Thursday, March 4, 2010
Anatomy Of A Running Shoes
(Click on image to enlarge view)
Running shoes are the most important piece of equipment that a runners has. They help prevent injury and they may help the running gait be more efficient. There is no best running shoe. Every runner is different; every brand of running shoes is different; each model of running shoe is different - the challenge is to match the features of each runner to the features of a particular brand and model of running shoe.
Basically, the difference between a running shoe and those made for aerobics and basketball is LATERAL STABILITY. Running shoes are designed for forward motion and to absorb shock. Those other athletic shoes are designed to keep the ankle from rolling.
Having said the above, it is then best to understand and know the four sections of a running shoe that make it complete.
The UPPERS of the shoe may be made of leather or, for the lighter shoes, a synthetic which is lighter, washable and breathable (to reduce heat from the foot). Another component of the upper is the tongue of the shoe, which should be padded in order to cushion the top of the foot against lace pressure. At the back of the shoe, the ankle collar should also be padded to prevent rubbing and irritation of the Achilles tendon.
The OUTERSOLE of the shoe is the treaded layer which is glued to the bottom of the midsole. It resists wear, provides traction, and absorbs shock. This is probably the most important layer for the ""street fighter"" or road runner. The outer sole usually consists of blown rubber, hard carbon rubber, or a combination. The blown rubber is the lightest, but is not durable as pure carbon. The stud or waffle outersoles are excellent for running on soft surfaces such as grass or dirt; they improve traction and stability. On the flip side, the ripple sole is better designed for running on asphalt or concrete surfaces.
The HEEL COUNTER is the inflexible material surrounding the heel. It must be made of a material that is both rigid and durable to support and stabilize the heel. Just look at any old shoes, and you will see the wear and breakdown of the inner heel counter, which, over a period of time, tends to lose its stiffness. That's why an external counter is typically placed between the midsole and the base of the heel counter. You will also see a wedge that adds height to the heel and enhances the shoe's ability to absorb shock and reduce strain. The advantage to the added heel height is that it will shorten the Achilles and Gastrocnemius-soleus muscle, reducing the strain upon those important posterior running structures. The downside is that the higher heel height may feel less stable, causing reduced flexibility in the tendon structure.
The MIDSOLE is located between the outersole and the upper. Many regard it as the most important part of the running shoe. It provides cushioning and shock absorption while concomitantly controlling excessive foot motion (pronation/supination).
The primary materials used in midsoles are ethylene vinyl acetate (EVA) and polyurethane (PU). EVA is a foam that is light and has good to excellent cushioning. The problem is that this material breaks down quickly. In fact, it can break down just sitting in a box in your closet. Compression-molded EVA is one answer, making it harder and more durable. PU is also a foam, usually denser, heavier, and more durable than EVA. PU will stand up longer, but you'll give up some of that precious cushioning in return.
Most shoes today are cushioned with gel, foam, or other manufacturer-specific materials that are designed within the midsole. This type of cushioning will extend the life of the midsole while simultaneously adding increased stability and shock absorption. This typically is where you will see the greatest quality difference between the various companies' shoes and their models. And this is where the technology wars are being waged.
Remember, shock absorption is related to how compressible the midsole material can be made. The more the material compresses, the more movement within the shoe is seen. The less the compression of the material, the better the shoe's motion control, but there is a trade off in shock absorption. In this case, the shoe may feel harder, and not as soft as the first case scenario.
From the four sections of a running shoes, comes the various components, and each component has a specific name it's referred to. Knowing what each part of your running shoe is called will help you understand what features certain shoes offer.
The collar of the shoe refers to the inside back portion that will provide you with comfort around the ankle. If this part is rubbing too much against your foot, blisters may result.
A dual-density midsole is a type of shoe that has a firmer wedge of foam placed on the inner side of the shoe, right around the middle of the foot. This is going to be a feature that those who suffer from excessive pronation should look into.
The eyelets of the shoe are the holes that the laces are going to run though. Different shoes may use slightly different lace-up strategies, so be sure you consider this when trying various shoes on.
Located in the heel, the heel counter conforms to your particular heel shape to offer greater support. Because the landing weight goes directly to your heel, it makes it extremely important that the heel is well supported.
The part of the shoe that surrounds where the Achilles tendon will sit is called the heel tab. This will help to ensure that the heel stays in place during your run, preventing any slipping.
Perhaps one of the most important features of a running shoe, the midsole is the area that sits right in between the upper portion of the shoe and the outsole. It is what is going to provide the most protection against impact and is often filled with supportive cushioning such as air or gel. The primary reason why you need to keep track of how many miles you've worn your shoes is because this midsole will wear out over time, decreasing the protection against impact it offers you.
The outsole of the shoe is the outer casing and includes the portion that makes contact with the ground. It is important to provide traction during a run and maintain the shape of the shoe.
The quarter panel of the shoe is the portion that runs along the outside of the foot. Breathable fabric sometimes makes a portion of this, allowing air circulation around the foot.
The sockliner of the shoe is an insert that sits below the foot to help the shoe feel better while you're running and prevent any movement within the shoe. Included in the sockliner is also the tongue, which is the large portion that covers the top of the foot, reducing excess pressure from the laces.
Lastly, the term 'upper' is used to refer to the part of the shoe that surrounds the foot. Included in the upper would be the tongue, the quarter panel, the heel features, and the eyelets.
As in any general field of knowledge, you need not master the different parts of a running shoes nor you need to be an authority to such, but, when you understand the anatomy of a running shoe, there is a better chance that you will be able to make an informed decision when it comes time to purchasing the perfect shoe for you.