Lateral wedges with and without
custom arch support for people
with medial knee osteoarthritis
and pronated feet:
An exploratory randomized crossover study.
ABSTRACT
BACKGROUND:
Pronated foot posture is associated with many
clinical and biomechanical outcomes unique to
medial compartment knee osteoarthritis (OA).
Though shoe-worn insole treatment, including
lateral wedges, is commonly studied in this
patient population, their effects on the specific
subgroup of people with medial knee OA and
concomitant pronated feet are unknown. The
purpose of this study was to evaluate whether
lateral wedge insoles with custom arch support
are more beneficial than lateral wedge insoles
alone for knee and foot symptoms in people
with medial tibiofemoral knee osteoarthritis (OA)
and pronated feet.
METHODS:
Twenty-six people with pronated feet and
symptomatic medial knee OA participated
in a randomized crossover study comparing
five-degree lateral wedge foot insoles with
and without custom foot arch support.
Each intervention was worn for two months,
separated by a two-month washout period of
no insoles wear. Main outcomes included the
Western Ontario and McMaster Universities
Osteoarthritis Index (WOMAC) pain and
physical function subscales, the revised short-
form Foot Function Index (FFI-R) pain and
stiffness subscales, and the timed stair climb
test. Regression modeling was conducted to
examine treatment, period, and interaction
effects.
RESULTS:
Twenty-two participants completed the
study, and no carryover or interaction effects
were observed for any outcome. Significant
treatment effects were observed for the timed
stair climb, with greater improvements seen
with the lateral wedges with arch support.
Within-condition significant improvements
were observed for WOMAC pain and physical
function, as well as FFI-R pain and stiffness
with lateral wedges with arch support use.
More adverse effects were reported with
the lateral wedges alone, while more people
preferred the lateral wedges with arch support
overall.
CONCLUSIONS:
Addition of custom arch support to a standard
lateral wedge insole may improve foot and
knee symptoms in people with knee OA and
concomitant pronated feet. These preliminary
findings suggest further research evaluating the
role of shoe-worn insoles for treatment of this
specific sub-group of people with knee OA is
warranted.
Current Pedorthics | January/February 2019
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