Background RA related foot problems can be managed by providing custom made foot orthoses (FO). A recent systematic review showed FO to be effective in reducing pain and high plantar forefoot pressures . However, a moderate effect on pain reduction was found (effect size 0.45) . The use of in-shoe plantar pressure measurement is a promising method for improving foot orthoses (FO). The immediate feedback from in-shoe plantar pressure measurements may be useful to evaluate and adapt FO . Therefore, we developed a protocol for the use of in-shoe plantar pressure measurements to evaluate and adapt the plantar pressure distribution properties of FO in patients with RA.
Objectives The objectives of the present study were to evaluate (1) the outcome on plantar pressure distribution of FO that were adapted according to the protocol and (2) the feasibility of the protocol in clinical practice.
Methods Forty-five RA patients with foot symptoms were included in this study. FO were custom-made by a podiatrist according to usual care. Usual care FO were constructed using prefabricated, semi-rigid FO and customized based on clinical reasoning by the podiatrist. In-shoe plantar pressure measurements were performed without FO and regions of interest (ROIs) for plantar pressure reduction were selected. Subsequent, in-shoe plantar pressure measurements with usual care FO were performed. Usual care FO were evaluated and adapted according to the developed protocol. In a within-subject design, plantar pressure-time integrals at ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.
Results Adapted FO were developed in 70% of the patients. In these patients, usual care FO showed a mean 9% reduction in pressure-time integral at forefoot ROIs compared to no-FO (p=0.01). FO adaptation showed an additional mean 3% reduction in pressure-time integral (p=0.05). The protocol was considered feasible by patients. The podiatrists reported a learning effect of the protocol and considered the protocol more useful to achieve individual rather than general treatment goals.
Conclusions Using in-shoe plantar pressure measurements for adapting foot orthoses leads to a small additional plantar pressure reduction in forefoot regions in patients with RA and foot symptoms. Further research on the clinical outcome of this approach is required.
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Disclosure of Interest None declared