The Influence of
Medial and Lateral Placement
of Orthotic Wedges on
Loading the Plantar
Aponeurosis
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METHOD
The
aim
of
this
study
was
to
quantify
the
strain
in
the
plantar
aponeurosis
with
different
combinations
of
wedges.
A
single
wedge
or
combination
of
wedges
was
placed
under
cadaveric
models
(varus
and
valgus
wedges
under
the
forefoot
and/or
rearfoot).
A
load
was
then
applied
to
the
cadaver
limb
in a
walking
apparatus,
and
a
strain
gauge
in
the
plantar
fascia
measured
the
effect.
RESULTS
A
wedge
under
the
lateral
aspect
of
the
forefoot
(valgus
wedge)
decreased
strain
in
the
plantar
aponeurosis.
A
wedge
under
the
medial
aspect
of
the
forefoot
significantly
increased
the
strain
in
the
plantar
aponeurosis.
There
was
no
significant
change
when
a
wedge
was
placed
under
either
the
medial
or
lateral
aspect
of
the
hindfoot.
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|
Significance of the
Article
|
Since wedges are
incorporated into the
orthotic treatment for
plantar fasciitis, it is
important to know how they
contribute to changes in
strain on the plantar
aponeurosis. The findings of
this study revealed that
"the placement of a wedge
under the lateral aspect of
the forefoot appears to be a
promising orthotic control
mechanism for shielding the
plantar aponeurosis from
strain".
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Significance for
Orthotic Therapy
|
The results of
this study
indicate that a
forefoot valgus
wedge pronates
the midtarsal
joint reducing
the stretch of
the plantar
fascia. The
midtarsal joint
likely
contributes to
the pathology
leading to
plantar
fasciitis as a
result of
supination of
the midtarsal
joint stretching
the plantar
fascia. This is
contrary to the
common thought
that subtalar
joint pronation
is the primary
contributor to
plantar
fasciitis.
When casting the
foot for custom
orthoses,
maximally
pronate the
midtarsal joint
to ensure that
there is no
additional
tension on the
plantar fascia
in the orthotic
device. Based on
this study, we
recommend adding
a forefoot
valgus wedge to
the orthotic
when treating
plantar
fasciitis to
pronate the
midtarsal joint.
If you choose
prefabricated
orthoses as part
of your initial
conservative
treatment of
plantar
fasciitis,
select one that
incorporates a
forefoot valgus
correction or
wedge.
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