How To Interpret Pain After ACL Surgery

There’s no getting around it — pain after ACL surgery is part of the process.  Those who understand pain and how to interpret it will be able to use the information to optimize their recovery outcomes.  They’ll understand when it’s ok to confidently push in to pain and when they may need to dial things back a bit. This article will cover what pain is and a few basic guidelines on how to interpret it during the ACL recovery process.

Note: The beginning of the article covers a lot of theory that helps develop a deeper understanding of pain.  If you just want the guidelines, scroll to the last section.

Pain is an alarm that’s sent through the nervous system when it perceives something to be dangerous. To understand how this chain of communication works, let’s go through a very basic example.

1.  You put your hand on a hot stove.
2. The nervous system senses the temperature of the surface and realizes that it is not safe.
3. The nervous system immediately sounds the “pain alarm,” which tells you to remove your hand from the hot stove.

In this case, the nervous system’s perception that your hand was in danger was 100% correct.  Obviously, if you leave your hand on a hot stove for a long period of time, there will be serious consequences.

However, there can be times when your nervous system may be tuned a little too sensitively, causing things to be “painful” that aren’t actually that dangerous.  This is particularly evident during after ACL surgery.

Pain after ACL surgery occurs because a lot of trauma has occurred in the knee. First, the ACL tore.  Then, the knee was cut open, a graft was harvested (if you chose an autograft), and the ACL was reconstructed.

Due to all of this trauma, the nervous system becomes highly sensitive towards stress on the knee and typically decides that ANY stress on the knee is dangerous.  In other words, it starts to become just as sensitive to stress on the knee as it is to your hand on that hot stove. With this perception of danger comes a more intense ringing of the “pain alarm.”

If you hope to return to sport without pain after ACL surgery, you must convince the nervous system that placing stress on the knee is “safe.”  As the nervous system re-builds trust in this idea, you will experience less and less pain after ACL surgery.

In order to convince the nervous system that it is no longer “dangerous” to place stress on the knee, you will need to gradually expose it to more and more stress over time.

This becomes a bit of a balancing act – you want to challenge the nervous system by introducing it to new stresses, but you don’t want to OVER do it, which could cause the nervous system to “double down” on its perception of danger and cause a set back. Those who understand this balancing act and play the game the best will set themselves up for an efficient recovery.

Here’s a few simple, basic guidelines to follow to help interpret pain after ACL surgery:

• Pain levels at or below 3/10 can generally be considered safe.  Explore these pain levels more deeply by continuing the activity.  For example, if you experience pain of a 2/10 the first time you perform a body weight squat, try several more squats.  If pain levels remain at a 2/10 or start to dissipate, you’ve successfully shown the nervous system that the movement is more safe than it originally thought.  If pain levels elevate to a 4/10, stop the activity for the day.  That’s ok – it just means your body isn’t ready just yet for the activity. Continue with your other strengthening exercises until you’re ready to test again (maybe even as soon as the next day).
• Be a little more cautious with “sharp” or “stabbing” pain.  Often times, these types of pain will elevate beyond the 3/10 threshold.  If you experience these types of pain, it may be best to consult with your physical therapist or physician to make sure it’s ok to continue working through.

My hope is that the information in this post will empower you throughout the ACL recovery timeline. You should now have a solid understanding of how pain works in the body, why there is so much pain after ACL surgery, and how you can challenge the nervous system’s perception of “danger” throughout ACL recovery.

As we tell all of our Accelerate ACL athletes, if you have any questions, always, always, always, feel to reach out.

Shoot us an email a support@acceleratetkr.com and we will get back to you as soon as possible.