ACL Injury Rehabilitation

An ACL tear is one that typically sidelines an athlete for an extended period, regardless of their level of professionalism in their sport.

The journey of recovery is certainly well documented and fortunately there are some solid scientific guidelines for goals along the way.

Doesn’t surgery fix it? Why do I need to do rehab?

The ACL and other structures within the knee provide many roles within the system. Your meniscus provides shock absorption, as does your cartilage tissue, while your ligaments restrain excessive movements in multiple directions. Beyond this, your ligaments can provide some information about where our knee is positioned relative to the ground or the rest of our body, allowing us to react and balance. 

Surgery will generally borrow a piece of tissue (often one of our four hamstring tendons) and insert this tissue where the ACL once was. This disturbs the knee’s system with the aim of enhancing the stability either by regaining the restraint of the ACL or by increasing the proprioception we lost in the injury. It is still surgery, so it also comes with some risks and in typical fashion, there are no guarantees.

Rehabilitation focuses on gradually regaining the strength, range of motion, balance and movement control of the whole lower limb and body, with a focus on the muscles around the knee. The goal is to reduce pain, regain function and encourage a safe return to ALL activities. 

The Journey

The path to rehabilitation from ACL injury can be a long one, so to break it down into more tolerable bites, we outline some typical phases and goals below:

  • Phase 1: ACUTE: 
    • AIM: Protect and mobilise (often 4-6 weeks)

This first phase aims to reduce the swelling, pain and start the work towards returning functional range of motion and normal daily activities. Gentle strengthening and flexibility exercises are common in this phase, combined with compression, massage therapy, cryotherapy and other adjuncts that can assist with reducing pain and improving movement.


  1. Return to normal walking.
  2. Full knee extension
  3. >120 degrees of knee bending
  4. minimal/ no swelling
  • Phase 2: Return to Daily Activities 
    • AIM: Regain strength, flexibility and control for daily activities (4-12 weeks)

As the swelling and inflammatory response reduces to a simmer, the focus on strength and control increases. Muscles such as your glutes, quadriceps, hamstrings and calves become key focus points in this phase. The introduction of isolated quadricep exercises (once a controversial topic: the knee extension exercise) is becoming highly valuable for people that find it difficult to regain strength. 


  1. Good single leg squat control
  2. Good single leg balance
  3. >80% symmetry between limbs for a variety of muscle strength tests
  4. Maintained goals from phase 1

* A key outcome of this phase is to unlock your opportunity to return to running!

  • Phase 3: Advanced SnC
    • AIM: High level balance, jumping and running activities (months 3-9)

Rehab activities become more intense and start to look like the movements of the desired sport. Exercises continue to be directed on identified weaknesses, so regular reassessment with your Physiotherapist is valuable throughout. This is where athletes start to work towards being capable of physical things that their competitors simply are not. Hopping, plyometrics, change of direction and high speed running are all very useful through this phase.


  1. >80% symmetry between limbs for simple hop tests
  2. >90% symmetry between limbs for muscle strength tests
  3. >1.5x bodyweight for Leg Press on 1 leg (your best weight for 1 repetition).
  4. Pain-free running, change of direction and daily function
  5. Maintained previous goals!
  • Phase 4: Sport Specific drills
    • AIM: Regain all skills and physical capacities required for the sport (months 6+).

This phase now starts to include sport specific activities. The focus will be doing these activities in an independent or “non-contact” environment before gradually increasing the difficulty and then introducing the chaotic nature of team-sports with other people. 


  1. Within 5% difference between limbs for hop tests and strength tests
  2. Return to maximum speed/ acceleration/ deceleration capacity
  3. Psychologically confident without evidence of fear or inappropriate beliefs
  4. A significant battery of tests should be completed to identify any remaining limitations.

* Returning to full training is the key outcome of this phase.

  • Phase 5: Return to full training + play
    • AIM: Safely return to full training in your sport (>9 months) 

If surgery was your chosen pathway, we advise waiting a minimum of 9 months and achieving a significant battery of performance tests to ensure you are safe to return to full training. 

If you return to sport after 9 months, your risk of re-injuring the reconstructed knee drops up to 7-fold. It’s worth the wait. 

If you achieve high level function in the battery of testing, the risk of re-injury is also dropped by approximately 4x. It’s worth the work!

  • Phase 6: Maintain it!
    • AIM: You’ve made it, now maintain it.

Once a successful return to sport has been achieved, the attention must turn to keeping you there! Reinjury is still a high risk, with the opposite knee just as likely to suffer an injury now. The work to get back to sport was worth it, so to get the most out of your new found physical function, you will have to keep chipping away!

We recommend frequent ‘check-in’ with your Physiotherapist to review any potential areas to address, whether you have lost a little strength or can find other opportunities to improve, this time is incredibly valuable to keep you out there!

Surgery vs. Non-Surgical Rehab

The decision to undergo surgery depends on various factors like your age, activity level, and the severity of the tear. It is generally accepted that high difficulty sports may warrant a surgical approach, however the research in this space is evolving. There are circumstances that may be more beneficial to the individual to opt for a non-surgical approach. And if you’re lucky, that injured ligament may even repair itself! 

Important Considerations

  • Always consult a healthcare professional: They will assess your injury, determine the best course of action (surgery or not), and guide you through a personalized rehab program.
  • Listen to your body: Pain is a red flag. Slow down or modify exercises if you experience discomfort.
  • Be patient: ACL rehab is a marathon, not a sprint. Full recovery can take 6 months to a year, so stay committed.

Remember, with dedication and a structured rehab program, you can bounce back from an ACL injury and reclaim control of your active life.

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