ACL Reconstruction: Identifying Deficits in the Return to Play Stage


Sports physiotherapists will regularly (I’m talking every day) rehabilitate knees that have undergone ACL reconstruction. As the vast majority of you will know, it is a common injury with a relatively long rehabilitation timeframe (generally 6 – 12 months depending on surgeon’s preference). This long rehabilitation and progression through to return to play (RTP) can be a challenging process for both the therapist and athlete.

Interestingly, the physiotherapist will find stringent guidelines in the early stages of the rehabilitation protocols, see an example of an ACL post-op protocol. However, in the later stages of rehabilitation (such as that in the RTP Phase) where restoration of full muscular strength and neuromuscular control is essential, the guidelines are frequently lacking. The most appropriate progressions and gauging when to make them is left up to the treating sports physiotherapist and frequently lacks objective criteria (Myer et al., 2006).

But as well all know, objectivity is the mother of good physiotherapy practice (yes, I definitely made that one up).

What Is The Importance of Objective Criteria to Identify Deficits?

Longer term readers would know how highly we value objective criteria for assessing return to play capacity, there is an example here. Quite obviously these objective criteria are exceptionally important following ACL reconstruction, particularly when making decisions regarding return to play.

Why? Well, I’m glad you asked you clever, discerning and good-looking physio.There are a number of reasons.

Firstly, following ACL reconstructions deficits in functional scores, tests and quadriceps musculature can persist for 18-24 months following surgery…even well after they have been cleared for sport (Myer et al., 2011).

Secondly, it is well established that following ACL reconstruction subjective criteria and reporting does not correlate with objective functional or strength scores (Neeb et al., 1997). This means that any athlete telling us “I feel great…put me in coach” is not nearly good enough.

Thirdly, there will be some significant pressure from a number of relevant parties in the late stages of ACL reconstruction rehabilitation. You will have to contend with the player, coaching staff, their teammates, and family members putting the heat on you to rush the player back onto the field. Thus, it is likely you will need cold hard numbers on why they cannot, clearly “I don’t think they are ready..” is just not good enough.

Finally, objective deficits in the involved limb will quite obviously lead to asymmetries in lower limb function. Lower limb assymmetries have been associated with an increased risk of lower limb injury (Knapik et al., 1991) and increased risk of second ACL rupture (Paterno et al, 2010). This is clearly the main reason why premature return to play is not a good idea.

So, How Do We Identify These Deficits?

Another great question, you are just on fire today. This is where new research from Myer and colleagues (2011) comes in handy. They investigated a range of objective functional tests to decipher which where useful in the identification of lower extremity deficits in late stage ACL reconstruction athletes (who had been cleared to return to their chosen sport). They investigated some standard tests as well as modified versions of common tests used by the NFL Combine (check out some of the workout videos). These included:

Double Limb Performance Tests

  • Broad Jump
  • Vertical Jump

Modified Double Limb Performance Tests

  • Modified Agility T Test
  • Modified Pro Shuttle
  • Modified Long Shuttle

Single-Limb Performance Tests

  • Single Leg Hop
  • Cross-Over Hop
  • 3 Hop
  • Timed 6m Hop

For a link to the descriptions of each test used from the Journal of Orthopaedic and Sports Physical Therapy, click here.

What Did They Discover?

As may be expected from previous studies, the authors identified some significant deficits in the involved limb of ACL reconstructed athletes, despite them successfully returning to their sport. These deficits were made clear during the single-limb performance or hop tests. However, these deficits were not evident for the double limb (or bipedal) functional tasks. This lead the authors to suggest that the deficits in the ACL reconstructed side is masked during bipedal tasks (Myer et al., 2011).

Thus, very clearly it is important that single limb assessments be made during late stage ACL reconstruction rehabilitation in order to identify any deficits or asymmetries. There is one issue with these functional tests though, which the authors do make reference to, and it is that they do not take into account the quality of the movement or task. Any sports physiotherapist will know the significant importance of movement quality, and it is therefore essential that this is taken into account when making return to play decisions.

Clinical Implications and Take Home Messages

  • Functional deficits or asymmetries will likely persist in ACL patients beyond RTP
  • Objective criteria for assessing RTP readiness is vital
  • Double limb performance tasks lack the sensitivity to identify unilateral deficits
  • Single limb performance (hop) tasks should be utilised to identify deficits in late stage ACL reconstruction athletes
  • Quality of movement is an additional and important component

What are your thoughts on identifying deficits following ACL reconstruction? I would love you to let me know in the comments or catch me on Facebook or Twitter

Remember, if you require any sports physiotherapy products be sure check out PhysioSupplies (AUS) or MedEx Supply (Worldwide)

Photo Credit: MonicasDad


Howe JG, Johnson RJ, Kaplan MJ, Fleming B, Jarvinen M. Anterior cruciate ligament recon- struction using quadriceps patellar tendon graft. Part I. Long-term followup. Am J Sports Med. 1991;19:447-457.

Knapik JJ, Bauman CL, Jones BH, Harris JM, Vaughan L. Preseason strength and flexibility imbalances associated with athletic injuries in female collegiate athletes. Am J Sports Med. 1991;19:76-81.

Myer GD, Paterno MV, Ford KR, Quatman CE, Hewett TE. Rehabilitation after anterior cruciate ligament reconstruction: criteria-based progres- sion through the return-to-sport phase. J Orthop Sports Phys Ther. 2006;36:385-402.

Myer GD, Schmitt LC, Brent JL, Ford KR, Foss KDB, Scherer BJ, Heidt RS, Divine JG, Hewett TE. Utilization of modified NFL combine testing to identify functional deficits in athletes following ACL reconstruction. J Orthop Sports Phys Ther 2011;41(6):377-387.

Neeb TB, Aufdemkampe G, Wagener JH, Mastenbroek L. Assessing anterior cruciate ligament injuries: the association and differential value of questionnaires, clinical tests, and functional tests. J Orthop Sports Phys Ther. 1997;26:324-331.

Paterno MV, Schmitt LC, Ford KR, et al. Biomechanical measures during landing and postural stability predict second anterior cruciate ligament injury after anterior cruciate ligament reconstruction and return to sport. Am J Sports Med. 2010 38:1968-1978.


  1. We’re waging an uphill battle against numbers to begin with, the idea is so ingrained to the public that an ACL will be fully recovered in ‘X’ amount of months. These days people are shooting as low as 3-4 months because of what professional athletes have done. Getting our own set of objective numbers specific to the athlete is quintessential.