Tears of the anterior cruciate ligament (ACL) are common in athletes. Over 100 000 ACL reconstructions are performed in the USA annually. The incidence rate of ACL tears is higher in female athletes compared to their male counterparts competing in similar activities (1).
Due to the detrimental effects of an ACL injury on athletes including loss of a sport season and long term disability, rehabilitation programs have been developed to guide the process. These protocols progress from the acute phase to return to sport.
Toward the end of rehab, there is increasing pressure on the treating clinician to allow the athlete to return to sport. Residual biomechanical, strength and neuromuscular deficits may increase injury risk during this phase. Further, asymmetry in the lower extremity performance during athletic tasks has been shown in patients following ACL reconstruction. Athletes with lower extremity imbalances are more prone to injury (2). Therefore, it is imperative that objective functional performance measures are performed to detect lower extremity insufficiencies.
Researchers found 3 tests were sensitive enough to measure side to side differences after ACL reconstruction. These tests could be used to guide the athlete’s stage of recovery and late stage exercise program (2).
Three hopping tests (see illustration) on a single leg could identify functional limitations.
The researchers suggest that the surgically repaired leg should perform at least 90% as well as the uninjured leg before the athlete is allowed to return to sport (2).
A cohort study with 5 year follow-up demonstrated that ACL reconstruction patients with asymmetrical limb biomechanics had a 44% chance of a second injury (2). Therefore, single limb tasks that identify unilateral deficits are needed as a part of a comprehensive and functional examination to ensure safe return to sport after ACL reconstruction.
A – Single hop for distance
B – Crossover hop for distance
C – Triple hop for distance
- Brukner P & Khan K. Clinical Sports Medicine 3rd ed. New York: McGraw-Hill;2006.
- Myer GD et al. 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.