FOOTWEAR CHARACTERISTICS AND FACTORS INFLUENCING
FOOTWEAR CHOICE IN PATIENTS WITH GOUT
Significance & Innovations
• Poor footwear is a major problem in patients with gout.
• Foot pain, impairment, and disability may contribute to the problem.
• Patients reported comfort, fit, support, and cost as important factors
in choosing their own footwear.
• Future research should be focused on assessing the role of
competitively priced footwear with adequate cushioning, motion
control, and sufficient width at the forefoot.
To date, the choice of footwear and factors impacting the choice
of footwear have not been reported in patients with chronic gout.
The aim of this study was to assess footwear characteristics and key
factors influencing footwear choice in patients with gout. We also
wanted to examine the relationships between footwear and foot
characteristics (pain, disability, and impairment).
PATIENTS AND METHODS
This was a cross-sectional observational study of 50 adult patients
with a history of gout attacks recruited from rheumatology
outpatient clinics at Auckland and Counties Manukau District
Health Boards, Auckland, New Zealand. All patients had a
physician diagnosis of gout and a history of acute gout according to
American College of Rheumatology (ACR) classification criteria
(14). Ethical approval was obtained by the Northern X Ethics
Committee, Auckland, New Zealand (NTX/10/EXP/231), and
local institutional approval was also obtained. Participants were
excluded if they were experiencing an acute gout flare at the time
of assessment or had lower extremity amputation. Patients with
diabetes mellitus or neurologic disease associated with gout were
not excluded from the study. A single podiatrist (MF) assessed all of
the patients at a single study visit.
The following data were collected: age, sex, ethnicity, body
mass index (BMI), disease duration, current pharmacologic
management, and history of cardiovascular disease and diabetes
mellitus. Foot type was assessed using the Foot Posture Index, which
is a validated method for quantifying standing foot type with scores
above +4 suggesting a flatfoot type (15).
Disease impact was measured using the Leeds Foot Impact Scale
(LFIS) (16). This self-administered questionnaire comprises 2
subscales for impairment/footwear (LFISIF) and activity limitation/
participation restriction (LFISAP). The former contains 21 items
related to foot pain and joint stiffness as well as footwear-related
impairments, and the latter contains 30 items related to activity
limitation and participation restriction. Turner et al (17) report
that an LFISIF score >7 points and an LFISAP score >10 points
indicate a high to severe level of foot impairment and disability.
Foot pain was assessed using the Foot Function Index (FFI) domain
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Pedorthic Footcare Association www.pedorthics.org
(17). The FFI is a self-administered questionnaire consisting of 23
items grouped in 3 domains: foot pain (9 items), disability (9 items),
and functional limitation (5 items). All items are rated using 100-
mm visual analog scales, and higher scores indicate greater pain,
disability, and limitation of activity, and therefore poorer foot health
(18).
An objective assessment of footwear was conducted by the
examiner to ascertain the type, structural components, and fit of the
participant’s footwear at the time of the study visit (8,19). Patients
did not receive any instructions about their footwear prior to the
study visit. Six aspects of footwear are evaluated and include: 1)
fit (length, width, and depth), 2) general (age of shoe, footwear
style, weight, and length), 3) general structure (heel height,
fixation, forefoot height, forefoot sole flexion point, and last), 4)
motion control properties (density, fixation, heel counter stiffness,
midfoot sole sagittal, and frontal stability), 5) cushioning (presence
of lateral, medial, and heel sole hardness), and 6) wear patterns
(upper, midsole, tread, and outsole wear pattern).
Based upon previous studies of patients with foot pain and
rheumatoid arthritis, we classified current footwear into poor,
average, and good footwear (10,20). The poor footwear group
consisted of footwear that lacks support and sound structure,
including sandals, flip-flops, slippers, mules, and moccasins. The
average footwear group included shoes such as hard-or rubber-
soled shoes and work boots. The good footwear group consisted of
athletic shoes, walking shoes, therapeutic footwear, and Oxford-type
shoes. Foot dimensions (foot length and width) were measured
using a Brannock measuring device (Liverpool). The device
allows the weight-bearing measurement of foot length and width.
Each patient was also asked by the examiner to identify the most
important feature on a validated checklist that included comfort,
style, fit, sole, costs, weight, and color (21).
All analyses were performed using SPSS, version 17.0. Sex,
ethnicity, clinical characteristics such as current pharmacologic
management, history of hypertension, cardiovascular disease,
diabetes mellitus, and renal impairment, and general footwear
scores are described as the number (percentage). All other
demographic characteristics are described as the mean ± SD. The
association of changes with foot characteristics (pain, disability, and
impairment) with footwear characteristics (shoe length and width)
were evaluated using Spearman’s rho correlation coefficients. We
examined significant differences between shoe category (good,
poor, and average) and foot characteristics (pain, disability, and
impairment) using one-way analysis of variance. We undertook
secondary analysis using independent t-tests to evaluate significant
differences in all footwear characteristics between participants with
diabetes mellitus and those without diabetes mellitus. All tests were
2-tailed and P values less than 0.05 were considered significant.