56 Running for Fitness
" Cantilever is a concave outsole design in which the outer edges flare out dur-
ing foot strike to provide better shock absorption." EVA is a foam-like material which is used in midsoles to provide cushioning.
" Polyurethane (PU) is a synthetic rubber that is used with EVA in midsoles. It
is more durable than EVA but provides less cushioning. PU is used in the rear
foot for firmness and EVA in the forefoot for flexibility and lightness in many
shoe models." Metatarsal pad is a soft wedge of EVA that is placed under the ball of the
foot to increase cushioning and shock absorption for runners who are fore-
foot strikers.Terms Related to Shape
" Last is a foot shaped piece of wood, plastic or metal which is used as a frame
for building a shoe. Lasts can be straight or curved as shown in Figure 4-2." Straight-lasted shoes are relatively straight shaped on the inner or medial
side and provide support and stability and are recommended for runners who
over-pronate." Curve-lasted shoes are shaped to curve inwards (see figure). This shape
allows greater foot motion and such shoes can be worn by runners with nor-
mal pronation and arches.Figure 4-2. Types of Lasts Used for Running Shoes
Straight Curve