title: Development of a test battery to enhance safe return to sports after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  There is a lack of consensus regarding the appropriate criteria for releasing patients to return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). A test battery was developed to support decision-making.
  
  
  METHODS
  Twenty-eight patients (22 males and 6 females) with a mean age of 25.4 ± 8.2 years participated and were 6.5 ± 1.0 months post-ACLR. All patients followed the same rehabilitation protocol. The test battery used consisted of the following: isokinetic test, 3 hop tests and the jump-landing task assessed with the LESS. The isokinetic tests and single-leg hop tests were expressed as a LSI (involved limb/uninvolved limb × 100 %). In addition, patients filled out the IKDC and ACL-Return to Sport after Injury (ACL-RSI) scale. RTS criteria to pass were defined as a LSI > 90 % on isokinetic and hop tests, LESS < 5, ACL-RSI > 56 and a IKDC within 15th percentile of healthy subjects.
  
  
  RESULTS
  Two out of 28 patients passed all criteria of the test protocol. The pass criterion for the LESS < 5 was reached by 67.9 % of all patients. For the hop tests, 78.5 % of patients passed LSI > 90 % for SLH, 85.7 % for TLH and 50 % for the SH. For the isokinetic test, 39.3 % of patients passed criteria for LSI peak torque quadriceps at 60°/s, 46.4 % at 180°/s and 42.9 at 300°/s. In total, 35.7 % of the patients passed criterion for the peak torque at 60°/s normalized to BW (>3.0 Nm) for the involved limb. The H/Q ratio at 300°/s > 55 % for females was achieved by 4 out of 6 female patients, and the >62.5 % criterion for males was achieved by 75 %. At 6 months post-ACLR, 85.7 % of the patients passed the IKDC score and 75 % the ACL-RSI score >56 criteria.
  
  
  CONCLUSIONS
  The evidence emerging from this study suggests that the majority of patients who are 6 months after ACLR require additional rehabilitation to pass RTS criteria. The RTS battery described in this study may serve as a framework for future studies to implement multivariate models in order to optimize the decision-making regarding RTS after ACLR with the aim to reduce incidence of second ACL injuries.
  
  
  METHODS
  III.
authors.affiliation: Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands. a.gokeler@rug.nl.
authors.forename: Alli
authors.identifier: http://orcid.org/0000-0002-6427-4225
authors.initials: A
authors.lastname: Gokeler
authors.affiliation: Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.|Medisch Centrum Zuid, Groningen, The Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: Welling
authors.affiliation: Rizzoli Orthopaedic Institute, University of Bologna, Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zaffagnini
authors.affiliation: Département de l'Appareil Locomoteur, Centre Hospitalier de Luxemburg, Luxemburg, Luxemburg.
authors.forename: Romain
authors.initials: R
authors.lastname: Seil
authors.affiliation: Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Darin
authors.initials: D
authors.lastname: Padua
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery; D008297:Male; D017063:Outcome Assessment, Health Care / Q000379:methods*; D052097:Quadriceps Muscle / Q000601:surgery; D020127:Recovery of Function; D000068958:Return to Sport; D019415:Torque; D055815:Young Adult
keywords: Anterior cruciate ligament reconstruction; Hop tests; Injury risk; Questionnaires; Return to sports; Second injury; Strength