3D-printed ankle-foot orthosis: a design method

Additive manufacturing offers several advantages when compared to conventional manufacturing technologies, especially where large scale customization is requested. In this article, a procedure for the design of a fully-customized 3D-printed ankle-foot orthosis (AFO) is described, with reference to a case study regarding a 21-year-old woman with an injured ankle. The first step is the acquisition of the geometrical data from the patient’s foot: this is done using photogrammetry. The second step is the data conversion and import in a CAD modeler; SolidWorks™ is chosen for this purpose. The AFO is modelled parametrically around the foot mesh and optimized in order to resist the predicted mechanical stresses. Finally, the device is 3D-printed on an FDM printer and tested on the patient. An excellent geometrical correspondence between the AFO and the patient’s foot is highlighted: this leads to great comfort and enhances medical functionality. The described procedure can be easily automated, further reducing the lead time and costs of the whole process.