Mathematical Modeling of Air Bladders for use as an Orthotic

Due to the Human foot constantly growing at a rapid pace, typical gel and mold orthotics quickly become ineffective as they no longer fit the foot properly. In pediatric patients, this situation is even more pronounced as their feet change geometry at an even more rapid rate. This project consists of designing an adjustable sizing Pediatric Orthotic for use in children as well as adult patient’s shoes to provide better foot support than not using one at all, or for that matter an inappropriately sized orthotic. This idea incorporates multiple air bladders that can hold pressure and adjust shape as is necessary to best accommodate the patient’s foot geometry to reduce the deformation and average stress presented within the foot. Results will be obtained by running simulation models of these phenomena in MATLAB as well as Ansys softwares. From the results, by incorporating two bladders into the middle arch of a ‘control’ patient who has a perfectly symmetric arch, maximum deformation of the foot was reduced by approximately 17%. Under this same scenario, average stress in the foot dropped by approximately 13%. In a more abnormal ‘experimental’ case, of a largely asymmetric arch, it was found that max deformation and average stress in the foot dropped by 21% and 17% respectively. This leads to the conclusion that incorporating this design will indeed lower the stress and fulfill the requirement of an orthotic while also being a removable and adjustable air bladder to fulfill the adjustability constraint.