C-Leg 4: Microprocessor Knee
Reclaim your determination
Real life stories from C-Leg users
To request a brochure about microprocessor knees, or to find a prosthetist near you, send us an enquiry.
Benefits at a glance
More freedom of movement
Movement patterns are considerably easier for C-Leg 4users, even on varying surfaces such as sand, grass or gravel. The flow of smaller step sequences and the user’s gait pattern when changing walking speeds are controlled more smoothly. Even if you have never worn a C-Leg 4 before, this technology typically makes the adjustment period quite short.
Fluid movements occur first and foremost when the prosthesis responds quickly to different everyday situations. The resistance of the C-Leg 4 microprocessor knee adapts to all walking situations in real time, whether on level ground, stairs, ramps or varying surfaces. This gives you a noticeably smoother and more reliable movement pattern as well as more energy.
Select the stance function yourself
The C-Leg 4 supports you when standing. Using a discreet movement pattern, you can assume a relaxed position with a slightly flexed knee. You might already be familiar with this function. It is especially comfortable on slopes and uneven surfaces. A new feature of the C-Leg 4 is that your prosthetist can also set the intuitive stance function at your request. With this function, the joint is able to detect from your movement when you’d like to stand in a relaxed position or when you need support for your next step.
Stumble recovery for enhanced safety
Safety has always come first with the C-Leg 4. A large number of studies have proven that the frequency of falls in people with a transfemoral amputation is significantly lower with the C-Leg 4 in comparison to conventional prostheses. This makes the C-Leg 4 one of the most reliable MPKs in the world. Scientific studies show that this increases confidence in the prosthesis and that users pay greater attention to their surroundings. We’ve taken the stumble recovery of the C-Leg 4 to a new level, making it even more precise and offering even greater stability.
The automatic sitting function provides you with crucial support. The free-swinging joint provides a relaxed and comfortable sitting position.
Smart control via app
The Cockpit app lets you operate the C-Leg 4 directly using your smartphone (Android or iOS) and access information about the C-Leg 4, such as the battery charge level. The C-Leg 4 communicates with the app via integrated Bluetooth®.
Wet or dry
The weatherproof C-Leg 4 is rated to IP67. This rating means the C-Leg 4 is protected from damage due to incidental contact such as a downpour or temporary submersion in fresh water up to one metre for thirty minutes. Now everyday activities such as washing the car or watering your garden are no longer a concern.
Protection and attractive design
The C-Leg 4 protective cover shields the prosthesis against impacts, environmental influences and wear and tear. It consists of a robust main protective cover component, a selectable shield insert for the front side, as well as a protector foot cuff. The protective cover also gives the C-Leg 4 a natural volume under long clothing.
Proven by studies
The C-Leg 4 is the most frequently fitted and most often studied MPK in its class. Users around the world trust the C-Leg 4 because it helps them lead an independent and self-determined life.
Download the studies in our Downloads Tab above.
The C-Leg 4 technology provides intelligent control of the MPK for people with transfemoral, knee disarticulation and hip disarticulation amputations and adapts it to their gait pattern in real time. Behind this is a complex sensor system that captures data in real time and recognises which phase of walking you are in. Whether you are on level ground, going down stairs step-over-step, on slopes, or on difficult surfaces such as forest floor, sand and gravel. This makes the C-Leg 4 one of the most reliable microprocessor knees available. Thanks to the C-Leg 4's capacity to adjust itself, the user can also master small obstacles, unclear terrain or large crowds.
C-Leg 4 specifications
Highly stable yet lightweight carbon fibre 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.
- C-Leg 4: User brochure 18.02 MB | PDF
C-Leg 4: User brochure
Download our latest C-Leg 4 brochure for end-users.
- NHS MPK Policy Patient Guide 4.30 MB | PDF
NHS MPK Policy Patient Guide
C-Leg 4 is now available on the NHS. Download our guide to the NHS MPK policy and learn more about C-Leg and what is available through the NHS.
- C-Leg 4 Clinical Evidence 634.21 kB | PDF
C-Leg 4: Clinical Evidence
Download our C-Leg 4: Clinical Evidence brochure. C-Leg is the most widely used and studied microprocessor-controlled knee on the market.
The C-Leg is the most trusted MPK across the world with more than 75,000 fittings carried out for people with transfemoral amputations since 1997. Studies have shown that the C-Leg is the safest microprocessor-controlled knee joint, extremely reliable and has the ability to help people achieve independence.
Ask your prosthetist about trying out a C-Leg. If you are not currently seeing a prosthetist, let us know, and we can help you find one in your area.
The C-Leg 4 is rated to IP67. This rating means the C-Leg 4 is protected from damage due to incidental contact such as a downpour or temporary submersion in fresh water up to one metre for thirty minutes. Now everyday activities such as washing the car or watering your garden are no longer a concern.
With Intuitive Stance, the joint recognises that you want to stand and responds immediately by locking the C-Leg 4. This makes relaxed standing with a slightly flexed knee possible. Manual Stance is consciously activated or deactivated in several steps. Your prosthetist can explain how this works in detail.
Activation is simple. As soon as you briefly assume a flexed position, the joint “recognises” that you are standing and therefore remains locked. To deactivate the function, simply take a step or move the prosthesis.
Can I use the Cockpit app or remote control to switch between the stance functions in my C-Leg 4, Genium and Genium X3?
You and your clinician decide which stance function is suitable for you. You can use the Cockpit app or remote control to turn this preset stance function on and off. Switching to an alternative stance function is not possible with the app or remote control.
Unlike other microprocessor knees and indeed our last C-Leg 3, the C-Leg 4’s Stumble Recovery function is armed and ready to support you immediately. C-Leg 4 does not need to detect a stumble to provide its enhanced level of support – it’s already prepared as soon as you start to swing through to take a step. This unique Stumble Recovery feature in the C-Leg 4 is certainly best in class.
Ottobock UK have a great place for people to share their stories, learn more about products, and connect with one another. Join the conversation!