Knee extension stretch

3 Ways to Avoid Loss of Motion After ACL Reconstruction

Approximately 200,000 anterior cruciate ligament, or ACL, injuries of the knee occur annually in the United States, leading to nearly 100,000 ACL reconstruction surgeries. This makes ACL reconstruction one of the most common orthopedic surgeries.

While excellent outcomes can be expected following surgery, not everyone is completely satisfied or returns to their full level of activity. However, the majority of complaints following surgery can often be avoided with proper rehabilitation.

The most common complication and cause for poorer outcomes following ACL reconstruction is motion loss, particularly loss of full knee extension. The inability to fully extend the knee results in abnormal joint motions, scar tissue formation in the front of the knee joint, and subtle changes in normal knee mobility. Thus, one of our goals is to achieve at least full extension and even some degree of hyperextension during the first few days postoperatively. As the patient progresses and the knee’s homeostasis is restored, we eventually work to restore symmetrical knee extension motion.

Many people have a certain degree of knee hyperextension, meaning it extends past a straight 0 degrees. Normal knee hyperextension is approximately 5 degrees but I’ve seen people have as much as 15-20 degrees of hyperextension.

knee hyperextension

All too often, I hear from patients that they were told that full knee extension equal to the opposite knee is not needed and that 0 degrees is good enough. Well, I’ve seen these patients a year or two out from surgery and let me tell you, it’s not good enough. Obtaining symmetrical extension (usually some form of hyperextension) is completely needed for multiple reasons.

A recent study showed that just a simple loss of 3° to 5° of knee extension resulted in worse outcomes and satisfaction after surgery.

Any loss of knee extension will cause long term issues Previous studies have shown anterior knee pain, patellofemoral pain, quadriceps weakness, and long term inability to return to daily activities and sports. I’ve also seen a 2 times increase risk of knee arthritis if the patient doesn’t obtain full ROM postoperatively. As you can see, it is critical that the patient regain full knee ROM, particularly hyperextension similar to the opposite knee.


How to Treat Loss of Knee Extension

The first step in treating someone with motion loss of ACL reconstruction is avoiding loss of motion during the early phases of rehabilitation. It is extremely important to find a good physical therapist and to start therapy soon after surgery. This will include specific exercises, stretches, and manual therapy to assure your knee and patellofemoral joint are progressing well.

On top of this, we educate our patients on performing multiple bouts of hamstring and calf stretches with a wedge under the heel to maintain soft tissue flexibility in the back of the knee. During both of these exercises, emphasis should be placed on moving the knee into full extension. This can be done throughout the day no matter where the patient happens to be…so no excuses!

3 Ways to Avoid Loss of Motion After ACL Reconstruction

Another technique that is really helpful is the use of a low-load, long-duration stretch, meaning a gentle stretch held for a long amount of time. This tends to help people improve mobility, especially those that are in more discomfort after surgery.

This can be performed by placing a 5-10 pound weight over the thigh with the heel propped up and gentle allowing the overpressure of the weight to stretch the knee into extension. The patient is instructed to use this stretch for 10-15 minutes, 2-4 times per day.. If someone is starting to lose motion, the frequency is often increased to total at least 60 minutes per day. We utilize this technique immediately following surgery to maintain and improve knee extension.

low load long duration stretch knee

I prefer this technique over the prone knee hang position for 3 reasons. First, the patient usually reports they feel vulnerable lying in on their stomach with their leg hanging off the table or bed. Second, it’s very difficult to control the pelvis and hamstring influence on restoring the knee’s hyperextension. Finally, I’ve shown many people the supine position after they’ve done the prone hangs with other therapists and 99% like it better than the prone hangs. That speaks volumes to me!

Finally, once motion is improving, we perform functional tasks utilizing this new mobility to lock in our gains. We have our patients perform backward walking to create an extension moment about the knee. We first do this in a controlled position while stepping over cones. We then progress to retro treadmill walking for 10-15 minutes at a time to further encourage that extension motion. I’ve had great success at improving a patient’s knee extension when they’ve been told previously that they’ll never get it to return.

retro cone walking

The literature seems to strongly show that restoring extension is imperative to a successful outcome and an asymptomatic knee long-term.  Loss of knee extension mobility will almost certainly lead to long term knee issues that will continually hamper the patients ability to return to their normal function.  Use these three techniques to avoid loss of motion following ACL reconstruction and improve your outcomes.



48 replies
    • Rob
      Rob says:

      Lenny: Thank you for the exceedingly helpful post. I’m four years post ACL surgery and thought I’d never get back to normal. I just did the stretching as you suggested and also the backward walking on the treadmill. My leg extension improved dramatically in literally two hours. My hip used to hurt constantly — it feels fine right now. I cannot wait to give the stretching more time to work. I wish my surgeon had told me to work on the extension. He actually suggested that hyperextension was a bad thing. Asymmetrical extension is the real problem. Anyway, I am very grateful. Rob

    • Karam Kogan
      Karam Kogan says:

      Hi, I had Acl surgery like 6 months ago and I didn’t get any full extention, then my doctor said I have a scar tissue and had another surgery to remove it and it’s been 24 days now, but still I have no full extention or bending, though I do all the exercise, what possibly the reason behind that, will I ever back normal again? Or that’s could take a life long? Please I need to know, and thanks

      • abbey
        abbey says:

        Hi Karen, I had issues gaining my extension also even after months of extensive physio I finally insisted another mri to rule out a “Cyclops lesion” very rare but turns out I had it…. a large mass that needed to be removed and my extension improved immediately. good luck

      • Kim
        Kim says:

        I had ACL Surgery October 27, 2017 I have a doctor appointment today and I am scared that I need to get surgery again. I can’t put my knee straight and if I do once I have it bent for a long time it bends again. What do you think? will I need surgery

  1. Herbert
    Herbert says:

    I am now about 8 months post reconstruction surgery and about 4 months post scary tissue removal surgery and I still lack knee extension. Is it even possible for me to get it back?

    • Lenny Macrina
      Lenny Macrina says:

      Herbert, I’ve seen this before and have had some success in gaining back some, if not all of your ROM. I believe diligence in home exercises from the exercises mentioned in the post, manual PT to work on soft tissue work and a good strengthening program to reinforce the newly gained ROM should get you over the hump. It is imperative that you do at least 60 minutes/day of low load, long duration stretching to make any gains. Good luck!

  2. Ashley
    Ashley says:

    My husband had knee surgery in September 2014. He’s now approaching 8 months post op and has not been able to regain full extension of his knee. He continues to go to PT twice a week and had a knee manipulation to break up scar tissue two months ago to no avail. He’s about 5 degrees off. He’s very disciplined about doing his exercises, and has been from the start. He’s very discouraged and even his PT seems to be losing hope. He’s a police officer and hasn’t been able to return to full duty because he can’t run. He’s also a big workout guy and though he’s still in the gym 5-6 days per week, not being able to run has really been a hard adjustment for him. Do you have any suggestions about what to do at this point? Is it even possible at this point to get extension back? Thanks for any insights you might have.

    • Lenny Macrina
      Lenny Macrina says:

      Ashley, Depending on what the surgery was and what else is going on in his knee, I would imagine that your husband would be able to get his motion back. As I mentioned above and in the post, diligence in performing the exercises mentioned in the post, manual PT to work on soft tissue work and a good strengthening program to reinforce the newly gained ROM should get him the rest of the ROM. Again, if he has an arthritic knee or didn’t have the motion before the surgery (even for a period of time), then it will be much more difficult (or he has a significant medical history including items like diabetes). It is imperative that you do at least 60 minutes/day of low load, long duration stretching to make any gains. Good luck!

  3. Tiphanie Hardacre
    Tiphanie Hardacre says:

    I had my surgery 4 years ago to fix a torn MCL, ACL, and meniscus in my left knee. Both of my knees use to hyperextend but know only my right knee does and I have noticed that my hip hurts more as well as my right knee but my doctor will not do anything to help and I don’t know what is wrong with my left knee. It constantly gives out on me it doesn’t even get to a 0 degree extension and there is a lot of scar tissue in the front of my knee. What can I do to help this I have tried physical therapy but I think it’s to late to get my knee to hyperextend again. Thank you!

  4. Mike Reinold
    Mike Reinold says:

    Hi Tiphanie, we work with people with similar situations and can improve their extension. What you are experiencing is why we really need to focus on restoring extension to the knee. If you are in the Boston area let us know, otherwise, I would recommend you continue seeing your therapist (or try another!). Good luck.

    • Abdul
      Abdul says:

      Dear Mike Reinold,

      Is it possible to make an appointmemt with you through Skype, and I will pay for the consultation. I can not come to your clinic since I am overseas. Thanks in advance.


  5. Toyya pujol
    Toyya pujol says:

    I got ACL reconstruction 16 yrs ago and my physical therapists didn’t focus on extension. I find that the stiffness in my knee is getting progressively worse and affecting my hamstrings (which have been injured 2x). I am not sure what options I have this many years post op. Is PT an option? Is getting surgery followed by PT best? What type of self care can i do in the interim?

  6. Anurag Thakur
    Anurag Thakur says:

    Hi There,

    I had an ACL and meniscus in my right knee(feb 25-2015). Exactly 4 months over since my surgery, I am getting around 140 deg bend and almost full extension, but not able to get hyper extension, I am doing regular exercise per my PT,(2 hr morning and 1 hr evening)..just wanted to check whether I ll be able to get full ROM, m mostly scared about full knee extension and hyper extension.

    • ankkit
      ankkit says:

      Hi, i’m 6 months down my acl&meniscus surgery.I have gained 0 deg of full extension but not getting hyperextension (which my non injured knee is 9 deg hyperextended) despite of hours of physio and home exercises.Can you please advise if any?

  7. jitender
    jitender says:

    My acl surgery is done on 8april but till 4month i not got range of extention or motion so what can i do for that.

  8. Cindy Woods
    Cindy Woods says:

    What about knee flexion. I am 9 weeks post op and am only between 110-115 and not making much progress even after 3-5 days per week PT. My dr and pt are now considering MUA.
    Any suggestions on getting my flexion back without having the manipulation?

  9. Luiz Focaccio
    Luiz Focaccio says:

    Hi, I, m Luiz Focaccio PT from Brazil, Some colleagues here in Brazil say that forcing extension in both prone and dorsal can cause graft laxity, I confess I have quite a doubt about this, have you heard about it, or have you read in any paper about it? Most of the grafts here are of hamstrings autograft, perhaps the early stretching may impair the healing of the graft withdrawal region

  10. Eli
    Eli says:

    Hi I’m 2 mouths post up from knee surgery ,I tore my patella in my knee and so far I’m only getting 70° range of motion my physical therapist tells me I should be at 110 at least should I be scared

  11. ForestChief
    ForestChief says:

    I have checked your site and i’ve found some duplicate content, that’s
    why you don’t rank high in google’s search results, but
    there is a tool that can help you to create 100% unique articles, search for; boorfe’s tips unlimited content

  12. GraigJuicy
    GraigJuicy says:

    I often visit your website and have noticed that you don’t update it often. More frequent updates will give
    your page higher rank & authority in google. I know that writing posts takes a lot of time, but you
    can always help yourself with miftolo’s tools which will
    shorten the time of creating an article to a few seconds.

  13. Sobia kalsoom
    Sobia kalsoom says:

    Hii .. Had medial meniscus removed followed by ACL reconstruction ..5 months back .. Flexion limited to 70° and is quite painful beyond that during exercise .. though I can extend my knee properly .. Any suggestions .. Please .. Thank you

    • Sarah
      Sarah says:

      Hi. Did you find a way to improve your flexion? I am 6 weeks out of surgery and have very poor and painful flexion. My pt wants me to return to the ortho to see if he sees anything preventing the flexion, but I’m wondering if you had any luck or answers?

  14. Lerato
    Lerato says:

    Hi I’m Lerato I had the ACL done 5 months ago I’m struggling with the knee extension and my motion too my hip is killing I’m in the military expected to do physical stuff please as I need to start running and getting back to netball by January.

  15. Ralph Carter
    Ralph Carter says:

    This has been helpful – at 7 months post allograft ACL repair I still had 5-6 degrees loss of matching hyperextension (unloaded) but the PT said as I had reached zero I was fine (which I was not). So six weeks ago I started passive loading forcing hyperextension (7kg on distal femur), and backwards walking on a treadmill, (5 mins three times a week), and I am down to zero difference under load and 2-3 degrees difference not under load. This is another n=1, and who knows what time alone would have done, but I am sure I am not doing any harm and the graft is rock solid.

  16. Kiran
    Kiran says:

    Hi ,

    Had my acl reconstruction and meniscus trim and it is 6 th week and can’t get my rom to 90 as expected by my physio …..I
    Am doing alllexercises regularly … it normal or I should be worried

  17. Becky Piacente
    Becky Piacente says:

    I need some information and guidance.I had an evulsed ACL. I was fortunate enough to have the orthopedic surgeon for the Washington Capitals do the surgery. He was thorough and very successful in my surgery. My problem now lies with the stumbling block that I have experienced in my therapy. When I first started therapy they didn’t do much if anything according to what I have just read. I was more or less just given some light stretching and they massaged the knee. Now I see that they should have been a bit more aggressive than they were and now…..4 months after my surgery I am still unable to straighten my knee to walk and I am only getting 133 degrees of reflex motion compared to my 146 on my other leg. This is very disturbing and to be honest very upsetting and depressing. I am an athlete having been a ski instructor/ski patroller in Europe, a volleyball player, tennis player and anything else…..besides a CHEF. I need my range of motion back. I have been out of work and was fired from my last job which I should have never taken but it was right after my surgery and it was killing me to try to function at the normal rate that I have been for the last 40 years.

    What can I do now to gain the last bit of motion that I had prior to my accident. I can’t handle this and I know I should not complain because there are those people out there…..those who have served our country and come home with missing limbs that I should not be such a whiner but this is really taking a toll on me mentally and emotionally. I need to be able to do what I have done all my life.

    What do I do?????

    • Jessica Martin
      Jessica Martin says:

      Hi Becky, i’m so sorry to hear about some of the set backs you’ve been experiencing. I tore my ACL/MCL/ both menisci and i shared a similar experience as your PT process. At 3 months I didn’t have full ext and i was only a little over 90 degree flection …..I’m now 6.5 months post op. I have full ext, and with flection It takes me 6-9 mins stretching to get my heal to actually touch my backside..still so much stiffness… having some concerns about scar tissue and hoping i won’t be needing a second surgery down the road. How’s your current flection at this point ? Does it require a lot of stretching/PT exercises daily to maintain ? …..Do you have issues with stiffness , such as sitting with leg bent (will then stay kinda bent) or when you wake up in the morning where leg is bent some?….I’m planning to get multiple opinions from diff ortho’s and one Airrosti dr and get a better idea of what’s going on exactly….If anyone has advise /insight, please feel free to share! Thank you :)

  18. Cat Hat
    Cat Hat says:

    Thanks for the sensible critique. Me & my neighbor were
    just preparing to do a little research on this. We got a grab a book from our local library
    but I think I learned more from this post.
    I am very glad to see such wonderful info being shared freely out there.

  19. Fitness Keto Pills
    Fitness Keto Pills says:

    You actually make it appear really easy along with your presentation but
    I to find this topic to be really one thing which
    I feel I would by no means understand. It seems too complex and very large for me.

    I’m taking a look ahead for your subsequent publish, I will try
    to get the grasp of it!

  20. says:

    Undeniably believe that that you said. Your favourite justification seemed to be at the web the simplest thing to take into account of.

    I say to you, I certainly get irked whilst other people consider issues that they plainly do not recognise about.
    You managed to hit the nail upon the top and also defined out the whole thing without having side-effects , people can take a signal.
    Will likely be back to get more. Thanks!

  21. Snap Slim
    Snap Slim says:

    Thank you for some other magnificent post. Where else may anybody get that kind of information in such an ideal approach of writing?
    I’ve a presentation next week, and I am at the search for such information.

  22. Slim Ambition Keto Advanced Weight Loss
    Slim Ambition Keto Advanced Weight Loss says:

    I loved up to you’ll obtain carried out right here. The
    cartoon is attractive, your authored material stylish.
    nevertheless, you command get bought an impatience over that you wish
    be turning in the following. in poor health for sure come
    more in the past again since precisely the similar just
    about very continuously inside of case you shield this increase.

  23. Helius Cream
    Helius Cream says:

    I simply wanted to thank you again for the amazing web-site you have made here.
    It’s full of useful tips for those who are actually interested in that subject, particularly
    this very post. You’re really all so sweet and also thoughtful of others as well as reading the blog posts is a superb delight if you ask me.
    And exactly what a generous reward! Jeff and I really have enjoyment
    making use of your tips in what we have to do in the near future.
    Our checklist is a mile long and tips will definitely be put to excellent use.

  24. says:

    I wanted to follow along and let you know how great I liked discovering your site today.

    I’d personally consider it the honor to do things at my office and be able to utilize the tips contributed on your web site and also participate in visitors’ responses like
    this. Should a position of guest article writer become available at your end,
    you should let me know.

  25. Bob
    Bob says:

    This was super helpful. Thank you for taking the time to write such an important article that has likely helped thousands of people, myself included. As good as the health professionals I’ve dealt with have been, there has always been a bit of a lack of knowledge translation as it seems like health professionals sometimes forget how base the knowledge level for lay people like myself really is. Also, you can add me to the majority that absolutely hates the prone knee hang and I’m overjoyed to find an alternative!


Trackbacks & Pingbacks

  1. […] Some often say that it is more difficult to get a patient’s range of motion back, especially their hyperextension, if a patella tendon graft was used. I, personally have not seen this and have addressed this in a past article on 3 Ways to Avoid Loss of Motion After ACL Reconstruction. […]

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *