Olympic Shoe: Technology War

26 bones, 33 joints, 20 muscles, more than 100 ligaments, thousands of nerve endings and blood vessels.

As Da Finch said, human feet are the masterpieces of art and engineering.

After standing upright in the African steppe by our ancestors, we completely gave our weight to our feet, so that it could bear twice the load than the quadruped animals.

Although there are tons of research reports coming out every year, we still do not yet fully understand the delicate relationship between legs, feet, shoes and ground under different sports conditions.

Shoes are uncomfortable, only the toes know.

Two little motors

Early canvas vulcanized rubber soles, heavy metal balls almost straight forward, soccer shoes in Berlin Olympics, Owens's running shoes, flying Jordan air cushion shoes, Stan Smith tennis shoes, Lewis's ceramic spikes, Jones's "crystal shoes", Johnson's "golden shoes" and Liu Xiang's "red magic shoes".

The history of sports shoes leaves behind the footprints of Science in an era.

Today's Olympic Games are no longer low tech sports, and the "faster, higher and stronger" Olympics have become "more scientific".

Although sports shoes are full of beautiful things, the basic principles are basically the same.

Its primary function is to absorb shock from the ground.

When the running speed of a person reaches 6 meters per second, the load on the sole is about 4 times that of the weight, and the increase in the jump is 7 times. In the three jump, the impact of the two feet is directly and hard on the two side. The impact force reaches 20 times the weight, and the strong oscillation will spread to the ankle, the knee and the hip to the spine and brain.

Thanks to our heel fat pad and natural "spring system" arch to resist this kind of injury effectively.

Modern sports shoes put a material with high "pressure and compliance" into the heel of the shoe, allowing it to absorb impact kinetic energy through its maximum deformation.

In addition, some sneakers make a "waffle" shape from the undersole, and some rubber pillars and air cushions are placed in the sole to play the role of the damping spring on the chassis of the vehicle.

When a basketball player jumps up and the foot of a track athlete gets wind, a good pair of shoes is like two small motors.

The second function of sports shoes is to pmit energy.

The PU and other microcellular foaming materials on the sole of the feet are highly elastic. The soles can release and store the absorbed and stored energy back to the sole of the feet when they are compressed and deformed.

In the process of repeated stretching, it is like stepping on a miniature springboard.

The essence of this technology is to find a balance between the elasticity and stability of the shoes, not only to achieve the ideal counterforce, but also to lose the precise sense of space and the hard support of "down-to-earth".

Tennis players and badminton players suddenly stop on the spot, while table tennis players frequently jump sideways. "Discus throwers" can not help but rotate their bodies.

The third function of sports shoes is skid resistance.

The friction at the foot is determined by the normal force, the coefficient of friction and the contact area of the sole and the ground.

From a microcosmic perspective, due to uneven surface, there is only a limited "point contact" between the sole and the sole.

The sole with high friction coefficient and high elongation can produce elastic deformation on the convex concave surface and increase the contact surface. This is the so-called "grasping the earth".

In the past, metal pins were used to consume energy between inserting and pulling out the ground. Modern pins are made of nylon, polyurethane and other composite materials. Cones, rectangles, blade shapes and so on, the number and location of spikes can also be adjusted and changed due to human and local conditions.

A large number of sports shoes replace the studs with different ridges.

As for the pattern of the sole, it is more and more varied, bringing different frictional differences in different directions to meet the needs of different sports categories.

It is worth reminding that the "braking" process of people in motion is changed from static friction to static friction. After landing, there should be a little "sliding stroke". If the friction force of the shoe is large enough, it will be prone to sprain and sprain.

　　科技為雙腳減負

As for the correction of the foot shape and movement of the torsion system of the sports shoes, the upper support for the ankles, through the "breathing" action of the stoma, makes the shoes breathe and absorb moisture, which are all remarkable designs.

Almost all sports have their own special shoes.

If you want to separate descriptions, you need a monographs capacity.

But football shoes are particularly worth mentioning separately.

Football is all about one foot, and the foot is counting on a pair of shoes.

Every game, footballers run about ten thousand meters, and the speed of 100 meter sprint should be reached.

More importantly, sports shoes are football players' racket and bat.

The power of catching, dribbling, passing and shooting must be issued by sneakers. The delicate footwork of pushing, dialing, picking, dragging, and buckles should be completed through sneakers.

The precise sense of foot and the combination of shoes and feet are very important.

Inspired by the small particles on the table tennis racket, with the rubber imitation toe on the edge of the football shoes, the Falcon sneakers on Zidane's and Beckham's feet can kick out 8 circles of banana balls per second.

The 100 meter sprint of a century ago increased by an average of 0.015 seconds per year, and now it has slowed to 0.006 seconds a year.

More and more people are paying more and more attention to the potential of unearthed from running shoes.

According to the test, athletes' physical energy consumption will increase by one percent when the weight of each running shoe increases by 100 grams.

In 1991 Tokyo Athletics World Championships, the American sprinter Lewis broke the world record of 100 meters when the running shoes were only 115 grams; in 2000 Sydney Olympic Games, the "golden hamstring shoes" of the "field Agam" Michael Johnson weighed only 116 grams, while Marian Jones's "crystal shoes" were only 99 grams; the Canadian "black leopard" Bailey's running shoes were described as "socks with nails".

People can't help wondering why some athletes can wear heavy gold necklaces around their necks, but they are so heavy on the weight of shoes.

Looking at those fast flying feet on the 100 meter runway, it is found that the heels of each athlete almost touch the hips. The folding of the shank can shorten the rotation radius of the hip joint axis, thereby reducing the rotational inertia and increasing the angular speed of rotation.

And the feet are at the far end of the knee around the knee and the rotation radius of the hip joint, so a slight reduction in the weight of the shoes will bring a significant reduction in leg inertia.

This is undoubtedly a great "burden reduction" for the two feet alternately marking the arc at the speed of 20 meters per second.

　　劉翔的戰靴

For 0.01 seconds, for the sake of more market share, sports stars and sports shoes brands are becoming a kind of "symbiotic relationship" which is difficult to give up.

At this Olympic Games, Nike dedicated the "Zoom Aerofly LX" hurdle shoes for Chinese flying Liu Xiang.

The main color of Zoom Aerofly LX shoe upper is brightly bright yellow. The side of the shoe is equipped with Chinese red Logo.. A lot of innovative technology has been brought together on such a pair of 214 grams of spiked shoes. It also makes people sigh that a lot of technology support is needed behind a gold medal.

The Zoom Aerofly LX nail shoe upper is made of this year's latest Flywire innovation technology and is made of special synthetic leather material, with a thickness of less than 2 microns, and only supported by fine-grained fibers. This technology is vividly described as "high strength fine fiber as the cable of suspension bridge, and the location of each fine line is precisely designed at the part where the foot needs support."

The weight of the shoe is lighter and even lighter than that of the banana skin.

The war shoes, which are regarded as secret weapons by Liu Xiang, are designed for Liu Xiang's technical characteristics. Liu Xiang revealed that he liked the elasticity of the soles and enabled the run-up to have explosive force, so the designers made a solid forehand from the special carbon fiber baseplate.

Liu Xiang landed on the front foot for hurdles landing, and his hind paw did not fall. So the designer used the design of the front half floor as carbon fiber board, and then the bottom plate used the characteristic rubber with good damping effect.

One of Liu Xiang's favorite sole parts is the design of the front sole with only five nails, which reduces the weight of the shoe.

The location of the studs accords with the biomechanical research results can reduce the pressure on the foot compression point and increase the ability of grasping the ground.

Since 2002, a dedicated equipment development team has designed Liu Xiang's exclusive spikes for him, including the design and development of all Liu Xiang's footwear products.

This pair of spiked shoes that will compete with Liu Xiang for the Beijing Olympic Games are also part of Liu Xiang's personal participation in the design discussion.

The vamp keeps the design of the hasp and zipper.

Liu Xiang attached particular importance to the hasp on the upper part of the shoe because it was more psychological for him. "Before the competition starts, I always have to think about whether the shoelace has been fastened."

Did I finish the last move before the match: fasten the clasps on the shoes.

Only after finishing the last move did I feel that I had made all the preparations.

In addition to Liu Xiang's request, in order to better protect his right foot, designers added the thickness of the foam cotton in the heel position of the right shoe upper to better lock the ankle.