Sunday, March 18, 2018

Injury and Soccer Boots: A brief review

Soccer ranks as a high-risk activity when injury is concerned (Lambson, Barnhill & Higgins, 1996). Each season more and more new boot designs appear yet the number of knee, lower leg, and foot injuries continue unabated. Epidemiological studies indicate adult males are likely to suffer one injury per 167 hours of play; female soccer players are at higher risk with approximately one injury per 147 hours of play (Nilsson, Roaas, 1978; Schmidt-Olsen et al 1985; Sullivan et al 1980). Most injuries are traumatic but there is a high incidence of overuse injuries also reported (6:4 ratio).

Traumatic injuries arise during games more than practice and the risk of injury increases with the playing season. Early injuries tend to prevent the player from regaining and maintaining fitness although position and age has little bearing on occurrence and severity of injury. (Morgan & Oberlander, 2001). The trend for females to suffer moderate injuries is one hundred percent higher than males. Major injuries for both remain the same i.e. between 13 & 14%. (Morgan & Oberlander 2001; Soderman, Adolphson, Lorentzon, & Alfredson 2001). Between 68%-88% of all soccer injuries involve the lower limb (Albert, 1983; Ekstrand, Gillquist, 1983; Engstrom, Johansson, & Tornkvist, 1991; Fried, Lloyd, 1992; Nilsson, Roaas, 1978;Schmidt-Olsen et al, 1985;Schmidt-Olsen et al 1991). The knee and ankle are the most likely to be injured. (Brynhildsen, Ekstrand, & Jeppsson, 1990; Ekstrand, Gillquist, 1983; Engstrom, Johansson, & Tornkvist, 1991; Fried, Lloyd, 1992; McCarroll, Meaney, Sieber, 1984; Schmidt-Olsen et al 1991).

Thought to be the most common occupational injury associated with soccer and reported by as many as 60% of soccer players is Anterior Ankle Impingement Syndrome (or Footballer's Ankle). The condition is caused by either; thickening of the tendon and joint capsule caused by stretching with the downward movement of the foot when the ball is kicked; or alternatively, osteophytic damage (bone) to the ankle joint caused by contact with the ball (Tol, Slim, van Soest, & van Dijk, 2002).

Kicking is the most widely studied soccer skill (maximum velocity instep kick on a stationary ball) and it would appear modern soccer boots provide poor protection to the foot and ankle from a career in kicking the ball.

The incidence and severity of knee injuries has also been significant among football players. The common factor in Anterior Cruciate Ligament (ACL) injuries is foot fixation, which has been described as leading cause of ankle injuries in sport (D'Ambrosia, 1985; Torg, 1982; Torq, Stilwell, & Rogers, 1996) .

The exact incidence of injury attributable to footwear in soccer remains unknown. Association between cleat design and injury rate is however reported within the literature (D’ Ambrosia, 1985; Torq JS Quedenfeld, & Landau,1974). Several specific mechanisms of injury have been described that produce ACL tears and many of these do not involve contact with another player. Instead problems appear to occur from torsional forces transmitted to the knee when the player makes a sudden directional change with a planted foot while decelerating. In the event of physical contact provided the foot can be released from the ground then injury to the ACL can be reduced. It is generally accepted high frictional forces between the foot and the playing surface result in fixation and this fixation is a least partially responsible for knee ligament injuries.

Traditional soccer boots provide traction with the ground, which is critical to a player’s performance, however it is now thought this shoe to surface traction may also contribute to injury. With no traction the player finds difficulty in maintaining balance when turning and twisting or running on wet surfaces. Too much traction permits twisting forces to move proximal on joints above the foot. Application of forces stressing the knee in a plane other than the normal joint motion results in injury if the force exceeds the elastic capabilities of any of the structures being stressed (Torg, Stilwell, & Rogers, 1996). The axial rotation at the playing surface appears to be affected by the magnitude and nature of impact. By the seventies researchers had discovered an association between cleat design and injury. Higher injuries were recorded in conventional shoes with a traditional seven-cleat pattern. The length of the cleats were " 3/4"" long; and "3/8 " in diameter.It was also found the composition of the cleat was a contributory factor. Researchers identified different patterns of injuries between shoe sizes and concluded the smaller distances between the position of studs, across the ball of the foot, might account for a higher magnitude of rotation. As a result of these finding the changes to the games rules have resulted and size restrictions and other restrictions on cleats. According to Levy, Skovron, & Agel (1990) any increase in fixation to the ground increases the risk of injury. Ekstrand & Nigg speculated as much as 60% of all non-contact soccer injuries may be due to excessive shoe surface tension. The conclusion of Bonstingi, Morehouse, & Niehel (1975) was torque developed between playing shoe and surface as a result of a force applied to the leg and an athlete depended on the type and design of the shoe¹s outer sole, the playing surface, the player weight supported, and the foot stance. The reduction of rotational force is thought by many to reduce the rate of injury to the knee. Tests on artificial turf indicate the more pliable the cleat the greater the release coefficient, although this alters with changes in surface temperature. The authors concluded release coefficients both within and among shoe models across a range of turf temperatures. Ironically on artificial turf the researchers found flat-soled basketball shoes performed better than cleated soccer boots did. Of particular concern was the introduction of a design that included round spike cleats on the interior portion of the sole with irregular cleats on the outer rim. Although this design enhanced traction, it was reported when worn by athletes it was also associated with a high incidence of serious knee injuries (Majid & Bader 1993).

A spate of high profile players were reported to suffer stress fractures at the same time lightweight boots were being introduced. Many sports scientists alarmed at the potential risk to players issued health warnings. March fractures of the metatarsal bones are usually fatique fractures caused by over use and not by one off trauma due to serendipidous trauma . High profile players reported with stress fractures of the metatarsals were more likely to be over training and/or have a heavy playing schedule. Injuries in the amateur game continue to be related to inadequate preparation and players not warming up and warming down. Genuine concerns were also expressed when the new generation of cleats were first introduced in particular when some players used them to rip and tear the flesh of opponents .

Some players will risk injury to enhance performance, by chosing inadequate boots and cleat designs. Most amateurs remain oblivious to the risks and there have been calls from concerned consumers for manufacturers to indicate clearly on their labelling the types of playing surface conditions their shoes are meant for. (Heidt et al, 1996). Further, concerns have been expressed at deceptive claims found in marketing sport shoes, according to researchers at McGill University. False notions of protection may lead to a higher rate of injury and this could include claims for improved performance. The majority of career ending injuries involve the knee, ankles and hips with osteoarthrosis (OA) a serious complication. Approximately 2% of professional players are forced to quite the game due to acute injuries. Despite being low this is higher than many other occupations. However there are a larger number of players forced to quit due to chronic injuries sustained and maintained by playing soccer. Further, Drawer, Fuller, & Waddington (2002) recently reported many retired professional players have admitted to playing games whilst unfit or receiving pain killing treatments for existing injuries with the full knowledge of their employer. Osteoarthritis in at least one of the lower extremity joints is very high and significantly greater than in the general population. Health and Safety regulations in the UK now require employers to identify hazards and risks from their work activities and to provide appropriate information and training about the risks. Employers are specifically required to provide health surveillance to employees where significant risk to their health is identified. (Drawer, Fuller, & Waddington 2001). By this token employers are now responsible for players suffering from industrial related injury which prevents them from earning a living. Published studies clearly indicate the provision of injury prevention and socio-economic services at professional soccer clubs (UK) remains inadequate and there are now calls to develop a long term strategy for managing players forced to retire through injury. The UK Industrial Injuries Advisory Council (IIAC) has so far dismissed these claims and refused to accept OA of the knee due to soccer is a boni fidi industrial injury and has refused to include it in the Industrial Injuries Scheme under Contributions and Benefits Act (1992). The IIAC are currently considering OA of the hip.

Albert M 1983 Descriptive three year data study of outdoor and indoor professional soccer injuries Athletic Training 18 218- 220.
Bonstingi RW, Morehouse CA, Niehel BW 1975 Torques developed by different types of shoes on various playing surfaces Med Sci Sports 7 127-131.
Brynhildsen J, Ekstrand J Jeppsson A 1990 Previous injuries and persisting symptoms in female soccer players Int Journal Spots Med 11 489-492.
Bucher S. 2002 Unplublished thesis. Northampton: Nene College.
D'Ambrosia RD 1985 Orthotic devices in running shoes Clinical Sports Medicine 4 611-618.
Drawer S, Fuller CW, & Waddington I 2001 Propensity of osteoarthritis and lower limb joint pain in retired professional soccer players British Journal of Sports Medicine Dec 35:6 402-408.
Drawer S, Fuller CW, & Waddington I 2002 Perceptions of retired professional soccer players about the provision of support services before and after retirement British Journal of Sports Medicine Feb 36:1 33-38.
Ekstrand J, Gillquist J 1983 Soccer inuries and their mechanisms: A prospective study Med Sci Sports Exerc 15 267-270.
Ekstrand J, Nigg B 1989 Surface related injuries in soccer Sports Medicine 8 56-62.
Engstrom B Johansson C Tornkvist H 1991 Soccer injuries among elite female players Am J Sports Med 19 372-375.
Fried T, Lloyd GJ 1992 An overview of common soccer injuries: Management and prevention Sports Med 74 269-275.
Grau S 1997 Quo vadis sport-shoes? Wish and reality of preventing injuries through sport shoes Third Symposium on Footwear Biomechanics, Tokyo 1997 International Society of Biomechanics
Heidt RS et al 1996 Differences in friction and torsional resistance in athletic shoe turf surface interfaces Am Journal of Sports Medicine 24:6 834-842.
Heidt RS, Sweeterman LS, Carlonas RL, Traub JA, X F 2000 Avoidance of soccer injuries with preseason conditioning American Journal of Sports Medicine 28:5 659-662.
Lambson R Barnhill BS Higgins RW 1996 Football cleat design and its effects on anterior cruciate ligament injuries: A three year prospective study American Journal of Sports Medicine 24:2 155-157.
Lees A & Nolan L 1998 The biomechanics of soccer : a review Journal of Sports Sciences 16:3 211-234.
Levy IM, Skovron ML, Agel J 1990 Living with artificial grass: A knowledge update Part 1: Basic science American Journal Sports Med 18 406-412.
Lineker G & Hey S 1998 Gary Lineker's golden boots: The world greatest strikers 1930-1998 London: Hodder & Stoughton
Luhtanen P 2002 Soccer: Biomechanics of soccer equipment Faculty of University of Edinburgh
Lambson R Barnhill BS Higgins RW 1996 Football cleat design and its effects on anterior cruciate ligament injuries: A three year prospective study American Journal of Sports Medicine 24:2 155-157.
Majid F & Bader DL 1993 A biomechanical analysis of the plantar surface of soccer shoes Proceedings Instn Mechanical Engineers 207:2 93-101.
Martin DR 1997 How to steer patients toward the right sport shoe The Physician and Sportmedicine 25:9 138-140
Masson M Hess H 1989 Typical soccer injuries: Their effects on the design of athletic shoe In Segesser B & Pforringer W (eds) The shoe in sport London: Wolf Publications 89-95.
McCarroll JR, Meaney C, Sieber JM 1984 Profile of youth soccer injuries Physician Sportsmed 12:2 113-117.
Morgan BE Oberlander MA 2001 An examination of injuries in major league soccer: The inagural season American Journal of Sports Medicine July/Aug 29: 4 426-430.
Nilsson S, Roaas A 1978 Soccer injuries in adolescents Am Journal Sports 6 358-361.
Schmidt-Olsen S et al 1985 Soccer injuries of youth British Journal of Sports Medicine 19 161-164.
Schmidt-Olsen et al 1991 Injuries among young soccer players American Journal of Sports Medicine 19 273-275.
Soderman K Adolphson J Lorentzon R Alfredson H 2001 Injuries in adolescent female players in European football: a prospective study over one outdoor soccer season Scandanavian Journal Medical Science Sports 11:5 299-304.
Sullivan JA et al. 1980 Evaluation of injuries in youth soccer Am Journal Sports Med 8 325-327.
Tol JL, Slim E, van Soest AJ, van Dijk N 2002 The relationship of the kicking action in soccer and anterior ankle impingement syndrome: A biomechanical analysis American Journal of Sports Medicine Jan /Feb 30:1 45-50.
Torg JS 1982 Athletic footwear and orthotic appliances Clin Sports Med 157-175.
Torg JS & Quedenfeld T Effect of shoe type and cleat length on incidence and severity of knee injuries among high school football players. The Research Quarterly 42:2 203-211.
Torq JS, Quedenfeld TC, Landau BS 1974 The shoe surface interface and its relationship to football knee injuries J Sport Med 2 261-269.
Torq JS Stilwell G, Rogers K 1996 The effect of ambient temperture on the shoe surface interface release coefficient American Journal of Sports Medicine 24:1 79-80.

Wednesday, March 14, 2018

Soccer boots: The power of player endorsement

Legend has it that Pele was paid $125,000 for his deal to wear the boots starting with the 1970 World Cup. The contract was sealed in the final between Brazil and Italy when Pele asked a referee for a moment so he could tie his shoe guaranteeing that the TV cameras were pointed at his Pumas.

Professional players now use boot companies as significant means to increase their off the field earnings and will be associated with those who pay well as opposed to the producers of the best shoes. No sportsperson alive would ever disadvantage themselves by sporting inferior footwear so discerning consumers are left to conclude not one branded shoe is better than another. Although one cautionary note here is for the best in the world have their shoes purpose made for them as opposed to the pair you and I will buy over the counter.

Signature shoes i.e. football boots fully personalised with either their name, initials, number or club logo embossed on the boot, are now common place and the ultimate status symbol for stars of the soccer field. In the past the standard way for football boots to be identified has always been the black permanent marker pen, ugly and not very professional. Many retailers now offer various options and colours to personalise football boots by using the very latest embroidery machinery. These are now found across all sports but rarely draw much official attention as long as they comply with the game’s regulations. There was some controversy in the past when conflict between team sponsors and the individual’s desire to self promote their own products. In the FIFA World Cup 2006 (Germany) rivalry between the key sportswear manufacturers, inevitably led to banning of all footwear other than those endorsed by the team’s sponsors. In Germany, the squad was sponsored by adidas and team members were told they must wear adidas boots otherwise they would not play. The German national soccer coach had to remind his players the equipment contract stated players must be completely kitted out in adidas gear. The contest has intensified since FIFA changed the rules and now footwear is the only piece of major equipment that does not have to be produced consistently by the same manufacturer. Team shorts and shirts are contracted to a specific company but individual players are free to wear the shoes they want, even if they are made by the rival of their shirt company.

According to Repucom’s Celebrity DBI tool which measures the perceptions of over 6,500 people in 13 international markets, representing the views of more than 1.5 billion people. The top three most marketable players in the world are: Portugal’s Cristiano Ronaldo who has an estimated $(US) 9.5m per year deal with Nike; Argentina’s Lionel Messi ; and Spain’s Gerard Piqué . Companies use celebrity endorsement to sell their product because it helps create in the ind of the consumer a strong emotional connection with a brand. Global awareness of an indivudual like Ronaldo.

Given the huge amounts of money at stake it is no surprise shoe companies do almost anything to attract people’s attention to their products. After all there is no doubt a pair of fluorescent boots stand out a lot more than staid black. Stars like Ronaldo,Messi, Neymar and Balotelli are paid undisclosed amouts to wear the shoewear of Nike, Adidas and Puma etc., Each company will do their very best to have their product stand out.

If you were to believe the sale rhetoric company revolutionary technological advantages with each new line of soccer boot. In truth the dominating companies supply similar product as in light weight soccer slippers with emphasis on tread and grip and an uninterrupted sweet spot. New polymer technologies and knitted fabrics are combined to give a comfortable foot protection which in the main withstands the rigor of all weather competition. Soccer shoes are available in high colourways for no other than reason than to sell shoes. The shelf life of a particular model is short (approximately 3 months) and replaced by the next fad. In true consumer traditions of the new line has no real advantage over its predecessor other than it has a different colour or incorporates novelties such as knitted ankle warmers or different coloured boots. Most consumers remain brand loyal, whilst others seek out justification from the marketing techo-gobbledygook, why they must have the latest pair.

The FIFA World Cup™ is the biggest single-event sporting competition in the world. Previous records indicate 715.1 million people watched the final match of the 2006 FIFA World Cup held in Germany and the 2010 event in South Africa was broadcast to 204 countries on 245 different channels. 3.2 billion people watched the 2014 FIFA World Cup™ world wide. Global events of this nature provide unique selling opportunity which commercial multi-nationals take full advantage. Players and clubs are routinely sponsored by soccer requisite suppliers and derive considerable income from this source. However it is the skill of the player, and not the calibre of boot that wins the glittering prizes. Marketing experts have more or less accepted this and subsequently reteric in more recent years gives greater reliance to personal endorsements. As with all things high profile there is at least a couple of problems with player endorsements, or at least risks to the sponsor as well as the endorser. Sponsoring a known personality may attract fans to the product but to those potential customers who do not like, or identify with, the personality then it becomes instantly less attractive. This is especially the case if the boot has direct reference to those who endorse it i.e. a signature boot. Companies also have an added problem if their player signs with a club which has a rival logo on the shirt, socks and shorts. Throughout his career Cristiano Ronaldo remains the ideal ambassador for the game.

Somethimes through no fault of their own players become embroiled in controversial circumstance associated with their sponsor's human rights policy's and or use of animal skins. English internationalists, David Beckham and Michael Owen were previously the target of animal rights activists because the boots they endorsed were made from kangaroo skins. Other time the bad behaviour of players on and off the field cause much concern to sponsors and whilst a degree of notoriety may enhance the commercial value of players anti-social behaviour can have a delitarious effect on sales.

In an unpublished thesis by Butcher (2002), a survey of buying habits of players indicated professional footballers did look for specific features in the choice of their footwear whereas amateur players bought their favourite brand and or were more likely to be influenced by the brand of their favourite player. Hence the marketing of boots continues with more and more spectacular stunts to entertain the discerning and attract the unwary.

Butcher S. 2002 Unplublished thesis. Northampton: Nene College.

Saturday, March 10, 2018

A short history of the Referee's Whistle

In the early games of soccer, disputes were settled by the two captains and because it was a gentleman’s game an umpire was not required. Once association rules were established and competition began in 1872 each team appointed an umpire. The two gentlemen ran about the pitch keeping an eye on play. They had no right to interfere with the game in progress but could be "appealed to" by the players, just as in the game of cricket today. Umpires signaled any infringement using a handkerchief and were given the power to award a free kick for handball in 1873 and for other offences in 1874. In the same year umpires could send a player off for "persistent infringement of the rules". In the event of a disagreement between the two umpires the game's timekeeper would arbitrate. The Nottingham Forest account book of 1872 recorded the purchase of an “umpire’s whistle.” Since referees were not allowed onto the field until 1891, the whistles were used by the umpires (Ruck 1928). It is likely Hudson’s pea whistle made of brass was used.

After a major restructuring of the laws in 1891 referees were finally allowed onto the field of play in the season 1891/92. Henceforth the two umpires acted as linesmen then later as assistant referees. The referee had the power to caution players who were guilty of ungentlemanly conduct, without consulting the umpires (though any such caution was made with the umpires present). If a player continued to transgress, or was guilty of violent conduct, the referee could send him off and report him, even if the player them offered an apology. They were allowed to award a free kick for foul play without waiting for an appeal. It is more than likely the whistle was introduced to soccer at this point. It is recorded William Atack, a referee from New Zealand, was reportedly the first referee to employ a whistle to stop a rugby game in 1884.

In 1860 tool maker Joseph Hudson (1848–1930) had an accident with a violin which he dropped. He became fascinated with the perfect sound created when the bridge and string broke. Determined to replicate the sound he developed a pea whistle. Hudson started to manufacture the ACME Whistle Company (based at Mills Munitions Factory, Birmingham) in the 1870s. In 1883 he invented a distinct sounding whistle for the Bow Street Runners which could be could be held in the mouth leaving the hands free. The Police whistle could be heard over a mile away and was adopted as the official whistle of the London Bobby.

A pea-style whistle gets its shrill from the movement of the small cork pea in its interior, which alternately covers and uncovers the hole through which air is released. This process produces a rapid alternation of sound and silence, the characteristic whistle vibrato until the pea gets stuck in the hole. Movement of a small ball enclosed in the whistle's air chamber produces the familiar trilling effect now commonly associated with referee whistles.

Early attempts in 1906 to produce molded whistles from a material known as vulcanite were unsuccessful. By 1914 Bakelite was used to mold the first plastic whistles but the metal 'Acme Thunderer' still was preferred. An improved version was produced in 1920. Designed for use in big crowds, it was smaller, shriller and with its tapered mouthpiece. This whistle may well have been used in the first Wembley Cup Final in 1923 between Bolton Wanderers (2) v West Ham United (0). The Model No. 60.5 is still available today.

For even greater power and a higher pitch in noisy stadia, the 'Pro-Soccer' whistle, first used in 1930, had a special mouthpiece and barrel. The modern version is still popular. The whistle was not mentioned in the Laws of the Game until 1936 when an IFAB Decision was added as footnote (b) to Law 2, stating "A Referee's control over the players for misconduct or ungentlemanly behaviour commences from the time he enters the field of play, but his jurisdiction in connection with the Laws of the Game commences from the time he blows his whistle for the game to start."

The Fox 40 "pea-less" whistle originated from an idea by Ron Foxcroft a USA basketball referee in 1987. He had experienced a common problem with pea whistles not reacting quickly enough, and not being able to be heard above a large crowd noise. The cork pea whistle may fail to operate in the extreme cold and wet and often the inside of the whistle clogs with dirt. Foxcroft designed a pealess whistle which works simply by routed air pressure.

The Fox 40 whistle was patented and now rivals ACME. It was first heard at the 1990 FIFA World Cup Italy.

Referees in the 1998 FIFA World Cup used the pealess (airfast) Tornado 2000. This is considered to be the world's most powerful whistle. In FIFA World Cup Korea Japan 2002 the referees had a free choice of whistles No surprise to learn most choose to use the whistle they most use in their general games. Modern whistles made from different plastics produce a wide range of tones and sounds. The design of the mouthpiece can also dramatically alter the sound. Even a few thousandths of an inch difference in the airway, angle of the blade, size or width of the entry hole, can make a drastic difference as far as volume, tone, chiff (breathiness or solidness of the sound) are concerned.

Most referees carry two whistles, one for regular game play and a second as a backup or safety whistle. The second whistle usually has a different pitch or tone, and is usually a different color (often color-coordinated with the uniform). Referees use a whistle to help in match control. The whistle is sometimes needed to stop, start or restart play but should not be used for all stoppages, starts or restarts. FIFA’s Laws of the Game document gives guidance as to when the whistle should and should not be used. Overuse of the whistle is discouraged since, as stated in the Laws, “A whistle which is used too frequently unnecessarily will have less impact when it is needed." The International Football Association Board (IFAB) in 2007 greatly expanded the Laws of the Game Additional Instructions section, a full page of advice on how and when the whistle should be used as a communication and control mechanism by the referee became available.

Ruck RM (1928) Footbal in the early “seventies” Royal Engineers Journal xlii
Thomson G. (1998)The Man in Black - A History of the Football Referee

Further Sources
History of the Whistle Ken Aston
ACME Whistles Obsessionistas Design Archive: ACME Whistles
The Whistle Museum

Tuesday, February 27, 2018

Evolution of football boots: From engineer's boot to soccer slippers

In the early days football boots weighed approx. 500 grams when dry and twice as much when wet. Manufacturers when made aware player’s boots were only in contact with the ball for about 10% of the game developed less heavy boots. Lighter footwear meant players were less exhausted and subsequently the overall speed of play increased. This made for a more enjoyable spectator sport. By the early 50's the soccer boot was streamlined with the ankle hugging component reduced to below the malleoli (ankle bones).

Initially this met with some concerns about ankle injuries but proved ill founded. The traditional soccer boot was now a slipper or soccus. Leather soles were first replaced by molded rubber, then injection molded PVC, before nylon and plastic prevailed. The new synthetic materials were waterproof, cheap to produce and substantially lighter than leather. The upper of the slipper became thinner and improved treatment of leather with synthetic waterproof compounds contributed to the development of the new styles. Development of latex foam, meant the soccer shoe could be cushioned with no detriment to overall mass and new lightweight synthetics were stronger and harder wearing than traditional soles. By the 60s the overall weight of the new era of boots dropped significantly.

The physical properties of kangaroo skin were recognised very early in the 19th century and most quality sports footwear was made from marsupial's skin. This tradition has quietly continued in soccer shoes and now most quality shoes are made from medium brown, vintage kangaroo leather. This is a name given to the process of tannage (preparing the leather) and often the leather is dyed to popular colours. Kangaroo hide is the toughest and most durable available and been used to produce quality sports shoes for rugby, American football, baseball, basketball, tennis and cycling shoes for over a century. It is lightweight yet very strong and many times stronger than the same thickness of cowhide. Comfortable and supple it requires no break-in period and gives the player a tight fit with optimal feel for the ball. Suitably treated Kangaroo leather is favoured because of its high performance nature. Kangaroo leather has a naturally high strength-to-weight ratio. In the 80's, Australia's CSIRO undertook independent tests which confirmed these findings and determined that, when shaved to 20% of its original thickness, kangaroo leather retains between 30% and 60% of its original tensile strength, as compared to a retention rate of 1% -4% for calf and bovine leathers. In a further study by the CSIRO, it was found that kangaroo leather was at least 50% stronger than goatskin gloving leather in tear strength and puncture resistance. Microscopically the hide displays high uniform orientation of fibre bundles in parallel with the skin surface. The skin of the Kangaroo does not contain sweat glands or erector pili muscles, which would weaken the skin surface. The yellow elastic fibres (elastin) are evenly distributed throughout the skin thickness which gives the leather greater tenacity. These properties remain even when the leather is split. Tanning further enhances the leather's properties by unsticking the fibre bundles thereby allowing them to move independently.

From time to time animal rights activists have brought the use of kangaroo skin to the public's attention by condemning players like David Beckham, who initially endorsed their use. Reputable firms collect kangaroo hides during the Kangaroo Harvest and agencies such as Environment Australia - Wildlife Protection regulate and control the harvest and manufacture of all kangaroo leather. There are several tyoes of kangaroo and only non-endangered species can be used for the clothing industries. Public concern however encouraged development of the pleather industry and many top quality boots now incorporated plastic polymers as an alternative to animal leathers.

According to Grau (1997) the focus of boot research from the 70s was primarily directed at anti-pronatory control (preventing the foot from rolling over). This was combined by using cushioning mechanisms to damped shock to the foot. Later researchers looked at torsion and pressure distribution across the foot. Initially it was wrongly assumed overloading of the weightbearing foot was the primary cause of most injuries. This research led to shoe design thought to cope with the problems but the number of reported injuries did not decrease. Moreover it seemed, in retrospect, many reported injuries arose as a result of the injury preventing solutions in boot design. Many injuries are attributed to adverse physical conditions at the interface between the soccer shoe and the playing support surface. No shoe can ever guarantee full protection against serendipitous injury. The function of the soccer boot provides both a means of attachment to the playing surface whilst encasing the foot for protection. The maintenance of static balance for a player performing an individual skill demands a significant level of torque. Excess torque or twist passes proximally through the foot pedestal to damage the ankle or knee. During contact, a static foot anchored to the ground negates its ability to dampen down (shock absorb) external forces, such as caused by contact with another player. The ankle and knee then have to absorb the energy of impact; alternatively torque within the short bones of the foot may cause them to fracture. This type of incident was illustrated by injury to England's captain David Beckham during the FIFA World Cup Korea Japan 2002 game against Sweden in the opening round.

Grau S 1997 Quo vadis sport-shoes? Wish and reality of preventing injuries through sport shoes Third Symposium on Footwear Biomechanics, Tokyo 1997 International Society of Biomechanics.

Saturday, February 24, 2018

A brief history of Shin Guards

Shin guards first made an appearance in 1874 and were made from large cricket pads to protect the front of the leg. As the speed of the game increased these grew smaller and many players discarded them altogether. Tired players preferred to play out the later stages of the games with their socks rolled down. This prevented cramp and gave them extra freedom. However the rules of the game no longer allowed this.

(Law No. 4- The Players Equipment Each player is required to wear a jersey or shirt, shorts, socks, shin guards and shoes. Socks must completely cover the shin guards. Goalkeepers must wear a color different from either team or any official. No player may wear any item that could cause danger, including any type of jewelry.) International Football Association Board (IFAB).

Cricket was the first sport to adopt the use of shin guards. Shin guards are used to cover what ever part of your shin is most susceptible to pain. Shin guards were made of leather and aluminum covered in cloth for extra protection. Initally shin guards gave an unfair advantage to the batsman because his leg pads covered the stumps. In 1809 the leg before wicket rule was introduced and the umpire could deduce whether a ball would have hit the stumps if the batter was not hit first. Leg pads became more popular as protective measures against the impact from the ball and are worn by the batsman, the wicket-keeper, and the fielders that are fielding in close to the batsman.

Sam Weller Widdowson (1851 -1927) was a cricketer and footballer and cut down a pair of his cricket shin pads and strapped them to the outside of his stockings using straps of leather in 1874. At first he met with derision from fellow players but shin guards eventually caught on as players saw the practical use of protecting their shins. Nottingham forest was the first team to wear shin guards. These products are the only protective covering permitted for players in football soccer game. After the application of shin guards in association football, they quickly spread to other sports and are now considered necessary for most contact sports.

There are a two basic types of shin guards used in soccer i.e. slip-in shin guards and ankle shin guards. Different player positions use shin guards to provide different types of protection and fit. Defenders need a heavier shin guard with extra ankle protection. Midfielders need protection, but also need to be able to move freely. Forwards need a light shin guard with protection and ankle support. Goalkeepers can wear a light shin guard with minimal protection.

Modern day shin guards are made of many differing synthetic materials. The properties of individual materials and combinations give specific function such as weight, strength, comfort, durability and resistance to impact. Modern shin guards are made with a hard outside casing and a soft inner layer. Outer surface is crafted in thermoplastic materials with shock absorbing inner material made from Ethyl Vinyl Acetate (EVA) or other foam type material. Shin guards do not absorb large quantities of energy and so are unlikely to prevent bone fractures from high energy type trauma.

Shin guards protect by spreading impact loads over wider areas of the skin. The force of the initial impact is reduced as peak pressure is dampened down. The properties of the materials display energy absorbing characteristics, which further protect the player's leg from injury.

Adidas is known as a leader in design and protection, but other names, such as Umbro, are known for comfort, and many people like Estero. From novice to expert, shin guards are an important piece of safety soccer equipment.

Wednesday, February 21, 2018

History of Studs & Cleats

The ability to play on different surfaces was recognised early on and hence the sole of the boot needed to offer resistance or ground traction. At first the metal tacks on engineer's boots were used, but Rule 13 meant greater care needed to be taken. Eventually leather cleats (or studs) replaced these.

By the twenties Adi Dassler had developed replaceable studs which firmly established his credentials as soccer boot specialist in Germany. The length of studs was governed for in 1951. When new polymers became available natural materials were replaced by synthetics. The idea for molded studs had been tried on hockey boots and when they were transferred to soccer boots a new revolution took place. Today plugs and cleats of variable length are used.

Soccer boots should afford confident contact with playing surfaces as well as adapt optimally to all types of surfaces and weather conditions. On hard surfaces, including hard natural turf, cleats of different configuration are recommended. On softer turf or wet ground surfaces shoes with detachable studs with varying length provide the best anchoring to the ground. On snowy surfaces other configurations are necessary and rubber studs preferred. Icy surfaces again demand a different sole configuration. Traditionally, Bootmen were retained by professional clubs and oversaw the maintenance of the football boots, usually via the apprentices.

One of the most famous soccer apprentices and bootboy was Rod Stewart (Bentford FC).

Using their previous experiences as players with a command for the game Bootmen advised the young players on the type of boot for the weather conditions. The Boot Room a place where the game strategy was worked out and the most famous Boot Room was at Liverpool FC under the direction of Bill Shankly. (Bootroom Boys: Ronnie Moran, Roy Evans, Bob Paisley, Tom Saunders, John Bennison & Joe Fagan)

Bt the beginning of the New Millenium tread patterns changed to incorporate curved cleats set into circular arrangements. The circular arrangement facilitates better grip in all directions and faster acceleration from the playing surfaces. Greater emphasis was given to the base area across the ball of the supporting foot, which reduces peak pressures on the soles of the feet over a long game. Cleat designs now allow the foot carrying the player's weight to pivot when the player twists or is struck by another player. This helps reduce injury form direct trauma. Further the anti-torque property offered by the circular configuration of compressible teeth (cleats) is thought by the designers to reduce rotational injuries to the knee and ankle.

As the game has improved and the demands of professionalism become a primary focus the number and types of injury recorded have increased. These in no short measure have been associated with boot design (Masson & Hess, 1989). Traditional conical cleats have been cited as the main cause of such injuries and lock into the turf. It was recognised as far back as 1948 that heel cleats were responsible for foot fixation and this contributed to knee damage in soccer players. The principle functions of cleats was to offer resistance next to the ground by holding the foot stable as the body's centre of mass passed over it. One major disadvantage is if the cleat fixed too firmly to the ground then damage to the musculo-tendonous, ligamentous, cartilaginous, or osseous structures of the joints may occur. When the foot was fixed by impact or rotation of the body, these corkscrew forces passed upwards to the knee and were thought to damage the joint and its peripheral attachments. Attempts were made to design a more useful sequence of cleats for heels and forefoot but in the absence of molded soles this meant few players were aware of them. According to Torq & Quedenfeld, there were two factors, which determined foot fixation and these are the number and the size of the cleats. The authors were able to show in a retrospective study of football injuries, players wearing cleats were less likely to suffer knee injury. (The shoes with molded soles containing fourteen, 3/8 inch cleats. Minimum cleat tip diameter of 1/2 inch and maximum cleat length of 3/8th inch.)