Load analysis of ankle foot orthoses during gait [thesis]

Atichart. Kwanyuang
2012
Different causes of gait deficiencies generate different symptoms. It is important for orthotists to gain a better understanding on how to design Ankle Foot Orthoses (AFOs) in order to address individual biomechanical requirements. The loads acting on AFOs during gait are important factors for orthotists to accurately understand so as to design AFOs more effectively. Therefore, the aim of this study is to develop a validated Finite Element (FE) model, which could be used to quantify and analyse
more » ... the loads acting on an AFO during gait. In this thesis, for mutual comparison and confirmation, pressures acting on the AFO are recorded by two different types of pressure transducers: resistive and capacitive. Trends of the results obtained from the two sensors are similar; however, the magnitudes tend to be different. Furthermore, an accurate digital 3D scanning model of an AFO is captured using the 3D digitiser which can be modified by Computer Aided Design (CAD) software before being exported to Finite Element Analysis (FEA) software to create an FE model. Both the loads measured from the experiment and the assumed constraint during heel off are then applied to the FE model. To make the analysis more complete, a number of features of AFO and a range of FEA methods are conducted. The results are validated by both empirical findings from previous literature and an additional experiment carried out. Based on a healthy subject with no pathological gait, this study reveals that, on the one hand, the AFO is able to assist walking by carrying 6.89% of the overall magnitude of ground reaction force. On the other hand, it resists walking by generating 18.63% in dorsiflexion of the overall magnitude of the moment generated by the plantarflexors. It is therefore claimed that these findings are useful for orthotists involved in fitting AFOs, in order to efficiently design and construct them. iii
doi:10.48730/7ty6-1q58 fatcat:36xvwyowozazfnyzlvc553uvoq