title: Quadriceps function in anterior cruciate ligament-deficient knees exercising with transcutaneous electrical nerve stimulation and cryotherapy: a randomized controlled study.
abstract: OBJECTIVE
  To compare strength and quadriceps muscle activation in anterior cruciate ligament-deficient patients who underwent a two-week rehabilitation exercise program using TENS or cryotherapy.
  
  
  METHODS
  Randomized, controlled study.
  
  
  METHODS
  Clinical research laboratory.
  
  
  METHODS
  Thirty patients: 20 males, 10 females, 31.6 (13.0) years, 172.8 (10.0) cm, 75.8 (13.0) kg with diagnosed tear of the anterior cruciate ligament.
  
  
  METHODS
  All patients attended four sessions of supervised quadriceps strengthening exercises over two weeks, prior to reconstruction surgery. Patients were randomly allocated (n = 10/group) to receive exercises alone, exercise while wearing a sensory transcutaneous electrical nerve stimulation (TENS) device on the knee joint for the duration of each daily session, or 20 minutes of knee joint cryotherapy immediately prior to each daily exercise session.
  
  
  METHODS
  Normalized knee extension force and quadriceps central activation ratio were measured before and after the first supervised treatment session and within 24 hours of the last session.
  
  
  RESULTS
  When accounting for differences in baseline measures, there were no statistically significant group differences immediately following the first exercise session for knee extension force (P = 0.10) or central activation ratio (P = 0.30) nor were there statistically significant group differences after the two-week intervention for knee extension force (P = 0.92) or central activation ratio (P = 0.94). Effect sizes for the change in knee extension force and central activation ratio after two weeks of therapy were all large.
  
  
  CONCLUSIONS
  Quadriceps strength and central activation in anterior cruciate ligament deficient patients improved after two weeks of rehabilitaiton exercises, however, there were no significant differences between treatment groups.
authors.affiliation: University of Virginia, Charlottesville, VA 22904, USA. jmh3zf@virginia.edu
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Hart
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Kuenze
authors.forename: Brian G
authors.initials: BG
authors.lastname: Pietrosimone
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Ingersoll
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology; D000070598:Anterior Cruciate Ligament Injuries; D017679:Cryotherapy; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000534:rehabilitation*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D004561:Transcutaneous Electric Nerve Stimulation