Athletic Footwear

A simple shoe change has a dramatic impact on foot alignment

Since the running boom of the early 70’s sports shoes have evolved dramatically. There have been many innovations during this time frame with shoe companies highlighting features that can have amazing beneficial effects. Some innovations have been short lived whilst others have been present for years. An example of something that works is the dual density midsole which has been around for a long time now proving that this configuration is effective. Generally speaking if a feature comes and goes then it wasn’t that great in the first place – often despite marketing telling us differently.

The role of footwear has been primarily to protect the foot (or body) from injury, and also to improve performance during activity.

The shoe protects the foot by shielding it from the ground and forces caused by certain activities. Try playing tennis in bare feet as an example. Reducing shock when the foot collides with the ground is another primary function. Each step when walking will yield approximately 1 ½ times your body weight and 3 times body weight when running. Accumulatively this leads to tonnes of impacts or jarring forces through the foot and up the leg into the spine after a moderate run. As well as cushioning the shoe must also provide stability for the foot. Running on an unstable surface can lead to injury due to abnormal positioning or subtle twisting movements. For years shoe companies have attempted to make shoes that both cushion and support the foot. This is difficult as softer materials whilst cushioning well does not provide good support and vice versa. Thus shoe company’s hedge their bets by placing cushioning components into firmer midsole materials. These are usually gel or air units in regions of greatest impact being the heel and forefoot.

Improving performance is another feature of the modern day athletic shoe. Being light-weight means there is less effort required when running such that you will run faster in shoes that weight less. The traction provided by footwear also allows improved performance. Think of football boot cleats as an example of this. Without them we would slide and fall – lessening our performance.

There are other features of shoes that seem to improve performance including the forefoot plate of an athletic spike in which a more rigid plate improved speed. There will be continued improvements in the athletic shoe over time however understand that this is a massive sales industry where marketing is key to gaining additional sales. Who wouldn’t want to wear cool looking shoes like those that a top athlete wears.

Helping you choose the right shoe

At Sportsmed we can help you choose the correct shoe for your foot type or condition. If you bring along a selection of shoes from your shoe store we can provide a clinical interpretation of what shoe is best suited for you. Our software offers immediate side by side comparisons of footwear so that shoe function can be compared and measured. All leading shoe stores in Christchurch will allow you to do this. Reviewing your old shoes can provide a good insight as to what type of shoe you may require. Place these on a bench or desk and look at them from behind. Do they lean inward / outward or sit perpendicular? If they do not sit at 90° then chances are you need a new pair – plus this shoe type may not be appropriate for you next time round.

How long does a shoe last?

This is a difficult question and one that even the shoe companies cannot answer. Studies have shown that after a relatively short time a shoe can lose 40% of its shock absorbency at around 400 to 700k’s. That’s 10 weeks of running at 40k-70k per week....what happens after this? The shoe would seem not to compress exponentially after this time frame and whilst cushioning is lost the body adapts slowly to this cushioning loss. So while the shoe loses its function it does not suddenly place the athlete at risk.

For a running shoe we recommend to the average jogger that 1 year of use at 30k per week will see it through. A heavier runner, a marked pronator will cause the shoe to deform and decrease this life span. Some shoe companies do recommend approx 1000k before the shoe should be replaced. Tennis players are notorious for wearing shoes rapidly. Some wear their shoes out in 4-6 weeks! Our advice to you is to consider the terrain you run on, the mileage you run, and your weight as key factors in the life of your shoes. If in doubt see us for an opinion.