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1.
It is desirable for the studs of a soccer shoe to penetrate the sport surface and provide the player with sufficient traction when accelerating. Mechanical tests are often used to measure the traction of shoe–surface combinations. Mechanical testing offers a repeatable measure of shoe–surface traction, eliminating the inherent uncertainties that exist when human participant testing is employed, and are hence used to directly compare the performance of shoe–surface combinations. However, the influence specific surface characteristics has on traction is often overlooked. Examining the influence of surface characteristics on mechanical test results improves the understanding of the traction mechanisms at the shoe–surface interface. This allows footwear developers to make informed decisions on the design of studded outsoles. The aim of this paper is to understand the effect gravimetric moisture content has on the tribological mechanisms at play during stud–surface interaction. This study investigates the relationships between: the gravimetric moisture content of a natural sand-based soccer surface; surface stiffness measured via a bespoke impact test device; and surface traction measured via a bespoke mechanical test device. Regression analysis revealed that surface stiffness decreases linearly with increased gravimetric moisture content (p = 0.04). Traction was found to initially increase and then decrease with gravimetric moisture content. It was observed that: a surface of low moisture content provides low stud penetration and therefore reduced traction; a surface of high moisture content provides high stud penetration but also reduced traction due to a lubricating effect; and surfaces with moisture content in between the two extremes provide increased traction. In this study a standard commercially available stud was used and other studs may provide slightly different results. The results provide insight into the traction mechanisms at the stud–surface interface which are described in the paper. The variation between traction measurements shows the influence gravimetric moisture content will have on player performance. This highlights the requirement to understand surface conditions prior to making comparative shoe–surface traction studies and the importance of using a studded outsole that is appropriate to the surface condition during play.  相似文献   

2.
Soccer boots are the most important piece of equipment used by a soccer player. They have been improved from heavy bold leather shoes to lightweight aerodynamic designer objects. As traction is one of the key factors of performance, industry experiments with new stud designs, hoping to improve traction behaviour in the different directions. However, excessive traction may contribute to the occurrence of non-contact injuries of the anterior cruciate ligament (ACL). Therefore, many researchers have investigated the shoe-surface interaction of studded boots with mechanical test devices. As yet, a final conclusion regarding correlation between stud design and ACL injuries has not been obtained. Most of the current test devices do not test the soccer boots under game-relevant loading conditions. A new approach has been taken in order to overcome this limitation. In the first step, real ACL injury situations were analysed in detail. The results of this analysis were then used as input data for a multi-body computer model of the human body, to calculate internal forces at the injured leg. Based on this data, a new test device, the TrakTester, was developed including an artificial lower leg with a replica human ankle joint. This paper presents details of the development of the new traction test device and gives an overview of the research options the TrakTester may provide for the future.  相似文献   

3.
Football shin guards were evaluated against a kick from a studded boot.The bending stiffness of their shells, and their response when impacted by a stud, were assessed using finite element analysis (FEA) and determined experimentally.A test rig was constructed with the leg muscle simulated by flexible foam, with the force distribution along the tibia and to the lateral muscle measured using flexible force sensors.High-speed photography confirmed deformation mechanisms predicted by FEA.Load spreading from the stud impact site correlated with the guard shell bending stiffness.The best guards use shells of complex shape to increase their transverse bending stiffness.  相似文献   

4.
Comfort has been shown to be the most desired football boot feature by players. Previous studies have shown discomfort to be related to increased plantar pressures for running shoes which, in some foot regions, has been suggested to be a causative factor in overuse injuries. This study examined the correlation between subjective comfort data and objective plantar pressure for football boots during football-specific drills. Eight male university football players were tested. Plantar pressure data were collected during four football-specific movements for each of three different football boots. The global and local peak pressures based on a nine-sectioned foot map were compared to subjective comfort measures recorded using a visual analogue scale for global discomfort and a discomfort foot map for local discomfort. A weak (rs = ?0.126) yet significant (P < 0.05) correlation was shown between the peak plantar pressure experienced and the visual analogue scale rated comfort. The model only significantly predicted (P > 0.001) the outcome for two (medial and lateral forefoot) of the nine foot regions. Subjective comfort data is therefore not a reliable measure of increased plantar pressures for any foot region. The use of plantar pressure measures is therefore needed to optimise injury prevention when designing studded footwear.  相似文献   

5.
Analysis of ankle protection in Association football   总被引：1，自引：1，他引：0  
Football ankle protectors were evaluated against a kick from a studded boot. An anatomically correct test rig was used to evaluate materials and designs. Sensors were used to determine peak pressures on the bony protuberances, and load spreading. Finite element analysis (FEA), varying the material parameters and component dimensions, were used to explore pressure distributions and shell buckling. Current designs, with thin ethylene vinyl acetate (EVA) foam and low-density polyethylene (LDPE) shells, cannot prevent some football kicks causing bruising of the ankle. The protection level could be improved by using thicker foams of higher modulus, and domed shells of higher stiffness.  相似文献   

6.
A protocol has been developed to obtain two-dimensional kinematic shoe data of football players in their training environment through high-speed video analysis. Such kinematic data can provide an understanding of how to better replicate the boundary conditions of football movements when simulated using mechanical traction and penetration test devices. As part of a pilot study, 11 youth academy players from a Premiership football club performed football-specific movements which were filmed at 1000 frames s-1. The protocol required minimal set-up time and the area of the pitch to be filmed could be positioned in any part of the playing area, causing low disruption to the players. This aimed to ensure that the movements performed were representative of those carried out during competitive play. Results in this study are concerned with the kinematics of the shoe during contact with the ground for movements identified to be important in terms of injury risk and loss of performance (slipping). Shoe velocities and orientations were measured for subjects wearing shoes of different stud types (traditional round studs versus contemporary bladed studs) on two surfaces (artificial turf, in-filled with rubber and sand, versus a natural surface). All the parameters measured from the relatively small population of subjects had high variances and therefore few significant effects of studs and surface could be found. The data does however provide insight into the appropriate boundary conditions to be used in mechanical test devices. For example, in the forefoot push-off movement it can be seen that test devices should measure the traction forces when the shoe first starts to move, as this is when the player would lose performance, as opposed to the maximum traction which can occur after significant displacement of the shoe through the surface. Analysis of the orientation and velocity path of the studs just before contact with the ground shows that the studs could be aligned to enhance their penetration into the surface and optimise the traction properties of the studs. In order to determine the orientation and velocity of the shoes at crucial phases in movements force-plate data obtained in the laboratory should be utilised in future studies.  相似文献   

7.
Footwear traction at different areas on artificial and natural grass fields   总被引：1，自引：1，他引：0  
Footwear traction has been linked to lower-extremity injuries with the theory that higher traction leads to an increased incidence of injury. Recent studies have challenged this showing similar injury rates on artificial turf, which has higher traction than natural grass. This could suggest that the magnitude of traction may not be as relevant for injury as relative changes from one location to another, due to inconsistencies in the surface. The purpose of this study was to compare the traction at various locations on an in-fill artificial turf and natural grass surface. A portable traction tester measured the traction of three shoes at six locations on both surfaces. The results indicate that over the course of a season the traction on natural grass changes considerably, especially rotational traction. Surprisingly the artificial turf surface also had areas of high and low traction due to the movement of the in-fill material during play.  相似文献   

8.
Non-contact injuries in soccer players may be related to the interplay between cleat type and playing surface, and bladed shoes were often blamed for non-contact injuries with no research support. The aim of this study was to compare the rotational resistance (stiffness and peak sustainable torque) among three types of soccer cleats (metal studs, molded rubber studs, and bladed) in a controlled laboratory environment. The shoes were tested on both natural and artificial turfs under a compressive preload of 1000 N and with internal and external rotations. The three shoe models showed comparable performances with a good repeatability for each individual test on both playing surfaces. A less stiff behavior was observed for the natural turf. A tendency toward highest peak torque was observed in the studded model on natural surface. The bladed cleats provided peak torque and rotational stiffness comparable to the other models. Studded and bladed cleats did not significantly differ in their interaction with the playing surface. Therefore, soccer shoes with bladed cleats should not be banned in the context of presumed higher risk for non-contact injuries.  相似文献   

9.
Laceration injuries account for up to 23% of injuries in rugby union. They are frequently caused by studded footwear as a result of a player stamping onto another player during the ruck. Little is known about the kinetics and kinematics of rugby stamping impacts; current test methods assessing laceration injury risk of stud designs therefore lack informed test parameters. In this study, twelve participants stamped on an anthropomorphic test device in a one-on-one simulated ruck setting. Velocity and inclination angle of the foot prior to impact was determined from high-speed video footage. Total stamping force and individual stud force were measured using pressure sensors. Mean foot inbound velocity was 4.3 m ? s?1 (range 2.1–6.3 m ? s?1). Mean peak total force was 1246 N and mean peak stud force was 214 N. The total mean effective mass during stamping was 6.6 kg (range: 1.6–13.5 kg) and stud effective mass was 1.2 kg (range: 0.5–2.9 kg). These results provide representative test parameters for mechanical test devices designed to assess laceration injury risk of studded footwear for rugby union.  相似文献   

10.
The robust design of the mass-produced British football boot from the late nineteenth century onwards appeared to evolve rather slowly compared with subsequent lightweight, flexible ‘continental’ fabrication. However, with careful reading we can identify considerable overlap and influence between manufacturers, distributors and retailers. Boot and shoe manufacturing was an intensely competitive industry and it was in the interests of entrepreneurs to pioneer advances in order to promote a particular brand. In developing football boots for the mass market this may have included much pseudo-science but even small innovations sought to improve performance and market share. Design ambiguities were also inherent because footwear manufacturers routinely borrowed and appropriated successful design elements for their own products. With more choice and consumer demand, football boots became increasingly less adapted from other outdoor footwear owned by the participant, to specialised models manufactured as part of the flourishing sporting goods industry. The internationalisation of the mass market for football boots is here explored though the distinct but related case studies of two family firms; Manfield from Northamptonshire, England and Adidas from Herzogenaurach, Germany. Arguing that there was much continuity between the designs and manufacturing processes of the two firms, the article explores how the design of the football boot became increasingly influenced by the fashion industry as items of conspicuous consumption. By 1954 the launch of the training shoe saw sportswear become a style trend worn on the street, rather than on the pitch. This in turn, influenced football boot design as both a highly technical item of elite sportswear and an expensive, aspirational essential in an everyday kitbag.  相似文献   

11.
Artificial turf advances have enabled surfaces to behave like natural grass, however, debate remains as to whether artificial turf is as safe as natural grass. To reduce injury risk, sport surfaces should have low rotational traction with artificial surfaces having a potential advantage as components can be manipulated to change surface properties and traction. The purpose of this study was to investigate the influence that different components of artificial turf have on rotational traction and athlete lower extremity joint loading. Twelve surfaces underwent mechanical testing to determine the influence of fibre density, fibre length, infill composition and compaction on rotational traction. Following mechanical testing, Control, Low and High Traction surfaces were selected for biomechanical analysis, where sixteen athletes performed maximum effort v-cuts while kinematic/kinetic data were recorded on each surface. Mechanically, fibre density, type of infill and compaction of the surface each independently influenced traction. The traction differences were substantial enough to alter the athlete kinematics and kinetics. Low traction surfaces reduced ankle and knee loading, while high traction surfaces increased ankle and knee loading . Reducing the rotational traction of sport surfaces is possible through alterations of individual components, which may reduce the joint loading at the knee and ankle joint.  相似文献   

12.
The aerodynamics of an American NFL football during an end over end kick were investigated utilizing a custom rotating apparatus and large-scale wind tunnel. Non-rotating lift and drag coefficients were measured and agree well with previous data from other athletic balls and a smooth sphere. The rotation effect on an American football increased both the lift and drag coefficients more dramatically than what has been seen with symmetrical objects over a wide range of rotational rates. The results from this study can be used to more accurately predict the flight trajectory of an end over end kick, and help optimize the balance between kick velocity and rotational speed for a given kicker’s leg strength.  相似文献   

13.
Touch/control football boots are reportedly designed for optimal passing and dribbling. Little research exists on the effect of boot design on touch/control performance and no validated protocol has been developed for assessing passing and dribbling from an equipment focus. This study aimed to assess the effect of upper padding on dribbling and passing performance using a test–retest reliable test setup. Eight university players performed a protocol of dribbling, short and long passing in football boots with 0 and 6 mm of upper padding (Poron foam). The protocol was completed twice; the 0-mm padding results were used for test–retest validation, while the 0-mm versus 6-mm padding results were used to investigate the effect of padding. Dribbling performance was assessed though completion time, number of touches applied and lateral deviation from cones and passing performance through ball velocity and offset from target. The protocol demonstrated good test–retest reliability and indicated no significant differences in any of the 12 performance variables between the 0- and 6-mm padded boots. These findings suggest an element of design freedom in the use of padding within football boot uppers without affecting dribbling or passing performance.  相似文献   

14.
In contrast to the situation with early artificial turf pitches, little information has previously been published on the characterisation of third-generation artificial surfaces. The spatial variation of ball rebound resilience and rotational resistance were measured here under dry conditions, late in the season, for two natural turf football pitches and a recently laid third-generation artificial turf pitch. Data for the natural turf pitches show a wider variation with position on the pitch than for the artificial pitch. The latter surface showed remarkable consistency in both quantities measured. Surprisingly, all ball rebound resilience data and some of the rotational resistance values were found to lie outside current FIFA specifications, possibly due to the level of wear in natural turf at this stage of the season. For the artificial turf, the deterioration in properties over a period of 6 months is significant and suggests more frequent testing is needed. Taking data from various pitch positions, the two measured quantities were shown for the first time, as far as we are aware, to be inversely related for both natural turf pitches. This correlation may be largely attributed to differences in the extent of grass cover and/or soil compaction. For artificial turf, the lack of variation in measured quantities with pitch position precluded the determination of any correlation.  相似文献   

15.
为探究足球训练与认知风格对分配性注意的影响,随机选取足球专项大学生和普通文化课大学生各100名进行《认知方式图形镶嵌测验》,筛选出60名场独立型被试和38名场依存型被试,通过视听双通道实验测量分配性注意水平。结果显示,场独立型大学生中,足球专项大学生的分配性注意水平显著高于普通大学生,场依存型大学生中,足球专项大学生和普通大学生的分配性注意水平不存在显著差异;场独立型大学生的分配性注意水平显著高于场依存型大学生。这表明,足球训练和认知风格对分配性注意水平都有显著影响,可以通过足球训练提高场独立型个体的分配性注意水平。  相似文献   

16.
During tennis-specific movements, such as accelerating and side stepping, the dynamic traction provided by the shoe–surface combination plays an important role in the injury risk and performance of the player. Acrylic hard court tennis surfaces have been reported to have increased injury occurrence, partly caused by increased traction that developed at the shoe–surface interface. Often mechanical test methods used for the testing and categorisation of playing surfaces do not tend to simulate loads occurring during participation on the surface, and thus are unlikely to predict the human response to the surface. A traction testing device, discussed in this paper, has been used to mechanically measure the dynamic traction force between the shoe and the surface under a range of normal loading conditions that are relevant to real-life play. Acrylic hard court tennis surfaces generally have a rough surface topography, due to their sand and acrylic paint mixed top coating. Surface micro-roughness will influence the friction mechanisms present during viscoelastic contacts, as found in footwear–surface interactions. This paper aims to further understand the influence micro-roughness and normal force has on the dynamic traction that develops at the shoe–surface interface on acrylic hard court tennis surfaces. The micro-roughness and traction of a controlled set of acrylic hard court tennis surfaces have been measured. The relationships between micro-roughness, normal force, and traction force are discussed.  相似文献   

17.
The existing knowledge of traction on artificial turf is based almost exclusively on mechanical devices. While most attention has traditionally been concentrated on rotational traction, sports such as soccer predominantly involve translational movements. The aim of the study was to investigate whether translational traction at the shoe-surface interface differed between various third-generation artificial turf systems in combination with different cleat configurations in vivo. Twenty-two male soccer players performed five short sprints with a 90° cut over a turf-covered force plate for each combination of three turf systems and three cleat configurations. The results showed that, despite various differences in other traction measures, traction coefficients were almost identical across turf systems and cleat configurations.  相似文献   

18.
This review study focuses on knee injuries in recreational alpine skiing. The objectives of this study were (1) to provide selected knowledge derived from current and past knee injury epidemiology; (2) to outline the most important knee injury mechanisms; and (3) to review and discuss how modifications of the skiing equipment might alleviate the risk of knee injuries. This review represents the essence of a comprehensive research report and considers the content of more than 230 scientific papers, further “grey literature”, patents, international standards and other publications. Knee injuries are the most frequent injuries in alpine skiing and their incidence rate remained high despite a decline of the incidence of other skiing injuries in recent years. Women have a higher knee injury risk, but age and tiredness appear not to be significant factors. Apart from the commonly described injury mechanisms “phantom foot” and “boot-induced anterior drawer” other more sophisticated injury categorisations are given. The ski radius, the ski length and the standing height on the ski may be relevant ski parameters. For the binding, the release mechanisms in different mechanical degrees of freedom, the impact tolerance and the maintenance frequency are discussed. In the ski boot, the height of the upper, the boot liner, the shaft stiffness, and the position on the ski may play a role. The biggest challenge, but probably also the biggest opportunity for a reduction of knee injury rates seems to be the development of a mechatronic binding. The current strategies to develop these types of bindings are explained and illustrated by one example. Some of the possible parameters which may be essential for the necessary control algorithms are described. Finally, considerations regarding the strategic and operational implication of the analysed technical measures are given.  相似文献   

19.
An articulated boot design is commonly used in skiing and skating sports because it allows sagittal plane ankle mobility while still providing critical frontal plane stability. Although articulated boots have been in use for several decades, current manufacturers of these boots differ in their articulation placement. In this study we determined an optimal position of the ankle articulation axis. We also calculated the amount of anterior skin movement that a boot tongue must account for during a full range of ankle motion. Three-dimensional kinematic data were collected and analyzed from 40 participants moving their right foot through a full range of sagittal plane motion. The calculated horizontal position of the articulation axis was found to be highly predictable from foot length (r = 0.87, standard error of estimate = 3.44 mm), while its vertical component displayed less predictability (r = 0.49, standard error of estimate = 7.46 mm). The expansion required by the boot tongue had a moderate association with foot length and low variability (r = 0.58, standard error of estimate = 0.07 mm). An accurate axis placement will minimize relative motion between the boot cuff and the ankle, reducing friction and motion resistance. An expandable tongue will accommodate full plantar flexion and reduce pressure on the anterior ankle during dorsiflexion, eliminating common pressure-related injuries.  相似文献   

20.
The purpose of this study was to evaluate the traction characteristics of four different stud configurations on Fédération Internationale de Football Association (FIFA) 2-Star, third-generation artificial soccer turf. The investigated stud configurations were hard ground design, firm ground design, soft ground design, and an experimental prototype. The concept of this study combines performance, perception, biomechanical, and mechanical testing procedures. Twenty-five soccer players took part in the different testing procedures. Variables of this study were: running times, subjective rankings/ratings, ground reaction forces, and mechanical traction properties. Statistical discrimination between the four stud configurations was shown for performance, perception, and biomechanical testing (p < 0.05). Unsuited stud configurations for playing on artificial turf are characterized by less plain distributed and pronounced studs.  相似文献   

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