Lateral wedges - a crossover study
"Since recent research has identified a link between foot symptoms
and development of knee OA, and the fact that shoe-worn insoles
evoke change directly at the feet, measurement of foot and ankle
symptoms with foot-based treatment for knee OA is necessary."
statistical differences when comparing group
mean comfort ratings, any effect of perceived
comfort would have occurred on an individual
basis. Jones et al also reported slightly more
perceived foot comfort with a combined insole
compared to a lateral wedge alone, though the
differences were also not statistically significant
[21]. Given that 19/26 individuals reported at
least some foot pain (values >25% on the FFI-R
pain subscale) at the initial baseline assessment,
assessment of changes in foot symptoms was
important. Within-condition assessment of
change in these symptoms from the current
study would indicate that the lateral wedges
plus arch support were able to improve foot
symptoms. Finally, while not statistically
tested, more self-reported adverse events were
recorded during lateral wedges use (n=11) than
during the combined insoles (n=5). While these
reports were relatively minor and short-term,
this finding provides further justification for the
need to comprehensively assess the feet when
providing any insoles treatment to people with
knee OA to primarily target knee symptoms.
Our study is novel, and an important
contribution to the literature for a number of
reasons. First, this is the first study evaluating
shoe-worn insoles in people with knee OA that
has considered foot type as an inclusion or
exclusion criterion. As noted above, given that
pronated foot posture is common in people
with knee OA [6], and is associated with a
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higher risk of developing knee pain and medial
tibiofemoral cartilage damage [11], this subgroup
in particular represents an important target for
the study of shoe-worn insoles for the treatment
of knee OA. More research with a homogeneous
sample of pronated foot posture is warranted.
This is also the first study, to our knowledge, to
assess the impact of insoles on foot symptoms
in people with knee OA. Since recent research
has identified a link between foot symptoms
and development of knee OA [9], and the fact
that shoe-worn insoles evoke change directly
at the feet, measurement of foot and ankle
symptoms with foot-based treatment for knee
OA is necessary. Indeed, given that more self-
reported adverse events (especially lower leg,
ankle, and foot issues) were reported in the
present study with the lateral wedges alone,
this finding provides important information
necessary to inform clinical decision making
in this particular subgroup. However, given the
potential cost difference between the two types
of insoles (potentially in excess of $300 per pair
depending on the provider), a cost-effectiveness
analysis of any symptomatic benefits of the
combined insole must be conducted to assist in
the justification of prescribing this addition to a
standard lateral wedge.
There are some limitations to this study.
First, although within-condition changes were
observed, our relatively small sample size for
this exploratory study likely impacted our