Einfluss einer 3D-gedruckten bionischen Fußorthese auf die Rückfußbelastung und Laufökonomie

Abstract

BackgroundDuring the propulsion phase (PP) of running, the greatest internal loads occur at the feet. An intact windlass mechanism (WM) is essential for physiological loading at the feet during PP and energy-efficient locomotion. In functional flat foot deformity, WM is insufficient. Overstressing can be the result. In addition, energy efficiency during running is reduced. Foot orthoses (FO) are used, among other things, to optimize positioning and loading of the lower extremities. Optimization of loading during PP and optimization of running economy have not been the focus of FO treatments. A 3D-printed bionic (BFO) is developed to improve loading in PP and to improve energy efficiency during running. The aim of the present study was to determine the influences of BFO on loading in the subtalar region and on running economy. Material and MethodsThirteen subjects with functional pes valgus (39 ± 7 J, 8 m) participated in the study. The subjects ran in randomized order under 4 conditions: without FO (oFO), supportive FO (CFO), sensorimotor FO (SMFO), and BFO on a treadmill. The vebitoScience measurement system (120 Hz) was used to detect torsional moments, respectively pronation/supination load in the subtalar region and time-related parameters. The influences of FO on running economy were determined by stance phase duration, PP, and AP. Statistical analysis was performed using one-way ANOVA with repeated measures and Pearson correlation. ResultsDuring AP, pronation loading occurs in oFO, CFO, and BFO conditions, and supination loading occurs in SMFO condition. All conditions differ significantly from each other. Pronation loading occurs under conditions oFO and SMFO, and supination loading occurs under conditions CFO and BFO during PP. BFO is significantly different from all other conditions. The duration of AP during running with BFO is significantly shorter and the duration of PP is significantly longer than in the other conditions. The duration of PP and supination load while PP correlate significantly strongly for both, FO and BFO. ConclusionsAll FO tested have significant influences on subtalar loading during AP. In subjects with pes valgus, lower supination loading during PP is significantly related to lower running economy. BFO significantly increases supination loading in the subtalar region during PP. The duration of the PP is significantly prolonged by BFO. This represents an optimization of running economy. The other FO tested do not provide these influences. In addition, there is a significant relationship between the greater supination load and better running economy with BFO. In conclusion, BFO have positive influences on loading and running economy in runners with pes valgus.