Prosthetics
I am surprised to learn that people who have been active amputees for years have never heard of a microprocessor knee or foot. I will not pretend to be an expert but I suggest asking questions and looking into the pros and cons of each device. After research and long consultations with prosthetists, I learned of devices that offer the ability to do many activities as close to normal as possible.
Knees
Below is a list of knees, and one system, the Linx. I like to call these "smart knees" because they use a microprocessor and apps. I will admit I am bias to the Linx because it is the only option that includes a microprocessor knee and foot that work together, although there are many great options to make walking less of a task, reduce falls, waterproof, and more. To learn more about these options, click on the links below.
Ottobock Genium X3
Ottobock C-Leg 4
Ottobock Genium
Blatchford Linx
Ossur Rheo
Blatchford Orion