Designing New Composite Foot Supports for Bunions

Abstract

This presentation outlines the details regarding the design and fabrication of a hallux valgus, or bunion support. Hallux valgus is a deformity occurring in a large amount of the population. Most individuals who suffer from this deformity have trouble walking due to the displacement of the hallux or largest toe placing pressure on the joints resulting in pain for the individual during movement. Current methods for hallux valgus correction require extensive surgery and extended recovery times. The use of the support for correction will allow the patient to wear the device daily and provides a non-invasive method to correct the deformity.

Two composite models are developed for the first time. Each model is consisted of a polymeric shell which wraps around two toes and also the foot and has an insert on the side, which keeps the large toe straight. The models allow for the toes to stay parallel with a certain distance apart. The second model was designed to accommodate various foot sizes easily. The top part has an adjustable closure, which makes the support ‘one size fits all.’ It has many holes on one side and a snap closure on the other side.

Design features built into the design allow for simple manufacturing and changes to be made as the patients’ recovery progresses. The models chosen for analysis and fabrication allow the patient to wear the support at any stage of deformity to allow for the correction process to begin. In both models, the insert can be bent and gradually get straight to apply a gradual force on the large toe.

The models were designed and analyzed using Solidworks finite element analysis. The trial inserts have been made of Aluminum, steel and carbon fiber. The first model is constructed using 3D printing techniques to validate the findings.