title: Isokinetic muscle strength and readiness to return to sport following anterior cruciate ligament reconstruction: is there an association? A systematic review and a protocol recommendation.
abstract: BACKGROUND
  Following anterior cruciate ligament reconstruction (ACLR), strength is a key variable in regaining full function of the knee. Isokinetic strength is commonly used as part of the return to sport (RTS) criteria.
  
  
  OBJECTIVE
  We systematically reviewed the isokinetic strength evaluation protocols that are currently being used following ACLR. A secondary aim was to suggest an isokinetic protocol that could meet RTS criteria.
  
  
  METHODS
  Articles were searched using ScienceDirect, PubMed and Sage Journals Online, combined with cross-checked reference lists of the publications. Protocol data and outcome measurements and RTS criteria were extracted from each article included in the review.
  
  
  RESULTS
  39 studies met the inclusion criteria and reported their isokinetic strength evaluation protocol following ACLR. The variables that were most commonly used were concentric/concentric mode of contraction (31 studies), angular velocity of 60°/s (29 studies), 3-5 repetitions (24 studies), range of motion of 0-90° (6 studies), and using gravity correction (9 studies). 8 studies reported strength limb symmetry index scores as part of their RTS criteria.
  
  
  CONCLUSIONS
  There was no standardised isokinetic protocol following ACLR; isokinetic strength measures have not been validated as useful predictors of successful RTS. We propose a standard protocol to allow consistency of testing and accurate comparison of future research.
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland.
authors.forename: Marit Baste
authors.initials: MB
authors.lastname: Undheim
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland.
authors.forename: Ciaran
authors.initials: C
authors.lastname: Cosgrave
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland Department of Life Sciences, Roehampton University, London, UK.
authors.forename: Enda
authors.initials: E
authors.lastname: King
authors.affiliation: Department of Life Sciences, Roehampton University, London, UK.
authors.forename: Siobhán
authors.initials: S
authors.lastname: Strike
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland Insight Centre for Data Analytics, Dublin City University, Dublin, Ireland.
authors.forename: Brendan
authors.initials: B
authors.lastname: Marshall
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland Department of Medicine, University College Cork, Cork, Ireland.
authors.forename: Éanna
authors.initials: É
authors.lastname: Falvey
authors.affiliation: Sports Medicine Department, Sports Surgery Clinic, Dublin, Ireland Centre for Health, Exercise and Sports Medicine, University of Melbourne, Melbourne, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Franklyn-Miller
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000534:rehabilitation*; D001265:Athletic Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D001696:Biomechanical Phenomena; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology; D000068958:Return to Sport / Q000502:physiology*; D000078202:Systematic Reviews as Topic; D016896:Treatment Outcome; D015201:Meta-Analysis as Topic
keywords: ACL; Isokinetics; Strength isometric isokinetic