Ottobock C-Leg

What it is

The C-Leg is a prosthetic knee joint for people with an above-knee amputation, made by Ottobock of Duderstadt, Lower Saxony. Ottobock presented it in 1997 at the World Prosthetics Congress in Nuremberg and describes it as the first computer-controlled leg prosthesis on the market. It has since been updated in several generations.

How it works

A conventional mechanical knee uses fixed settings, so the user must adapt to the prosthesis. The C-Leg contains sensors that measure the angle of the knee and the forces acting on the prosthesis. A microprocessor evaluates this data continuously and adjusts the hydraulic resistance of the joint, making it stiffer when the leg bears weight and freer during the swing phase. This allows the knee to adapt to walking speed and to different situations such as slopes and stairs, and helps the user recover from a stumble.

Why it stands out

The C-Leg marked the beginning of microprocessor-controlled prosthetic knees, a category that has become a standard of care in many countries. Users can walk more naturally and with less conscious effort, which can reduce falls and increase confidence in everyday life. Ottobock was founded in Berlin in 1919 to provide prostheses for wounded soldiers of the First World War and has developed into one of the world's leading companies in prosthetics. It is still controlled by the Näder family, which listed on the Frankfurt Stock Exchange in October 2025.

Where you meet it

The C-Leg and its successors are fitted by orthopaedic technicians in clinics around the world. Users include people who have lost a leg through accidents, illness or war, and Paralympic athletes have helped raise the profile of such technology.