Lateral wedges - a crossover study
ability to detect significant between condition
differences. In addition, certain limitations of a
randomized crossover study in general (such as
the potential for carryover and learning effects)
must be considered. However our findings
provide justification for larger studies in this
area. Second, the two-month intervention was
shorter than previous similar studies which
utilized 6- or 12-month (or longer) intervention
periods [33–35]. Although we did observe
improvements in pain and function with the
combined insole over this timeframe, it is
unknown if these benefits would be maintained
over the longer-term. Further, we relied on
self-report data to examine outcomes such as
usage and adverse events. Future research
would benefit from more objective outcomes
of wear time such as instrumented insoles that
more accurately measure usage and would
include some form of assessment of load during
dynamic movement. Finally, more than half
of our sample was comprised of individuals
with mild radiographic disease severity.
Recent research suggests that the relationship
between biomechanics and knee symptoms in
individuals with knee OA is stronger in more
advanced radiographic disease [36], suggesting that shoe-worn insoles that attempt to evoke
biomechanical changes at the knee may be less
effective at improving knee symptoms in people
with mild disease. Further research in samples
with more advanced radiographic knee OA
and pronated feet is required to determine the
effectiveness of shoe-based intervention in this
cohort.
ABBREVIATIONS: AVAILABILITY OF DATA AND MATERIALS:
EVA: Ethyl-vinyl-acetate; FFI-R: Foot function index revised
version; FPI: Foot posture index; KAM: Knee adduction
moment; KL: Kellgren and Lawrence; NRS: Numerical
rating scale; OA: Osteoarthritis; WOMAC: Western
Ontario and McMaster Universities Osteoarthritis Index. The datasets used and/or analyzed during the current
study available from the corresponding author on
reasonable request.
FUNDING:
This study was funded, in part, by a grant from the
Pedorthic Research Foundation of Canada. The funding
body had no role in any aspect of this study. RSH is
supported by an Australian research Council Future
Fellowship (FT130100175). The funders had no role in any
aspect of this study.
CONCLUSIONS
In conclusion, we found that the addition of
custom arch support to standard lateral wedge
shoe insoles resulted in improvements in foot
pain and function in a group of individuals with
knee OA and pronated feet. However, changes
in symptoms were not statistically different from
those observed when participants were treated
with lateral wedges alone. Given that shoe-
worn insoles represent a relatively inexpensive
treatment option with little patient burden,
findings from the present study suggest further
research is required to evaluate the role of
combined insoles in managing knee and foot
symptoms in these patients.
—END
AUTHORS’ CONTRIBUTIONS:
MH was involved in study design, data analysis, as
well as drafting and approval of the manuscript. JT was
involved in study design, data collection, and approval
of the manuscript. NK was involved in participant
recruitment, data collection, and approval of the
manuscript. GH was involved in data collection and
approval of the manuscript. RH was involved in study
design, data analysis, and approval of the manuscript. RC
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