Microprocessor Prosthetic Knees

Since Ottobock introduced the first computer-controlled knee, the C-Leg®, in 1999, the advantages of microprocessor-controlled knees have been well established. Microprocessor knees (MPK) improve mobility and reduce the risk of injury from falls, which leads to better overall health and well-being for wearers. The technology continues to evolve, offering prosthetic wearers even smarter knees with improved sensors and longer battery life.

Hanger Clinic has access to all of the latest technologies. Your prosthetist will select the most appropriate solution for you and show you how to use the hardware and software.

How Microprocessor Technology Works

All computerized knees include a microprocessor, software, sensors, a hydraulic or pneumatic resistance system and a battery. Sensors monitor and detect changes in the environment, such as walking on a different surface, going up or down a slope or walking at a different speed. Based on that feedback, the microprocessor adjusts the resistance to knee flexion (bending) and extension (straightening) to accommodate walking speed and terrain. This enhances stability and security for the user. Other features are typically included such as stumble recovery, controlled descent of ramps and controlled recline into a seated position.​

C-Leg Patient Poses for CameraC-Leg® Microprocessor Knee

The C-Leg® provides microprocessor control of both the swing and stance phases of gait. You can walk faster or slower, take on hills and go down stairs step-over-step—all with a secure, more natural gait. The revolutionary microprocessor inside receives feedback from multiple sensors 100 times a second from the gyroscope and accelerometer, allowing the knee to anticipate your next move and make adjustments in real time. This keeps your knee stable when you put weight on it and free-swinging when you step through.

Learn more about the C-Leg

Stumble Recovery 

Whenever the C-Leg Microprocessor Knee senses that you're in an insecure position—such as when you trip or stumble—it will stiffen to provide the support you need to recover. When it senses that you're secure again, it offers its normal, reliable support.

Multiple Modes for Multiple Uses

The C-Leg Microprocessor Knee offers several functional modes:
•    Walking
•    Other favorite activities, such as driving or riding a bike
•    "Standing" mode, which lets you lock the leg yourself between 7 and 70 degrees, helping you use less energy

Switching between modes is as easy as bouncing on your toe—or a press of the wireless remote control.

Protecting Your Investment

The C-Leg Microprocessor Knee Protector is a tough exterior shell that keeps your hardware safe from the environment. It's easy to put on and take off and includes an anti-slip feature to make the knee more stable when you kneel. Otto Bock provides a standard three-year warranty and a free service check at 24 months with a loaner microprocessor knee during the service period.


The Ottobock C-Leg-Compact provides microprocessor control during the stance (foot in contact with the ground) phase of the gait cycle. It is provided to lower functional level three ambulators who still need to change walking speed but who do so at a lesser velocity than a C-Leg user. Features include stumble recovery, step-over-step descent of inclines or steps and secure controlled recline to a seated position.

Plie Microprocessor Controlled Knee

The Freedom Innovations Plie provides microprocessor control of both the swing and the stance (foot in contact with the ground) phases of gait. It is fully waterproof and can be immersed in water. The release from stance phase into swing phase is a fully customizable setting with two separate trigger points. Features include stumble recovery, step-over-step descent of inclines or steps and secure controlled recline to a seated position.

Learn more about the Plie


The Endolite Orion provides microprocessor control of both the swing and the stance phases of gait.  The stance control is hydraulic and the swing control is pneumatic. Additional features include cycle mode, fixed angle flexion lock, stumble recovery, step-over-step descent of inclines or steps, secure controlled recline to a seated position and up to three days of battery life.

Learn more about the Orion

Rheo Knee

The Ossur Rheo provides microprocessor control of both the swing and the stance phases of gait. Additional features include a manual lock, stumble recovery, step-over-step descent of inclines or steps, secure controlled recline to a seated position and up to three days of battery life. When not weight-bearing, the Rheo is in free swinging mode which is ideal for cycling. The Rheo Knee 3 and Rheo Knee XC include waterproofing and facilitate step-over-step ascent of steps.

Learn more about the Rheo

Genium Bionic Prosthetic System

The Genium Bionic Prosthetic System is the world’s only microprocessor controlled knee that can anticipate your movements and adapt instantaneously in order to function as close to a natural leg as possible. The Genium allows you to focus on what you are doing instead of your prosthesis.

Learn more about the Genium

The World’s First Intuitive Knee Tested, Proven and Fit First by Hanger Clinic
Creating natural, multidirectional movement, Genium optimizes gait and gives you the confidence to engage in activities and try things you may not be able to do with a normal prosthetic knee. Features include five modes to switch using a remote control, one of which is a “walk to run” mode.

Realizing Your Potential Naturally
Based on decades of research and development, the Genium Prosthetic Knee combines an accelerometer and gyroscope with today’s most advanced sensing and control technologies.  

Genium’s gyroscope collects data in three dimensions to identify where it is in space while the accelerometer tracks its speed. This is the first prosthetic use of the same technologies that enable user interaction with Wii gaming systems and that keep iPad screens in a “right side up” orientation.

Genium’s array of four sensors deliver an unprecedented quantity and quality of data to three microprocessors – the most ever utilized by a prosthetic knee – that allows them to predict what will happen next. By applying sophisticated rule sets, these microprocessors intuitively move the prosthesis in multiple directions in much the same the way a normal leg would respond. Users can side-step, walk backwards, shuffle step, stop short, pivot on their prosthetic leg and perform a wide range of common movements naturally without concentrating.

Genium also adapts immediately to changes in direction, speed or pace. Its fluid motion allows the knee to get in front of the body rapidly and support it even in a bent position. Unlike other prosthetic legs, it lets amputees step over obstacles instead of walking around them.

Based on their long-standing commitment to advancing microprocessor knee technology, the U.S. Military partnered with Otto Bock Healthcare in 2006 to create a more durable and intuitive prosthetic leg for wounded soldiers. The Genium Bionic Prosthetic System is the civilian counterpart to the product that was ultimately developed. From 2010 to 2011, Hanger Clinic worked with Otto Bock on its clinical evaluation, application and testing. Hanger Clinic fit the first five out of six patients wearing the Genium, which is available to active men and women who are above-knee amputees.


The Ottobock X3 was initially a military grade prosthetic knee that is now available to the general public. It is very similar to the Genium with an additional running mode and silent mode (where any alarms can be set to silent), and it is fully waterproof and submersible.

Learn more about the X3

Available Today from Hanger Clinic

To find out which microprocessor-controlled knee may be the best solution for you, talk to one of our expert clinicians. Call 1-877-4HANGER to find the closest Hanger Clinic location to you.