Effect of a Thin Customized Insole in RA

50-90% of patients with RA reports foot problems and the metatarsophalangeal joints of the forefoot are most frequently afflicted. Studies shows that foot problems can influence negatively on the walking function, physical activity and quality of life. Different foot orthoses and insoles are used as an intervention. Studies find that different insoles do have effect on pain, but there are no or minor effect on walking ability. The literature reports a further need for research and indicates the importance of studies on the effects of cost-effective insoles for patients with RA.

Custom-built insoles takes time and are often expensive, and many patients, especially women, do not wear them since they often do not fit the shoes they prefer to wear. In this study, a 4-mm thin, flat insole of a malleable plastic material (CI-Core®) with synthetic textile material on the upper side is customized to provide support for the transverse and longitudinal arches of the foot to reduce pressure on painful joints. The insole is easily customized and ready for use the same day. The purpose of this study was to determine whether this insole can reduce foot pain and increase walking distance in patients with RA and forefoot pain.

An experimental study was performed on patients with RA and forefoot pain in either one or both feet. The patients walked as fast as they could in 6 minutes (6MWT) with either insoles (situation A) and without insoles (situation B). The order of situation A and B was randomized, and the assessor was blinded for the order of the two situations. Both tests were conducted the same day. After each test round, the patient was asked to register pain in the foot and perceived exertion. A telephone interview was conducted one year after the effect study to examine whether the insoles were still being used.