Intro to Knee Rehabilitation Post ACL Injury & Surgery
Other articles will cover some details, but this is just your basic introduction to the general flow of rehab post ACL injury and surgery.
Rehab will vary greatly among patients. We have varying types and severities of injury. We are of different ages, genders and initial physical health. We have different recovery goals; from just getting back to day-to-day to returning to sport at high levels. It’s all over the place. That being said, there are some common features.
The ACL Rehab Challenge

ACL Rehab follows the cliché “it’s a marathon, not a sprint.” Proper rehab to the fullest possible recovery will take a long time, as in 9 months to a year or longer. At least, this is typically what’s anticipated in order to return to high-level sports. Lesser activities can likely be accomplished sooner. Not everyone is an athlete, but pretty much everyone wants to get back to 100%. Getting to 100% might not always be possible, and it’s even hard to understand what that is as there’s no way to specifically test the ACL. (There are orthopedic tests like the Lachman test and so on, but no way short of arthroscopy to directly see or test the actual ligament.) However, if you come out of rehab and maintain a higher level of fitness, it might be possible to continue to excel in a sport of choice. There’s plenty of examples of professional athletes who have done so. Of course, pros have amazing resources, are likely already in top shape, and so on.
Why so challenging? Why is ACL rehab often seen as being one of the more challenging injuries from which to recover?
The knee is the largest joint in the human body. It connects the thigh bone (femur) to the shin bone (tibia) and plays a critical role in weight-bearing, movement, and stability, especially during walking, running, and jumping. The ACL is essential for knee stability, especially in terms of pivoting or sudden directional changes. There may be surgical complexities, often involving tissue grafts, post injury muscle atrophy, and the sometimes not as well considered emotional and mental issues.
The good news? Yes, there is good news! If taking rehab seriously, most people who want to can get back to pre-injury levels. Today’s surgical techniques are more effective and less invasive than ever. Rehab protocols have also become sophisticated, using evidence-based methods and sport-specific activities where appropriate. Patients can come out of rehab stronger and with better movement patterns than pre-injury.
With commitment and the right guidance, ACL rehab can lead to a strong comeback. Physical effort, mental health, motivation and resilience are also required. Sports psychologist or rehab support groups can also help.
When to Start Rehab?
As soon as medically feasible. Regardless of whether surgery is coming up or not. When surgery is anticipated, often people will call it “prehab.”
Where to Do Rehab and With Whom?

Rehab can take place in several settings: at home, in a physical therapy clinic, or even at a sports rehabilitation facility. Early on, having access to a licensed physical therapist experienced with ACL injuries is key. They’ll guide recovery, monitor progress, and adapt exercises as needed. Over time, some patients transition to more independent routines, sometimes with periodic check-ins. And some use apps or virtual meetings if managing at home with no nearby facilities. Athletes may benefit from specialized sports therapists or trainers who understand the demands of returning to high-level activity. What matters most is consistent, high-quality rehab with someone who understands your goals, your injury, and how to get you there safely.
Rehab Progression: Patient Perspective of a Rough Timeline
You will possibly get tired of hearing “Your Journey Will be Your Own.” You just want to be fixed. Now. As in Right Now. And even if you fully realize it could take 9 – 12 months, (maybe longer), to recover as fully as possible, you’ll want to know if you’re on track. You’ll look at and hear stories about others; both in rehab and online. This is natural. We all look to others for stories, tips and tricks, methods, and so on. It’s just what we do as people.
Here’s the thing… There are some people raising their legs and shuffling about the evening of their surgery. And there’s others who can barely move their leg for several weeks. In some cases, ideally more rare, there’s additional delays in recovery for various reasons. Most are somewhere in between. And then, you may experience inconsistencies in activities. For example, maybe you have great flexion with a heel slide. Ahead of schedule! Great job! But then, kneeling at all on the bad knee? No go. There will be inconsistencies and maybe occasional setbacks. Also realize that as you seek out comfort and help that if you do so online you’ll also come into some interesting groups. Finding support online can be one of the best things ever. Maybe there’s very few around your location, or as a practical matter, you just wouldn’t have contact with others who understand what you’re going through. But also realize that some that are seeking help may represent some of the more challenging cases, and are not necessarily representative of a typical healing timeline.
There are many charts and graphs for what “typical” might look like. Here’s a kind of real world approximation, excepting those who might have some adverse issues. Note that while this procedure has become fairly common, there are sometimes complications. Some studies report complication or re-injury rates ranging from 10% to 30%, depending on age, activity level, and surgical choices.
Let’s forget about official medical talk and just call things what they are. Here’s a rough sequence from a common person’s perspective. This is obviously not at all a checklist. It’s just a very general idea of a typical scenario to give you an idea of how things might play out.
- Injury Day and initial treatment.
- The beginning of a rough journey. There’s maybe some denial, certainly unknowns. Maybe immediate treatment for those who went down hard enough to go right to the hospital. Or perhaps a few days just icing it and trying to walk it off before seeing someone. Some people might just “walk it off” until they have a problem at some later point.
- The beginning of a rough journey. There’s maybe some denial, certainly unknowns. Maybe immediate treatment for those who went down hard enough to go right to the hospital. Or perhaps a few days just icing it and trying to walk it off before seeing someone. Some people might just “walk it off” until they have a problem at some later point.
- Prehab
- From your injury until surgery. This could be a couple of weeks to several months or even over a year. Varies widely based on healthcare availability and decision-making. But this is where you’ve made a choice for surgery. If your choice is non-surgical options, you’ll be on a different rehab path.
- From your injury until surgery. This could be a couple of weeks to several months or even over a year. Varies widely based on healthcare availability and decision-making. But this is where you’ve made a choice for surgery. If your choice is non-surgical options, you’ll be on a different rehab path.
- Surgery
- Most often just a few hours and outpatient basis. For some complicated cases, there could be a need for a short hospital stay. People sometimes get scared of surgery. And while there are some risks, in modern times it can often be the least troublesome part of all of this. (Though some patients can certainly find surgery anxiety-inducing.) You have a drug induced sleep, wake up, and probably have a snack. Getting home might be a hassle, but it’s often just not that much of a day. Yes, it can be nerve-wracking beforehand, but that day and evening? Chances are you’re still kind of out of it on drugs and nerve block.
- Most often just a few hours and outpatient basis. For some complicated cases, there could be a need for a short hospital stay. People sometimes get scared of surgery. And while there are some risks, in modern times it can often be the least troublesome part of all of this. (Though some patients can certainly find surgery anxiety-inducing.) You have a drug induced sleep, wake up, and probably have a snack. Getting home might be a hassle, but it’s often just not that much of a day. Yes, it can be nerve-wracking beforehand, but that day and evening? Chances are you’re still kind of out of it on drugs and nerve block.
- Post Op Week 1: Some call it Hell Week, Others have few issues
- The first week can vary widely. Some just sail right through it wondering why so many others are whining about things. For others it’s a time of significant pain, sleeplessness and extreme discomfort with significant lack of mobility. This is the point where people are online asking when this will possibly end. Again, most will be somewhere in between. But it can be rough. And perhaps especially so for those instructed for zero weight bearing for some time.
- The first week can vary widely. Some just sail right through it wondering why so many others are whining about things. For others it’s a time of significant pain, sleeplessness and extreme discomfort with significant lack of mobility. This is the point where people are online asking when this will possibly end. Again, most will be somewhere in between. But it can be rough. And perhaps especially so for those instructed for zero weight bearing for some time.
- Week 2: Still Lousy
- Pain is ideally easing up, maybe starting to abandon heavier medications. Possibly some small degree of mobility and more weight-bearing, which is highly variable depending on injury. As always, things vary. Some are weight-bearing and cleared to drive within two weeks, others are still mostly lying down. Highly likely to be starting physical therapy if not started already.
- Pain is ideally easing up, maybe starting to abandon heavier medications. Possibly some small degree of mobility and more weight-bearing, which is highly variable depending on injury. As always, things vary. Some are weight-bearing and cleared to drive within two weeks, others are still mostly lying down. Highly likely to be starting physical therapy if not started already.
- Weeks 3 – 4: Emergence
- Starting to come out of the fog of the first two weeks. Maybe moving around more easily, but with obvious deficits. Most are likely in physical therapy at this point.
- Starting to come out of the fog of the first two weeks. Maybe moving around more easily, but with obvious deficits. Most are likely in physical therapy at this point.
- Month 2 – 3
- This will be ongoing physical therapy more “in earnest.” Meaning, PT should be turning into a habit. How PT is handled will depend on injury status, patient goals, and availability of PT facilities or self-care tools.
- This will be ongoing physical therapy more “in earnest.” Meaning, PT should be turning into a habit. How PT is handled will depend on injury status, patient goals, and availability of PT facilities or self-care tools.
- Month 3 and Onward
- Your schedule will vary greatly. Typically, a fuller recovery can take 9 – 12 months, though for some possibly longer. Graft strength supposedly varies over this time period, but there is a risk period somewhere in 6 – 9 months where the graft ends are not wholly integrated with bone, but a patient may be feeling more normalcy. Early return to sport is potentially a risky proposition. Research into how much strength is achieved is not wholly conclusive. It’s probably fair to assume a full year to get to whatever the maximum best might be, which still might not be 100%.
Progression from a Goals Perspective
Pain Management
One of the first milestone achievements in ACL recovery is effectively managing your pain. Initially, you may experience discomfort and soreness, but as you continue with your rehabilitation exercises and follow your physical therapist’s recommendations, you will start to notice a decrease in pain levels.
Regaining Range of Motion
Another important milestone is regaining full range of motion in your knee. Through targeted exercises and stretches, you will gradually improve flexibility and mobility in the injured knee, allowing you to perform daily activities with greater ease. This includes at least both flexion and extension.
Achieving Functional Stability
Functional stability is the ability to perform daily tasks without pain or limitations. Once you reach this milestone, you will feel confident and comfortable moving around, knowing that your knee is fully recovered and capable of supporting your body weight.
Restoring Strength
Building strength in the muscles surrounding your knee is crucial for ACL recovery. As you progress through your rehabilitation program, you will notice improvements in muscle tone and strength, which will support and stabilize your knee joint.
Returning to Physical Activities
One of the most rewarding milestones in ACL recovery is being able to return to your favorite physical activities. Whether it’s running, hiking, or playing sports, reaching this milestone signifies that your knee is strong and stable enough to handle the demands of these activities.
Preventing Future Injuries
Lastly, an important milestone in ACL recovery is learning how to prevent future injuries. By maintaining proper form, using appropriate equipment, and incorporating strength and conditioning exercises into your routine, you can reduce the risk of re-injuring your ACL and stay active and healthy in the long term.
Remember, every individual progresses at their own pace, so it’s important to listen to your body and follow your healthcare provider’s guidance throughout your ACL recovery journey. Celebrate each milestone you achieve, no matter how small, as they all contribute to your overall progress and success.