[P]Rehab Clinical Pearl: Regaining Knee Extension After Surgery

The ability to fully extend the knee equal to the other side is usually one of the most important early goals in knee rehab. Our library has TONS of exercises to help with regaining knee extension which we’re going to cover and show you throughout this member’s only clinical post!

The 3 TPG templates we will be discussing in these posts are the ones below. We have included links to each of them and recommend opening them in a new tab while reading through the [P]Rehab Clinical Pearl on Knee Extension to reference the exercises to see the entire linear progression all at once!


Passive Knee Extension Exercises

The single most important variable for regaining full terminal knee extension is the amount of volume and time spent working on knee extension. That is undeniably the most important concept to grasp. 3 sets of 1 min of stretches for a total of 3 minutes (out of 1440 minutes in a day aka 0.2% of the day) is just not enough end range stretching to regain full knee extension! With your patients, aim for a total of 10 minutes of knee extension exercises at first, then slowly keep adding the time until they are spending at least 30 minutes a day working on terminal knee extension.

We’re hand-curated our favorite low load, long duration knee extensions below as well as in a sample program and a TPG Template called Passive Knee Extension Exercises! Learn more about creating your own templates or using ours here.


Set Realistic Expectations

Don’t expect for patients to always know everything they should expect after a knee surgery. Yes, often times there are explanations by the surgeon and other healthcare providers before the patient sees you the physical therapist; however, patients may be quick to forget every little detail as surgery can be an overwhelming experience. For anything in life, you want to set individuals up with realistic expectations! Know what to expect, and there will be no surprises. These are some educational tidbits we always communicate with patients from the VERY beginning to ensure they understand normal responses to surgery.




Each Person Responds Differently to Surgery

What also is important to understand is that every patient responds differently to a surgery, and that is ok! Each individual’s response will be different in regards to pain, swelling, tolerance to exercise, and the overall healing process. With more experience and with seeing more of these patients who have a knee surgery, you will gain more exposure to this concept. With that being said, when attempting to gain knee extension after surgery, keep an open mind and be patient! Some patients may not be able to progress as quickly as others. Trying to hammer knee extension by pushing down on a patient’s knee as hard as possible often times is not the answer. That can often lead to guarding, increased pain, and a poor healing process. Some individuals may require more frequent rest breaks, or may require more passive approaches to recovery to assist in pain modulation. Having a toolkit of various ways you can gain knee extension as well as how you can modulate symptoms will help you tailor appropriate interventions to each patient.


Position: Seated or Supine?

The seated position is undeniable more feasible for our patients to do throughout the day, whether they are at the office, eating at the dinner table, or watching TV. It is VERY easy to prop your leg up and work on passive knee extension! The drawback with this though is that the hamstrings are in a stretched position with the hip flexed. This means that we may not really be targeting the posterior capsule when stretching in a seated position – which could be your clinical goal. Thus for me, I will prescribe both. Seated versions throughout the day. And then dedicated time in the supine version to ensure I am hitting the posterior capsule! As always, we ensure we have both versions in our library so you can prescribe the exact variation you are looking for your patients ๐Ÿ™‚

You’ll notice that I have my heel propped on an elevated surface.ย This is crucial to work on hyperextension. It seems like something obvious to us, but don’t forget to tell your patients to make sure to prop their heel up! Another key point in this video (and the next) is not letting your hip rotate out during passive knee extension stretching. Typically our hips will lay in a more externally rotated position rather than neutral. If not accounting for this during our stretching, we again may not be hitting our desired tissue of the posterior capsule with our mobility work. You may not feel this difference on your healthy knee, but your patients with mobility deficits will definitely feel the difference!


Prone Knee Hangs: Good or Bad?

If you’ve been following along with our channel, you’ll know that we do not like to label any exercise as inherently good or bad! It’s simply whether it’s appropriate for the patient at this point in time or not. Typically, I have found that patients tend to guard with their hamstrings during the prone hang – which is the last thing we need when working on improving knee extension. However, if your patient does not guard with this exercise, it can be very effective.


Add External Load When Able

Just like adding weights to a strengthening exercise, we recommend adding external load to your patient’s knee extension mobility work. This can come in the form of ankle weights, a grocery bag, or manual overpressure provided by your patient’s hand! Once a patient is able to hang out for a few minutes without any stretching sensations with just gravity pushing the knee into extension, I’ll typically begin adding external load so they get that stretch sensation sooner! These are some of our favorite exercises with external load; but remember, you can essentially add external load to ANY exercise!





Ankle Pumps

Boring? Yes. Effective? Just as much! Ankle pumps in the first week is important in the prevention of DVTs by keeping the active muscle pump going. Take advantage of this time by prescribing them in supine with the leg elevated. Not only does gravity help us flush the lower limb, but it also provides a passive knee extension stretch! That’s like knocking three birds with one stone!

Active Knee Extension Exercises

Itโ€™s extremely important to follow up any passive knee extension exercise with active knee extension exercises to โ€œlock-inโ€ that hopefully newly acquired knee extension range. While the standing terminal knee extension (TKE) is the classic go-to exercise for active knee extension, there are a plethora of other options as well. The key component to every single one of them is to make sure your patients are actually firing their quads and squeezing it as HARD as they can! Their goal has to be to try to feel a stretch behind the knee!

Clinically, I will almost always combine these lower level active knee extension exercises with personalized blood flow restriction training. We teach tons of BFR courses for SmartTools, if you’re interested in taking a course with us check out the course schedule here!

We’re hand-curated our favorite active knee extension exercises below as well as in a sample program and a TPG Template, called Active Knee Extension Exercises!


Weight Distribution With TKEs

Far too often, I see patients performing TKEs with little to no weight through the leg with the band around it! The goal of a TKE is to teach active, end range extension in a functional and weight-bearing position. We are trying to mimic the stance phase of gait. In the late stance phase of gait before toe-off, almost 100% of your body weight is on the front leg in an extended position! We should try our best to mimic that position when we drill TKEs. This is why we also have 3-way TKEs in our exercise library where the band is around the front leg in a staggered position and this is typically what I will use with my patients.

Add a TKE to Almost Any Exercise

Technically you can increase quad demand on ANY exercise by anchoring a monster band in front of the stance leg and stepping into it. In the early to mid stages, I will almost always incorporate a TKE to ensure that we are working on active, end range extension! You must cue people to go into their hyperextension if they don’t have it yet!








Prone TKEs

The prone TKE is an early stable in my post-op knee protocols and usually occurs even before a standing TKE. This is because the knee is technically unloaded from a compressive standpoint. This is also how I sneak in active end range quadriceps settings and mobility work for my non-weight bearing patients (non-weight-bearing and the disuse atrophy that comes with it is tough to overcome in early rehab). However, combining these prone TKEs with BFR gives you have an absolute killer that hits on all early goals for a post-op knee including:

Usually, the limiting factor in performing prone TKE’s is your client’s core and/or shoulder strength! You have your clients keep their hips down to completely eliminate any core work if this is the case. To bring in the core, try the plank or tall plank TKE variations below. The down dog TKEs have a special place in my heart. Not only are we working on active knee extension at end range, but we are getting a nice stretch of the entire posterior chain including the hamstrings, calves, nerve, and fascia all at the same time.








Retro Walking

Don’t underestimate retro walking! It’s a great way to force active end range extension in a close chain fashion. This is very similar to sled pushes (more mid stage). We have a ton of other gait training videos as well that you can check out in the library!

Using assistance to work on Active End Range Control

Quad setsย are a must, no matter how boring they are. There is no better way to work on active quad control in the early stages. The issues become when our clients don’t have full active knee extension in comparison to their passive knee extension. So how can we work on those last few degrees of active extension! Check out this quad set with end range activation – ideally use a non-elastic strap like a belt or towel!

Bonus Exercise

I stole this one from our good friend Dr. Wesley Wang. I’ve used it with great success on a few patients – but only reserve it if a patient is REALLY stubborn. I like to use a lot of the other exercises that we’ve shown above first. This exercise places a LOT of load on the posterior capsule/PCL and I’ve overdone it with a patient before and caused low-grade inflammationย  interstitially in the PCL that took almost a month to calm down (yeah it’s possible…crazy right?!)


Knee Extension Education

Education is the key to [P]Rehab. 10 of the “best” exercises in the world won’t do a thing if the patient doesn’t know what to expect, why they are doing the exercise, and more importantly how to do it! We have made educational resources that you may find useful to send to your patients. These educational videos are accessible on the library and you can easily add them to your programs for your patients!

TPG Templates

You can find all of the programs in this post under “TPG Templates” on the [P]Rehab Exercise library. To use them, simply click “Load” to load it into your program builder, adjust as you see fit, then save it as your own program! Remember, you can design your own customized templates with the exact exercises and parameters that YOU want. To do so, simply click “Save New Template” at the top and you’ll have this customized template ready to load for your next patient! TPG templates are labeled as the following:

I hope you guys have enjoyed reading the 1st installment of the [P]Rehab Clinical Series as part of your [P]Rehab Exercise Library Subscription. If you have any comments or suggestions, shoot us an email anytime ๐Ÿ™‚

Now go explore more of the library and start adding these great exercises into your programs to get your patient’s extension back!


Looking for more knee extension knowledge?

We have tons of great content, including a blog, podcast, and video if you are interested in learning even more about regaining knee extension.

Clinician: Michael Lau, PT, DPT, CSCS