. [ABSTRACT FROM AUTHOR]

To understand the perspectives taken in the assembly of this synopsis, first I will say a few words about my own field of research – which is focused in the area of exercise physiology issues in connection with practical performance diagnosis, computer-aided interpretations as well as the occurring relevant questions concerning this subject. The main work has been done in the area of top elite sports (energy supply mechanisms, muscular adaptation, high altitude physiology), but also many studies have taken place in the field of basic working / exercise physiology and advanced sport science, for the industry and also for the use of different facilities in the practical field of sport and the army. [ABSTRACT FROM AUTHOR]

The importance of innovation and innovation-related research to my great pleasure has strongly increased in the sports engineering community during the last decade. Whereas just a couple of conferences ago I was feeling like a lone voice crying (the innovation doodle) in the wilderness, delightedly teaming up with those very few reporting on systematically designed pieces of sports equipment, by this year we had to split the topic area: You will not only find a number of contributions on various perspectives on innovation in the following, but also a good, share of innovative design oriented contributions summarized in another synopsis by Caine, and further trans-disciplinary papers opening up new perspectives on sports engineering in yet other topic areas. [ABSTRACT FROM AUTHOR]

Research activities are strongly affected by actual developments in computer science, such as in the areas of hardware (increasing processor speed and storage capacity, advances in communication technology), software (powerful tools), information management (data bases, data mining) and media (internet, eLearning, multimedia). [ABSTRACT FROM AUTHOR]

The presented concept of a new traffic system for metropolitan areas ˵VeloVent″ suggests a number of innovative developments that may help to solve two major problems of these areas – too much motorized traffic and poor physical health of the citizens. The idea is based on human powered vehicles which run through a tube network with transparent covers (i.e. shopping centers, major company facilities, parks, university campus) are connected by the tube. Emphasis was put on the premises and results of human powered VeloVent vehicles for different transportation purposes in the urban environment. [ABSTRACT FROM AUTHOR]

For the interaction between athlete, sports equipment and environment there are general characteristics which are important to consider during the product design process of performance oriented sports equipment. The aim of this study is to describe these aspects of the athlete-sports equipment-system and to get a model for the interaction between athlete, equipment and environment. The model comprises the athlete himself, his activities, the sports equipment and environment. Furthermore the subjective criteria in the model, perception, emotion, status symbol and trend-setting, are of interest. Some examples will illustrate the model. This approach can be used to assist the designer of performance oriented sports equipment and thus to support a systematic product design process in sports. [ABSTRACT FROM AUTHOR]

It can be shown that there is a strong link between paddler performance and paddle stiffness. Despite the fact that composite materials are often chosen to enable design of more rigid sporting equipment, readily available flexural modulus values for composites other than proprietary blends are not easily obtained. Therefore, when composition deviates from proprietary blends, accurate prediction of material properties becomes necessary. A mathematical model for predicting the flexural modulus of short fibre reinforced composite materials is developed based on the application of simple beam theory. The flexural modulus can be modelled by considering a small section of the composite comprising a finite number of polymer and reinforcement layers. Simple beam theory assumes that there is perfect bonding between these layers, but it is well known that interfacial adhesion plays a significant role in composite properties. To account for the interfacial layer and interfacial bonding the second moment of area of the composite beam element was modified by assuming that the contribution to the second moment of area from the matrix layer is reduced by an amount representing the nonbonded interfacial layer. The flexural modulus values obtained from the model are compared to experimental values for glass-fibre reinforced linear low density polyethylene. It has been found that the use of non-contact regions in the model resulted in improved accuracy over the model with perfect bonding for short fibre reinforced LLDPE. [ABSTRACT FROM AUTHOR]

As a consequence of our intensive Nordic Walking research from the last three years, it was found out that the use of special shoes is essential. The pole length, pole construction and the construction of the handle have a biomechanical influence. Furthermore there should be a difference in Nordic Walking techniques. There is one fundamental technique from Finland, which is more or less a sporting one. But in Austria Nordic Walking is a health-movement and so we have developed, with the knowledge of the physio-therapeutics, a new, matching technique, which also requires new equipment (handle, strap…). Our last research covered the influence of Nordic Walking on the prevention of muscular tensions in the upper range of the back (M. Trapezius…). The subjects had an office job and had to work almost all day long in a sitting position in front of a computer. The subject΄s muscular activity was measured with EMG before and after a training cycle, in which they went Nordic Walking with the finish technique. The results have shown that the subjects trained muscles which are parts of the flexorloop. The muscular tensions became lower but they did not disappear. So a new Nordic Walking technique was developed. Thsi new technique trains the muscles of the extensorloop, which is not possible with conventional Nordic Walking equipment, in particular with the conventional handle and strap. Therefore we developed a new ˵strap system″. This ˵strap system″ does not only differ from the conventional handles and straps in form and look, there is also a difference in the transmission of force and the performance of the technique. With that new ˵strap system″ and the new technique it is possible to train the muscles of the extensorloop effectively, which results in a prevention of muscular tensions in the upper range of the back and a prevention of muscular dysbalances. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine critically the safe usage of equipment used for research tests on athletes and to propose improvements. The equipment examined in this study is a bought-in hydrostatic weighing unit which is used in a research environment. Hydrodensitometry is a technique which is widely used to assess body composition. It uses Archimedes Principle to calculate the body density of a subject and this gives a measure of body fat levels. Levels of body fat and muscle are used to assess body composition to optimize muscle mass and as a performance indicator within professional sport environments. Body fat levels are used as training guidance in many sports and optimal limits are set for different sporting applications. The safety of subjects while undergoing testing is paramount. The responsibilities of testers to their subjects, as well as to themselves and their co-workers, has grown in importance from both an ethical and safety stance. With a general increasing consciousness of safety, the user needs to be aware of their legal duties but also all testers have a moral obligation to their subjects to keep them safe from harm. This coupled with the increasing numbers of personal injury claims means that the researcher is required to demonstrate a reasonable level of care for the subject΄s health and safety. Awareness of health and safety is an absolute requirement. The hydrostatic weighing equipment was examined in line with relevant European based legislation and safety requirements and these are discussed along with good practice for international testers. A full equipment and task risk assessment was carried out and hazards were identified. The main hazards found were slips and falls, exposure to chemicals, drowning and electrocution. The outcome from this study was in the short term, safe working procedures were needed with safety controls. These included a winch to remove subjects in an emergency, movement of an electronic display, chemical usage assessment and guidelines. In the long term, redesign of the equipment was necessary as, the hazards and risks were found to be significant. The redesigned equipment changed the orientation of the subject from vertical to horizontal position. The elements that were addressed were the access method into the hydrostatic system became less hazardous and adding a mechanism, which removes subjects from the water should they encounter difficulties during the testing. The redesign should also improve the accuracy and repeatability of the readings. [ABSTRACT FROM AUTHOR]

A player΄s swing motion is analyzed and the head speed is assumed as a cubic function. Then, swing accelerations and forces acting on a sweet spot of a club head are calculated. Under these forces, the deflections and twists of a shaft with optimum stacking sequences are analyzed right before the impact and at the instant of impact. An efficient optimization algorithm is introduced to optimize the stacking sequence of the shaft and wall thickness that satisfy the strength, weight, flex ratings, a kick point and dynamic torsional flexion using a genetic algorithm and finite element analyses. Unlike steel, the shaft made of graphite/epoxy materials shows many different static and dynamic behaviors during swing, depending on its ply orientations. The cost function is a minimum twist of a composite club shaft and seeks the stacking sequence satisfying flex, kick point and weight requirements. After iterative 28 generations, the optimal stacking sequence for the minimum angle of twist is obtained as [30/45/–30/0/–45]s and results in the twisting angle of 1.1°. Before the impact, the maximum deflection is 22.6 mm and the largest twist is 0.121°. At the impact, the maximum deflection is −168.991 mm and the largest twist is 0.217°. [ABSTRACT FROM AUTHOR]

Impact studies under dry conditions have been carried out for a range of golf balls (multi-piece solid construction balls representing a variety of compression ratings with both polyurethane (PU) and ionomer covers) using a gas cannon. The balls have been fired, at a speed of 30 m/s, at grooved and un-grooved plates at effective lofts between 20 and 70° with surface roughness, Ra=1 μm. The ball speed, launch angle and backspin magnitude post-mpact were measured using a stereoscopic launch monitor system. Analysis of backspin was successfully carried out using effective coefficient of friction and spin ratio measures. Within the range of lofts investigated the backspin rate for each of the balls showed a maximum, which was dependent on the ball type and presence of grooves. This behaviour has been rationalised as the deformation of the cover into surface features (particularly grooves at higher loft angles) leading to a higher effective friction coefficient and greater rolling. The behaviour of two-piece balls is largely characterised by the cover hardness, but the mantle needs to be incorporated for three-piece balls. [ABSTRACT FROM AUTHOR]

Traditional regression techniques have shown limited use in the development of empirical models for the traction performance quantities of studded footwear on surfaces. This is due to the unknown and often non-linear relationships between performance parameters, such as traction force, and input variables, from the shoe and surface. Experimental data has been used to train artificial neural networks to model the relationship between stud parameters, namely cross-sectional area, length and two shape coefficients, with dynamic traction as the output variable. A variety of neural network structures and optimisation algorithms were evaluated. The most promising network gave an average prediction error of 10%, compared to an error of 36% when an optimised linear model is employed. This study shows that the neural network technique has powerful potential in understanding the effect of shoe and surface parameters and in the optimisation of traction forces experienced by athletes. [ABSTRACT FROM AUTHOR]

The need for efficient and cost effective methods of recording the structural response of running shoes under simple mechanical testing was identified in order to allow virtual prototyping. Digital video was chosen over other methods due to its availability and relatively low cost. Two complementary experiments were set up to test the performance of the data collection methods: (1) Quasi-static, uni-axial loading was applied up to 1.5 kN (+/−1N) over a period of 30 seconds and the 3D structural response recorded using two 50 Hz video cameras, (2) Dynamic, uni-axial loading to 1.5 kN (+/−200N) was performed using a drop-test rig. Shoe deformation was recorded using a high-speed video system operating at 4 kHz. Testing was performed on two shoe types with no uppers, one with a foam midsole, one with a TPU structure midsole. Analysis of the video data was done using ImageJ in conjunction with Visual Basic routines. Results showed a resolution of 0.68 mm for the quasi-static tests (in the plane of the camera) and 0.46 mm for the dynamic testing. These results were acceptable for use, although the resolution of depth using the two 50 Hz camera was only 6.81 mm, so use of another 3D method is recommended. [ABSTRACT FROM AUTHOR]

Stefanyshyn and Fusco (2004) demonstrated that sprint performance can be improved if the stiffness of standard running spikes is increased. The authors concluded that in order to maximise performance individual tuning of the athlete΄s shoe stiffness to the athlete΄s particular characteristics is required. Rapid manufacturing processes, such as selective laser sintering (SLS) of nylon, offer numerous advantages over conventional manufacturing techniques. Key advantages include the ability to produce complex geometries and internal structures in a single process. Of particular relevance to sprint shoe design is the ability to produce customised outsoles that are specific to the requirements of individual athletes. Sprint spike mechanical performance values were measured using a standard test and the data obtained used to produce benchmark values. The results were catalogued into an incremented range of outsole stiffness responses. Additionally, a range of SLS outsoles were subjected to the same benchmarking procedure, their performance is compared to that of commercially available spikes. The future potential to maximise sprint performance by tuning shoe stiffness to the individual characteristics of an athlete is discussed. [ABSTRACT FROM AUTHOR]