Do’s and Don’ts of ACL Rehab

ACL injuries are an unfortunate reality in the world of sports. With their prevalence showing no signs of reducing, it’s more important than ever for rehab professionals to stay informed and deliver effective rehabilitation. To help, I’ve come up with a list of some important “Do’s” and “Don’ts” for ACL rehab, which I hope will help improve your clinical practice. Let’s get into them!

The Do’s:

“Listen” to the knee

If your patient experiences pain and swelling after progressing their exercises, it might be a sign to pull back, especially regarding any impact loading they might be doing. Ignoring this feedback from the knee can slow down efforts to improve range of movement and quadriceps activation in the early stages of ACL rehab.

Isolate the quadriceps with leg extensions

Don’t fear the leg extension machine, especially after the 2-3 month mark. Quadriceps strength is critical for ACL rehab, and in compound exercises like squats, lunges, and leg press, other muscles (like the glutes and adductors) can compensate for weak quads. I have seen it time and time again – a patient has even strength between sides on single leg leg press and split squats, but when you get them on the leg extension machine, a 20% deficit between sides shows up! So I would recommend using leg extensions as there is nowhere for the quads to hide in this exercise.

“Run before you run”

Before returning to running it’s important to introduce some low level impact loading. This helps prepare the knee to tolerate the impact load from running and also helps prepare the patient mentally for running too. Low level plyometric drills like tall-to-shorts and pogos are great for this, as well as running drills like wall drills, A-marches and A-skips. Do these for a few weeks before the first run session and not only will you see your patient running better and more confidently, but they will be less likely to pull up sore afterwards as well.

Perform proper strength training

ACL rehab past the 3-month mark should just look like a progressive strength and conditioning program! Get your patients strong – particularly in the quadriceps, hamstrings, glutes, and calves. Heavy loading (e.g. 4-6 RMs) should be a staple of mid-late stage rehab. Improving your patient’s strength will go a long way to both reducing their risk of re-injury and helping ensure they return to full performance when going back to their sport.

Perform return to play testing

Numerous studies have shown that patients who pass return to play tests are less likely to re-injure their ACL compared to patients who don’t. As a bare minimum, patients need to have >90% LSI on hop testing (single hop, triple hop, crossover hop and 6m timed hop), and > 90% LSI on quadriceps and hamstring strength testing.

The Don’ts:

Rush the patient into surgery

If there is no serious meniscal damage that warrants surgery, patients should highly consider doing a period of non-surgical management for 3-6 months, then reassess the need for surgery. With progressive, structured rehab many people with torn ACLs can become ‘copers’ meaning that they can function well without an ACL, and for some people the ACL may even heal on its own. If your patient still has instability after trying non-surgical management then surgery will always be there as an option for them!

Return to running at 3 months based off time alone

The decision on when to return to running should primarily hinge on performance-based criteria, not time-based criteria. Your patient should tick off these things before returning to running – full (95%+) range of movement, minimal to no pain or swelling, >70% LSI for quads and hamstrings strength, and at least a few weeks of “running before you run” drills as per the above.

Return back to training without doing reactive agility work

Reactive agility training is a component that physiotherapists often overlook. While many physios do a great job of incorporating change of direction exercises into their rehab programs, they frequently miss out on implementing genuine agility drills.

Change of direction and agility are not synonymous. Change of direction involves pre-planned movements by the athlete, while agility drills require the patient to react to an external stimulus, such as a called colour cone, a pointed direction, or another person’s movement, before changing their direction. This introduces a cognitive element which is critical in ACL rehab. Consequently, reactive agility training in a closed environment is a great bridge between change of direction work and training drills with team members that require agility e.g. small-sided games.

Rush back into full training

Just because the patient is cleared to return to training doesn’t mean they should return back to full training right away. Training is normally a lot more demanding than rehab, and it’s vital in this return to training process that we don’t spike an athlete’s training loads. A good idea is to start by picking a couple of drills the athlete can do and allow them to jump into more drills over time. Start with drills that are less demanding on the knee and progress to more challenging/demanding ones over time.

Assume clearance from the surgeon means clearance to return to sport

Return to sport should be a shared decision-making process, and not fall on the shoulders of any one person. The surgeon, physio, coach, strength & conditioning coach and most importantly the athlete should all have a say in when the athlete is cleared to return to sport. It’s important to educate your patients about this shared decision-making process early in their rehab journey so they don’t get too excited when their surgeon clears them (usually) at around the 9-month mark.

Assume rehab is done when the patient returns to play

Even after ACL patients have returned back to full training and games, there are often still a few key ‘work ons’ that they should be including in their ongoing training, to ensure they continue to minimise their risk of re-injury. This might be some extra quadriceps or hamstring strength work if their LSI isn’t quite at 100% yet, some extra hop/land work, or anything you have identified that they should continue to focus on, depending on the patient.

Wrapping Up

While not a comprehensive list, I hope this blog highlights some of the key “Do’s” and “Don’ts” to consider when treating ACL injuries. By following these recommendations and other evidence-based guidelines for ACL rehab, I hope we as physios can play a key role in reducing the scarily high re-injury rates of up to 30% associated with this injury.