Covering of treadmills
libre 12
It is not enough to have fast legs to run fast. Athletic success in many sports does not only depend on the "action" of the legs, but also on the surface of running tracks.
Treadmill surfaces are an aid to walking
When a person walks or runs, their feet must push off the ground and meet an equal and oppositely directed opposition from the road (more: Newton's Third Law). In other words, the foot needs to have a good walking stop.
If the stop is insufficient, the runner will not be able to move at full force. It is very difficult to run on loose, shaky sand, on viscous wet clay or on the ground covered with a crust of ice. On such ground it is not that to run - even to walk is difficult.
On loose sand, a person spends a lot of effort to compact the sand with each step before it is able to give the foot the necessary support. And on clay, the feet get stuck and sprawl, you have to pull your foot away from the sticky mud with effort.
On the slippery ice of a skating rink or during icy conditions you have to walk with caution, it is too easy to slip and fall - the ice does not give your foot a reliable support.
The builders of stadiums and sports grounds take care of the quality coating of running tracks in advance: in the past, running tracks were covered with cinders - ash from steam boilers. Cinders were considered to be an excellent material; it is hard enough, freely passes water and almost does not absorb it, is always dry, can be easily compacted under the spikes on the shoes of runners and does not allow the feet to slip.
Later, treadmills were covered with asphalt. Modern athletes train on tracks covered with various synthetic materials.
The spikes on the soles, pressing into the surface of the treadmill, provide useful friction and allow the foot to be planted firmly, and the foot, meeting a reliable stop in the ground, uses all its force to push off from it. In this way, the small amount of friction lost by the spikes is more than returned to the runner through a reliable interaction with the road.
Athletes' shoes
Athletes' shoes have undergone a long history of development.
- Footballers' cleats in the middle of the twentieth century were special shoes, to the soles of which thick leather rubs and special protrusions-spikes were stuffed.
- Runner's shoes were also made with spikes, but already - metal, thin and sharp.
- The spikes on the mountaineer's shoes were almost the same as those on the horse's horseshoes.
Over time, the quality and design changed, but walking in alpine or soccer shoes is still uncomfortable, but running or climbing in the mountains is very good.
Grip
For the same purpose - to get a good grip on the road - the wheels and tracks of tractors are also equipped with spikes, the treads of car tires are made patterned, and horses are shod.
However, on a slippery or muddy road, car tires often lose traction, (more: The benefits of friction) and begin to slip, spinning in place, splashing mud, and the car does not move a step.
Chauffeurs, when they have to run over a bad road, pre-wrap the wheels with chains, and then the car overcomes difficult parts of the road more easily. Modern trucks have not one driving axle, but two and cling to the road with all four wheels.
Such a device, as experts say, increases the "passability" of the car.
The ability of any transportation vehicle to move depends not only on the power of its engine, but, to the same extent, and on the condition of the path, just as for an athlete from the quality of the surface of the treadmill.
