The cushioning of running shoes varies from trainers to racing shoes.
Trainers are
used in racking up mileage by the runner to help them improve their
bodies for
the races. This is where the cushioning of the shoes comes into play
and is
very important as it helps relieve stress applied to the feet of the
runner.
The
foot strike of the runner can range from the back of the foot to middle
to the
forefoot and the normal force to the shoe is known as the impact force.
Whatever the case may be the cushioning of the shoe lies in the back
and front
of the shoe where it’s needed since those are the areas where most of
the
impact force is applied to according to the figure (Cavanagh &
LaFortune,
1980) which shows the pressure according to runners that strike the
ground from
the heel area, the middle, and the forefoot.
Cavanagh
& LaFortune, Strike Index, 1980,
Nike
Inc.,
Illinois
Cushioning works
by increasing the amount of time the force is applied. A small force
applied
for a long time can produce the same momentum change as a large force
applied
briefly.
I = F∆t
where
J is impulse
F is the force, and
∆t
is change in the amount
of time.
| Home |
Anatomy |
Friction |
Cushioning |
Pronation |
Bibliography |