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Saturday, 24 September 2016

Running Shoes Anatomy



Anatomy

A running shoe is made up of three big parts: the upper, the midsole and the outsole.

1. Upper: Holds the foot in place, protects the foot from rocks and dirt, has synthetic leather for durability, washable mesh for breathability and reflective material for safety. Your running shoe should have a padded tongue to cushion against lace pressure and a padded ankle collar to cushion the ankle, help prevent Achilles tendinitis, and also stops debris getting into your shoes. If your shoe has laces, there may be a variety of lace holes so you can customize the width up the upper according to the breadth of your foot. Parts of the upper are often reinforced where wear is most likel. Further reinforcement is usually present to increase lateral stability. 

2. Midsole: The midsole is located between the outsole and the upper. Is the most important part of shoe. The mid-sole absorbs impact, flexes in the ball of the foot at toe off and determines the level of foot control. There are three materials that make up the midsole: EVA (ethylene vinyl acetate): Lightweight, foam-based cushioning. EVA is a foam that is light and has good cushioning, but breaks down fairly quickly. Dual-Density EVA: When you double the density of something it gets stronger, firmer and heavier (twice the mass in the same amount of space). The dual-density EVA is called a "medial post". 'Medial' because it is on the inside of the shoe and 'post' because it has a beginning and an end. The length of the post determines the amount of control. 

Polyurethane (polyurethane): Very durable cushioning. More durable/stable than EVA and weighs more than EVA. Most shoes are also cushioned with gel, air, foam or various manufacturer-specific technologies that are encapsulated in the midsole. This cushioning lasts longer than previous methods and often adds stability as well as shock absorption. Three factors determine how good a mid-sole is: 
  • Shock absorbency. This can be tested by pressing the material. If it's extremely spongy then it may not provide the shock absorbency required by heavier runners, and conversely, if it's too taut it may be inappropriate for lighter runners. When longitudinal creases develop - those parallel to the ground - the mid-sole will be losing its shock absorbency
  • Heel height/heel toe drop. Most people require a small heel to help reduce forces within the foot and stress on the Achilles' tendon. Heel height can be determined by taking the thickness of the sole at the ball of the foot from the thickness at the heel. An increased heel height is preferable for calf problems or rigid feet. 
  • Pronation control. Some trainers incorporate a wedge within the mid-sole - making the sole thicker on the inside than it is on the outside - to increase foot control. Other shoes use plastic inserts to achieve this. A more popular method is to use two densities of material within the sole. Typically, the material on the inside of the heel is harder than it is on the outside, so when a load is applied there is more compression on the outside of the foot forming an effective wedge.

3. Outsole: The outsole is the treaded layer glued to the bottom of the midsole. It resists wear, provides traction, and absorbs shock.. The outsole is made of two materials: Carbon Rubber: The most durable (same material as tires). Blown Rubber: Lighter, more flexible and more cushioned, but not as durable. There are several different types of outsole to choose from. Some are designed for road running and offer very little in the way of grip while off road shoes have molded lugs designed to provide lots of traction on loose surfaces. Stud or waffle outsoles are good for running on dirt or grass because they improve traction and stability. Ripple soles are better for running on asphalt or cement surfaces. The outsole is also the first part of a shoe to show wear and provides a good indicator of what part of your foot is most heavily loaded when you run.

Shape



Shoe manufacturers make shoe models in shapes from almost completely straight to curved and points in between. Shoe shape ties in with the shoe category: the straighter a shoe is the more stable it is. The shoe acts like a "steering wheel", guiding your foot in the direction of the curve of the shoe. 

1. Straight: Shape found in motion control shoes built for overpronators. 

2. Semi-Curved: Shape found in stability shoes and most neutral shoes. 

3. Curved: Shape found in lightweight neutral shoes for faster runners.

As you can see, the shape of the shoe actually helps it do what it does. Plus, these shapes generally match the shape of the feet in each of these shoe categories. And the fit will always be better when the shape of the shoe matches the shape of your foot. 


The Others Parts

Collar: The inside back portion of the shoe that provides comfort around the ankle

Eyelets: The holes that the shoe laces run through

Heel Counter: The heel counter is the inflexible material surrounding the heel. It must be rigid and durable to support and stabilize the heel. Because the internal heel counter material is thin and tends to lose its stiffness, an external counter is usually placed between the midsole and base of the heel counter. This ensures the shoe moves with your foot and that your foot does not move independently of your shoe which would cause a blister.

Heel Tab: The part of the shoe that surrounds the Achilles tendon and helps lock the shoe around the heel; also called Achilles tendon protector or Achilles tendon notch Heel tab. Ironically, stiff or high heel tabs can cause inflammation of the Achilles tendon so avoid shoes like this if you are prone to Achilles tendonitis. Some heel tabs are fitted with webbing or cord loops to make it easier to pull your shoe on and off. 

Insole/Sockliner: This sits on the foot bed, inside the bottom of the shoe. The insole is often removable and is the contoured layer of foam designed to support your arch and provide a small percentage of your shoes’ shock absorbing capability. Because the insole is removable, you can replace it with insoles of your choice. 

Tongue: Soft elongated flap that fits over the top of the foot to protect the tendons and blood vessels from pressure caused by the laces

Shank: 




Designed to stiffen the middle of the shoe so that energy is effectively transferred from the front to the back of your foot, the shank is usually made of semi-flexible plastic although in older running shoes it was made of metal. Most shoes have shanks with the exception of ultra lightweight racing shoes. Some shanks are housed inside the midsole while other manufacturers build the shank into the outsole. 




Source:
http://www.aapsm.org/runshoe-running-anatomy.html
http://www.runnersworld.com/running-shoes/the-parts-of-a-running-shoe
https://www.roadrunnersports.com/rrs/content/content.jsp?contentId=content1106
http://www.active.com/running/articles/anatomy-of-a-running-shoe
http://healthandstyle.com/fitness/anatomy-running-shoe/
https://www.timeoutdoors.com/expert-advice/running/shoes/the-anatomy-of-running-shoes


Run On!



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