Foot Health Clinic www.NBwebexpress.com (800) 595-9138

Introduction

Purchasing a new pair of sneakers can be a daunting task, especially when faced with today's ominous array of styles, colors, and brands. Is there really a difference between them? Does it really matter which pair I choose? Yes. Your feet are as unique as a fingerprint and sneakers will fit you differently from everyone else. Thus, selecting the shoe that best fits your foot can enhance its functionality in activity. In addition, today's sneakers are fully equipped technological wonders that can help overcome abnormalities in function.

Studies of the foot dating back to the beginning of modern medicine have given us insight into the dynamics of the foot while being used for standing, running, jumping, climbing and dancing. This has enabled us to design proper shoes for special occasions. Can I walk in running shoes? Can I play tennis in running sneakers? Do high-top athletic shoes help prevent ankle injuries? Knowing basics of shoe anatomy, construction and what to look for in sport specific shoes will help you make the correct choice and reduce your risk of injury.

Shoe Anatomy

Toebox: The area in the front of the shoe containing the toes. The size of the toebox is important to accommodate bunions, hammertoes, and other maladies. Having adequate space can decrease the friction and irritation from these problems. Toebox design varies from model to model. Some models are specifically made deeper and wider to accommodate for various foot shapes.

Vamp: This is the area of the shoe where the laces are found. Lacing pattern can affect how the shoe fits. Some people experience impingement of nerves and tendons on the top of their foot if the laces are not in the proper place. The best way to see if this will be a problem is to try the shoes on and test them. There are alternative methods to lace shoes up that can help prevent the heel from slipping during ambulation/running or relieve pressure points that can result from a high instep.

Insole: The bottom inside portion of the shoe that is in direct contact with the foot. Most shoes have removable insoles that aid in creating space when prescriptive inserts or orthotic therapy is needed. Good insoles are made from compressible foam that will mold to the contours of your feet. It should be noted, however, that most insoles that come with shoes will break down a lot faster than the shoe itself. There are a large variety of over-the-counter shoe inserts that can aid in prolonging the comfort and life of the shoe.

Outsole: This is the portion of the shoe in direct contact with the ground. The traction pattern and materials of the outsole are specific for the playing surface. For example, a court shoe will be flat and flexible with a lot of traction, while a trail-hiking shoe will have a more rigid outsole with more aggressive traction pattern.

Midsole: This is the layer that lays between insole and outsole. Most of the technology of shoes is focused on this area. The majority of the midsole contains ethylene vinyl acetate (EVA) foam, polyurethane foam or a combination of the two (dual-density midsole). EVA foam provides better cushioning but has less durability than polyurethane. In addition to foam, many companies have their own cushioning systems, such as air bladders, honey-comb cut foam, shock-absorbing gel materials and various other high-tech materials.

The support of the shoe is very much based on the construct of the midsole. In the past, there was a tradeoff when it came selecting between support and cushioning. In general, it used to be that the more supportive midsoles resulted in a heavier and less cushioned shoe. Today, knowledge of foot function and advances in materials and shoe design has blended together to produce shoes that offer maximum support without sacrificing cushioning or weight. Some shoes contain different densities of foam or more rigid devices (such as plastic heel plugs) in the midsole that aid in controlling abnormal foot motion.

It should be noted that midsole cushioning can be too soft, leading to maximum compression of the material, which can in turn result in a loss of support [1]. Also, with less cushioning comes less shock absorption-less shock absorption is linked to degenerative changes in joints and low back pain [1]. Finally, one needs to be aware that the use of orthoses in shoegear with extremely soft midsoles may decrease their ability to control abnormal motion.

Heel Counter: The heel counter wraps around the back of the heel and acts to stabilize the heel and aid in motion control.

Sole: The sole refers to the insole, midsole and outsole combined.

Upper: The upper holds the foot to the sole and is generally the most aesthetic part of the shoe (colorful, company logo, etc). One should be warned... while how a shoe looks is important; it should never take precedence over the function of a shoe. The fact is that the "look" of a shoe will not prevent injuries associated with improper fit or function. The good news is that most companies are designing great shoes with a decent blend of support, cushioning and style.

Shoe Construction

Important aspects of shoe design include the last of the shoe and how the shoe is lasted. The last is the mold or form on which the shoes are built with the more common shapes being straight and curved. The last is usually designed to reflect the shape of the foot. However, as we all know, no two pair of feet are identical. In fact, each foot is slightly different, unique like our fingerprints. Shoe manufactures construct shoes over a model called a last, which resembles a generic foot. Actually, this last represents the shoe designer's idea of what the average foot is shaped like. Therefore even if you know your shoe size, if you are trying a new model it is a good idea to try both shoes on prior to purchasing them.

Three Types of Lasts

Straight: The arch area is filled in for increased stability. People with flat feet and heavy heal strikers do well in shoes built on a straight last.

Semi-curved: This last has a gentle arc from front to back. Shoes built on a semi-curved last are considered best for the "normal" foot.

Curved: As the name implies, the arc is greater than in the semi-curved last. It is designed for the high arch foot that under-pronates. These shoes have a wider lateral aspect to provide stability.

How a shoe is lasted is the way the upper of the shoe is attached to the sole. Removing the insole will often reveal the type of lasting used in the construction of a shoe.

For more information about New Balance shoe lasts, click here.

Three Methods of Lasting

Slip: The upper is sewn together at the bottom then glued to the sole. This gives the shoe flexibility and lightness. It offers no rigidity for motion control.

Board: The upper is sewn to a board, similar to cardboard, then attached to the sole. This gives the shoe support and rigidity.

Combination: This has a slip lasted front and a board lasted back. The combination allows good flexion and cushioning along with rearfoot control.

Both board lasted and combination lasted shoes tend to work better with orthoses. The slip lasted shoes' softness allows the orthoses to dig into the sole, decreasing the ability of the orthoses to control foot motion.

Sport Specific Shoes

Running Shoes: There are a wide variety of running shoes. The main types are motion control shoes, stability shoes and cushioned shoes. Regardless of the type of running shoe, the constant pounding will wear out the midsole cushioning before the rest of the shoe. The impact at heel strike is typically 2.5 times or more your body weight [2]. This is the same force that is translated to the ankles, knees and lower back. Running shoes are specifically designed to redistribute and absorb shock to preserve the health of these joints. It is recommended to change running shoes every 350-500 miles or every 6 months to maintain proper shock absorption and help prevent injury [3].

Weight of running shoes is also significant in competitive runners. It has been shown carrying 100 grams of excess weight on each foot while running can decrease energy expenditure by 1%. This may seem insignificant, but it can add one to two minutes to the time required to run a competitive marathon [1].

Motion control shoes are made to control overpronation. Many of these shoes have rigid devices made out of plastic or fiberglass in the midsole. They are often built on a straight last and are either combination or board lasted. Straight lasts with more medial support and a wider base in the heel significantly reduce maximum pronation [1]. Flat-footed, as well as heavy runners, do well in these shoes.

Stability shoes aid with mild pronation. They provide stability with extra medial (arch-side) support and usually higher density foam. This is apparent on most shoes by the gray colored foam on the medial aspect of the shoe. They are usually built on a semicurved last and combination lasted. This provides rearfoot stability and forefoot flexibility. These shoes are good for runners with normal arches and only mild motion control problems.

Cushioned shoes have little, if any, motion control properties. They are the softest of all the running shoes. They are built on a curved or semicurved last and are usually slip lasted. This construct provides minimal rigidity with optimal cushioning. Runners with high arches and rigid feet do well in these shoes.

›Men's Running Shoes   ›Women's Running Shoes

 
Basketball: The game of basketball is full of short explosive moves. These movements occur in all directions. Shoes with a thick, stiff sole and rigid heel counter provide the most stability [5].

If ankle injuries are a problem, high top shoes should be worn. Make sure that the top of the shoe is above the ankle joint. Quarter cut shoes that rest at the level of the ankle joint may actually increase the frequency of ankle sprains in an unstable ankle.

Well-cushioned shoes are also a must, especially in the heel. The constant motion, as well as the high impact of jumping, requires adequate cushioning to reduce shock and prevent injury. If you are playing basketball five days a week shoes should be replaced every two to three months [5]. Even if the rest of the shoe is in good condition the midsole cushioning will be greatly reduced by this time.

The outsole in basketball shoes is very important. It must provide traction for running and cutting, but must also allow for pivoting motions. The tread pattern of running shoes provides too much traction, often locking the foot on the floor during pivoting motions, leading to injury. The 'herringbone' tread pattern is ideal for basketball shoes.

›Men's Basketball Shoes   ›Women's Basketball Shoes

 
Cleated Shoes: These are shoes used in baseball, football, and soccer. The main advantage of these shoes is the traction they provide. These sports all involve running and jumping on natural playing surfaces exposed to the elements. Shoes that have removable cleats allow the shoes to be adjusted for the condition of the field. The soft field requires a longer cleat to provide traction and stability. Cushioning is not as important as in sports played on harder surfaces. The natural give of the field allows for a thinner midsole, decreasing the weight of the shoe. The shoe for all these sports requires good stability, looking for those qualities as mentioned for basketball shoes above. Soccer shoes have an additional feature of specially constructed toe box, to protect the toes and allow ball control [5].

›Men's Cleated Shoes

 
Cross Trainers: As the name implies, cross trainers are designed for a number of different sports. To accomplish this goal there is some give and take. These shoes have more side-to-side stability than most running shoes to allow for cuts in court sports. They also have greater flexibility than most court-specific shoes to aid in low mileage running.

Today, cross trainers are becoming more specialized. Some companies have designed shoes based on the most prominent activity. For example, if most of your activity is running, these shoes are built closer to running shoes with additional support for side-to-side motion for some court activity. This holds true for the outsole as well. If you are more active in court sports, the tread pattern will be closer to a basketball shoe than a running shoe to provide appropriate traction.

›Men's Cross Training Shoes   ›Women's Cross Training Shoes

 
Tennis Shoes: This sport requires the same stability and cushioning elements as basketball shoes. They also have a padded toe box that helps prevent injuries suffered by tennis players [5].

The most important difference is the outsole. This is made for the specific court material on which the game is played. The material from the outsole is often wrapped around to the front of the shoe to protect the toes from the friction that occurs while the foot is being dragged during the serve. Some newer models have heel plugs to stabilize the heel during the side-to-side cutting utilized during intense volleys. These shoes are usually designed to keep the foot closer to the ground to give the most support and stability without sacrificing function.

›Men's Tennis Shoes   ›Women's Tennis Shoes

Shoe Fit

No matter how expensive your shoes are or how much technology your shoes contain, they will not do their job unless they fit correctly. Here are some useful tips that can help assure you are getting the proper fit [3,4,5].

• When trying on shoes put on all the equipment worn or used on your feet such as socks, braces and orthoses.
   
• Make sure there is adequate space in the toe box. Leave 1/4 of an inch between the longest toe and the end of the shoe. This is about the width of your finger or thumb. This measurement should only be done while you are standing, since the foot elongates with weight on it. If this measurement is done while sitting, there is a good chance that the shoe will not fit properly when you go out for your first stroll or run.
   
• Check the heel counter to make sure your heel won't slide and is rigid enough to provide stability.
   
• Try on shoes in the afternoon or evening to insure you have enough room in your shoes as your feet expand through the course of the day.
   
• Walk, run and jump in the shoes. They should be comfortable right away, not needing to be "broken in." General rule of thumb: If it hurts in the store, it will hurt at home. Also the shoes that need to be broken in tend to actually reverse the role by causing the owners feet to "break in" to the shoe.
   
• Use the knowledge of the employees at a quality athletic shoe store.

For additional sizing tips, please visit our Width Sizing Section!

Conclusion

Having a basic understanding of what to look for in sport specific shoes and how to obtain a proper fit will help you sort through the numerous options available. Finding the right shoe for you will aid in your performance, as well as help prevent injury. Look beyond the neon coloring to find a shoe that will help you compete at your highest level.

References

1. Fredrick, EC: The Running Shoe: Dilemmas and Dichotomies in design. NP.
    
2. Fredrick, EC Ed: Sport Shoes and Playing Surfaces. Human Kinetics Publishers Inc, Champaign, IL, 1984.
    
3. Cavanagh PR: The Running Shoe Book. Anderson World Inc, Mountain View, CA, 1980.
    
4. Martin DR: Athletic Shoes: Finding a Good Match. The Physician and Sports Medicine, 12: 9, 1997.
    
5. Radovic PA: Feetfixer.com, 2000.

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