When Can I Run After ACL Surgery?

Beginning to run after an ACL reconstruction is a big deal.  It is a major milestone after this type of surgery that many athletes look forward too.  Unfortunately, far too often, athletes are under-prepared for the demands of running on their body and their knee.

I have seen and heard of athletes starting to run as early as 1 month out from surgery and upwards of 4+ months and everything in between.

Every case is unique, but in order to commence running, an athlete needs to have the mobility and strength pre-requisites in order to tolerate those stresses.

One factor I consider before ever thinking about having an athlete start running is that have they gone through a well-structured PT/strength and conditioning program.  You notice there is a “/” there.

You Need BOTH. At this point in the rehab, the PT still needs to be involved and either have a trusted strength and conditioning professional doing the coaching and programming side of that equation OR if the PT is qualified and comfortable, doing the programming as well in their sessions with the athlete.


As far as when to return to run, that is a key indicator.  If a good strength and conditioning program hasn’t and isn’t being been performed, then that is a factor to consider.

In the past couple of years, I came across Mick Hughes’ Melbourne ACL Guide and found some great and useful information on Returning to Run post-op ACL.  When an athlete is approaching that milestone, I utilize some tests and measures that he recommends.

Single Leg Squat to a Box

With the Single Leg Squat to a Box, the athlete starts sitting down on a box.  The box should be high enough where their knee is at a 90 degree angle.

I will demonstrate to the athlete how to perform it.  The athlete starts in a sitting position and attempts to stand up from a sitting position and then return back to sitting in a controlled fashion.  I want to see them perform 10 clean repetitions.

Key Points:

-No lateral trunk sway

-No use of other hand or leg

-No knee valgus

This is a great test that measures quadriceps, hamstring, and glute strength.  This is definitely challenging on the quads which is an important aspect of any ACL rehab.

Forward Step Down Test

The Forward Step Down Test looks to see if the athlete has the eccentric quadriceps control as well as frontal plane stability.

I will demonstrate to the athlete how to do this.  You start on an 8-inch step and step down, tap the ground and return to the starting position.  I like to see the athlete be able to perform 5 repetitions per side with good technique.

Key Points:

-No hip drop (non standing hip dips down towards the floor when stepping down)

-No lateral trunk sway/knee valgus

Single Leg Bridges

The Single Leg Bridge Test is where the athlete is lying on their back with their feet elevated approximately on a 12-18 inch box.

Then, they remove one of their feet and perform a single leg bridge.  I like to see the athlete be able to perform 15 per side with no pelvic drop to the non-working side and achieve full hip extension.

Again, this will test hamstring, glute, and core/trunk strength/stability.

Single Leg Calf Raises

The Single Leg Calf Raise test is pretty self-explanatory.  The athlete goes up and down on one leg. I also like to see 15 reps per side and I am looking for good symmetry right versus left.  When looking at symmetry, the height their heel comes off the ground one side compared to the other.

This is a measure of Gastrocnemius strength which is a very underappreciated knee stabilizer when running, cutting, pivoting, etc. as it eccentrically acts to control knee flexion during those movements.


Side Plank

The Side Plank measures an athlete’s lateral core strength, stability, and endurance.  Frontal plane strength/stability aka lateral core strength is key with any injury in order to control the trunk, hip, knee and ankle.  Lack of trunk control will place increased stress further down the chain.

The athlete needs to be able to hold a side plank with their ear, shoulders, hips, knees, and ankles in a line for 30 seconds per side.

Single Leg Balance

Single leg balance is another underappreciated test.  It seems simple, but when running, an athlete is on one leg every step.  If they cannot control their body on one leg, that needs to be addressed.

Again, I instruct the athlete to stand on one leg and hold for 30 seconds per side.

I want to make sure they can do it, remain upright, not leaning forward/back, and aren’t leaning side to side being able to control their body in the frontal plane.

Those are the tests I like to incorporate when an athlete is approaching the point in their rehab where they can considering running.

As I said before, a well-structured strength and conditioning/PT program that understands the demands and needs of a good ACL rehab are key.  There are no perfect tests, but this is a good starting point when considering returning to running as they look at key areas for strength and stability.

Andrew Millett