title: Differences in Isokinetic Strength of the Knee Extensors and Flexors in Men With Isolated and Combined Cruciate-Ligament Knee Injury.
abstract: BACKGROUND
  The extent of knee extensor and flexor weakness after disruption of knee ligaments affects a rehabilitation output and functional recovery and may give prognostic information on a possible risk of development of knee osteoarthritis.
  
  
  OBJECTIVE
  The hypothesis tested was whether patients with a multiple-ligament tear would have larger abnormalities in strength of the knee extensors and flexors than patients with an isolated-ligament rupture.
  
  
  METHODS
  Cross-sectional study, level III.
  
  
  METHODS
  Outpatient orthopedic clinic.
  
  
  METHODS
  3 groups of recreationally active men: noninjured control (CON, n = 12), with an anterior cruciate ligament injury (ACLI, n = 10), and with combined anterior and posterior cruciate ligament injury (APCLI, n = 9), matched according to age, body mass, and height.
  
  
  METHODS
  All patients received conservative treatment and rehabilitation and awaited ligament reconstruction surgery.
  
  
  METHODS
  Isokinetic maximum-repetition peak torque per body mass (PT/BM) and total work (TW), PT and TW limb-symmetry index (LSI), and flexor-to- extensor PT ratio were evaluated during concentric knee extension-flexion movements at lower (60°/s) and higher (240°/s) isokinetic velocities.
  
  
  RESULTS
  The main finding was that compared with the individuals with ACLI, patients with APCLI produced in their injured limbs lower mean TW (extension: 30.3%, flexion: 28.2%) and had lower mean TW LSI (extension 74% in APCLI vs. 91.6% in ACLI; flexion 61.3% in APCLI vs. 90.8% in ACLI) at the higher but not lower speed of isokinetic testing. However, at the lower velocity the quantified size of reduction in PT/BM and TW was greater in subjects with APCLI than ACLI as compared with the CON individuals.
  
  
  CONCLUSIONS
  After bi-cruciate-ligament injury the capacity to produce torque by concentric muscle contractions throughout knee-extension and -flexion movements performed with high speed is lower in injured limbs than after isolated anterior cruciate ligament tear.
authors.affiliation: Dept of Kinesiotherapy, University School of Physical Education, Poznan, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kaminska
authors.forename: Tomasz
authors.initials: T
authors.lastname: Piontek
authors.forename: Marzena
authors.initials: M
authors.lastname: Wiernicka
authors.forename: Grazyna
authors.initials: G
authors.lastname: Cywinska-Wasilewska
authors.forename: Jacek
authors.initials: J
authors.lastname: Lewandowski
authors.forename: Dawid
authors.initials: D
authors.lastname: Lochynski
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology*; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000293:injuries*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology; D019415:Torque