Phone: 03 8822 3723

5 Critical Things You Need Before Returning To Sport After ACL Surgery

Written by: Nick Jack
Category: 2014
on 05 July 2018
Hits: 10908

Returning to sport after an ACL injury is a long and demanding road. The common time frame following surgery is 9-12 months before a person can make a safe return to sport. The main reason for this is the time it takes the anterior cruciate ligament to vascularize (more on this later). However there is several problems within providing a recommendation based solely on a time frame, or even just evaluating the knee itself to see if it is intact. What I am going to show you in this article is that the evaluation criteria for returning to sport which uses a blanket template can be majorly flawed, for it often ignores that each person is different, and their weaknesses or reasons for sustaining the injury in the first place is what must be identified and corrected before returning to sport. Neglecting to address faulty movement patterns or restrictions at other joints is why so many athletes, both professional and amateur will suffer repeated injury and can derail even the best of athletes such as Derek Rose a former MVP with the Chicago Bulls. If you are an amateur or professional athlete and looking to return to sport after ACL surgery this article is a must read as I show you 5 critical factors you must achieve if you want a safe return to sport and minimize your risk of another rupture.

Why Does The ACL Take So Long To Heal?

Firstly we should explain why it takes so long for the anterior cruciate ligament to heal.

Unlike other ligaments the ACL is entirely within the knee joint. It's unique anatomical position is what allows for it to provide our ability to protect the knee during pivoting and twisting turning movements, but this comes at a price as due to it's location in that it has a poor healing capacity! The ligament is found inside the knee joint itself, and sits within a pool of synovial fluid along with all the other structures of the joint. And because of this it receives a very minimal amount of blood supply. And anything that does not receive a good blood supply will not heal effectively.

You simply cannot do this any faster, although there is some LARS surgical procedures now used that claim it can provide a much faster return (3-4 months). However there is much controversy surrounding this with procedure and it is not often recommended.

The poor healing ability of the ACL is also why it is extremely risky for anyone who has suffered a partial ACL tear to return to sport and not had it surgically repaired. The chances of a full rupture is very high as the ligament will not have knitted itself together. The knee is now fully exposed to injury and the full rupture will often damage the surrounding cartilage and meniscus leading to a lifetime of osteoarthritis.

Read our articles below for more detail on risk factors and what to do for partial tears

We know that surgery is an absolute must and if you hope to return to pivoting sports like basketball, football or soccer with many studies showing good to excellent knee function after reconstruction, whether hamstrings or patellar tendon grafts are used. The same studies also confirm that most patients (65–88%) are able to return to sport within the first year. Thus it is fair to state that surgery is effective in allowing injured athletes to resume their sports career.


You will have to put a lot of work into your rehab, and unfortunately this is where there can be a big difference between a professional and amateur athlete. While the ACL reconstruction is able to give the person a mechanically stable knee and greatly reduces the risk of further injury to the menisci and cartilage it does not nothing to address the factors that contributed to placing the knee in the "point of no return" in the first place. When you consider that 70% of all ACL injuries are non contact injuries this makes the rehab process even more critical. For if you fail to address the fault that was there before the surgery, you are guaranteed to suffer another rupture!

The clue in finding the test to use is in the movement that causes the injury. ACL tears happen when you plant your foot on the ground and attempt to rotate your body in relation to the planted foot, placing your weight on it or land awkwardly from a jump. This creates a twisting force through the knee joint, which the ACL must absorb. When the ACL cannot cope the force it ruptures.

You must use tests to see if these movements are ideal and all of the joints needed in these movements are capable of providing the correct stabilization.

ACL Rehab Is Tough?

Rehab following surgery is very unpredictable and very frustrating for many. The rehab program requires a lot of hard work, consistency and time.

For the professional athlete however, this is a lot easier which is why you’ll find that a high percentage of them will be back training and playing sport within 8-12 months. For starters they don't have a full time job to go to, they often have a large team of medical services at their disposal, and they are more likely to be much fitter and stronger than most of the general population. The amateur person is rarely given a well designed program based on the needs of their body but a template (cookie cutter) program given to everyone and they are left on their own to get it done.

This means that a professional has a much greater chance of achieving the necessary return to sport criteria than an amateur in a quick time frame. It is fair to say the amateur is not even tested on many of the criteria and believes they are ready to go by the fact they can run okay and maybe do some body weight squats.

What is the criteria used to determine a return to sports? Below is 3 of the most popular tests used.

  • Quads strength: no more than 10% difference between sides
  • 4 single leg hop tests: no more than 10% difference between each leg
  • T-Test agility drill performed in under 11 seconds.

While these are all great tests, I find they have several problems. Firstly the quad test tells me absolutely nothing. I would almost argue that hamstring strength is a more useful test! See our article on hamstrings for reasons why.This is usually the easiest thing to get back and many people will have a difference in leg strength anyway. The single leg hop test is a great test however the big problem with this is the measurement is on being able to hop for distance or time, not on the quality of the hops. The body is very smart at adapting and finding another way to do things and it can easily find a compensatory way to achieve it's goal. The same thing can be seen on the T-agility drill. Again a great drill but when the emphasis is for time, it allows for cheating and compensation which is a potential disaster with ACL injuries.

This criteria really lacks looking at the person's ability to perform quality cutting, pivoting and change of direction movement, along with good foot/hip mechanics on landings from a jump. Notice I did not say anything about the knee? For knee injuries rarely have anything to do with the knee itself! Read this article to see exactly what I mean by this "When You Have Knee Pain The Knee Is Not The Problem".

I use quite a few extra tests to determine if a person is ready to return to sport and these are all chosen due to the results of tests that identify their weakness. Remember we are not all the same so how can you follow an identical program to someone else.

To keep this article relatively short I have left a stack of stuff that is vital for a successful rehab program. If you need help with your ACL rehabilitation program I encourage you to get a copy of our special report below, Strength Training Secrets For ACL Injuries. This is both an injury prevention and rehabilitation report complete with pictures, instructions and video links to all the assessments, exercises and drills we use in our ACL programs. Click here to see more or click the image below to get your copy straight away.

Okay what are is our return to sports criteria?

Firstly our goal with all these tests is to determine if you can avoid the point of no return which is pictured below.

Level 1. Full Range Of Motion With The Hip, Knee, Ankle & Adequate Foot Stability

You might be thinking this is a "no brainer". But this is the part most people dangerously skip as it is boring and really not much fun to do. I cannot tell you how many people I see with only 90 degrees of knee flexion a few years after their surgery! This is not even half of what the ideal range should be. Straight after surgery this should be priority number one and you must get full extension and flexion back. Many will  get extension back quickly, but flexion will take some time and you must be very dedicated to this process. If you fail to do this properly ALL of the strengthening and functional movements are now compromised!

There is many ways you will need to do this and this will vary a lot depending on what stage of your rehab you are in. Early stages you will need to be very careful and the help of a therapist is highly recommended. You should also have received a few stretches to do that must be done daily! Later stages you should be able to progress to more difficult quad and hip stretches as shown in the video below.

In addition to this I look for any restrictions at the ankle and hip knowing that they will play a massive role in putting your knee into the point of no return.

You can read more about how to improve mobility at these specific joints by reading the articles below

Lastly foot stability is an area rarely looked at but make no mistake this can be the hidden problem. Our feet are designed to be shock absorbers for our body and all of our joints above. But when they fail to work correctly the shock moves up the body towards joints like the ankle and the knee. The foot needs to act like a spring being soft flexible foot to cushion the stress of each step we make, and then instantly become stiff enough to provide enough power to move us forwards or upwards. This is also known as being able to lock the foot at one point and then being able to unlock the foot at the very next part of the movement. Problems arise if we lose either one of these two things, and ultimately lose our spring. This is where injuries will occur at other joints. Read our article Exercise Solutions For Weak Feet for more information on this and refer to the video below for ideas on how to improve your foot stability.

Make no mistake if you cannot do any of things here you will not be able to any of the remaining tests properly and you are already at risk of future injury!

Level 2. Squat & Deadlift Strength

This is the part most people skip straight to. Notice I don't mention quad strength, glute strength or hamstring strength? These are all extremely important but are completely useless if tested in isolation for these muscles do not work on their own. They all work together within patterns like squats, lunges and multi directional movement. Testing someone's hamstring without the others tells you nothing for it does not say how it works when used in conjunction with it's partners.

Developing your skills in the area of basic squats which is more of a quad based movement, and at the same time working on your deadlift form which is more of a posterior chain movement you get the best of both worlds. The squat is much harder to do as it requires much greater knee movement, whereas the deadlift requires little knee movement and greater hip movement. For this reason you will find you will be able to do the deadlift in the earlier stages of rehab more easily. Both are vital ingredients for preparing you for the next stage of the single leg exercises.

In terms of strength I would want to see a person perform a barbell back squat maintaining good form and range within the movement. Weight on the bar should be 80% of bodyweight minimum. I must stress however that range of movement and alignment is of more importance than how much load. Many load up the bar with massive weight but their technique is awful. This achieves nothing. Quality over quantity every time.

I encourage you to read our article - Top 7 Squats For Bulletproof Knees to see our best squats to perform.

Below is two videos of both squat form and deadlift form.

Level 3. Single Leg Squat Ability

Now we are starting to get to the more important elements. Before the single leg hopping test you must be able to maintain good stability with the simple movement. This always reveals instability and any weakness within the body. This is also why just assessing someone's quad or hamstring strength is a waste of time for neither of those will be the most important factor in maintaining the alignment or control of this movement. They will play a part for sure, but the bigger problems will be found at other joints and even coordination from the brain to put it all together. Below is 2 great videos showing you what to look for and common mistakes.

Also a great in depth article on this is here - How To Use The Single Leg Squat As An Assessment Tool.

You must be able to perform 15 single leg squats on each leg with perfect form to pass to level 4.

Level 4. Single Leg Hopping & Landing

These single leg tests are the ones often used by therapists as their “exit criteria” before allowing athletes to return to sport. There is four common tests that are often used and you need to compare the results of the non injured leg to the injured side with your goal being to make them the same.

They include:

  1. Single leg hop for distance
  2. Triple hop for distance
  3. Crossover hop for distance
  4. 6-meter timed hop

See video below

I do like these as an assessment however as mentioned earlier the one drawback on these tests is that the athlete can find ways to do these by compromising form. And the one thing this does not prove to me is that the person can perform the cutting movement correctly. Which brings us to level 5.

Level 5. Cutting Technique

This is the most important stage and this is exactly where you will see disaster if not performed well. Quad and hamstring strength will have little influence here if you move poorly.

There are three critical factors to always remember when moving to lateral cutting drills.

First, you need to learn how to control what is known as “shoulder sway”. This is important in maintaining balance during explosive change of direction and if you witness an ACL tear you will often see the person demonstrating shoulder sway right at the point the knee goes. When you plant your foot quickly to change direction but do not control the upper body by recruiting good stiffness through the core, the shoulders will move you sideways to the direction you are moving. As a result, you will have too much of your body weight heading in one direction and it to change back the other way will not only be slower but risky as you will need to twist over your knee to get back! There is many reasons why this may happen but knowing to avoid this mistake will already make you more efficient.

Secondly, you must learn to stay low by keeping your hips behind you. This is a common mistake we see at all levels and you fail to stay low during a cutting move, your ability to effectively brake the movement is compromised. If the body is not loaded well, it certainly cannot explode concentrically as well. The athlete must learn to reposition the feet from a low athletic stance so that proper loading occurs.

Lastly, the previous 2 mistakes often occur as a result of improper plant foot angle. Stutter steps or poor balance often stem from this error. The plant foot angle is intended to provide an optimal base for eccentric control of deceleration and concentric force production during the subsequent acceleration or push-off movement. If the foot plant is correct, the deceleration and the push-off movement become smoothly linked. Can you see now why we place such a huge focus on foot and ankle stability in level 1!

While these drills may look very easy to you, make no mistake these can be very dangerous if you do not complete them correctly.

I like to use speed ladders, cones, low box steps and rubber tubing for these drills to build into the program the skill of reactivity. This is a very unique skill to learn in the gym environment but often overlooked. When you consider that the game is so unpredictable and that you need lightning quick reflexes combined with split second decision making it makes sense to train reactivity. Reaction skills determine an individual’s ability to read and react explosively. Think of a tennis player needing to react to a serve or a basketball defender trying to react to a crossover move. You cannot premeditate, you know your opponent has the advantage and it up to you to react fast and effectively. You will find as the drills become more difficult we begin to introduce the reactivity component so the athlete cannot premeditate any of the drills but learn how to adapt and react to what is presented to them. Just like sport.

Great article with more ideas on how to implement plyometrics and sports specific exercises is here - Change Of Direction Is All About Learning How To Brake


I hope this article provides you with a clearer understanding of exactly what you need to do following ACL surgery. The information we provided is a guide on how to choose the right exercises and strategies needed to not just rehabilitate ACL Knee injuries but also how to prevent them. Unfortunately, There is no magical program or exercise that I can give you that is completely perfect. Even two people with the identical injury caused from the same incident could have completely different programs. I wish it was that easy, it would save a lot of time and pain. A thorough examination is still needed which is why I encourage you before jumping straight into the programs to get a complete diagnosis and assessment of your injury. Everybody will present differently, which will require a variations on how you approach the rehabilitation program. If there is one thing you should really understand about all injury and ACL injuries is it has nothing to do with the knee. When you understand this concept and begin looking at how you move you are already halfway there.

Always ask WHY you have pain. When you find the answer to the why you will find the source of your problems. Good luck!

Also if you loved this article you will love our members only newsletter even more. You can subscribe for free by clicking the image below

If you live in Melbourne and would like to know more about our ACL rehabilitation or prevention programs click the image below to request a free consultation and I will get back to you within 24 hours to schedule time.

About The Author

Nick Jack is owner of No Regrets Personal Training and has over 14 years’ experience as a qualified Personal Trainer, Level 2 Rehabilitation trainer, CHEK practitioner, and Level 2 Sports conditioning Coach. Based in Melbourne Australia he specializes in providing solutions to injury and health problems for people of all ages using the latest methods of assessing movement and corrective exercise.


  • Movement - By Gray Cook
  • Corrective Exercise Solutions - by Evan Osar
  • Athletes Acceleration Speed Training & Game Like Speed - by Lee Taft
  • Diagnosis & Treatment Of Movement Impairment Syndromes - By Shirley Sahrman
  • Low Back Disorders - by Stuart McGill
  • Knee Injuries In Athletes - by Sports Injury Bulletin
  • The ACL Solution - by Robert G Marx
  • Understanding & Preventing Non-Contact ACL Injuries - American Orthopaedic Society For Sports Medicine
  • Anatomy Trains - by Thomas Meyers
  • Motor Learning and Performance - By Richard A Schmidt and Timothy D Lee
  • Assessment & Treatment Of Muscle Imbalance - By Vladimir Janda
  • How To Eat, Move & Be Healthy by Paul Chek
  • Scientific Core Conditioning Correspondence Course - By Paul Chek
  • Advanced Program Design - By Paul Chek
  • Twist Conditioning Sports Strength - By Peter Twist
  • Twist Conditioning Sports Movement - By Peter Twist
  • Twist Conditioning Sports Balance - By Peter Twist