ACL Return to Sport Criteria

Written By Scott Harrison

How do you know when returning to sport is safe after an ACL injury?

Following strict return to sport testing criteria can help ensure the lowest risk of re-injury.

Returning to pivoting sport following an ACL injury can be scary and daunting, and ensuring you are safe and ready prior to resuming is paramount for making a successful come back.

Unfortunately, many people return too soon, and without meeting critical criteria, leading to poor performance and in many cases subsequent re-injury.

What are the return to sport criteria?

 

·        At least 90% maximum voluntary isometric quadriceps strength compared to the uninjured limb

Maximum voluntary quadriceps contraction

Maximum voluntary quadriceps contraction

Quadricep strength is one of the single most important factors following ACL injury.
Grindem (2016) found that for every 1% increase in quadriceps strength (closer to the non-injured limb), there was a 3% reduction in re-injury rate following return to sport. For example, if someone returns to sport with 80% quadriceps strength compared to the non-injured limb, they are 30% more likely to suffer an injury than someone who returned with 90% limb symmetry.

·        At least 90% maximum voluntary isometric hamstring strength compared to the uninjured limb

ACL injury is significantly associated with hamstring injury. Green (2020) found that previous history of ACL injury increased the risk of hamstring injury by 70%. Messer (2020) found that 6 years post-operatively after the use of a semitendinosus (hamstring) graft, patients continued to have altered hamstring structure and atrophy.

Maximum voluntary isometric hamstring constraction

Maximum voluntary isometric hamstring constraction

The hamstrings complex generates the greatest posterior shear force during single leg drop landing tasks to reduce shearing forces on the ACL (Maniar, 2020).

Kryistis (2016) found that among a cohort of 158 athletes who returned to sport after ACL reconstruction, those who suffered re-injury within the first 12 months had lower hamstrings to quadriceps strength ratio on their injured limb compared to those who didn’t suffer re-injury.

·        At least 90% repetition maximum on single leg bent knee calf raise compared to the un-injured limb

Single leg bent knee calf raise

Single leg bent knee calf raise

The soleus muscle generates the single largest contribution to prevent anterior shear forces on the ACL during hooping and landing tasks and is also involved in preventing valgus shear forces on the knee (Maniar, 2020).

·        At least 90% limb symmetry on 6 hop tests (Dingenen, 2019; Ebert, 2021; Grindem, 2016; Grindem, 2020; Gustavsson, 2006; Kryitsis, 2016)

Hop Tests: Grindem, 2016; Gustavsson, 2006

Hop Tests: Grindem, 2016; Gustavsson, 2006

Those who do not pass return to sport hop testing criteria are at significantly greater risk of re-injury.

Grindem (2016) and Grindem (2020) found that those who pass return to sport criteria including hop testing and strength testing are between 84 and 91% less likely to suffer re-injury compared to those who do not pass return to sport criteria.

Dingenen (2019) found that the test re-test reliability, and discriminative ability of the medial triple hop, and medial rotational hop test we’re excellent for assessing inter-limb asymmetries in patient post ACLR.

Ebert (2021) found that traditional hop tests (forward hop for distance, triple hop for distance, and 6m timed hop test) may not be sensitive enough to detect some asymmetries in athletes looking to return to sport.

Davies (2020) suggested that including tests that assess hop function in different/ multiple planes and assessing change in performance over time may provide greater sensitivity than the 4 traditional hop tests commonly used in current return to sport criteria.

A performance at least 90% as good as the uninjured limb and with good lower-limb biomechanics is considered a pass on each of the tests.

For the side hop test Gustavsson (2006) found that males should score at least 55 and females should score at least 43 with a maximum side to side difference of less than 10%.

·        Score at least 76.6 on the ACL Return to Sport After Injury Scale (ACL-RSI)

Ardern (2011 and 2015) report fear of re-injury is the most cited reason for lack of return to pre-injury sport.

McPherson (2019) found that psychological readiness to return to sport, as tested by the ACL-RSI was significantly associated with re-injury rates in younger athletes. Those who scored less than 76.6 on the ACL-RSI at 12 months post-operatively were more likely to sustain a second injury within 2-4 years.

·        Score less than 19 on the Tampa Scale-11 (TSK-11)

Paterno (2017) found that patients with higher self-reported fear were significantly more likely to suffer a second injury, and less likely to have good knee function.
Patients that scored greater than 19 on the TSK-11 at the time of return to sport were 13x more likely to suffer a second ACL injury.

·        Wait at least 12 months post-operatively (surgical patients only)

Grindem (2020) found that those who return to sport before 12 months post-operatively are up to 6x more likely to suffer re-injury within 2 years. Furthermore only 36% of athletes in their cohort passed return to sport criteria before 12 months.

·        Complete at least 4 weeks of unrestricted training prior to returning to competition (recommendation)

Exposure to the demands of the sport in a relatively safe environment prior to returning to competition allows the body to adjust to the required training loads, and helps the athlete build confidence.

Returning to competition without exposure to sport specific tasks and training volumes for at least 4 weeks may increase the risk of re-injury and may expose other tissues to injury.

Bowen (2020) found that athletes who had a sharp increase in training workload were 5-7x more likely to sustain an injury. Sharp increases in load were strongly associated with non-contact injuries.

Does this guarantee a safe successful return to sport?

Unfortunately, there is always a risk of re-injury following ACL injury, returning to high intensity sports involving pivoting, cutting, and hopping and landing tasks is significantly associated with re-injury (Grindem, 2016; Grindem, 2020).

We cannot guarantee that re-injury will not occur, but ensuring the athlete is physically and mentally ready to return to sport can minimise the risk and make return to sport, competition, and performance safer and more achievable.

References:

Grindem, H., Snyder-Mackler, L., Moksnes, H., Engebretsen, L., & Risberg, M. A. (2016). Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study. British journal of sports medicine, 50(13), 804-808.

Maniar, N., Schache, A. G., Pizzolato, C., & Opar, D. A. (2020). Muscle contributions to tibiofemoral shear forces and valgus and rotational joint moments during single leg drop landing. Scandinavian Journal of Medicine & Science in Sports.

Kyritsis, P., Bahr, R., Landreau, P., Miladi, R., & Witvrouw, E. (2016). Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. British journal of sports medicine, 50(15), 946-951.

Grindem, H., Engebretsen, L., Axe, M., Snyder-Mackler, L., & Risberg, M. A. (2020). Activity and functional readiness, not age, are the critical factors for second anterior cruciate ligament injury—the Delaware-Oslo ACL cohort study. British Journal of Sports Medicine.

Gustavsson, A., Neeter, C., Thomeé, P., Silbernagel, K. G., Augustsson, J., Thomeé, R., & Karlsson, J. (2006). A test battery for evaluating hop performance in patients with an ACL injury and patients who have undergone ACL reconstruction. Knee surgery, sports traumatology, arthroscopy, 14(8), 778-788.

Ardern, C. L., Webster, K. E., Taylor, N. F., & Feller, J. A. (2011). Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play. Br J Sports Med, 45(7), 596-606.

Ardern, C. L. (2015). Anterior cruciate ligament reconstruction—not exactly a one-way ticket back to the preinjury level: a review of contextual factors affecting return to sport after surgery. Sports health, 7(3), 224-230.

McPherson, A. L., Feller, J. A., Hewett, T. E., & Webster, K. E. (2019). Psychological readiness to return to sport is associated with second anterior cruciate ligament injuries. The American journal of sports medicine, 47(4), 857-862.

Paterno, M. V., Flynn, K., Thomas, S., & Schmitt, L. C. (2018). Self-reported fear predicts functional performance and second ACL injury after ACL reconstruction and return to sport: a pilot study. Sports health, 10(3), 228-233.

Bowen, L., Gross, A. S., Gimpel, M., Bruce-Low, S., & Li, F. X. (2020). Spikes in acute: chronic workload ratio (ACWR) associated with a 5–7 times greater injury rate in English Premier League football players: a comprehensive 3-year study. British journal of sports medicine, 54(12), 731-738.

Dingenen, B., Truijen, J., Bellemans, J., & Gokeler, A. (2019). Test-retest reliability and discriminative ability of forward, medial and rotational single-leg hop tests. The Knee, 26(5), 978–987. https://doi.org/10.1016/j.knee.2019.06.010

Ebert, J. R., Du Preez, L., Furzer, B., Edwards, P., & Joss, B. (2021). Which Hop Tests Can Best Identify Functional Limb Asymmetry in Patients 9-12 Months After Anterior Cruciate Ligament Reconstruction Employing a Hamstrings Tendon Autograft?. International journal of sports physical therapy, 16(2), 393–403. https://doi.org/10.26603/001c.21140

Davies, W. T., Myer, G. D., & Read, P. J. (2020). Is It Time We Better Understood the Tests We are Using for Return to Sport Decision Making Following ACL Reconstruction? A Critical Review of the Hop Tests. Sports medicine (Auckland, N.Z.), 50(3), 485–495. https://doi.org/10.1007/s40279-019-01221-7

Scott Harrison
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