ACL rehab lessons

I have been very fortunate since I graduated as a green and keen physiotherapist to have spent a large proportion of my career working within the NHS in Scotland. Within that setting, I spent many years working with a population I became very interested in/fully nerded out on; those with an Anterior Cruciate Ligament reconstruction (ACLR) and presenting for ACL rehab.

Fortunately, I had a large sample size of ACLR patients on my caseload within one of the largest orthopaedic hospitals in the UK, the Royal Infirmary Edinburgh. Valuable lessons were gained from a combination of a great team and a large amount of varied patients .

I am standing on the shoulders of giants in the field here with these thoughts and have learned countless lessons from the likes of clinicians like Erik Meira, Enda King, Nicky van Melick, Bart Dingenen, Dustin Grooms, Lee Herrington…the list is extensive.

Whether you are a physio treating this population or a person recently managing an ACL reconstruction/ACL rupture, you may find the following lessons helpful for ACL rehab.

1: It’s not all about the basics in ACL rehab, but its at least that.

The immediate days after surgery can be a difficult time for patients. Very often, a patient’s identity as a person heavily involved in sports like skiing, gaelic games, football or basketball, quickly becomes threatened. The contrast between that identity and the current one, a person reliant on two crutches to get about, is stark.

The end goal of returning to the playing field or just simply looking after young children seems so far off in the distance it can get overwhelming. It is very important that corners are not cut in these early days in response to trying to get this journey over and done with asap.

A good therapist will walk the patient through the journey and milestones involved from start to finish. The basics in these early days are vitally important, yet sometimes so often forgotten, in an attempt to go straight to boss level.


Early goals like

  • restoring range of motion
  • allowing the knee to quieten down
  • restoring normal gait +/- crutches
  • waking the quadriceps muscle up

are vitally important. It makes me cringe when I hear therapists saying they are looking to get rid of crutches as soon as possible before gait is normalised.

There is a lot more to ACL rehab than the basics, but it’s at least that.

2: Poor engagement in ACL rehab is a joint responsibility.

Research from Della Villa et al in 2020 suggested that the more ‘compliance’ patients had with their rehab, the more successful they were is getting back to their sport at the same level.

From personal experience (and I’m not the only one), follow up rates in physiotherapy sharply decline between the 3 to 6 month mark in patients post ACL repair both in private and public settings. This is no doubt down to a number of factors but these are not always exclusively on the patients side.

It is our role as clinicians to ensure we keep the process engaging for our patients. Ensuring decisions taken adopt a shared decision making model and not purely dictatorial.

Being injured sucks, however it does present an opportunity to work on aspects of your physical performance that may not be possible whilst playing the sport (upper body strength/power, cardiovascular capacity, linear speed, your iron game on the golf course, etc.)

It is our role as the facilitator in this long journey to ensure that journey is fun, goal orientated and engaging. If patients stop showing up, it may not always be purely down to them.

3: Nutrition during ACL rehab is important.

There is quiet a lot of research looking into the process of weight gain in the period after ACL reconstruction (here and here). It is very understandable.

Commonly the mechanism of ACL injury usually occurs on the playing field in a change of direction sport. Those involved in regular sport, require a certain amount of calories to perform.

Commonly, the body habitually gets used to triggering off hormones that regulate the intake of these calories and does not always account for the large reduction in activity that would occur post surgery.

Over three years ago, I treated a former professional football player who lost their way two months after surgery during the Christmas months. The patient had not attended (as above, that accountability was a shared responsibility) in that two month time frame, cancelling two sessions in a row.

This patient put on almost two stone (~12kg) weight in that time period. Strength testing was worse on their return so this weight was assumed to be largely body fat rather than muscle.

Body image is a sensitive topic however increased body fat in this instance did not match with the goals of the patient. A difficult conversation was needed in that first session back and plans were put in place to try and get on top of these unhelpful habits that crept into the patients life.

Setting expectations early days is important and our role as therapists is not just physical but also nutritional and psychological. I regretted not getting ahead of this barrier early days but I did not see it coming. Since then, when with patients with high level activity goals, I have sown that seed early days as a heads up, especially around holidays.

4: If you’re not assessing you’re guessing

A good friend, Luke Murray, has recently written extensively on the topic of testing during the ACL rehab journey here at the Physio Network. I was extremely fortunate in the clinics I worked within the NHS to have access to an isokinetic dynamometer to test all patients knee strength throughout their rehab journey.

Having access to that level of detail in terms of peak force values and how fast patients were able to create these values (rate of force development) was invaluable.

Not everyone has access to such expensive devices however that should not mean we assume things are going in the right direction. I now use a hand held dynamometer to get a peak value and whilst not as fancy as a €30k machine, it definitely points both myself and the patient in the right direction.

Up to eight times bodyweight can go through the knee joint during high speed running. It is therefore important that that knee joint has sufficient power, fatigue resistance and deceleration capacity to accept this load without breaking down. Strength testing along the rehab journey is vitally important to get an idea of how much load the muscles involved are willing to accept. Particular focus should be given to the quad, the hamstring, the soleus and the quad (did I mention the quad?).

5 rep max testing in the gym in movements that ideally isolate those muscle groups are very useful to compare left to right and relate to the patient’s bodyweight (seated calf raises using a Smith machine, knee extension machine, leg press, etc.).

It does not take much time for the body to compensate in the presence of injury. We cannot always trust what we see with our eyes when viewing patients squatting or hopping. Strength testing isolated muscles makes sure we are shining a light on these compensations.

people men grass sport
Photo by Pixabay on

Further to this, it is also very useful, where possible to test the uninjured limb as soon after the ACL injury as possible. Research has shown that we can overestimate limb symmetry during the rehab process when comparing injured to non injured limb. This is simply due to the fact that the non injured limb can tend to get weaker in the time between injury and testing post surgery. Getting an ‘Estimated Pre Injury Capacity’ as soon as possible is very useful to keep an eye on this fall off in non injured limb strength/power.

5: Training the brain

Finally, research by Swanik et al in 2007 looked at 80 intercollegiate athletes post ACL reconstruction and compared this group to 80 matched athletes for age, weight, position and gender. Swanik and his team looked into aspects such as verbal memory, visual memory, processing speed and reaction time.

The authors found that the ACL rehab group performed lower on all four of these neurocognitive aspects as compared to the controls. This research hints that ACL injury can impact on baseline neurocognitive function in athletes and ideally should be considered in the rehab journey. Alli Gokeler is a researcher who details this process very well in his research and YouTube lecture.

These functions above have all one thing in common. There are all dependent on visual processing.

How often are we involving our patient’s vision in their rehab to process a movement skill? Often in the past, I have looked largely at conscious motor control. In recent years, I have started to challenge my patients with a hint, followed by a large dollop, of chaos.

At the end of the rehab journey, the game or life demands the patient returns to will involve a large amount of chaos. If rehab has focused largely on the predictable and visually dependent, then this may not serve the patient well.

That’s the lot. If you are a patient who would like to discuss their ACL rehab journey, please get in touch at the homepage today.

Thanks for reading.

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