Lateral wedges - a crossover study
knee OA and concomitant pronated feet. We
were also interested in the safety of these
interventions and adherence to treatment. It was
hypothesized that the combined insole would
produce greater improvements in knee pain
and physical function, as well as foot pain and
stiffness, and would be more comfortable.
METHODS
Participants: Community-dwelling individuals
with medial tibiofemoral OA were recruited via
advertisements in print media. Inclusion criteria
included: (i) definitive medial tibiofemoral
osteophytes on radiograph; (ii) joint space
narrowing greater in the medial tibiofemoral
compartment compared to the lateral
compartment; (iii) history of knee pain longer
than six months; (iv) average knee pain of at
least 3 out of 10 (using an 11-point numerical
rating scale (NRS) with terminal descriptors of
0=“no pain” and 10=“worst pain imaginable”)
over the one month prior to initial screening;
and (v) pronated feet, defined as +4 or higher
on the Foot Posture Index [23], with at least
four items rated as +1 (indicating pronation).
Exclusion criteria included: (i) knee surgery
or intra-articular injection for pain within the
previous six months; (ii) current or past (within
six weeks) oral corticosteroid use; (iii) history
of knee joint replacement or tibial osteotomy;
(iv) any other condition affecting lower limb
function; and (v) current, or failed previous (i.e.
premature cessation of orthotic treatment due
to adverse effects), wearing of shoe insoles/
orthotics. The study was approved by the
Institution’s Clinical Research Ethics Board
and all participants provided written informed
consent. In contrast to information provided on
the trial’s registry (Clinicaltrials.gov identifier:
NCT02234895), gait biomechanics data were
only collected at the initial baseline data
collection session, rather than at all time points,
and are presented elsewhere [24].
STUDY DESIGN
This was an exploratory, within-subjects
cross-over study.
PROCEDURES
Interested participants were initially
screened for inclusion and exclusion criteria,
and eligible individuals were referred for a
physical screening of foot posture. Individuals
who passed the foot posture eligibility criteria
described above were referred for radiographic
evaluation. Standing, semi-flexed, postero-
anterior radiographs were obtained and graded
for disease severity using the Kellgren and
Lawrence (KL) OA classification system [25].
Individuals who met all study eligibility criteria
were then referred to a Canadian Certified
Pedorthist, who obtained foot measurements
and made volumetric casts of both feet to inform
manufacture of insoles. Participants returned to
the same Pedorthist following manufacture of
both sets of the insoles for final modifications
and instruction on insoles wear. Insoles were
made for bilateral wear, even in cases where
knee OA was unilateral. Both sets of insoles
were then sent directly to the University
laboratory, and participants were scheduled
for their first baseline testing session. Following
baseline assessment of outcomes (month 0),
participants were randomly allocated to either
i) lateral wedges alone or; ii) lateral wedges plus
custom arch support. Allocated insoles were
worn for a two-month period in their own usual
shoes, and then participants were reassessed
Current Pedorthics | January/February 2019
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