C-Leg® above knee prosthetic leg

What you need to know

Why is C-Leg the best choice?


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 about getting caught in the rain or being 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 backward or while 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

Weight of the knee joint only: about 2.8 lbs

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.


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C-Leg 4 Instructions for use

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Clinical Studies comparison list – C-Leg and other MPKs

Clinical Studies comparison list – C-Leg and other MPKs

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C-Leg clinical studies bibliography

C-Leg clinical studies bibliography

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C-Leg Brochure


  • How do I know if a C-Leg is right for me?

    Together with your prosthetist, you can determine if the C-Leg may work for you. Start the process by requesting a C-Leg trial here. Upon form submission, an Ottobock clinician will evaluate if the C-Leg 4 could be right for you. A phone consultation may be necessary to further determine your eligibility.

  • Can I try out a C-Leg?

    To request a trial, please fill out our trial request form here. Upon form submission, an Ottobock clinician will evaluate if the C-Leg 4 could be right for you. A phone consultation may be necessary to further determine your eligibility.

  • What happens if I get an insurance denial for the C-Leg?

    Insurance denials are expected and anticipated when seeking insurance coverage for a C-Leg. This is your insurance company’s way of requesting more information. We know reimbursement can be a mystery, that’s why Ottobock and your practitioner are here to help. Check out our reimbursement 101 video series to learn more.

  • Which foot should I use with my C-Leg?

    We can guarantee functionality with other Ottobock feet listed in the C-Leg IFU. These products have been tested and proven to work together. Chat with your prosthetist about your goals to determine which products would be right for you.

  • Are all microprocessor controlled knees (MPKs) the same?

    No, not all MPKs are the same.

    The C-leg was the first microprocessor-controlled knee (MPK) to enter the market. Since that time, several other MPKs have been introduced. But do all MPKs work the same, no matter how they’re designed? A recent study found that that they are not all the same and found clear differences both during stance phase (when the leg is weighted) and swing phase (when the leg is swinging). Among the four MPKs investigated, the C-Leg was the clear leader.

    To find out more, ask your prosthetist, or request a trial here.

  • Why would I need an MPK over a mechanical knee?

    Compared to a mechanical knee, 94% of amputees prefer a C-Leg. Confidence, safety, and the history of being the first of its kind make the C-Leg a clear choice for above knee amputees. To see if C-Leg could benefit you, request a trial here.

Not finding what you are looking for? Please contact us!

User testimonials







C-Leg Trial Prep

Prepare for your Trial

Prepare for your C-Leg trial using this checklist to review the steps you can take to ensure a successful trial. The C-Leg is designed for users with knee disarticulation, transfemoral amputation and hip disarticulation, for unilateral or bilateral amputation.

Download our Trial Prep Checklist

C-Leg Trial Prep Video

Trying out a new prosthetic device can be an exciting occasion for individuals living with limb loss. It can also be a little intimidating if you’re not quite sure what to expect. Watch our trial preparation video to better understand the process so you’ll be ready to experience the advanced features the C-Leg has to offer.


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