It's now nearly 20 years since Craig Johnston changed the appearance of football boots forever. While most players who retired in the 1980s used to buy a pub or sports shop, the Australian midfielder who was part of Liverpool's 1986 double-winning squad instead turned his hand to innovation.
Johnston had been coaching kids in Australia when he hit upon his big idea to attach rubber strips from a table tennis bat to the forefoot of his boots, instantly improving the amount of spin and power that could be applied to the ball. Having finally convinced adidas – by calling in German World Cup-winning legends Franz Beckenbauer, Karl-Heinz Rummenigge and Paul Breitner – to test out his prototype for a promotional film, the "Predator" was an instant success when it launched in 1994.
Within two years the new boots also featured Johnston's pioneering "Traxion" soles that were a hybrid of traditional studs or cleats and blades, which enabled a player to turn in tight spaces and at high speed. Yet even as global superstars including David Beckham, Jonny Wilkinson and Zinedine Zidane ensured that Predators became the must-have item for a generation of schoolboys, their creator was growing increasingly concerned.
Johnston sold his patents to adidas for a significant fee in 1998 but left them with a warning that the never-ending quest for improved performance through new technology was becoming increasingly hazardous.
"As I was in the process of selling up, I told them about my fears that the way these boots were developing could become dangerous for players' health," Johnston, who now lives in Florida, remembered this week. "The studs were getting deeper and started to be made out of a different plastic which was basically a Pebax plastic material. When the ground is a bit sandy or there are rocks in the soil, they tended to sharpen up the plastic cleats and they became like lethal weapons. I even told the Fifa doctor when we had lunch together four or five years ago that they had to do something about the materials and the shape of all the new cleated configurations."
Since the turn of the century, there have been numerous injuries caused by blades or hybrids to back up his theory. In 2002, Burnley striker Andy Payton was forced to retire after needing 38 stitches in his leg – "It was like a carving knife slitting it open," he said last year. Gillingham player Andy Hessenthaler had suffered a similar injury the year before, with a cut so deep he reported that he could fit a whole mobile phone inside it, while last month 13-year-old schoolboy Kavan Ryan was rushed to hospital with a 10-inch gash sustained in a youth match in the Midlands.
But while Sir Alex Ferguson went as far as banning blades at Manchester United in 2005 after he claimed they were responsible for Roy Keane breaking his foot and several junior leagues around the country followed suit, it wasn't until Wayne Rooney suffered a horrific gashed leg against Fulham last year that the problem was once again highlighted on the big stage. In the immediate aftermath of that incident, PFA chief executive, Gordon Taylor, called for tighter regulations and raised the issue in a meeting with the FA's Medical Committee, although no action was taken.
"Bearing in mind some of the nature of the accidents there have been I feel it is incumbent on us to have some kind of measure of regulation and a Kitemark," Taylor said.
"They've been forewarned with the potential dangers and we should be doing all that we can to protect against this problem."
The International Rugby Board introduced law 4.3 last summer stating that "studs/cleats of player's boots must...not be longer than 21 mm, and must not have any burring or sharp edges". Now Johnston believes it is time football followed their example.
"The geometry and the depth of the cleat has got to be formalised, regulated and deemed safe. And they have to change the material used because it's dangerous," he added.
"Mass production of these boots means that it's drifted to the cheaper kind of plastic compounds, which tend to fray around the edge and become very sharp. There have been so many incidents in the professional game but we can only imagine how many there are every weekend involving kids in local parks that never get reported."
There have also been concerns that some new-style boots have contributed to an increase in serious foot, ankle and knee injuries among footballers. "You've got much more powerful players and the forces coming through their body are just too much to take, so what happens is the most vulnerable part has to give, which is usually a knee ligament or the metatarsals.
"The problem is not going away," Johnston added. "Players have adjusted and are a bit more careful. But it's still an accident waiting to happen."
A slice of history: Injuries timeline
July 1996 Adidas release the first boots with bladed studs – known as a Traxion soleplate.
Feb 2001 Sunderland youth team goalkeeper Craig Turns needs 33 stitches after a bladed boot slices his face open.
Jan 2005 Sir Alex Ferguson bans bladed boots at Manchester United after a series of injuries.
Apr 2005 Annan Athletic goalkeeper Charlie McCulloch comes close to losing an eye when his head is sliced open. He needs 16 stitches and is scarred for life.
Oct 2008 Accrington Stanley call for blades to be banned after losing both Phil Edwards and Ian Dunbavin to gaping leg wounds which needed stitches.
Aug 2012 Wayne Rooney needs 10 stitches after being caught by Fulham's Hugo Rodallega.
Aug 2013 Rooney again needs stitches after his head is sliced open by Phil Jones' boot in training.