Microprocessor knees – Everything you need to know



The C-Leg is the original microprocessor knee, launched in 1997. This prosthetic has set the foundation for all other prosthetic knees available and, as such, is the most studied prosthetic device.

The C-Leg leads to fewer falls in its users, giving your more freedom and confidence to walk wherever you want, with no worries about the terrain. Additionally, the C-Leg is made with a carbon frame design, which is very strong while also lightweight. The new design of the C-Leg also gives it a lower system height which means it can fit a broader range of individuals.

Ottobock C-Leg

The C-Leg contains a sensor in the knee that measures the flexion angle and angular velocity of the joint. This provides valuable data for the hydraulic unit that controls the entire prosthetic by generating movement resistance for flexion and extension during the swing and stance phase.

This prosthetic has an IP 67 rating, which means it is safe against damage from incidental contact or temporary submersion in fresh water. This weatherproof ability means you don’t have to worry about how being stuck in a rainstorm or being near water will affect your leg.

One feature of the C-Leg, which is only available in Ottobock microprocessor knees, is the intuitive stance which automatically activates to block the C-Leg from bending or buckling when standing. This allows you to distribute your weight evenly between both legs, alleviating pressure from your sound side and creating a more comfortable and stable standing position, especially when standing for an extended period of time.


Genium is a leg prosthetic that opens new horizons for its users, including walking backward and taking stairs step-over-step.

Adapting the prosthetic to your everyday life is easier than ever with the ability to have day-to-day assistance using the stairs and obstacles function. Genium also offers more than ease of movement; there are two different stance functions that allow you to rest on the prosthetic side, which is especially appealing for bilateral users.

The Genium prosthetic consists of the AXON tube adapter, which measures the ankle movement and vertical force acting on the joint in real time. This is accomplished using a gyroscope and acceleration sensors. Control of the prosthesis is then based on the analysis of these measurements and achieved using a hydraulic unit that controls the flexion and extension of the joints.

The Genium prosthetic leg also has integrated Bluetooth technology, allowing simple communication with the joint. The app included with Genium allows for five pre-settings that can be programmed for special activities, allowing for smoother adaptation of the prosthesis to your everyday life.

The back of the Genium has an inductive charger that can be used even through clothing and cosmetic covers, making convenience the highest priority.

Additionally, water is of minimal worry with the device because its improvements allow it to withstand brief rain showers and splashes of water.

genium X3

X3 Prosthetic Knee

The X3 prosthetic knee offers smoother and more intuitive walking with better support for everyday activities and improved safety.

This prosthetic can handle anything you throw at it, including physically demanding activities, swimming, sports, and vacations to the beach. Essentially, anything that puts you in contact with water, sand, and dirt can be handled by the X3 prosthetic. This is because of the protective cover, which protects the prosthesis from everything it can come into contact with, including water, dirt, and dust. It also protects the prosthetic from impacts.

The X3 prosthetic knee also features an inductive battery charger on the back of the joint, allowing for easy charging even through clothing.

The actions of the X3 are controlled through a hydraulic unit, and two control valves independently control flexion and extension resistance.

An inertial motion unit determines the position and acceleration of the X3 prosthesis, in addition to the flexion angle and speed as movement occurs. This means that it adapts with you as you change walking speed, overcome obstacles, walk backward, and stand in a relaxed position. This is especially beneficial when switching from walking to running spontaneously and for a short sprint, such as when trying to keep up with your kids.

The app also offers the ability to pre-program five settings for activities you frequently do, such as recreation, work, and sports.


Rheo Knee

The Rheo Knee is a dynamic microprocessor knee that detects your movement and adapts to your walking style. This allows you to walk naturally and effortlessly, even on different terrains.

Additionally, because of the ability of Rheo Knee to sense your walking style, you can more easily navigate tight spaces, stairs, slopes, and a brisk pace. The enhanced stability control goes a long way in increasing your confidence in your prosthetic.

The Rheo Knee is also weatherproof, so if you are in wet or humid conditions, you don’t have to worry about damaging your prosthetic.

This prosthetic is ideal for those who are nervous about using a prosthetic for the first time. The Ossur Logic App contains training tools so that you can practice using your prosthetic knee, increasing your confidence and improving your gait so that you can manage wearing it for longer periods of time. You can complete these exercises at home and on your own time, so you can ease into using your prosthetic on your terms and at your own pace.

The Rheo Knee also offers heel-height adjustability, which means you can wear whatever shoe you like without worrying about how the different shoes may affect your posture and movements. It’s a quick and simple process to change shoes, but it has long-lasting benefits that include greater independence and the ability to express oneself. You can even walk barefoot if you want.

Power Knee

The Power Knee is the first motor-powered microprocessor knee that provides active assistance while walking on level ground, ramps, stairs, and when climbing or standing up.

Power knee helps to supply the power that is missing when you have a lost limb. Without certain muscles, you can expend between 30-60% more energy, but Power Knee helps to lower the amount of additional energy you have to use. By using less energy you will be able to go for a longer period of time without additional pain and fatigue.

Having a limb difference can make walking symmetrically challenging, impacting stamina and leading to greater risks of low back pain and osteoarthritis. Power Knee helps to improve symmetry in all activities, including walking, climbing stairs, and standing up. This is accomplished by delivering active extension when standing up, active extension and flexion when walking, controlled resistance when descending, and stance flexion that return energy.

The Power Knee also offers real-time stance and swing control through sensors that detect the user’s movements and allow the knee to respond accordingly.

The battery offers 25 hours on a single charge, and it is also replaceable and can be charged in the knee or separately, so you can always use your Power Knee.



The Orion knee is designed for activity level 3 walkers, and similar to Ottobock’s C-Leg and Ossur’s Rheo Knee, it can handle the stance phase by detecting the current task and the angle and speed of knee movements. It is suitable for those who walk on different terrains, slopes, and steps and need a knee that can keep up and provide stability. The Orion can also handle varying speeds.

The swing phase of the Orion knee is handled by releasing the knee at the optimal point to initiate the swing phase. The transition from the swing phase to the stance phase is then supported by achieving proper extension and terminal swing damping of the knee.

There is also enhanced safety performance, with five levels of stance resistance to optimize safety:

  • standing support
  • controlled stance support
  • stumble recovery
  • dynamic slope and stair descent
  • supported sitting

The stumble recovery feature increases the knee’s resistance when a stumble is detected, aiding in recovery and preventing a fall. The Orion knee also offers specific support for standing, sitting, and cycling.

Orion Knee


Linx is the only fully integrated limb to exist in the world, and it mimics the complex structure of the human leg. It accomplishes this by sensing and analyzing data on the user’s movement, environment, activity, and terrain as it is occurring. It then provides a stream of instructions to the hydraulic support system based on the information gathered.


Linx- Microprocessor knee

Linx can gather data such as the movement and speed of the user, which it can then respond accordingly to in real time.

Similar to the Orion knee, Linx also offers five levels of stance resistance, which helps to ensure optimal safety at all times.

Linx connects the entire limb, ensuring that the knee and ankle work together, creating a more natural and effective movement.

Changing elevations are no challenge for Linx, with its ability to detect changes in slope and adjust accordingly. Whether you are going up or down, or if the slope you are traveling is steep or shallow, the rate of plantar-flexion and dorsi-flexion are optimized. Additionally, knee resistance is adapted.

Linx also offers standing support by subtly redistributing body weight when standing, increasing comfort and making standing for an extended amount of time feel more natural, which also minimizes tissue stress.



There are 20 available modes with this prosthetic; nineteen are customizable, and the 20th is the cycle mode. The many programmable modes allow you to customize your experience to match your lifestyle, no matter what you are doing.

The Quattro is to the first microprocessor knee to provide a unique user experience that specifically captures the user’s distinctive gait patterns. It accomplishes this using Proteor’s innovative H.A.R.T. Control Technology.

Hyper Active Real Time (H.A.R.T.) Technology continually adjusts the valves without using preset positions. This offers increased flexibility in the valve diameter, which provides hydraulic resistance. Whether fully open or completely closed, or anything in between, the resistance you need can be precisely what you need.

Whether you want to walk, hike, run, or even dance, the Quattro can keep up with you. Additionally, like other prosthetic knees, the Quattro is IP67 tested for occasional submersion in water, so you do not need to worry about being caught in a rainstorm.

Another benefit of the Quattro is that the battery can be charged while in use using the Booster Adapter accessory.


The Allux knee is the only 4-Bar microprocessor knee to control both swing and stance phase, providing a smooth and natural gait. Additionally, the 4-Bar linkage allows the distance from knee center to toe to shorten during the swing phase, which increases toe clearance and greatly reduces the risk of stumbling.

The 4-Bar linkage also allows for more comfortable sitting by folding under itself when seated, which provides a more natural sitting position.

Safety is a high priority with the Allux knee. In addition to increased toe clearance, the Allux knee also constantly monitors the knee position and movement to allow it to respond to any abnormal situations. For example, if the prosthesis becomes stuck on something during its swing phase, it will immediately increase resistance which helps to prevent the knee from buckling.

This knee also offers an industry-leading range of motion with 180º flexion. This offers you a greater range of motion than any other microprocessor knee available, which is especially beneficial for activities such as biking, changing shoes, or kneeling.

Using the associated app, you can easily switch modes and check the battery level of your prosthetic. With a battery life that lasts four days and a charge time of only 3 hours, you get to enjoy minimal downtime and more time enjoying your days.

Have more questions about Microprocessor Knees?

Choosing the right type of prosthetic can be overwhelming. Lawall Prosthetics & Orthotics has highly skilled prosthetists who can help you pick the right prosthetic for you. Call us today if you have any questions regarding microprocessor knees or any other type of prosthetic or orthotic.