FOOTWEAR SOLE STRUCTURE
di Sergio SEGALIN
***CERTIFIED BY THE UNIVERSITY OF PADUA
This paper describes a novel, original product deriving
from many years of research and experimentation. Having
passed numerous practical and empirical, and ultimately
also clinical and instrumental tests, this sole is now
ready for application in the fine footwear sector. It
is intended for mature, demanding customers, and designed
to meet their expectations in terms of comfort, light
weight and flexibility, to prevent leg fatigue in the
wearer's daily activities and to favor the relaxation
of the posterior tibial muscle mainly responsible for
bearing the weight of the body when a person is standing
or walking for lengthy periods of time.
This sole is suitable for use in the production of all
kinds of footwear. It has been conceived to provide a
slightly elevated support for the rear part of the foot,
with a particular lateral slant and a supporting curve
on the medial side, so as to aid muscle function and reduce
fatigue in the leg and foot.
This "footwear sole structure" was invented
by Sergio Segalin of Venice and is now covered by an Industrial
patent (Application: TV2004A000123 of 29.10.2004). It
is probably unique in the footwear sector, in that it
can boast UNIVERSITY
CERTIFICATION, granted after numerous medical and
instrumental tests conducted at the University of Padua's
Orthopedics Clinic (Prof. Raffaele Scapinelli and Dr.
Giuseppe Taglialavoro) and Neurophysiopathology Service
(Prof. Paolo Negrin).
The patented sole structure is the outcome of lengthy
research and experiments by its inventor over decades
of activity in the design and manufacture of various models
of corrective footwear. It emerged from these studies
that - despite the variety of cases presenting themselves
and the numerous different methods being applied to footwear
for corrective purposes, or to compensate for anatomical
deficits or peculiarities - the structural anatomical
characteristics of the underside of such footwear (insole
and sole) were always founded on the same concept, i.e.
that laterally tilting the surface supporting the foot
has a positive effect in reducing the fatigue deriving
from prolonged standing and walking.
Using such a supporting surface, inducing a mild supination
of the heel, helps to create a particular three-dimensional
configuration of the foot as a whole that is capable of
optimizing both the distribution of the body weight on
the surface of the sole and the function of the posterior
tibial muscle, having the tangible effect of reducing
the sense of fatigue and improving the feeling of wellbeing.
This prompted the creation of the "footwear sole
structure" explained overleaf. By way of example,
two graphic illustrations are provided to demonstrate
the unique, original nature of its shape.
This "footwear sole" can be applied to any type,
model and size of shoe for men or women. It is suitable
for use by people with feet presenting a normal physiology
and function, as well as by people whose feet have anomalies
or pathologies, such as excessive arch relaxation or contraction.
It may be a good idea to mention here that the sole of
a shoe is normally flat. An insole can be inserted, as
and when necessary, which can be shaped more or less anatomically,
also adding pads designed to raise the arch passively,
or adopting other specific corrective measures depending
on the wearer's needs.
The present footwear sole, on the other hand, has a particular
shape for the surface supporting the back of the foot
so as to transfer the load more on the lateral side of
the heel bone than on the medial side (*).
The invention also prevents any excessive twisting of
the sole of the foot (as explained in the footnote) and
thus prevents the foot from becoming too flat, thereby
helping to preserve a normal morphology of the foot in
the static phase and optimizing the work of the posterior
tibial muscle in the dynamic phase of heel lift and toe
off (otherwise the muscle would be forced to contract
excessively, thus producing fatigue).
For all the above reasons, the product presented here
is responsibly recommended as a tool for use in the medical
footwear sector too, where the acquisition of new experience
may point to other interesting prospects that, for the
time being, are still only theoretically feasible.
* According to the tester, Dr. G. Taglialavoro, it has
now been well established in the scientific literature
that, "the foot as a whole does not work like a tripod,
which would inevitably have exclusively static functions;
instead, it forms an architecturally three-dimensional
screw-like structure capable of coiling and uncoiling
in relation to the static and dynamic functions of the
foot. This coiling and uncoiling action influences the
appearance of the footprint and thus also the extent to
which the medial margin of the foot lifts off the ground.
The degree to which the foot uncoils and coils depends
on the heel's intra- and extra-rotational motion. Pronation,
i.e. when the heel rotates inwards (becoming valgus with
respect to the tibia) uncoils the foot, while supination,
i.e. when the heel rotates outwards (becoming varus) has
a compressive effect. Pronation and supination are physiological
heel movements in deambulation as a function of the static
and dynamic phases of the stride. In static terms, the
pronated heel uncoils and hollows the foot. Thus, during
deambulation, the foot passes from an anatomo-functional
condition of relative flatness to a phase of relative
hollowness. The foot's morpho-functional "normality",
and the consequent amplitude of its footprint, are assured
by a certain degree of uncoiling, which must be neither
too much nor too little."