Article

Although plantar pressure measurement systems are being used increasingly during
gait analyses to investigate foot orthotics, there is limited information
describing test-retest reliability of such measurements. Objectives of this study
were to (1) examine the test-retest reliability of lateral heel pressure (LHP)
and centre of pressure (COP) during walking with and without lateral heel wedges,
and (2) evaluate the effects of 4 degrees and 8 degrees lateral heel wedges on
the magnitude of LHP, the pathway of the COP and the peak external knee adduction
moment (KAM) in subjects with and without knee osteoarthritis (OA). Twenty-six
subjects, 12 patients with knee OA and 14 healthy subjects, were evaluated during
three lateral heel wedge conditions (control, 4 degrees and 8 degrees ) with
standardized footwear. Three-dimensional analyses of gait with optical motion
capture, floor-mounted force plate and in-shoe plantar pressure were completed on
two occasions. Intraclass correlation coefficients (ICC(2, 1)) for LHP were
excellent (0.79-0.83) while ICCs for COP in the medial-lateral and
anterior-posterior directions were more variable (0.66-0.86). Reliability was
slightly diminished when using heel wedges. Standard errors of measurement
suggested considerable day-to-day variability in an individual's measures.
Lateral heel wedges significantly (p<0.001) increased LHP, shifted COP anteriorly
and laterally, and decreased the KAM. No significant differences were observed
between subjects with and without OA. Although the day-to-day variability appears
too large to confidently evaluate changes in individual patients, and decreases
in reliability with increases in wedge size indicate caution, these results
suggest in-shoe measurement of LHP and COP are appropriate for use in studies
evaluating biomechanical effects of foot orthoses for knee OA.
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Langue : ANGLAIS