Biomechanical Considerations in Choosing an Athletic Shoe

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Biomechanical Considerations in Choosing an
Athletic Shoe
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(No Transcript)
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Form Fits Function

• Evolving technology, training specialization,
  sports medicine advancements and commercialism
  contribute to changes in athletic shoe
  construction
• Different physical activities place different
  biomechanical demands on the human body
  
• Athletic shoe manufacturers are forever trying to
  come up with better products, more marketable
  products, and innovative products
  
• Shoe manufacturers make many different types and
  models of shoes to meet the needs of their
  consumers

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Last Construction
Last The template or model of a shoe the
general shape of the shoe is determined by the
shape of the last on which it is built
Running shoes generally have one of three last
constructions Straight, Curved, or Modified
The last can be constructed in one of several
ways Board, Slip, or Combination
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Last Construction (cont.)

• Straight larger base with more support
  materials suited for severe overpronaters
  
• Modified hybrid shape between straight and
  curved this is the most common last seen in the
  construction of running shoes
  
• Curved smaller curvilinear shaped construction
  most appropriate for supinated feet lightweight
  construction at the expense of stability most
  common construction of track shoes

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Anatomy of an Athletic Shoe
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Anatomy of an Athletic Shoe- 3 Main Components

• Upper uppermost portion of the shoe typically
  comprised of lightweight breathable materials
  often reinforced with additional materials for
  support and aesthetics
• Outsole the very bottom of the shoe, composed
  of various rubber materials (i.e. high carbon
  rubber for durability or light weight low density
  rubbers to minimize weight, or combination of the
  two)

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Anatomy of an Athletic Shoe- 3 Main Components
(cont.)

• Midsole situated between the upper and the
  outsole primary role is shock absorption
  manufacturers often build accessory or adjunctive
  components into the midsole, i.e. pronation
  controls, air or gel chambers must also be
  flexible and must transfer force to forefoot
  during gait this portion of the shoe has
  undergone the most amount of change over the past
  few decades
• EVA (ethylene vinyl acetate) lightweight, soft
  and flexible, can be constructed with different
  densities within the same midsole
  
• Polyurethane Foam more stable and durable
  compared to EVA excellent shock absorption, but
  more firm, heavier and stiffer
  

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Midsole Adjunctive Components

• A pronation control device has been added to the
  midsole of this Motion Control New Balance
  shoe
  
• Note the wide, relatively straight last
  construction typical of pronation control shoes
  and the generous midsole foam
  
• Also note the outsole design that takes into
  account a rearfoot strike and a metatarsal break
  
  

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Midsole Adjunctive Components (cont.)
In this shoe, Nike has introduced a midsole
comprised of varying pressured air chambers
supported with structural materials to enhance
the function of the shoe
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Categories of Running Shoes

• Neutral Cushioned Shoe designed
• for runners with a neutral to high arched
• foot who do not over pronate these shoes are
  softer and
  
• more flexible in construction, and do not have
  any adjunctive
  
• components built into the midsole to control
  pronation
  
• Stability Shoe also known as cushioned
  stability shoes
  
• often have some pronation control support may be
• incorporated into midsole designed for runners
  with a
  
• normal to slightly low arch, mild to moderate
  pronators or
  
• for heavier runners that want cushioning,
  durability and control
  

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Categories of Running Shoes (cont.)

• Motion Control Shoes rigid, highly supportive
  and
  
• largely inflexible shoes these shoes have
  motion control
  
• devices built into medial rearfoot midsole to
  block
  
• excessive pronation built on a wide, straight
  last
  
• designed for moderate to severe over-pronators
  with flat
  
• feet, and for heavy runners desiring more support

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Running Shoe Examples
Saucony
Asics Brooks
motion control cushioning
stability
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Cross Training Shoes
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Various Specialty Shoes
Recreational Walking
Track Sprint
Tennis Shox
Nike Free
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Analyzing the Athletes Shoe

• Gait Analysis Can be invaluable in analyzing an
  athletes gait patterns, and therefore shoe need
  
• Running Gait pattern may significantly differ
  from walking gait pattern, and can be difficult
  to pick up without high speed video analysis
  
• i.e. A runner who mildly over pronates during
  walking may pronate very little while running due
  to decreased time in stance phase
  
• Shoe Analysis wear of outsole can be helpful
  but the material of the outsole must be
  considered. Also most runners will strike with
  lateral heel and will likely wear there quicker.
  Midsole analysis may show greater compression
  either medially or laterally, and may result in
  the heel cup being deviated inwardly
• Shoe recommendations must also take into account
  the size and habits of the runner. One runner who
  over pronates may have a greater motion control
  need than another who over pronates based on size
  or time spent in stance phase (running speed)

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References

• Wilusz, P. Podiatry Today Volume 18 Issue 10
• OConnor, F and Wilder, R (2001). Textbook of
  Running Medicine, McGraw Hill
  
• Pribut, S. Separating the Buzz from the
  Biomechanics Podiatric Management, Oct 2004
  
• Dilbert