Effects of unstable footwear on joint reactions and muscle forces: an inverse dynamics study
- Michael Schwarze1Email author,
- Frank Seehaus1,
- Christof Hurschler1 and
- Hazibullah Waizy2
https://doi.org/10.1186/1757-1146-5-S1-O7
© Schwarze et al; licensee BioMed Central Ltd. 2012
Published: 10 April 2012
Keywords
Background
Unstable shoe designs should support the muscle activity and promise the treatment of leg, back and foot problems. According to manufacturers, they should activate additional muscles and reduce joint reaction forces. Goal of this study is to investigate the effect of an unstable shoe design to gait patterns of healthy volunteers and by the means of inverse dynamic multi-body simulation.
Materials and methods
Seven subjects (age: 46.5±7.6 years, weight: 91.7±11.1kg) familiar with unstable shoes performed five trials of level walking in three testing conditions (barefoot, conventional and unstable shoe). As an unstable shoe the Anti-Step (Chung-Shi) was chosen. Kinematic and kinetic data was acquired with a motion capturing system (Vicon) and two forceplates (AMTI). The inverse dynamics model of the lower extremity consists of nine rigid bodies which are connected with idealized joints and a set of all relevant muscles.
Results
Muscle activation of the ankle muscle groups around the ankle for one subject. Lines representing results for barefoot (red), conventional shoe design (green) and unstable shoe design (blue).
Joint reaction forces in the ankle for one subject. Lines representing results for barefoot (red), conventional shoe design (green) and unstable shoe design (blue).
Conclusions
The simulation reveals muscle activation patterns that indicate instability along the inversion/eversion axis of the ankle, which is also found in the literature [1]. The additional activation of the everter group during stance phase possibly exercises this group and could lead to an effect on the arch of the foot.
Authors’ Affiliations
References
- Nigg B, Hintzen S, Ferber R: Effect of an unstable shoe construction on lower extremity gait characteristics. Clin Biomech. 2006, 21: 82-88. 10.1016/j.clinbiomech.2005.08.013.View ArticleGoogle Scholar
Copyright
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
