Paul Thawley MSc Choosing the Correct Shoe

1. Paul Thawley MScChoosing the Correct Shoe

2. Definitions • Last: The template or model upon which the shoe is built. Different manufacturers use different lasts.

3. Definitions (cont.) • 3) Outsole: Has tread for traction, flex grooves for flexibility, protects from dirt and rocks. Made of two materials: • Carbon rubber (durable - same material as tires) • Blown rubber (lighter, more flexible, more cushioned, not as durable). Blown rubber is rubber with airinjected into it (blowing a bubble with chewing gum) • Outer-Sole: The outermost part of the sole, which is treaded. On running shoes the tread is designed for straight ahead motion. Court shoes and cross trainers have their tread optimized for lateral or side-to-side stability.

4. Definitions (cont.) • Upper: The uppermost part of the shoe. This part encompasses your foot and has the laces. • 1) Upper: Holds the foot in place, protects the foot from rocks and dirt, has synthetic leather for durability, mesh for breathability and reflective material for safety.

5. Definitions (cont.) • Midsole: The portion between the upper and the outer-sole. This is the area whose major contribution to the shoe is shock absorption. It is also usually quite important that the midsole be stable from the heel until the distal third of the shoe where it should be flexible at the point where your toes attach to the foot and bend. • 2) Midsole: Most important part of shoe. There are three materials that make up the midsole: • EVA - lightweight, foam-based cushioning • Dual-density EVA: • What happens when you double the density of something? It gets stronger, firmer, heavier (twice the mass in the same amount of space) • We call this dual-density EVA a "medial post" • Medial - because it is on the inside of the shoe • Post - because it has a beginning and an end. The length of the post determines the amount of control • Polyurethane: • very durable cushioning • More durable/stable than EVA, weighs more than EVA.

6. Definitions (cont.) • Counter: A rigid piece surrounding the heel that provides some stability.

7. Look at your old shoes • Examine the soles of your shoes. Note where wear has occurred. Most people walk and run with their feet slightly rotated from center. Runners, however, also have what is called a narrow base of gait. A narrow base of gait means that the feet contact close to the midline of your body. This creates additional varus (tilting in) of the limb. This results, for the rearfoot striker, in the first point hitting the ground being the outer corner of your shoe. • Forefoot wear may point to an individual who is a sprinter, runs fast, contacts the ground with the forefoot first or all of the above. Uneven forefoot wear may show where one metatarsal is plantarflexed relative to the others or where one metatarsal may be longer than the others. In the presence of significant forefoot wear, you are at risk of stress fractures.

8. RUNNING SHOE FIT • Running shoes don't need to be broken in. They are made of synthetic materials that DON'T stretch, and the cushioning is ready to go, so they fit "right out of the box". The way they fit the first time is the way they are always going to fit. • Running shoes are used for running, so they need to be more roomy than a regular shoe. Why? Remember the force of heel strike… each foot does this 500 TIMES EACH MILE, so your feet tend to spread out.

9. 3 KEYS to a GOOD FIT 1) You should have about a thumb's width of room at the toe. If you can't wiggle your toes, then move up to the next size. 2) The shoe should hold your foot securely around the midfoot (arch and instep) and at the heel, with little or no slipping. 3) The shape of the shoe should match the shape of the foot (more on this later).

10. Bigger is Better • If you aren't sure of which size to buy, it's nearly always better to choose the larger size because much more can be done to fine-tune the fit: • change to a thicker sock like Thorlo • add a replacement insole; these are thicker and more durable than standard insoles • adjust the lacing to snug up the fit (lace lock, for example) • If a shoe is too small, there's not much you can do. Since running shoes don't stretch, the only option is to try a thinner sock.

11. Running Biomechanics • Gait Cycle - the progression of the foot as it heel strikes (phase #1) • Heel Strike Running is a "High Impact" activity, meaning that at some point, both feet are off the ground. How much impact? Wanna Guess? A runner comes down with 3.5 times his/her body weight. What does our body need to do with that shock? Absorb it! Cushion it! Dissipate it! Disperse it! If we don't, it travels back up the legs, causing injury.

12. Running Biomechanics • rolls to midfoot (phase #2) • Midfoot phase What do we have in the midfoot? (The arch!) 3 Types of Arches: • Flat - flat arches are extremely flexible and require a great deal of control • Medium - neutral arch is ideal and requires a degree of stability • High - high arches are extremely rigid and inflexible and require little if any control

13. Running Biomechanics • then to toe-off (phase #3) • Toe-offThe toe-off tells us what type of pronator a runner is. Most runners will look at the bottom of their running shoes and conclude that they wear out the outside of their shoe because the outside heel is worn. From this, they may conclude that they need a cushioning shoe. Most are wrong! Everybody wears out the outside heel. It's the wear pattern at "toe off" that will determine your rate of pronation, and therefore the type of shoe you should be running in.

14. 2 Styles of Shoe Shape • Volume: (high or low) - some shoes have more space at the mid-foot to accommodate a high instep. Others have less room than average and are a better match for a low instep.

15. Shoe Volume and…. • Curve: some people have feet almost as straight as a ski; others are almost as curved as a banana. Shoes vary nearly as much. The amount of curve is usually linked to running mechanics.

16. 2 FACTORS! • Do you have a flat, neutral or high arch? • Is your foot straight or curved? • These two factors have to do with the amount of pronation taking place…

17. Pronation • Pronation is the natural, inward roll of the foot; • Pronation begins when the heel contacts the ground, the foot then rolls inward to absorb shock and transfer weight to the ball of the foot as it prepares to push off. It is a natural and necessary motion for running and walking. Ion, • They’re three types of runners: the overpronator, the neutral pronator, and the supinator (also underpronator).

18. Motion Control: Low Arch • Motion control: excessive over-pronators, in addition to low arches, generally have rather straight feet. Motion control shoes have the same straight shape.

19. Motion Control: Overpronator • Overpronator - The excessive inward roll of the foot. A flat foot absorbs a lot of shock. It's very flexible and needs support. Motion control shoes work best for overpronators. • Straight - shape found in motion control shoes built for overpronators

20. Stability: Medium Arch • Stability: the majority of people have some curve in their feet; that's why the semi- curved shape of a classic stability shoe like the Asics GT-2000 series fits so many people well.

21. Stability: Neutral • Neutral pronator - The foot pronates naturally. Mild pronators disperse shock effectively. A medium arch absorbs shock moderately. Stability shoes work best for the neutral pronator. • Semi-curved - shape found in stability shoes built for mild pronators

22. Cushion: High Arch • Cushion: efficient/ underpronators tend to have feet more curved than average to go with their high arches. Shoes like the adidas Response Trail are also more curved than average.

23. Cushion: Supinator • Underpronator (Supinator) - the lack of sufficient inward motion of the foot. A high arch absorbs less shock. Cushioning shoes that are highly flexible are best for the underpronator. Only a small population truly underpronates. • Curved - shape found in cushioned shoes built for underpronators

24. If you say: • I can't close my shoe laces…

25. It Means This: • Your shoe doesn't have enough volume. That means you need a wider shoe.

26. If you say this: • My shoe laces close up all the way…

27. It means this: • Your shoe has too much volume, and you need a shoe that is narrow.

28. If you say this: • My big toes are squished….

29. It means this: • Your shoe is too straight  (curved foot runs into shoe) sometimes causing blisters, irritation on the big toe side.

30. If you say this: • My small toes are squished…

31. It means this: • Your shoe is too curved  (curved shoe runs into foot) and you need a straight lasted shoe.

32. If you say this: • Tight at ball of foot, foot falls asleep, circulation reduced

33. It means this: • Shoe is too small, size up. Women especially get their running shoes too small.

34. Shoes for different weight • Average male weight 165-180 - anything below range is considered a lightweight runner, anything above is considered a heavy weight runner • Average women's weight 125-150 - anything below range is considered a lightweight runner , anything above is a heavy weight runner

35. Shoe Construction • Last thing to know is the construction:There are three types:Board, Combination & Slip

36. Board Construction 1. Board - Cardboard piece in shape of footbed that adds stability • Purpose of a board last: Provide full length support (not common in running shoes) (Anyone have a bad back? Anyone ever put plywood under a mattress or know someone who does? Why? To provide support. Same concept as Board/Combination lasts)

37. Combination Construction • Combination - Half board in heel, half soft, moccasin like construction in forefoot • Purpose of combination last: Provides stability in the heel and support in the midfoot

38. Slip Construction • Slip - entire footbed is built like a moccassin to promote flexibility • Purpose of slip last: Provides flexibility