When can I return to running post ACL injury?

Usually, anterior ligament reconstruction surgery is carried out with the goal of returning to sport. These sports often involve running and / or change of direction. So, when is it safe to start running post ACL injury?

Our ACL protocol involves 5-Stage testing at critical time points in your recovery to guide your progression through rehab, and clear you for each phase. The most common question we’re asked is, when can you start running? Well, our return to run testing answers this question.

Return to running clearance should be based on objective measures, assessed on an individual basis and not based just upon time post-surgery. At around the 9 – 12 week mark, testing should begin that specifically aids the decision making process. 

What does the testing involve?

At Motus HP there are a few non-negotiables. 

The Knee must be ‘quiet’ with: 

  • Full Active Extension Range of motioning 
    • (straightening) 
  • No Effusion 
    • (swelling) 
  • Pain 0/10 on the VAS scale 
    • (Visual Analogue scale that rates pain from 0-10) 
  • Symmetrical gait pattern 
    • (walking comfortably and well) 
  • Greater than 90% Knee Flexion Range of Motion of the un-injured side 
    • (bending movement)
  • Greater than 70% Isometric Hamstring and Quadricep strength 
    • (strength tested at a fixed knee angle) 
  • Greater than 70% Single leg squat or step up capacity without increase in knee valgus 
  • Greater than 70% Single leg hopping function


We also ensure a ‘pass’ on IKDC subjective testing, where you complete a form split into sections that self-ranks knee symptoms, and level of function with daily tasks and sports activities. This allows us to match your level of confidence, with your physical capabilities.

Is your therapist just using the number of weeks post your operation to guide when you’re fit to return to certain activities? 

‘Traditional’ discharge criteria of ‘time passed’ and a ‘stable’ knee on clinical examination is not best practice. It is vital that the decision made to allow you to commence a return to running program is made collaboratively by your physiotherapist and surgeon based upon you passing the above clinical, strength and functional criteria, rather than being on an arbitrary time point.

If you would like to read more about the ACL, its function or the difference between operative vs non operative management, check out our previous blog posts here.