C-Leg above knee prosthetic leg

Know the difference

In order to own your outcome, you need to know the difference.

The Ottobock C-Leg is the original microprocessor knee. Since 1997, it has set the standard for every other knee available. It’s also the world’s most studied prosthetic device, period.

Our research proves that with C-Leg you’ll experience drastically reduced falls. (1) Because of that, your confidence in the knee will increase. That confidence provides freedom from always thinking about how you walk. And that freedom improves quality of life. It’s no wonder why 94% of amputees who use C-Leg prefer it to their previous prosthesis. (2) Not all microprocessor knees are the same, know the difference.

1 Kannenberg, A., Zacharias, B., & Pröbsting, E. (2014). Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: systematic review. Journal of rehabilitation research and development, 51(10), 1469.

2 Wismer, N., Mileusnic, M., Sreckovic, I., & Hahn, A. (2016). First results on next generation C-Leg. Poster presentation at OTWorld, Leipzig, Germany.

Bluetooth®

Integrated Bluetooth® technology permits straightforward communication with the joint. An existing connection is displayed with an LED. Bluetooth® can be deactivated if necessary.

New carbon frame design

In order to withstand the varied demands of everyday life, the frame is made of carbon – an especially strong, high-grade and lightweight material. The frame houses and protects the electronics, the hydraulic unit and the battery.

Thanks to its new design, the C-Leg has a lower system height and therefore a larger fitting spectrum.

Inertial motion unit (IMU)

The gyroscope and acceleration sensors allow the position and acceleration of the C-Leg in space to be measured.

Prosthetic Control is based on motion analysis and additional force determination.

Lithium-ion battery

A lithium-ion battery provides energy for controlling the knee joint. It is located right in the rotation axis of the C-Leg. If you use the C-Leg on a daily basis, we recommend that you always charge the battery overnight.

Knee angle sensor

The knee angle sensor provides important data: It measures the flexion angle and angular velocity of the joint.

Electronic control unit

The integrated microprocessor receives and processes sensor signals. It controls the movement of the knee joint in real time.

Hydraulic unit

The hydraulic unit controls the C-Leg. It generates movement resistance for flexion and extension during the stance and swing phase.

What you need to know

Why is C-Leg the best choice?

Weatherproof

The C-Leg 4 has an IP 67 rating, which protects it from damage due to incidental contact with or temporary submersion in fresh water. Because the C-Leg 4 is considered weatherproof, you don't have to worry while walking in the rain or using it around water.

Intuitive Stance

Available only in Ottobock microprocessor knees, Intuitive Stance automatically activates to fully block the C-Leg from bending or buckling while you are standing, allowing you to distribute your weight evenly between both legs. This helps alleviate pressure on your sound side and helps you maintain a more stable, comfortable position when standing for a long period of time, even on slopes or uneven terrain.

Backward Walking

The patented inertial motion unit (IMU) on the C-Leg provides stability when taking steps backwards or backing up. Contrast this to other manufacturer’s microprocessor knees, which do not accommodate backward walking, potentially causing their knees to collapse when stepping backward.

Stairs, Slopes & Ramps

The stance flexion feature in C-Leg provides hydraulic resistance against knee flexion (bending) mimicking the quadriceps muscle. This controlled knee flexion occurs early in the stance phase of your gait cycle while you are bearing weight on the prosthesis. Providing shock absorption, stance flexion allows you to securely walk up and down slopes and ramps, negotiate uneven / challenging terrain, and to descend stairs step over step.

Enhanced Stumble Recovery

With sensors that are always actively controlling and adjusting resistance while you are in the swing phase of gait, the C-Leg 4 can detect the pattern of movement that resembles a fall and will respond immediately by providing even greater resistance. This constant presence of swing flexion resistance paired with an immediate increase in resistance allows you to safely put your full weight onto your prosthesis so you can easily recover from a stumble and prevent a potential fall.

MyModes & Cockpit App

The Cockpit app allows you to adjust the C-Leg to your individual needs in everyday life using an iOS or Android device. With the cockpit app, you can check your C-Leg’s battery life, determine your daily step count, or select preconfigured MyModes for specific activities like biking or golfing.

Technical info

C-Leg 4 specifications

Highly stable yet lightweight carbon fiber frame

Patient weight: Max. 300 lbs/136 kg

Weight of the knee joint only:about 2.8 lbs / 1,235 g

Height of the knee joint with adapter: between 11.2 inches / 28 cm and 21 inches / 53 cm (with torsion adapter)

Adjustable activity modes: 2

Operating time with fully charged battery: 40 to 45 hours

Maximum possible knee flexion angle without flexion stop: 130°

*All components of your prosthesis must be appropriately rated to reach this weight limit. See your prosthetist for specifics.