How to Nail Your First 6 Weeks of ACL Rehab

How to Nail Your First 6 Weeks of ACL Rehab


The rehabilitation process after ACL reconstruction surgery is a long and difficult process. It takes effort, time, consistency, and patience. In this article we are going to discuss how to nail your first 6 weeks of ACL rehab.

The first 6 weeks set the foundation for the rest of your rehabilitation. If early goals are not met, everything else gets delayed or becomes harder to achieve as time goes on. Just because you are limited in how much you can do in these early weeks does not mean this time is any less important than the last few weeks when you are (hopefully) lifting heavy, jumping a lot, sprinting, and progressing into your sport.

6 Goals for the First 6 Weeks of ACL Rehab

To really nail those first weeks of ACL rehab, it is important that you have goals in mind to achieve. These big goals are written in chronological order (mostly, some may overlap). Let’s get into it!

Goal #1 – Diminish Pain and Inflammation (and be aware of medical emergency signs)

First and foremost, because you just had surgery, you likely have pain, swelling, and bruising, as well as open wounds. You can help manage pain with medication prescribed by your physician. Stay on top of the pain before it escalates.

Ice is also your friend and should be applied to help pain management. We generally recommend 15 minutes every hour immediately after surgery. As swelling/pain is better managed in the coming days or weeks, ice for 15 minutes 3x/day.

To address swelling, you were likely given a compression bandage. Wear it! Also spend lots of time with your leg propped up above the level of your heart. Place a pillow (or three) beneath your ankle and perform lots and lots of ankle pumps. These will help move fluid out of your knee. Ankle pumps are also critical to reduce the fluid from sitting still throughout your leg and help prevent clots (which are a medical emergency).

Performing these help move the blood throughout your leg while you are limited in your mobility

Lastly, be aware of any excessive burning, bleeding, or redness throughout your knee, calf and even foot. You do not want to go back into the hospital because of an infection. Knowing these tell-tale signs will help you be aware in case you need to reach out to your physician.

signs of infected wounds

Goal #2 – Restore Full Knee Extension Range of Motion

After we know how to manage pain and inflammation, we can start talking about more “functional” goals. Restoring knee extension (or straightening of your knee) is one of THE most important goals of early ACL rehab. Why?

If we don’t get full knee extension back early, it becomes harder and harder the longer this goal is delayed. I like to reach full knee extension within the first 1-2 weeks after surgery.

Losing full knee extension can lead to several consequences once you start walking and progressing through rehab. First, it will make it difficult to have a solid quadriceps contraction to control your knee when you bear weight, which may alter your movement mechanics. Second, it may be a cause of prolonged knee discomfort, and likely make it next to impossible to walk normally (scroll down – walking is a HUGE goal). If we don’t get the knee straight early, scar tissue can build up and turn into something called a cyclops lesion that will need to be surgically managed.

So how can you start working on getting your knee straight? The easiest way is to prop your leg straight and do it often. We know it’s more comfortable to put a pillow under your knee when you’re sitting on the couch, but doing so will NOT be helpful in your rehab.

You can also prop your leg up with a pad under your heel and GENTLY push down on your knee as instructed by your PT. We also recommend performing band/belt assisted hamstring stretches and calf stretches while also focusing on getting your knee as straight as you can.

Lastly, working on your quadriceps function by doing lots and lots of quad sets helps this goal a lot (see goal #5).

Common Exercises to Restore Knee Extension:

Goal #3 – Gradually Restore Knee Flexion Range of Motion

To answer your question, the answer is yes: Yes we also want to work on bending your knee, but we take a more gradual approach. Most times your surgeon limits how much you should bend your knee after surgery AND bending generally comes back easier than straightening. It is okay to take your time working back into bending.

In general, we like to see 90 degrees of bending by week 2, 125 degrees of bending by week 4, and full bending by week 8 (but it is also okay if it takes a little longer than that).

You can work on bending your knee by performing heel slides with or without hand assistance while sitting on the floor or bed, sitting in a chair, or laying on your back with your feet on a wall and letting gravity lightly pull your foot down as your knee bends.

We also like to work on bending your knee once you can bear weight using mini squats, lunges, and progressing range of motion as your body allows.

Common Exercises to Restore Knee Flexion:

Goal #4 – Restore/Maintain Patellar Mobility

Your patella (or kneecap) also needs some love after surgery and restoring its motion is an important aspect to help you regain full knee motion and prevent scar tissue formation. Your kneecap moves as you bend and straighten your knee. If the kneecap mobility is limited, your knee motion will also be limited and/or uncomfortable.

Your physical therapist should instruct you in how to perform soft tissue mobilization around your kneecap, as well as how to properly mobilize your kneecap right after surgery.

Goal #5 – Restore Quad Function

I have this listed as goal #5, not because it is less important than the first 4, but because if the first 4 are not addressed, restoring quadriceps’ function will be much harder than it already is.

For those of you who have had ACL surgery, you know the feeling of not being able to control your quads. For those of you who have not had ACL surgery, it is not an easy task to get your quads firing and here’s why: Quad weakness is frequently observed after ACL surgery and may lead to difficulty straightening your knee, difficulty walking, quadriceps atrophy (muscle loss), and decreased stability.

This quad weakness is not just due to atrophy and disuse, but a process called arthrogenic muscle inhibition (AMI). AMI is a process stemming from neural inhibition, or a poor signal from your brain to the quadriceps, making it difficult to contract.

In addition, sometimes the surgeon may perform a femoral nerve block to help with pain after surgery. This blocks the femoral nerve from sending its signal to the quadriceps, further adding to why your quads aren’t working.

Lastly there is often swelling around your knee that makes it even more difficult to get a good signal to the knee.

So how do I get my quad to fire?!

We need to minimize the swelling and strengthen the signal from your brain to the quads! We can minimize swelling by icing, elevating, using a compression garment, and performing light muscle contractions (like ankle pumps and gentle movement of the knee) to help decrease the swelling in the joint.

To help strengthen the neural signal, we can use a tool called neuromuscular electrical stimulation (NMES). NMES uses a device that sends electrical signals to the muscle via the placement of electrodes on the skin. These electrical signals, along with voluntary contraction, help to improve the quality of contraction and strengthen the signal to the quads.

In addition to using NMES, performing frequent voluntary contraction of your quads (AKA quad sets) help to reinforce the signal from your brain to the muscle. We often tell our patients they can’t do too many and to try to get in hundreds every day.

Other exercises to help get the quad firing include straight leg raises, prone terminal knee extensions, standing terminal knee extensions and quad isometrics at 90 and 60 degrees of knee flexion.

Common Exercises to Restore Quad Function:

The faster we can get a strong quad contraction, the stronger the neural signal becomes, and the quicker you can start to work on strengthening and getting back into the things you love.

Goal #6 – Walk Normally!

Last but not least, as soon as we can, we want you to start walking and walking normally. If goals 1-5 were neglected, walking will be immensely harder. You may be able to perform steps, but walking will probably be labored, unstable, and people will probably look at you funny.

In general, we like to have this goal achieved within 4 weeks after surgery. (However, depending on your graft type, if any other surgeries were performed, or your surgeon’s protocol, this timeline may be delayed and that’s okay.)

First Steps in ACL Rehab

Taking your first steps in your ACL rehab can be both a very exciting and very scary moment. We like to slowly work into walking by first performing weight shifts onto the involved leg. This helps get a sense of what it feels like to put most or all your weight onto the leg while keeping a stable knee by contracting the quads.

After that, we like to use cones or hurdles as a means to exaggerate the stepping motion. This also helps groove the pattern of lifting your leg up and over, as well as weight acceptance on that leg. If you were in a brace locked straight for a period of time, it will be easy to walk and accidentally keep your knee straight from habit.

The hurdles make you bend your knee and lift your foot up and over as you should naturally. We also like to use hurdles to simply step over and get used to transitioning onto one leg and full single leg stance. Once that pattern is grooved and you’re feeling confident, walking will feel easy again.


The exercises and goals listed in this article should not be the entirety of your rehab. You should also be focusing on training your other 3 limbs and trunk, as well as hip strength on your involved side.

Just because the first several weeks of rehab are not “fun”, please take just as much time and effort into your early rehab as you do your training. These goals set the foundation of everything going forward. A more solid foundation sets the stage for a higher peak.

Everyone’s rehab progress is their own and only their own. We know it’s easy to look at other people and compare yourself to where they are, but you cannot compare apples to oranges. Every person is unique. Every surgery is different. Everyone’s sleep, nutrition, stress, pain, swelling etc. are all different. All of these differences impact the rehabilitation timeline. Control the controllables and focus on you.


Are you an athlete who recently suffered an ACL injury, is currently undergoing ACL rehabilitation or are looking for that next step to bridge the gap from ACL physical therapy to return-to-play? We work with all types of athletes recovering from ACL injuries, taking them through a detailed process to return them back to sport safely and prepare them to play!

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We focus on areas such as strength restoration, movement re-education and objective testing with the latest strength and force plate technology to assess progress and readiness for return-to-play. Learn more about our approach to ACL Rehabilitation, and feel free to check out our full array of services or reach out today to schedule a free consultation to see if we can help you.