Effect of an orthosis on foot center of pressure translation for treatment of hallux valgus in patients with rheumatoid arthritis: A report of 17 cases

Abstract

ObjectivesWe aimed to investigate the change in the center of pressure (COP) path and distribution with or without orthosis for hallux valgus (HV) in patients with rheumatoid arthritis (RA). MethodsIn total, 17 patients and 21 feet were enrolled. We measured the COP path using the COP path measurement device (F-Scan II system). The HV angle (HVA); the anteroposterior COP path length, which was measured as a percentage of the foot length (%Long); transverse width of the COP path which was measured from the most medial to the most lateral point and expressed as a percentage of maximum foot width (%Trans); and the final site of the walking locus were analyzed by comparing patients with RA with and without orthosis. ResultsTesting without and with the orthosis showed that the HVAs were 31.8° ± 9.3° and 25.2° ± 6.8° (p < 0.001), the %Long values were 61.1% ± 5.5% and 69.2% ± 5.9% (p < 0.001), and the %Trans values were 28.0% ± 9.1% and 30.1% ± 8.3% (p = 0.108). The final site of the walking locus for the 1st interphalangeal joint without and with orthosis were 8 feet (38.1%) and 15 feet (71.4%) (p = 0.020), respectively. ConclusionsThe results indicated that the orthosis for HV improved the walking path and should be considered as a therapeutic option in nonpharmacological treatment of RA.