Effect of trim line on stiffness in dorsi- and plantarflexion of posterior leaf spring ankle-foot orthoses

J Phys Ther Sci. 2022 Apr;34(4):284-289. doi: 10.1589/jpts.34.284. Epub 2022 Apr 8.

Abstract

[Purpose] This study aimed to objectively clarify the effect of the trim line setting on the stiffness of posterior leaf spring ankle-foot orthoses. [Participant and Methods] Posterior leaf spring ankle-foot orthoses were fabricated with two thickness levels and three trim line conditions for the posterior upright width and the dorsi- and plantarflexion moments and stiffness exhibited by the orthoses were measured using an evaluation tester. [Results] The trim line of the posterior upright width affected the dorsiflexion moment generated by the orthoses in plantarflexion. [Conclusion] A strong linear correlation was found between posterior upright width and orthotic stiffness, suggesting that it is highly feasible to standardize orthotic settings according to individual conditions of patients after stroke, even for posterior leaf spring ankle-foot orthoses.

Keywords: Posterior leaf spring ankle-foot orthoses (PLS-AFO); Stiffness; Trimming line.