Restrictions in the ankle sagittal- and frontal-plane range of movement during simulated walking with different types of orthoses

Different types of orthoses are available to clinicians for non-surgical treatment of acute ankle sprains. The goal of this study was to scientifically compare the movement restrictions in the sagittal and frontal plane during simulated walking between one adaptable semi-rigid brace (OrthoTri-PhaseTM), four non-adaptable semi-rigid braces (OrthoStandardTM, MalleoLocTM, MalleoSprintTM, VACOankleTM), and one rigid cast. Predefined time sequences of rotational moments and axial loading during gait were applied via an ankle joint simulator, with the pneumatic pressure inside the orthoses kept constant to ensure the same condition for different trials and orthoses. The peak ranges of motion (RoMs) in the frontal and sagittal plane during gait were analyzed for statistically significant differences using single-factorial ANOVA with post-hoc Bonferroni analysis. Significant differences in peak plantar-/dorsiflexion and in-/eversion RoM during gait were found between different types of orthoses. In the sagittal plane, the rigid cast most significantly restricted overall RoM followed by the Ortho Tri-PhaseTM in Phase 1 and the Ortho StandardTM. The peak restriction in-/eversion RoM of the VACOankleTM came closest to the rigid cast, with a shift towards inversion. The VACOankleTM allowed for significantly larger dorsiflexion movement compared to all other orthoses. The present results may help clinicians in the decision-making process of finding the optimal orthosis for individual patients.