The effects of sandals on postural stability in patients with rheumatoid arthritis: an exploratory study

Rheumatoid arthritis results in postural instability, pain and functional limitations. As rheumatoid arthritis progresses, localised forefoot deformities such as hallux valgus and clawing of the lesser toes occur, leading to a high proportion of people with rheumatoid arthritis wearing sandals. Sandals may affect postural stability due to poor motion control. The aim was to assess two different open-toe sandals on postural stability in people with rheumatoid arthritis.

Twenty women with rheumatoid arthritis were assessed in quiet standing under four conditions: (1) open-back sandal; (2) closed-back sandal; (3) own footwear and (4) bare feet. Postural stability was assessed as postural sway in the anterior-posterior and medial-lateral directions, with eyes open and eyes closed, using a pressure mat. Repeated measures analysis of variance tested the interaction effect of the footwear and eye conditions on anterior-posterior and medial-lateral sway.

In eyes-open, there was no significant difference in anterior-posterior sway (P=.169) and medial-lateral sway (P=.325) for footwear conditions. In eyes-closed testing, compared with barefoot conditions, increased anterior-posterior sway was observed with participants' footwear (P<.0001), the open-back sandal (P=.005), and the closed-back sandal (P=.017). With eyes closed, increased anterior-posterior sway was also observed with the participants' footwear compared with the closed-back sandal (P=.041). Increased medial-lateral sway was observed with the closed-back sandal compared with bare feet (P=.014).

Sandals may be detrimental to older women with well-established rheumatoid arthritis when eyes are closed. Further investigation is needed to evaluate the effect of sandals on dynamic tasks.