Welcome to my 3D model of a polycentric leg prosthetic! This model was made in Fusion 360 with the help of a 3D model I found online to serve me as a guide. The knee mechanism is called polycentric. There are 2 kinds of polycentric knee prosthetic: a 4 bar and a 7 bar. This model shows the 4 bar knee mechanism. The purpose of these is to resemble as much as possible the natural movement of a human knee to give as much of normal movement as possible to amputees. 

Below is a picture reference model I used as a guide for my prosthetic model. 

https://grabcad.com/library/polycentric-prosthetic-knee-1

This project was very challenging for me but also a big milestone as it has helped me increase my knowledge in how movement in prosthetics works. After I graduate from college, I am interested in working in the medical technology field like assitive technology in medicine. So it made sense to model this prosthetic as my final project for 3D modeling. 

I modeled this using 4 main components: the thigh, the knee mechanism (with more components within this main one), the foot, and the curved foot. I modeld this prosthetic with the ability to screw off the bottom leg to be replaced with the blade leg, as the blade is more useful when it comes to exercising. The person will be able to easily switch out whenever they find the need to do so. The knee mechanism does the basic needed movements of a human knee. It has the ability to stand straight and bend back to sit and walk.

Below are more renders of this leg prosthetic.

In this model, the knee mechanism is modeled bigger than what is really is in real life. This is for presentation purposes so the knee components can be seen more easily. 

Here is a video of how the knee moves.

Finally an animation showing different angles of the prosthetic and an exploded view of the components.