Maximum Bend After Knee Replacement (What I’ve Learned)

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I was impressed by the improvement of my maximum bend after knee replacement surgery. What I enjoy the most, however, is regaining the bend of my knee minus the pain!

Regaining the bend in your knee is critical after knee replacement surgery. How much you can bend it before TKR surgery, and following TKR, will be different for everyone.

Measuring the maximum bend is not an easy task. Each person will have TKR surgery for different reasons and experience successes and challenges during each person’s recovery.

There are some approximate knee bend measurements that you can shoot for, and I will share them with you.

Explanation of Maximum Bend (Flexion and Extension)

A completely straight (unflexed) knee joint will measure 0 degrees of flexion. A fully bent knee will max out at about (full range of motion) at approximately 135 degrees.

As a general rule, having knee flexion, or a knee bend, of 125 degrees will allow you to function well in most activities.

According to my literature review (study 1 and 2), the range of flexion required to do daily activities is as follows:

  • 65 degrees to walk
  • 70 degrees to pick an object off the ground
  • 85 degrees to climb stairs
  • 95 degrees to stand from a sitting position
  • 105 degrees to tie shoelaces
  • 115 degrees to squat
  • 125 degrees for most other activities

Getting The Most Knee Bend – A General Schedule

0-2 weeks 65 to 90 degrees – This amount of flexion allows you to walk without assistance, stand, and do some stair climbing.

2-6 weeks 115 degrees – now you should be able to move around normally

Note: From week 2-6 is when I noticed the biggest increase in knee bend. It coincided with reduced swelling as well.

3-12 weeks 125 degrees is great, 135 degrees is excellent (whether you have had TKR or not)

What’s The Maximum Bend (My Experience)

My doctor was very encouraging and told me that after knee replacement surgery I might improve the range of motion in my knee. He said that one of the best indicators of your range of motion after TKR surgery would be your range of motion before surgery.

Ask yourself, “what is/was my maximum bend before surgery”? Focus on attaining that level first, then as you recover you can try to improve upon it.

My surgeon encouraged me to strengthen my knee and work on “range of motion” exercises before my knee replacement. He told me a good goal was to aim for a minimum of 110 degrees of flexion six weeks after TKR.

My Maximum Bend Progress

Before my total knee replacement surgery, my knee was bone-on-bone with no cartilage left in the joint. It was painful to walk and to put weight on the knee.

It was also painful when I tried to use leg machines at the fitness center.

Fortunately, I was able to ride a bike and a stationary bike without pain. This allowed me to work on my range of motion before my surgery.

Before knee replacement, I was measured between 120-125 degrees of flexion. My straight-leg extension was 7 degrees, which meant I could not fully straighten my leg.

After my knee surgery it was time to get to work.

During my first in-home physical therapy session, just 3 days after surgery, I was at 70 degrees. I was in pain and trying my best to do my exercises (read more about my physical therapy after surgery).

I was, however, able to completely straighten my leg to 0 degrees.

Six days after surgery, again during exercise, I measured 88 degrees. Nine days after surgery 95 degrees. 10 days, 98 degrees. 12 days 100 degrees. 14 days, 110 degrees.

During my first offsite physical therapy session I measured 113 degrees.

Twenty-seven days post-surgery I measured 115 degrees

Eight weeks after surgery 121 degrees

After my last formal physical therapy session, I measured 125 degrees.

At my three-month visit to the doctor, I measured 121 in street clothes and without prior exercise to loosen the joint.

In the early stages of my recovery, flexion exercises caused me the most pain and I had to practice self-discipline in order to keep going and do my exercises.

It was not easy but the results were amazing. I saw a good deal of early improvement but as time went on the increase in flexion was much slower. As I mentioned earlier the critical time for improving flexion is the first few weeks and months after TKR.

3 Exercises I Used To Improve My Maximum Bend

#1 Seated knee flexion

Sit in a chair with arms to support your upper body. The floor should have a smooth surface (you can also use a plastic bag under your foot to help your foot slide on the surface).

In the seated position, slide the surgical leg back as far as you can and hold for 10 seconds. It’s much more difficult than it sounds. Repeat 10 times.

#2 Short Quad Arcs

Lie on your back with a rolled towel supporting the back of your knee. Slowly straighten your leg by lifting your foot while keeping the back of your knee on the rolled towel. I did this 20 times each day.

#3 Heel Slides

Lie on your back with your legs straight. Keep your non-surgical leg flat (read my article on heel slides).

Bend your surgical knee by sliding your heel towards your butt. You can use a bathrobe belt to pull your foot towards you for extra bend (and pain).

#4 Ankle Pumps

Lie on your back with your legs straight. Gently raise your foot off the ground and then point the toes down (then back up) twenty times (read my article on ankle pumps).

You can roll your ankle clockwise and counterclockwise twenty times. You can also exercise both ankles at the same time.


Consider a pre-surgery exercise program before your TKR surgery. The stronger your surgical leg is before knee replacement surgery and the more overall fit you are the better your TKR recovery will be.

Try and build strength and movement in your joint before surgery.

From day one after TKR surgery, it is important that you exercise your surgical knee. The first few weeks and months of your recovery are the most important for gaining back flexibility, bending, extension, and overall movement.

If you give up or are inconsistent during your rehab, and if you are not fully committed to gaining back range of motion, you may end up with a stiff knee.

There is always the risk of more surgery or lifelong joint problems so take preparation and recovery seriously.

Be optimistic and be prepared to work hard during recovery. Be patient, your maximum knee bend after surgery will return, and may even improve.