Jordan's air cushion shoes, Lewis's ceramic spikes, Jones's "crystal shoes", Johnson's "golden shoes", Liu Xiang's "red magic shoes" and the history of sports shoes leave behind a footprints of the times.

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

Human feet are the masterpieces of art and engineering.

After walking upright from the human ancestors, we completely gave our weight to our feet, so that it could bear twice the load than the quadruped animals.

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 people run at speeds of 6 meters per second, the load on their feet is about 4 times that of their weight, and 7 times higher when they jump high. The strong oscillation will spread to the ankle, knee, hip, spine and brain.

The human heel fat pad and the natural "spring system" arch are effective against this kind of injury.

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 sports shoes have rubber columns and air cushions in the sole of shoes, playing the role of damping spring of automobile chassis.

According to the test, when the weight of each running shoe is increased by 100 grams, the athletes' physical energy consumption will increase by 1%. When the US sprinter Lewis broke the world record of 100 meters, the running shoes were only 115 grams; the weight of "golden hamstring shoes" by Agam of the field "Michael Johnson" was only 116 grams, while Marian Joan's "crystal shoes" only had 99 grams; the Canadian "black leopard" Bailey's running shoes were described as "socks with nails".

People are wondering why some athletes have a heavy gold necklace around their necks in the competition, but the weight of the shoes is so good.

Looking at those fast flying feet on the 100 meter runway, it is found that each athlete's heels almost touch his hip. Folding the calf can shorten the radius of rotation of the hip joint, thus reducing the moment of 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.