title: Knee joint position sense ability in elite athletes who have returned to international level play following ACL reconstruction: A cross-sectional study.
abstract: BACKGROUND
  Following an ACL injury, reconstruction (ACL-R) and rehabilitation, athletes may return to play with a proprioceptive deficit. However, literature is lacking to support this hypothesis in elite athletic groups who have returned to international levels of performance. It is possible the potentially heightened proprioceptive ability evidenced in athletes may negate a deficit following injury. The purpose of this study was to consider the effects of ACL injury, reconstruction and rehabilitation on knee joint position sense (JPS) on a group of elite athletes who had returned to international performance.
  
  
  METHODS
  Using a cross-sectional design ten elite athletes with ACL-R and ten controls were evaluated. JPS was tested into knee extension and flexion using absolute error scores. Average data with 95% confidence intervals between the reconstructed, contralateral and uninjured control knees were analyzed using t-tests and effect sizes.
  
  
  RESULTS
  The reconstructed knee of the injured group demonstrated significantly greater angle of error scores when compared to the contralateral and uninjured control into knee flexion (p=0.0001, r=0.98) and knee extension (p=0.0001, r=0.91). There were no significant differences between the contralateral uninjured knee of the injured group and the uninjured control group.
  
  
  CONCLUSIONS
  Elite athletes who have had an ACL injury, reconstruction, rehabilitation and returned to international play demonstrate lower JPS ability compared to control groups. It is unclear if this deficiency affects long-term performance or secondary injury and re-injury problems. In the future physical therapists should monitor athletes longitudinally when they return to play.
authors.affiliation: Edge Hill University, Department of Sport and Physical Activity, Sports Injury Research Group, St Helens Road, Ormskirk L39 4QP, UK. Electronic address: Nicola.Relph@Edgehill.ac.uk.
authors.forename: Nicola
authors.initials: N
authors.lastname: Relph
authors.affiliation: University of Salford, School of Health Sciences, The Crescent, Salford M5 4WT, UK. Electronic address: L.C.Herrington@Salford.ac.uk.
authors.forename: Lee
authors.initials: L
authors.lastname: Herrington
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction; D001265:Athletic Injuries / Q000503:physiopathology / Q000601:surgery*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular; D000068958:Return to Sport; D055815:Young Adult
keywords: Elite sport; Knee injury; Proprioception