Proven, preferred performance

Discover the new C-Leg 4 Microprocessor Knee.

Available through NHS England

Celebrating C-Leg the signature microprocessor knee prosthesis

Since 1997, one particular microprocessor knee has set the standard for every other available option. Over 100,000 fittings later, it’s still the most popular prosthesis of its kind. See how the C-Leg keeps users moving forward with decades of innovation in every step.

Thrive with C-Leg

C-Leg: Trusted for good reason.

Since 1997, one particular microprocessor knee has set the standard for every other available option. Now, with the new C-Leg 4, our signature knee is raising the bar even higher.

It’s the one patented technology that empowers you with the proven performance you need to live the healthy, active life you want. C-Leg adapts to your unique gait pattern and walking speeds, so you can keep your focus where it matters — not on your next step, but on where you want it to take you.

Proven performance

It’s the world’s most studied prosthetic device. Full stop.

Up to 90%

of C-Leg users prefer it to their previous mechanical prosthesis*

25 years

of continuous microprocessor knee development and user input have led to the new C-Leg 4.


fittings have helped more users regain their mobility than any other microprocessor knee.

With C-Leg, I’m living again - traveling, working, taking care of my home and family. I feel good!

Patricia, office assistant

With C-Leg, I’ve started a new chapter in my life. I used to be shy about my prosthetic leg, but now I feel strong and confident.

Royal, estate agent
C-Leg success stories

Why do more people choose C-Leg than any other microprocessor knee?

C-Leg has changed the lives of thousands of people just like you — and many of them have shared their stories with Ottobock. Discover how our technology has empowered them to achieve the life they want.

I’ve always had a burning desire to do something positive with my life.

As a kid, Rebecca tried to hide her limb difference. But as her awareness of other people like her grew, she realised it was ok to embrace being different. She’s always looking to challenge herself and inspire others as she participates in a variety of activities with her C-Leg.

I describe myself as strong-willed - made of steel.

After losing her leg when a bomb struck her home in Syria, Dima began her journey to recovery on crutches. She’s come a long way since then and now enjoys a healthy active lifestyle with her C-Leg 4.

The C-Leg has improved my life tremendously.

After losing his leg in a motorcycle accident, Brandon recovered from the traumatic experience with the support of his family and friends. He went on to found The Mind Clothing, a fashion brand that harnesses his unwaveringly positive spirit.

With C-Leg, I was able to pursue an athletic career.

Born with a limb difference, Amy shied away from sports while growing up. But after college, she discovered a passion for athletics. Now, she regularly participates in fitness competitions and calls herself a competitive adaptive athlete.

With C-Leg, I live a full, active life as a father, non-profit leader, and musician.

Billy is a drummer at heart. But after losing his leg to cancer, he now leads the Steps of Faith Foundation to help people with limb difference get the prosthesis they need. With his C-Leg 4, Billy is as active as ever, playing drums whenever he can and hanging out with his two kids, all while serving the greater amputee community.

I’m still the same person — just with a special accessory.

Rebecca loves to express creativity in every facet of her life. With the new custom shield insert for her C-Leg 4 guard and protective cover, Rebecca’s unique style and personality shine through with each step she takes.

My life was more restricted before the amputation than now.

Georg maintains an unwavering positive attitude toward life. In fact, he believes his amputation has created new possibilities for him, such as realising his childhood dream of skiing, discovering a passion for the javelin, and becoming a para-athlete. The C-Leg 4 supports him during sports, daily routines, and everything in between.

Key features

Discover how C-Leg 4 supports your active day-to-day life.

With its innovative design and exciting new features, C-Leg 4 provides a highly personalised user experience that helps you move more easily through your day and stay focused on what matters most to you.

New Colour Option

Many updates to our signature C-Leg Microprocessor Knee are based on feedback we received directly from C-Leg wearers. That’s why the C-Leg 4 is available in the original lighter Desert Pearl color as well as a new darker shade, Midnight Shadow, which is a deep gun metal grey colour. The Volcano Shadow colour is no longer available.

Customisable Shield Insert

You can personalise the look of your prosthesis thanks to a new customisable shield insert. Not only does this robust, durable cover protect the C-Leg 4 from wear and tear, it also empowers you to show off your unique style with each step. So be unique and unleash your inner creativity!

Deep Sleep Mode

Now it’s even easier to get the most out of your C-Leg. With deep sleep mode, you can save battery when sitting for long periods or when the prosthesis is not in use, such as on long flights. You can also operate the newly redesigned charger using just one hand.

Supported Ramps & Stairs Function

As you walk down the stairs or down a slope, you will use the stance flexion resistance to allow you to descend safely. With the new C-Leg 4, we’ve given you the option to select how you want the stance flexion behaviour to be delivered. With the supported function enabled, the knee joint resistance will dynamically increase as the knee joint angle increases - giving you confidence and self assurance that you are safe on the ramp or on the stairs. This feature is selectable within C-Soft Plus and works independently to the 'Supported Sitting' function.  

Improved Stance Release

In the new C-Leg 4, we have improved the stance release feature so that if you need to move in small, confined spaces and take smaller and quicker steps, you can achieve stance release easily and safely.

Stumble Recovery Plus

The C-Leg's Stumble Recovery feature has now been upgraded to our well known 'Stumble Recovery Plus'. Unlike other MPK's, our Stumble Recovery Plus feature is always active throughout the entire swing phase. During both swing and flexion and swing extension, the Stumble Recovery Plus feature is ready and armed to support you should a stumble occur.

Supported When Sitting Down

Independently selectable within C-Soft Plus, the 'Supported Sitting' Function can change the behavior of the C-Leg when you sit down. This new feature will provide you with even more support by dynamically increasing the resistance as the knee joint angle increases.

Deliberate Stance

For people who happen to exit the Intuitive Stance Function too easily, we've added a smart new feature that can be selected to support you. The Deliberate Stance function provides a more robust standing lock which is harder to exit and therefore is more appropriate for C-Leg wearers that require enhanced standing support.

MyMode Plus

Want more support for your favorite activities? MyMode Plus offers extensive options for work, leisure, and athletics. Select two settings for your prosthetist to program for easy activation in the Cockpit app or via movement pattern.

Helpful training function

Ideal for those first steps and for sessions with your physiotherapist, the new Training Function lets you and your therapist hear a beep when stance release has been performed correctly.

Improved Charging Slot

We listened to your feedback that some C-Leg wearers found it difficult to insert the charging plug using only one hand. We've changed the design of the plug hole by adding a sliding flap and we've added an audible and tactile "click" so they can feel when the plug is inserted correctly.

Get a closer look

See some of the new features of the updated C-Leg 4 microprocessor knee in detail.


FAQ C-Leg 4

What benefits of the C-Leg have been proven in clinical trials?

What benefits of the C-Leg have been proven in clinical trials?

Numerous studies have investigated the advantages of C-Leg technology for people with a transfemoral (above-knee) amputation. These studies have shown that the frequency of falls is much lower with the C-Leg compared to conventional prostheses, proving a high level of safety.

In addition, studies show that C-Leg users don’t have to concentrate on their prosthesis at all times, but rather can move more freely in everyday situations. C-Leg users have more confidence in their prosthesis, and are also able to boost their activity levels, vary their walking speed and expend less energy while walking.

Where can I get a C-Leg?

Where can I get a C-Leg?

You can get the C-Leg from your NHS Limb Centre via the Microprocessor Knee Policy if you qualify against the specific criteria, or through a Private Prosthetic Provider, who will adapt the prosthesis to your individual needs.

Where can I try out a C-Leg?

Where can I try out a C-Leg?

Many practitioners offer trial fittings which take place over a predetermined period of time and are monitored by Ottobock when needed. Just talk to your prosthetist for more details.

What’s included in a prosthetic fitting?

What’s included in a prosthetic fitting?

A prosthetic fitting includes all components from the foot to the knee joint system, including the socket, which will be customised to your individual needs by your prosthetist. The assembly and setup of the system are also included, as well as regular service inspections during the entire period you use the C-Leg.

What happens when the battery is drained?

What happens when the battery is drained?

A vibration signal notifies the user well in advance when the battery starts getting low. When it’s drained, the C-Leg automatically switches to a predefined safety mode so that the user’s preferred resistance in the stance phase is activated.

Can I take a shower or go swimming with the C-Leg?

Can I take a shower or go swimming with the C-Leg?

Although the C-Leg is weatherproof and well suited for contact with water in various everyday situations, such as rain showers or light splashes. It is not fully waterproof. You should not wear it in the shower or for activities like swimming.

How long does it take to learn how to use the C-Leg?

How long does it take to learn how to use the C-Leg?

Many users are able to walk downstairs step-over-step on their first day with the C-Leg prosthesis. However, it can also take several days or even weeks for users to completely acclimate to using the C-Leg in everyday situations depending on their unique condition and circumstances.

Discover the new C-Leg 4

Find out more about the features and benefits of the new C-Leg 4.

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*Kannenberg, A., Zacharias, B., & Pröbsting, E. (2014). Benefits of microprocessorcontrolled prosthetic knees to limited community ambulators: systematic review. Journal of Rehabilitation Research and Development. 51(10), 1469-96.

Orendurff, Michael S.; Segal, Ava D.; Klute, Glenn K.; McDowell, Martin L.; Pecoraro, Janice A.; Czerniecki, Joseph M. (2006): Gait efficiency using the C-Leg. In: Journal of rehabilitation research and development 43 (2), S. 239–246.

Hafner, Brian J.; Willingham, Laura L.; Buell, Noelle C.; Allyn, Katheryn J.; Smith, Douglas G. (2007): Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee. In: Archives of physical medicine and rehabilitation 88 (2), S. 207–217. DOI: 10.1016/j.apmr.2006.10.030.