After a total knee replacement (TKR), one of the most important goals is to achieve a functional range of motion at the knee joint. Functional range of motion simply means that you are able to move your knee enough to perform your day to day activities with comfort and ease. Regaining range of motion after surgery is a common struggle amongst many patients, but there are ways to set yourself up for success. In this blog post we will cover what functional ROM is, some common TKR goals and questions, and what you can do to maximize your ROM after surgery. For a more in depth look at ROM, see our post titled “The Importance of Range of Motion.”
What is considered a functional ROM?
In order to complete your normal activities of daily living (ADLs) with ease, your knee has to be able to move freely. After a total knee replacement, at the very least 100-110° of knee flexion is needed to perform basic ADLs such as sitting, walking, and stair climbing. However, some activities may require even more knee flexion for optimal performance and comfort.
- Walk on level surfaces: 60-75°
- Go up and down stairs: 80-90°
- Sit and stand from a regular chair: 90-95°
- Sit and stand from a low chair: 90-115°
- Squat: 110-165°
- Sit in a bathtub: 135°
What are important ROM milestones during the recovery process?
While everyone’s recovery process will look very different based on their overall health status, age, and other personal factors, there are some key milestones your physical therapist will look for as indicators of ROM progress.
End of week 1: the goal is to reach at least 90° of knee flexion and be working towards full knee extension.
Weeks 2-3: the goal is to achieve at least 100° knee flexion and full knee extension.
Weeks 4-6: you should be approaching or have already achieved 110-120° of full knee flexion.
Weeks 6+: the goal is to focus on strengthening the lower extremity muscles with functional range of motion at the knee joint.
I feel pain when performing ROM exercises. Is it normal?
While total knee replacements are routine surgeries with great outcomes, there’s no denying that movement during the recovery process is likely to be painful. Be patient with yourself - your knee just underwent a surgical procedure and the surrounding tissues are healing. Contrary to what you might think, early movement is essential for recovery and will decrease pain and stiffness in the long run. Your physical therapist will guide you through exercises that are safe for you to perform in order to increase ROM, even if you feel some soreness. Don’t worry, just breathe, take it one step at a time, and know you are on your way to getting better.
Why is early ROM important after a total knee replacement?
After surgery, you will likely experience some degree of pain and swelling surrounding the knee joint. In addition, scar tissue formation as part of the healing process can cause the knee joint to become stiff or “stuck” in a position that negatively impacts range of motion. Performing ROM exercises early on can help reduce swelling around the joint and decrease the formation of scar tissue, both of which will help the knee to move with greater comfort and allow for increased range of motion so that you can get back to doing the things you love sooner.
What steps can I take to improve my knee ROM post surgery?
The best way to ensure you have a holistic recovery program after a total knee replacement that will help you regain full ROM and strength is to regularly check in with a physical therapist and assess your progress. We recommend you make sure your physical therapist has experience with musculoskeletal disorders and post-op treatment plans.
Don’t have a physical therapist that has experience in musculoskeletal disorders or post-op treatments? Download our OneStep Digital Physical Therapy app to be connected directly with a skilled licensed physical therapist who will build a customized recovery program based on your needs and goals - walking you through your entire rehabilitation process, even if you have not yet had surgery!
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Jette DU, Hunter SJ, Burkett L, et al. for the American Physical Therapy Association, Physical Therapist Management of Total Knee Arthroplasty. Phys Ther. 2020;100(9): 1603–1631. https://doi.org/10.1093/ptj/pzaa099
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