Rheumatoid arthritis (RA) often affects feet with progressive pathologic changes to foot morphology and pressure distribution. Studies in RA suggest that reductions in forefoot peak pressures can reduce pain. We investigated the effects of off-the-shelf foot orthoses on plantar foot pressures in patients with early RA.
Thirty-five patients with early RA were recorded walking. Variables measured were forefoot peak plantar pressure (PPPft), forefoot pressure-time integral (PTIft), and hallux and lesser toe and midfoot contact areas. Patients were analyzed while walking barefoot, with shoes, and with shoes and foot orthoses. Measurements were taken at baseline and at 3 and 6 months.
There were significantly increased PPPft values between barefoot and shod and between barefoot and orthoses (P < .01). However, there was a significant reduction in PPPft during the 6 months with orthoses compared with shoes only (P < .01). Foot orthoses significantly reduced PTIft over 6 months (P < .01). Results also demonstrated a significant increase in hallux and lesser toe (P < .01) and midfoot (P < .01) contact areas during the 6 months with foot orthoses.
In patients with early RA, off-the-shelf foot orthoses cause a significant reduction of 22% in PPPft and 14% in PTIft as soon as insoles are worn compared with shod. Further reductions for orthoses compared with baseline were found by 3 months (15% in PPPft and 14% in PTIft) and 6 months (33% in PPPft and 33% in PTIft). These findings could contribute to reductions in foot pain.