How does orthotic walker boot design influence lower limb and trunk function during gait?

Abstract

Background: Undesirable lower limb gait deviations have previously been reported when wearing orthotic walker boots, therefore there is a need to optimise orthotic walker boot designs to facilitate normal gait. Objective: This study explored the biomechanical effects of two designs of orthotic walker boot on the lower limb and trunk compared to usual footwear. Study Design: A repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic and kinetic variables under different walking conditions. Methods: Sixteen healthy participants walked in three conditions using: Walker A (Airselect Elite, Enovis, USA), Walker B (Townsend XLR8 Series Walker, Thuasne, France) and a usual shoe. A 10 camera motion analysis system and 4 force plates were used to collect kinematic and kinetic data. Results: Gait speed was significantly slower in both orthotic walker boots, and significantly decreased ankle range of motion (ROM) which is their primary function. Significant deviations in normal knee and hip kinematics and kinetics, shank to vertical angle and pelvic and trunk movements were noted with both walker boots, with the greatest deviations from the shoe condition observed in Walker B. Recline and incline shank angular velocities showed the greatest differences in Walker B which could be associated with adverse knee joint moments and a significantly greater perceived ease of walking in Walker A. Conclusions: Orthotic walker boot design significantly affects walking mechanics. Orthotic walkers with greater forefoot rocker profiles and inclined vertical shank angles may at least in part mitigate known gait deviations when wearing orthotic walkers.