what-when-how
In Depth Tutorials and Information
5
Outer sole and heel
The under surface of the shoe can be made from a variety of materials
and joined to the upper in several different ways, for example welted,
stitched or adhesive applied. There should be a small amount of toe
spring at the front part of the sole so that the foot does not catch the
ground during walking.
The heel raises the rear part of the shoe above the ground. The height
of the shoe dictates the pitch. If there is no raise at the heel area or the
heel is lower than the sole, this is termed a negative heel. The material
covering the area of the heel which contacts the ground is called the top
piece, and this can be replaced or repaired.
Key
Concept
The design of the sole and the heel has an effect on function and
needs to be considered if foot orthoses are being provided.
Materials used in footwear construction
Upper materials
Leather is the most common material and has the benefit of being perme-
able so that moisture can evaporate away from the foot. The advantage
to foot health is that the skin is less macerated and it is therefore less
likely that fungal infections will proliferate. Leather also stretches and
accommodates to the uniqueness of the foot shape.
The advantages of leather can be negated by the use of synthetic
linings and/or special coatings often used to protect the leather, or provide
a special finish such as patent leather. Some modern synthetic materials
are breathable, however, but often less supple than leather. The use of
footwear with synthetic uppers should not be dismissed as long as they
it well and a suitable period of drying out is allowed between periods of
use, but it is useful to remember that there is little stretch in this material,
therefore footwear made from synthetic material may not be suitable for
feet with prominences. Likewise, materials such as cotton corduroy may
feel comfortable but stretch in only one direction and require reinforce-
ment, particularly in the heel counter.
Linings
In traditional footwear the linings are usually made of soft leather or syn-
thetic material. This does not generally cause a problem, as these are
