Quantifying lower limb gait coordination in off-the-shelf orthotic shoes

Abstract

Orthotics are thought to alter the relationship between the motion of lower extremity segments during walking. Recently, off-the-shelf foot orthotics incorporated into a shoe have been offered as alternatives to customized orthotics. The aim of this study was to investigate the use of ‘off-the-shelf’ orthotic shoes using the quantification of segmental coordination. Eleven healthy male subjects (age: 28 ± 5 years, mass: 60 ± 6 kg, height: 1.7 ± 0.3 m) consented to participated in this study. Subjects walked in the Non-ortho condition (i.e. their own normal pair of neutral business shoes) or, in the Ortho condition (i.e. the orthotic business shoes) on a motorized treadmill. Joint coordination coupling between the calcaneus (inversion/eversion) and the tibia (internal/external rotation) was evaluated using a modified vector coding technique. Angles, γ, from 0° to 360° were computed to examine both angle–angle and angular speed–angular speed coordination. Results indicated that the coupling patterns were not significantly different for angle–angle coordination but were significantly different for angular speed–angular speed coordination when comparing Ortho and Non-ortho conditions. The two conditions were similar throughout the Early, Mid, and Late portion of the stance phase. Greater variability with out-of-phase couplings was observed during the Early and Late periods in angular speed–angular speed coordination for the Ortho condition. These results indicate that an off-the-shelf orthotic shoe can alter calcaneal–tibial coordination and coordination variability significantly. While increased coordination and coordination variability is associated with a potentially healthier gait, it should be noted that the subjects in this study had no injury or pathology that would have caused them to use orthotics.

Keywords:

• coordination
• variability
• orthotics

Acknowledgement

We will like to thank Amrish Soundararajan and Sulaiman Ahmed Suhyl for their help in the data collection as well as Ergo Lab for their support in this project for their provision of the footwear.