title: Quadriceps muscle function after rehabilitation with cryotherapy in patients with anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL.
  
  
  OBJECTIVE
  To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI.
  
  
  METHODS
  The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises.
  
  
  METHODS
  We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period.
  
  
  RESULTS
  After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30).
  
  
  CONCLUSIONS
  After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone.
authors.affiliation: University of Virginia, Charlottesville;
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Hart
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Kuenze
authors.forename: David R
authors.initials: DR
authors.lastname: Diduch
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Ingersoll
mesh_terms: D000293:Adolescent; D000328:Adult; D000842:Ankle / Q000503:physiopathology; D000843:Ankle Joint / Q000503:physiopathology*; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects* / Q000379:methods; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D017679:Cryotherapy / Q000379:methods*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology; D008297:Male; D018908:Muscle Weakness / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation; D052097:Quadriceps Muscle / Q000473:pathology / Q000503:physiopathology; D016059:Range of Motion, Articular; D016896:Treatment Outcome; D016474:Weight-Bearing
keywords: arthrogenic muscle inhibition; disinhibition; knee; therapeutic exercises