Running is an impact sport. Every time we take a stride our whole body suffers an impact: feet, legs, column etc.
Suitable shoes
Your ideal shoes have to be able to cushion well impacts, provide stability, support and also adapt to your type of footprint. It happens many times that in the course of the use of a pair of shoes, begin to appear discomfort and sometimes injuries, due to a bad choice of them. You have to take into account, in addition the life of the shoes. After that time, the behavior of the materials is not the same.
Types of footprints
In the foot race there are three phases first one of impact in which the heel hits the ground a second of support, where the sole of the foot is in contact with the ground and the third phase which is the impulse, which is when the fingers cause displacement. Pronation occurs when in the second phase: the foot 'sinks' inward. Supination is the opposite reaction, 'sinking' to the outside, and the neutral tread is where there is no sinking of the foot, being the axis of linear displacement.
When pronation is increased above the parameters physiological, in that case we speak pronator corridor. Between 50 and 60% of runners suffer from overpronation.
In the neutral or normal foot, the ankles do not tend to turn either inside the foot or outwards when you run. Approximately 40% of the runners have a neutral foot.
The supinators have a very structured foot and with little mobility with an enlarged plantar arch and the ankle out. This alteration is infrequent, approximately 10% of the total runners are supinators, and it is often confused with the excessive wear of the external area of the heel.