What do you know about the insoles?

Insoles are used for many reasons: to correct the distribution of body weight, to balance the gait, to improve at sports or to avoid injuries.

You have to know insoles are like glasses, without them you can see but in a wrong way. This happens with insoles too, you can walk but your gait will be worse.

As we know, there are many injuries related to a wrong gait, like chondromalacia patella, ankle sprains, lower back pain and increased possibilities to develop other injuries like muscle tightness, meniscus tear, ACL injury… We can prevent them with the proper insoles.

Most important things to know about insoles are these:

– Tailored: Insoles must be tailored, every pair of feet is unique. A pair of insoles will not be suitable for two people. They have to be tailored to fit on your feet in a perfect way.

– Study: Insole shape has to be a consequence of a biomechanic study, having checked and studied all the wrong movements and try to fix them with the insoles.

– Material: Every material is not suitable for insoles. In order to chose the right one, some factors should be considered, being endurance, flexibility, weight and comfort the most important.

Most important materials are:

Polypropylene:

– Light

– Washable

– Discreetly elastic

– Provides stability

– Good correction of biomechanics

– Good resistance to traction

– Good resistance to tearing

– High remaining deformation

– Impact resistance

– Maximum temperature of continuous use over 100ºC

It is indicated in pathology when you want to perform some significant correction, for example for kids, when you need more control (flat foot) and for sports when you need stability.

EVA:

– Very light

– Washable

– Low water absorption

– Easy to cut and paste

– Not toxic

– Good stability

– Medium correction of biomechanics

The harder, the more mechanic support. If you choose a low hardness insole, it will accomplish a cushioning function.

Poron:

– Easy adaptation

– Great capacity of absorption and cushioning

– Low remaining deformation

– Maximum comfort

– Maximum absorption of energy

– Optimal sweat management

– Durability

– Washable

– Resistance to bacterial and fungal growth

It is used to get the maximum comfort. It also get a great capacity of discharge and cushioning. It is always used as an addition or upper lining, but Poron should not be in direct contact with patient’s skin. It can produce heat in the face of friction.

Carbon fiber:

– Light

– Elastic (greater elasticity than natural polypropylene)

– Radiotransparent

– Good stability

– Good correction biomechanics

– Impact resistant

– Resistant to traction

– Good balance between stiffness, abrasion resistance and chemical resistance

Indicated in cases when we want some significant correction adding the feature elastic mechanics. For example, for athletes who need control provided by a plastic, but at the same time looking for good elasticity trying to avoid tissue stress.

– Sport: It depends on the kind of sport you practice, the insoles will be diferent for each one. Sports that involve jumping need insoles with cushioning, and sports with a lot of changes of direction should have enough flexibility and endurence material to help us in this task.

Enrique Simal Aguado