Effects of walking in sandals with foot orthoses on navicular kinematics during stance
P. Eichelberger1, D. Lambelet1, N. Chavaillaz1, F. Krause1, H. Baur1 (1Bern)
Introduction
Foot orthoses are commonly used in the conservative treatment of foot complaints such as posterior tibial tendon dysfunction. While certain studies explored effects on multi-segment foot kinematics, the knowledge about the influence on midfoot kinematics measured by cranio-caudal (CC) and medio-lateral (ML) navicular translation is limited.
Méthodologie
Navicular kinematics were measured in 22 healthy participants with a 3D motion capture system and a set of four reflective markers during walking barefoot (BF) and in sandals with (SO) and without (S) orthoses, which provided medial longitudinal arch support.
Résultats
CC and ML navicular displacement showed generally consistent patterns of caudally dropping and medially bulging during loading response, mid- and terminal stance followed by cranially rising and laterally shifting during push-off. Maximum caudal displacement 6.2/6.9/7.2 mm (BF/S/SO) was not significantly affected by the shoe conditions. There was a tendency for a more flattened arch in late terminal stance due to shoes with orthoses when looking at the CC navicular position. Maximum medial displacement 4.3/5.4/7.0 mm (BF/S/SO) was significantly increased by shoes with orthoses compared to barefoot walking. Shoes with and without orthoses restricted the arch rise during push-off up to 3 mm and 4 mm, respectively. Shoe conditions led up to 22.5 mm/s reduced rates of caudal and medial displacement during early loading response and up to 54.5 mm/s reduced rates of cranial and lateral displacement during push-off.
Discussion et conclusions
Walking in shoes with foot orthoses affected midfoot kinematics. The tendency of increased caudal arch drop and medial arch drift might be a consequence of reduced muscular stabilization due the footwear intervention or because the sandals provided not enough support for the orthoses to fulfill the intended requirements. However, foot orthoses delayed the arch drop during the first half of stance. Shoes possibly restricted dorsal extension in the metatarsal-phalangeal joints during push-off and consequently prevented the windlass mechanism from passively rising the medial longitudinal arch.
Importance pour la pratique
Instead of reducing assessments to features, like range of motion, the whole stance phase should be considered when analyzing effects of footwear. Studies combining biomechanical measurements with patient outcomes are needed to further explore the effectiveness of foot orthoses.
