Sports Medicine: Just the Facts

CHAPTER 72 • FOOTWEAR AND ORTHOTICS 439

•Foot structure plays a significant role in the quantity
of force transmitted to bone and soft tissues (Barnes
and Smith, 1994).

• The rigid arch of a cavus foot, while stable, passes on
  a significant amount of stress up the kinetic chain
  (Barnes and Smith, 1994). This foot should be shod
  with a slip lasting, curved shaped last with a soft mid-
  sole and no or lateral posting (Foot and Ankle, 2002b;
  Running Course, 2002).
  •The flexible or planus foot dissipates considerable
  vertical force loads inside the foot structure, but needs
  additional stability control from the shoe to perform
  (Barnes and Smith, 1994). This foot type would ben-
  efit from increased medial support with a firm heel
  counter, multidensity midsole, and medial heel stabi-
  lizer. As the medial posting extends upward toward
  the toes, the amount of forefoot control increases as
  well. This foot should be in a straight last (shape) shoe
  with a board lasting (Foot and Ankle, 2002b; Running
  Course, 2002).


• The athlete’s foot type should guide your recommenda-
  tion toward the ideal last configuration with the goal of
  increasing shock absorption of the cavus (high) hypo-
  mobile arch, increasing stability of the planus (low)
  arch, or promoting the mechanics of the neutral foot.
  •A basic foot assessment is a good starting point. The
  wet foottest has the athlete wet the foot and place it
  on an absorbent surface to observe the high or low
  arch alignment of the foot. This test is easily repli-
  cated and is a good starting point for foot wear
  selection; however, several literature references
  advocate dynamic assessment observing both walk-
  ing and running gait since a significant proportion
  of runners do not observe a normal heel–toe gait,
  but a forefoot contact (O’Connor and Wilder, 2001;
  Stacoff, Kalin, and Stussi, 1991; Roniger, 2002). It
  is therefore a good idea to assess the athlete’s bio-
  mechanics, flexibility, and running pattern when
  making recommendations.

THE FIVE SHOE TYPES (Foot and Ankle, 2002)

• Motion control: Board lasting, dense midsole,
  straight last, rear and forefoot postings for overprona-
  tors and heavy runners


• Stability:Combination last, semicurved shape, dense
  midsole, usually only rear foot posting, usually fore-
  foot cushion, mild pronators, and light runners


• Cushion: Slip lasting, soft midsole, curved shape
  last, cushion in the heel and forefoot, mostly for
  supinators


• Trail:Usually a stability shoe for increased support on
  uneven surface, carbon rubber for additional durability
  
  
  • Racing flats:Light thin midsole with little to no post-
    ing. Not designed for extended mileage due to limited
    support.
  
  
  
  

WHAT TO LOOK FOR WHEN BUYING SHOES

•Foot type

•Weight: Heavier runners need increased support and

stability

•Type of running: Marathon versus speed work

• Running surfaces/Trails vs. road: Harder surfaces
  require increased cushion


• Previous pathology and wear patterns


• Heel counter must be perpendicular to supporting sur-
  face.
  •Try on shoes in early evening as a result of foot
  swelling during the day.


• Ensure 1/2 in between longest toe and the shoe toe
  box adequate width (most shoes are a size D).
  •Too tight of a shoe can lead to neuroma formation, too
  short of a toe box can cause black toenail.


• If using orthotics for stability purposes, use board or
  combination lasting to avoid the orthotic pronating
  through the shoe.


• Check for toe box for free flex across the metarsal
  heads.


• Arch cookies are not an effective substitute for a poor
  fit or performance adaptation since the arch should be
  not a weight bearing part of the foot.


• Durability: Expect 300–500 mi or 3–6 months out of
  a pair of shoes prior to midsole break down. Midsoles
  lose 40% of their cushioning ability after 400–500 mi
  (Reinschmidt and Nigg, 2000). Breakdown is variable
  based on weight, shoe type, and foot biomechanics.
  Look to purchase new shoes when the midsole has
  shown signs of compression, outer sole has sign of
  wear, or injury rate increases.

SPECIAL CONSIDERATIONS

• The least amount of pronation occurs while barefoot;
  however, the greatest amount of torsional loading of
  the foot also occurs barefoot (Stacoff, Kalin, and
  Stussi, 1991).
  •Midsole characteristics are the primary determinant of
  the rate of loading imposed during initial ground contact
  (McCaw, Heil, and Hamill, 2000). Midsole stiffness has
  a marked effect on proprioception illustrating that
  peripheral sensory information is a variable in perform-
  ance (Kurz and Stergiou, 2003).
  •Too much or poorly designed cushioning can lead to
  instability as a result of excess cushioning from the