Plantar Pressure Distribution in Individuals With Medial Knee Osteoarthritis and Correlation With Foot Morphology.

OBJECTIVE

To investigate plantar pressure (PP) distributions in patients with knee osteoarthritis (OA) and their correlations with foot morphology.

DESIGN

This was a cross-sectional study.

SETTING

Participants were recruited from 2 local orthopedic clinics.

PARTICIPANTS

Fifty-two women with symptomatic medial knee OA (Kellgren-Lawrence grade ≥2) and 38 adults without OA aged ≥60 years of age (total N = 90).

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Hallux valgus angle, navicular/foot ratio, and calcaneus eversion angle were measured as foot morphology indices. PP distribution was recorded during comfortable walking using a PP distribution platform. Statistical parametric mapping analysis of variance was conducted to compare PP between patients with knee OA and those without knee OA. Statistical parametric mapping correlation analyses were performed to confirm the correlation between PP and foot morphology variables in knee OA group.

RESULTS

Compared with the non knee OA group, peak PP values under the first metatarsophalangeal joint, lateral midfoot, and heel region were larger (all P<.01) in patients with knee OA, whereas under the toe and medial midfoot region, peak PP was not significantly different. Positive correlations were found between 1st metatarsophalangeal joint PP and the hallux valgus angle (P<.01), as well as between heel PP and both the navicular/foot ratio and calcaneus eversion angle (P<.01), whereas under the midfoot region, no significant correlation was observed.

CONCLUSIONS

Patients with knee OA showed increased localized PP during walking, as well as a potential association between the PP and foot morphology. These findings could contribute to the development of future treatment interventions for knee OA, including insoles or shoes modifying foot deformity and PP distribution.