Running shoe technology – what are good features of running shoes?
Every individual has a particular foot type, or even types, as one foot may differ from the other. Current running shoe technology accommodates each foot type, providing cushioning and stability as needed.
There are three basic foot types, based on the biomechanical features exhibited by each foot type as demonstrated by the wet foot test.
Neutral foot:
During the gait cycle, the outer part of the heel strikes the ground first and then the rest of the foot makes contact with the ground. As the load shifts from heel towards the midfoot area, the foot slightly rolls inwards (pronates) to allow for better shock absorption. A normal degree of pronation leads to even dispersal of the load.
This is the ideal kind of foot; however, only about 25% of runners exhibit neutral foot type.
Over-pronating foot:
The foot strikes the ground on the lateral side of the heel, but rolls inwards excessively (over-pronates). There is partial or total collapse of the arch with inward rolling of the ankles. This disrupts the load distribution, with excessive load placed on the big toe.
People with this biomechanical abnormality exhibit a collapsed arch footprint on wet foot tests and their shoes wear more on the medial side in the forefoot area.
Under-pronating foot:
The initial strike is on the lateral side of the heel as with other foot types; however, as the rest of the foot touches the ground it does not roll inwards sufficiently. This leads to inefficient shock absorption, along with uneven load distribution with excessive load placed on the lateral side of the foot.
There is more wear on the outer side of the shoe towards the hind foot area.
Running shoes are designed keeping in mind the diverse dynamic features exhibited by the different foot types. In any case, for efficient running let your foot type dictate your shoe selection.
Neutral/Cushioned Running Shoes:
These shoes suit neutral types best, as well as those with a rigid foot type that does not pronate adequately during the gait cycle.
In such cases the main aim is to provide better shock absorption and cushioning to the foot. As there is no concern regarding foot stability (the foot is stable enough), no design adjustments are required in this regard. The shoes are cushioned well for efficient shock absorption and are designed to disperse the load evenly over a wide area, preventing excessive loading of the lateral metatarsals.
Stability Shoes:
These shoes are best to stabilize feet that undergo mild to moderate overpronation during the gait cycle – a feature exhibited by about 70 percent of the population.
These shoes have specific design features to limit overpronation. These include a dual density midsole and a roll bar. These features are sufficient to prevent overpronation, and excessive cushioning on the inner side is not required.
A dual density midsole is made with two different densities of a material. The medial or inner side is firmer to allow for better arch support. Triple and multiple density midsoles are also available.
These midsoles are mostly made from polyurethane (PU), ethylene vinyl acetate (EVA) or a combination of both.
Motion control shoes:
These are made to control the motion of feet that demonstrate extreme over-pronation.
Their specific design features include a firm rigid sole (these are the least flexible shoes), a firm heel counter and added cushioning on the inner side from the heel to the midsole area. These features allow better arch support, thus preventing their collapse and the consequent uneven load distribution.
These shoes are also provided with a dual density midsole or a roll bar for additional arch support. The midsole is more rigid than other shoes, thus providing maximum support to the foot.
