UP TO 60° RANGE OF MOVEMENT GAIN
weeks programme
VERY SATISFIED WITH TREATMENT
Up to 20% of patients suffer from knee stiffness and pain after knee replacement surgery, a condition often caused by arthrofibrosis. But stiff knees don't have to be permanent.
The STAK knee rehabilitation device is an innovative tool that provides high-intensity home-based stretching therapy – proven to be up to 10x more effective than standard physiotherapy exercises. Whether you're recovering from recent knee surgery in the UK or struggling with stiffness years later, the STAK Tool can help you restore mobility, reduce pain, and get back to the activities you love.
The gadget definitely works! The STAK exercise has removed much of the pain in my knee, there's a massive increase in movement and I'm walking normally after1 week!
To get my knee bending to its full potential that I have got now has to be down to The STAK tool because with normal exercises it just wouldn't work.…….. the STAK is more intense.
My knee is bending 100% better than it was… I can walk 7-8 miles! On holiday the walking is tremendous…. I‘ve climbed a lighthouse with 137 stairs!
After using the STAK tool I know I can keep up with my friends, just after 4 weeks I could feel a huge difference
They sent me home and I was nowhere near 90° so for me having this STAK would have been ideal right from the from the beginning.
After 1 week the STAK has made a huge difference. My Physio was amazed! ..and its all down to the STAK. You can stretch effectively yourself using your body weight, before I had nothing.
After 6 weeks I’m now back riding my bike, coaching netball and I’ve got my life back!
I feel that it's been very useful, it's great and should be in physio departments for people to use.
I didn't expect it to help this much when I was already 6 months after surgery but it's brilliant and feels much stronger!
The STAK was fantastic! It held my knee in place, you knew you were doing it right. It makes you want to do more and gives you encouragement and confidence so you can do it.
She only had 62° flexion, I spoke about the STAK and I was surprised that she had reached 108° flexion just a few weeks later
Stiffness in knee replacements is a top priority for management, ongoing innovation is crucial. The STAK really enhances our non-surgical approach to this challenging issue.
It’s just a fantastic, low cost and really effective alternative treatment compared to the traditional treatments we had before. Since we have been using the STAK tool the MUA rates have fallen.
The STAK tool provides a measurable outcome improvement. The patients get and maintain extra functions over and above what they normally get.
In the most challenging cases where traditional methods, such as extensive physiotherapy, hydrotherapy, continuous passive motion (CPM) machine hire, and manipulation under anaesthetic, fell short the STAK proved to be the solution.
Patients can perform high-intensity stretches while maintaining control over the intensity and we can clearly track their progress.
Patients find it user-friendly and highly motivating, boosting their treatment throughout the critical 4 to 6 weeks of rehabilitation.
Our tailored knee rehabilitation programme combines STAK tool rental with optional virtual physiotherapy sessions to deliver professional-grade recovery—right in your home.
You can hire a STAK Tool through our website, which will be delivered directly to you in 2-4 days
Your initial session includes a detailed knee assessment and custom recovery goals designed by our experienced physiotherapists.
We recommend pairing the STAK Tool with our weekly physiotherapy sessions to ensure correct use, track your progress, and enhance your results
When your program ends, returning your STAK device is simple and hassle-free. We provide clear instructions and prepaid return labels.
You can hire a STAK Tool through our website, which will be delivered directly to you in 2-4 days
Your first session involves an in-depth assessment of your knee and we will set tailored targets to match your individual case.
STAK is provided with weekly physio sessions to keep you on track with your recovery.
Once your program is complete, we make it easy for you to return the STAK Tool.
If you’re experiencing limited range of motion, pain, or tightness, you may be affected by arthrofibrosis—a common complication after knee surgery or serious injury.
This condition occurs when the body forms excess scar tissue inside the joint. Left untreated, this scar tissue reduces knee mobility, causes chronic stiffness, and impacts your quality of life.
The STAK device enables safe, controlled, and high-torque stretching—far more powerful than ordinary exercises. This intensity helps to break down scar tissue, restore range of motion, and support full knee rehabilitation at home.
Unlike traditional methods, the STAK Tool allows you to perform multiple high-quality stretches daily, which is essential for beating arthrofibrosis and restoring flexibility after a total knee replacement.
Structured home-based knee therapy with guided support. Includes weekly video coaching to help you maximize the results from your STAK sessions..
We provide online physiotherapy tailored not only to knee replacement recovery, but also to other orthopaedic injuries and mobility issues.
We partner with hospitals across the UK to improve patient outcomes post-surgery. Healthcare professionals can rent STAK Tools for 6-month trials, helping patients benefit from advanced home physiotherapy solutions..
Whether you’re recovering from ACL reconstruction, knee replacement, or long-standing joint stiffness, the STAK Tool is your solution for fast, measurable recovery.
✅ Trusted by physiotherapists
✅ Backed by clinical results
✅ Designed for safe, daily use at home
In a clinical trial lasting 8 weeks arthrofibrosis patients using the STAK gained on average 30° range of movement compared to patients receiving standard physiotherapy who gained only 8°.
“The STAK tool increases ROM and function whilst reducing stiffness and pain. This study shows the STAK tool would benefit clinical practice for a cost-effective and professional treatment for arthrofibrosis.”
1st Aug 2020
“In a clinical trial patients using the STAK increased their ROM on average
30° compared to receiving standard physiotherapy gained only 8°. The STAK patients also reported greatly reduced knee pain.”
9th Feb 2021
The device can be considered a cost-effective and valuable treatment following TKA. This is likely to increase the overall satisfaction rate and has potential to reduce the need for MUA.
7th July 2022
We’re so confident that your patients will see and feel immediate improvements after their first session with the STAK that we’re offering a money-back guarantee:
The STAK is a class 1 medical stretching device for home or clinic use. It enables patients to regain knee range of movement and reduce stiffness and pain following knee surgery or injury. It offers daily intense stretching capabilities, crucial for successfully breaking down scar tissue in between physiotherapy appointments, ensuring quick progress and superior results to standard physiotherapy alone.
The STAK enables you to generate high-intensity stretches, breaking down scar tissue in the knee joint. This process helps reduce stiffness and pain, allowing new, healthy tissue to form and restoring your knee’s range of movement.
It is recommended to use the STAK device as part of a treatment programme for 4 to 8 weeks, depending on the severity of your stiffness and how long after surgery you start treatment. The majority need 8 weeks, but if you already have 100˚4 weeks should be adequate.
Yes, the STAK can be beneficial even many years after knee surgery. The latest to date is 6 years following TKR. If suffering severe stiffness an extra 4 weeks may be required but the average 30˚ increase still stands.. STAK helps patients with severe motion loss or those looking to improve their activity levels and quality of life.
You can start using the STAK shortly after your knee replacement surgery once clips have been removed. Early intervention with the STAK can pre-emptively address stiffness, yielding exceptional patient outcomes. If wanting to use prior to 2 weeks following surgery please consult Dr Sara Aspinall.
Yes it is beneficial to have physiotherapy support for guidance and monitoring progress. Your physio can help tailor the use of the STAK to your specific needs.
Yes, you can take the STAK to your local physio. We will supply them with a short physio training video. They can assist you in incorporating it into your rehabilitation programme and guide you as you progress.
Absolutely. The STAK can be integrated into your hospital physio sessions. Your hospital physio can help you use the STAK effectively as part of your rehabilitation programme, ensuring you achieve the best possible outcomes.
The frequency of use will depend on your individual treatment plan. Typically, patients use the STAK device 3 times a day for optimal results. If you have less severe stiffness 1-2 times may suffice.
Virtual STAK physio sessions provide remote support and guidance from a STAK Specialist Physiotherapist. They will monitor your progress, adjust your treatment plan as needed, and ensure you are using the device correctly.
Yes, the STAK is designed for ease of use. It comes with clear instructions for self-setup, enabling you to perform effective stretches at home.
The STAK generates high-intensity stretches necessary to break down scar tissue, which standard physio exercises cannot achieve. In clinical trials, patients using the STAK experienced an average gain of 30° in range of movement over 8 weeks, compared to only 8° with standard physio.
Yes, a clinical trial published in The Bone & Joint Journal showed that arthrofibrosis patients using the STAK experienced a significant average gain in range of movement, far surpassing the results of standard physio.
The STAK has received praise from surgeons and physiotherapists. EG Professor Andrew Toms from the Exeter Knee Reconstruction Unit highlighted its ‘unique effectiveness in improving non-surgical approaches to treating knee stiffness’ (see testimonials on our website for more details).
In your first session, we will discuss your goals and what activities you would like to return to. Your knee will be assessed, and your range of movement measured accurately using an App (you will be sent a copy of this if you wish). You will be taught how to complete the STAK programme and all elements will be completed by yourself. You will be shown how you can measure your progress. We will discuss several important elements of the programme and how to tailor it to your individual need. You will feel improvements in your knee after the first session.
In your follow-up sessions, your progress will be monitored, range of motion recorded and any issues which may arise worked through together.
Most insurance companies will cover the physiotherapy sessions such as AXA Health, Vitality Health, Simply health, Benenden Health, Westfield Health. Please inform us if you plan to use insurance and we can assist.
Some will include STAK hire but please reach out to your insurance company and check with them.
If not please contact us and we may also be able to help get the insurance company on board.
