NHS funding for Microprocessor Knees

What is it about?

NHS England has made the momentous decision to approve the funding of Microprocessor Controlled Knees (MPKs) for those living with above knee and hip disarticulation amputations. Over the next several years patients previously restricted to mechanical knees, will get access to some of the most technologically advanced and life-changing prostheses in the world. Sharing the same technology and providing the same benefits as the prosthetic knee joints used by the country’s serving and ex-service men and women, this news will revolutionise the lives of so many people.

Unlike mechanical knees, MPKs use an internal computer and sensors to monitor each step of the wearer’s walking pattern (gait cycle) and use this information to make real-time adjustments to the knee. These adjustments typically involve changes to resistance and make walking at various speeds easier, allow wearers to manoeuvre ramps and challenging terrain as well as facilitate walking down stairs step-over-step. As a result of this technology, patients often comment that their energy levels are much higher, they can do more, walk further and more often. Because of the enhanced safety systems in place within the knee, wearers also note a reduction in back pain; which is very common within the amputee population. For patients with hip disartulation amputations, this ultimate level of security is an absolute must in order for them to walk safely and confidently. All of these features are only a handful of the benefits that a microprocessor knee can offer a patient and this is truly what sets them apart from their mechanical counterparts.

By funding MPKs, the NHS is helping to improve the quality of rehabilitation for patients nationally and make a significant and positive difference in the lifestyles and health of amputees.

C-Leg 4: The safest Microprocessor knee, now available on the NHS .

The People’s Choice

The C-Leg has stood the test of time and changed the lives of countless amputees by helping them to achieve increased mobility and independence. No other computer controlled knee prosthesis is trusted by as many users worldwide. More than 60,000 fittings have been carried out since 1997, defining it as ‘The People’s Choice’.

Clinical studies prove it: The C-Leg is the safest and most popular microprocessor-controlled knee joint in the world.

Take a look at our Downloads tab below, where you will find the latest clinical evidence highlighting and proving the benefits of C-Leg.

Now in its fourth incarnation, the C-Leg 4 is safer, more dynamic and has become even closer to a natural walking pattern than ever before. From stairs and ramps to varying surfaces and walking backwards – the C-Leg adjusts itself dynamically to various everyday situations, tailoring every movement to meet your needs, whilst providing absolute peace of mind and security for every step.

Learn more about the C-Leg


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

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.

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.

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.

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.

What you need to know

What is available?

The funding means that amputees will have access to one of the safest and most popular MPK's on the market – the C-Leg. The C-Leg is the most trusted MPK across the world with more than 60,000 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.

The C-Leg 4 Microprocessor Knee

Now the C-Leg is available on the NHS, amputees now have the opportunity to experience life with increased safety and can reclaim their determination.

Launched in 1997 and in its fourth and most advanced incarnation, the new C-Leg 4 marks the start of a new era: It’s the best C-Leg of all time. The daily challenges that are faced by amputees all over the world are now a thing of the past. No longer do you need to concentrate on every step, whilst you are looking at the ground for any potential obstacles that lie ahead. The safety systems inside the C-Leg 4 have that covered so you can relax, look forward and enjoy life.

The most natural walking pattern

The main aim of a prosthetic knee joint is to replicate normal anatomical movement; with C-Leg 4 we are closer than ever to achieving this. The on-board sensors and microprocessors within the C-Leg 4 are constantly measuring information from the knee joint in real-time. Unlike other microprocessor knees, there is absolutely no delay from detecting a change, to adapting the settings to the new situation. Whether you’re walking down a slope, quickly changing your direction and pace of walking, or stopping abruptly to avoid danger, the C-Leg 4 has the technology to provide the wearer with the most natural and responsive walking pattern.

It's not all about walking!

Life isn’t always about moving around. Sometimes the hardest thing for an amputee is to stand still in a comfortable and relaxed position, without having to waste energy controlling the movement in the knee joint. Without a C-Leg, simple things like standing outside in the garden on uneven ground, holding your child at the park or even certain jobs that require you to stand and face people can become a daily struggle. These situations can also often generate significant back problems and joint aches and pains. With C-Leg 4’s unique stance function, it naturally and intuitively allows you to stand completely safely on a slightly bent knee joint, and then when you’re ready to move, the movement is detected and will allow you to walk off without you even having to think twice.

Scientifically proven; World Class Safety!

During normal daily life, safety is of upmost concern to those who use a prosthesis. The C-Leg 4 has the most precise and safest Stumble Recovery feature in the market. Unlike other microprocessor knees, the C-Leg 4’s Stumble Recovery function is armed and ready to support you immediately. Without any delay between the detection of a stumble and the knee joint providing you extra support to prevent the fall, the C-Leg 4 is certainly best in class. A large number of scientific research studies have proven that the number of falls in people with transfemoral amputations is significantly lower with the C-Leg in comparison to conventional prostheses.

MyModes and smart control via app

The C-Leg 4 lets you connect via Bluetooth to your knee by using the Cockpit App on your mobile device. Information such as remaining battery life and step count can be easily viewed and tracked. Patients can also use the app to activate and deactivate the C-Leg 4’s sitting function. This is extremely helpful when sitting in confined spaces where you may need to reposition your leg. Another feature of the app is its ability for users to switch between modes. No matter whether your hobby is golfing, dancing or riding a bike, C-Leg 4 allows amputees to programme their knee to a specific mode, so you can continue doing what you love.

Wet or dry!

The C-Leg 4 is weatherproof and is protected against splashed water. Simple things that were previously avoided like bathing the children, getting caught in the rain or washing the car are no longer a problem.

The finest protection.

The C-Leg 4 Protective Cover safeguards it against knocks and scratches. It consists of a robust main protector component, a choice of decorative inserts for the front section as well as a foot cuff. The Protective Cover also gives the leg a natural volume and shape under clothing.

The Policy & Process

Available within NHS England centres only, the policy aims to help patients recover from the effects of amputation with improved rehabilitation and prosthetic choice. Amputees will now be able to select, with their Prosthetist, the right prosthesis based upon their needs and will not only be limited to mechanical options. There has been much documented evidence on the benefits and advantages of Microprocessor knees compared to mechanical alternatives. MPKs are able to provide wearers with more safety and stumble recovery software, which reduces the risk of falls significantly. Patients who have trialled both mechanical and microprocessor knees also noted their improved mobility and independence when wearing an MPK. The policy will allow above knee and hip disarticulation amputees with a medium to high ability level the opportunity to be fitted with a fully funded microprocessor knee on the NHS. All applicants will need to follow the outlined patient pathway, mandatory for MPK provision. Patients will be prioritised for funding based on clinical need.

If you wish to be fitted with a funded C-Leg 4 you will need to contact your local NHS England centre. You will then be assessed individually by the centre’s full rehabilitation and care team including your Prosthetist, Consultant, Physiotherapist, Occupational Therapist and Councillor (if applicable). The assessment will aim to gather a full patient history as well as understand the daily activities, needs and challenges you may face as an amputee. A physical examination will also be required. Patients need to be able to demonstrate a daily need for a microprocessor knee as well as a commitment to rehabilitation through active therapy participation.

You will then, along with your care team, outline clear rehabilitation goals you would like to achieve. The goals will be centred around your ability, needs and aspirations and must be able to justify the need for a microprocessor controlled knee.

Upon the successful completion of the above, the multidisciplinary team will then look to organise an MPK trial. The trial will last roughly 4 weeks, allowing you to take the prosthesis home and get the feel of what using an MPK in daily life is like. During the trial you may need to attend some physiotherapy, where you will be taught how to use your C-Leg. You will also need to prove that you have enough strength and balance to activate the knee as well as sufficient physical fitness to walk outdoors with the prosthesis. You must also be able to master the control, operation and care for a microprocessor knee.

Your Physiotherapist will also record how you walk on a non-microprocessor knee, compared to your MPK trial performance. Otherwise known as outcome measures, these should include information on your mobility and noticeable changes that may have taken place as a result of wearing your C-Leg. For example, if you have a history of instability documented through falls, stumbles or near misses it is imperative you share this information with your Prosthetist prior to your trial. Studies have found 64% of C-Leg 4 wearers had a reduction in falls compared to wearing a mechanical knee. If the results of an MPK trial illustrate a higher level of stability for you, this will be a key finding to support your need for a microprocessor knee.

Upon successful trial completion and based on your Prosthetist’s and care team’s recommendations, you should then be eligible to be fitted with an NHS funded C-Leg.

Eligibility Criteria

In order to be eligible for an MPK, patients must meet certain criteria stipulated in the NHS commissioning policy. Firstly, you must fall into at least one of the following categories:

- Single, above knee amputation

- Hip disarticulation amputation

- Knee disarticulation amputation

- Double, above the knee amputation

- Double lower limb amputation with at least one being at above the knee level

At a minimum, you must have the potential to walk with a mechanical knee at a medium to high speed as well as at differing speeds and simultaneously overcome most natural obstacles (mobility level 3 and 4). MPK funding candidates should be unrestricted outdoor walkers and be capable of walking more than 50 yards on level ground. Lower mobility patients may also be considered for funding, if it can be demonstrated through a trial that the use of a Microprocessor knee improves their mobility and environmental obstacle negotiation to the levels described above.



C-Leg 4: User brochure

Download out latest C-Leg 4 brochure for end-users.


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.


  • Who can have a MPK?

    This policy will provide funding for eligible lower limb amputees with an activity level of SIGAM D or above. This includes unilateral trans-femoral amputees and bilateral lower limb amputees, including those with at least one trans-femoral amputation who fall into the Mobis 3 and 4 categories.

    Knee disarticulation or hip disarticulation amputees with the same Mobis categories are also eligible for an MPK. However, a patient with mobility lower than K3 (SIGAM D) but can be improved through a MPK trial would also be considered.

  • What is the C-Leg?

    The C-Leg is the most trusted MPK across the world with more than 60,000 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.

  • How do I get a MPK?

    If you wish to be considered for a MPK you should visit your local prosthetic centre to check

    if you are eligible. To be eligible for a MPK you must fit a certain criteria and if successful, a trial will be undertaken to see if it is the right option for you.


Ottobock UK

Our specialist Academy team are dedicated to providing outstanding support up and down the country. As well as being able to assist your prosthetist with the initial fittings, they are also on hand to answer any questions or concerns you may have. If you need to speak to one of our team please contact them on:

Rachel Neilson - Rachel.Neilson@remove-this.ottobock.com

Alan McDougall - Alan.McDougall@remove-this.ottobock.com