Wondering when you should replace your athletic shoes?
There are a few things that come into play when deciding if it is time to replace your athletic shoes. Three ways to determine if they need to be replaced are amount of usage, signs of wear, and the age of the shoe. The components of an athletic shoe that can break down and wear out are the outer sole, midsole, and heel.
The outer sole is typically made of carbon rubber, which is very abrasion resistant and also consists of 2 components. Most athletic shoes will have a harder and more resilient rubber in the heel of the shoe since this is where most of the wear will occur.
The mid-sole is normally composed of a foam material, such as ethylene vinyl or polyurethane, sometimes even a blend of these materials. This area of the shoe is intended to be shock absorbing and in some shoes, controls excessive foot motion. The midsole will begin to compress over time, because of the repetitive load that is placed on that area. The shoe will no longer absorb shock, or control the foot as well as it did when new. Sometimes the midsole can compress and deform unevenly which can create alignment changes in the foot. This can ultimately lead to injuries associated with over-use, such as achilles tendinitis, stress fractures, plantar fasciitis, and metatarsalgia.
Midsoles should be considered worn out if any of the following occur:
- After 300-500 miles of running or walking.
- Shows signs of unevenness when placed on a flat surface.
- Display noticeable creasing
The heel counter of the shoe helps hold the heel on top of the midsole and prevents excessive heel motion. This area is considered broken down when it feels flexible, when compressed side to side, or appears to lean to one side or the other when viewing from the rear of the shoe.
It is typically best to replace athletic shoes that are over a year old, whether they are worn out or not. Replacing athletic shoes when necessary may be costly in the short term, but can help prevent injuries and keep you active in “the long run”.Read the rest of this entry.