Technology in modern football boots
During a match, footballers are not allowed to wear any technological devices except… their boots! It is difficult to imagine the amount of research, testing, and technology that goes into this accessory. A football boot has to have several qualities, which are not always compatible with each other.
The athlete is running, sometimes very fast, on the ground that may be uneven, slippery, and muddy. He changes direction abruptly. He shoots the ball with force, but also with precision, sometimes with effect. The football boot must be able to cope with all these actions, but above all, it must protect feet that can be worth millions of euros.
For many decades, a football boot was a simple black leather boot with studded soles to increase grip on the ground. The upper was made of calf or kangaroo leather, which was more expensive but soft and durable. The revolutionary screw-in studs were introduced in 1954 for the World Cup final between Germany and Hungary. The same year saw the end of the high boot in favor of a low boot.
Today’s boots have almost nothing in common with their valiant predecessors, the leather boots. Technological developments, but also marketing demands, have turned them into a colorful scientific application. Companies spend a considerable amount of money on the design of a new model, which can exceed one million euros.
To begin with, the materials used have changed radically. Although calf or kangaroo leather is still sometimes used, most of the high-end models are made of microfibre. This is a composite material, made up of polyester filaments embedded in a polyurethane matrix. Compared to leather, this solution has the advantage of being lightweight, as a microfibre boot can weigh less than 200 grams. Microfibre is also a water-repellent substance, which means that you don’t end up with waterlogged shoes in bad weather, and it is easier to color than leather.
A technological development that can make all the difference
The sole is usually made of polyurethane with carbon fiber inserts for added strength. The studs are immersed in the sole during the molding process. The number and length of spikes vary depending on the type of game. In addition to the traditional conical studs, there are now triangular, lamellar, comma-shaped, and even pivoting studs. This variety is due to the different nature of the playing field, which can be artificial or natural, dry, compact, or greasy. The studs must provide a good grip on the ground without blocking the foot excessively, to avoid distortion and other injuries.
To study the behavior of boots, sports engineers have invented systems that seem to come straight out of the laboratories of Géo Trouvetou or Professor Tournesol: for example, the boot to be tested is mounted on an aluminum leg driven by an electric motor, which shoots a ball thousands of times at a controlled speed. The speed imparted to the balloon can reach 150 km/h! This machine is also used to test the behavior of balloons. To observe the interaction of the boot with the ground, a sort of small tractor is used. As the tractor moves forward, two rollers bring the soles and studs into contact with the ground (in this case synthetic grass), to check the grip and wear of the materials used.
The connected football boot
A chip with an inertial platform and onboard memory is inserted into the sole of the boot. The chip acquires data on the player’s movement and calculates the speed, the number of kilometers covered, the frequency of acceleration, etc. It then transfers this data to a computer. It then transfers this data via wireless technology to a computer or handheld device. The data collected in this way can even be assigned to a virtual player to make the dream of every little footballer in the world come true: to go out on the pitch with their favorite players.