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Knee replacement range of motion Getting the knee to bend and straighten again
Knee replacement range of motion has two goals after a total knee replacement: get the knee fully straight (0 degrees, or close to it) and bend it far enough for daily life, usually about 110 to 120 degrees. Straightening matters most early, because a knee that stays bent makes walking painful and harder to fix later. Physical therapy, a home exercise plan and swelling control get you there, always within your surgeon’s protocol.
A new knee joint only works as well as it moves. In the first weeks after a total knee replacement, stiffness and swelling compete with your efforts to bend and straighten the knee, and the window to regain motion is limited. This post explains the knee replacement range of motion targets, why extension comes first, and what our physical therapists do in the videos above. Physical therapy after surgery always follows your surgeon’s instructions, and our pre- and post-surgical rehab program is built around them.
Knee replacement range of motion goals
- Straightening (extension): fully straight, or within a few degrees of it. You need this to walk without limping
- Bending (flexion): around 90 degrees to sit and stand from a chair, about 105 degrees for stairs, and roughly 110 to 120 degrees for most daily activities
Every surgery and every person is different, so your surgeon and therapist set your exact milestones.
Why straightening the knee comes first
In the second video, Zoya Reznik, DPT, OCS describes a patient who started therapy after a total knee replacement with swelling, weakness and, most of all, a knee that would not straighten. As she explains, “When he’s walking, he’s putting a lot of pressure on the front of the knee, creating more pain and swelling.” The focus became “improving range of motion, specifically into extension, doing manual work, doing stretching.” She adds that the main goal with extension is “to prevent scarring inside the joint, because the longer it is limited, the harder it is to gain back.”
How physical therapy restores range of motion
- Hands-on work: joint mobilization and soft-tissue work around the knee and the healed incision, as the last video shows
- Stretching: held positions that gradually ease the knee straighter and bend it further
- Walking retraining: keeping the knee straight when you put weight on it and bending it as the leg swings through
- Strength and balance: quadriceps, hip and calf work, plus balance drills like the balance-pad work in the first video
- Swelling control: ice, elevation and paced activity so swelling does not block motion (see swelling after knee surgery)
For some patients, the AlterG anti-gravity treadmill lets walking practice start at a fraction of body weight; here is how an anti-gravity treadmill works.
At home between sessions
- Rest with a rolled towel or pillow under the ankle, not under the knee, so the knee can straighten
- Do your heel slides and stretches several times a day, little and often
- Ice for short sessions after exercise to keep swelling down
- Keep walking in short, frequent bouts as your surgeon allows
Our knee replacement recovery timeline shows when most people reach each milestone, from the walker to driving. Our earlier post on how to recover after knee surgery covers the first weeks in more detail, and alternatives to knee replacement covers the options people try before surgery.
When to call your surgeon
Call your surgeon promptly for increasing redness, warmth or drainage at the incision, fever, calf pain and swelling, or a knee that suddenly loses motion you had gained. Seek emergency care for chest pain or shortness of breath.
More videos on knee motion after surgery
More clips from our YouTube channel @precisioncaremedical about rebuilding knee motion after a knee replacement.
Related care at Precision Care Medical & Sports Performance
Knee replacement physical therapy near you
Physical therapy after a knee replacement is offered at two Precision Care Medical & Sports Performance offices. For post-surgical rehab in Brooklyn, Zoya Reznik, DPT, OCS and the team at our Brooklyn physical therapy office, 2781 Shell Rd, see patients from Bensonhurst, Midwood, Sheepshead Bay and Gravesend; the team also includes Maggie (Yi) Zhang, DPT, Dennis Furman, PTA and Leila Nahmoud, PTA. For knee replacement physical therapy on Staten Island, physical therapists Victoria Lynn Kain, DPT and Nicholas “Nick” Ursini, DPT see patients at our Staten Island physical therapy office, 1630 Richmond Rd, convenient to Dongan Hills, New Dorp and Todt Hill.
Searching for a physical therapist near me after a knee replacement? The same teams handle other knee operations too, so if you are looking for ACL rehab near me, start here. Request an appointment or call the Brooklyn or Staten Island office. Physical therapy is not offered at the Midtown Manhattan office.
Questions patients ask
What is a normal range of motion after a knee replacement?
Most people aim to get the knee fully straight, or within a few degrees of it, and to bend it to about 110 to 120 degrees. Around 90 degrees is needed to stand up from a chair and about 105 degrees for stairs. Your surgeon and therapist set your exact goals.
Why is straightening the knee so important after a knee replacement?
A knee that stays bent forces you to walk with extra load on the front of the knee, which causes more pain and swelling. Limited straightening can also allow scar tissue to form inside the joint, which becomes harder to fix the longer it lasts.
How long does it take to get range of motion back after a knee replacement?
Most motion is regained in the first six to twelve weeks, with smaller gains for several months after that. Starting physical therapy as soon as your surgeon clears you, and keeping up home exercises, makes the biggest difference.
Is it too late to improve range of motion months after a knee replacement?
Improvement is often still possible with focused physical therapy, hands-on work and stretching, though it is usually slower than early on. Talk with your surgeon if the knee is not improving.
What exercises help range of motion after a knee replacement?
Common ones include heel slides, quad sets, seated knee bends, propped-ankle straightening stretches and stationary cycling. A physical therapist chooses and progresses them based on your surgeon’s protocol.
Where can I get physical therapy after a knee replacement near me?
Precision Care Medical & Sports Performance offers post-surgical physical therapy in Brooklyn and on Staten Island. Physical therapy is not offered at the Midtown Manhattan office.
- Brooklyn2781 Shell Rd, Suite 101, Brooklyn, NY 11223(718) 648-1234 · Get directions
- Staten Island1630 Richmond Rd, Suite 101, Staten Island, NY 10304(718) 339-7100 · Get directions
Educational only, not medical advice. These videos and this article explain common problems and treatments in general terms. They are not a diagnosis or a treatment plan for you. Results vary from person to person. See a qualified clinician about your own symptoms, and call 911 or go to an emergency room for an emergency.
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