title: Quadriceps function after exercise in patients with anterior cruciate ligament-reconstructed knees wearing knee braces.
abstract: BACKGROUND
  Knee braces and neoprene sleeves are commonly worn by people with anterior cruciate ligament reconstructions (ACLRs) during athletic activity. How knee braces and sleeves affect muscle activation in people with ACLRs is unclear.
  
  
  OBJECTIVE
  To determine the effects of knee braces and neoprene knee sleeves on the quadriceps central activation ratio (CAR) before and after aerobic exercise in people with ACLRs.
  
  
  METHODS
  Crossover study.
  
  
  METHODS
  Fourteen people with a history of ACLR (9 women, 5 men: age = 23.61 ± 4.44 years, height = 174.09 ± 9.82 cm, mass = 75.35 ± 17.48 kg, months since ACLR = 40.62 ± 20.41).
  
  
  METHODS
  During each of 3 sessions, participants performed a standardized aerobic exercise protocol on a treadmill. The independent variables were condition (brace, sleeve, or control) and time (baseline, pre-exercise with brace, postexercise with brace, postexercise without brace).
  
  
  METHODS
  Normalized torque measured during a maximal voluntary isometric contraction (T(MVIC)) and CAR were measured by a blinded assessor using the superimposed burst technique. The CAR was expressed as a percentage of full muscle activation. The quadriceps CAR and T(MVIC) were measured 4 times during each session: baseline, pre-exercise with brace, postexercise with brace, and postexercise without brace.
  
  
  RESULTS
  Immediately after the application of the knee brace, T(MVIC) decreased (P = .01), but no differences between bracing conditions were observed. We noted reduced T(MVIC) and CAR (P < .001) after exercise, both with and without the brace. No differences were seen between bracing conditions after aerobic exercise.
  
  
  CONCLUSIONS
  The decrease in T(MVIC) immediately after brace application was not accompanied by differences between bracing conditions. Wearing a knee brace or neoprene sleeve did not seem to affect the deterioration of quadriceps function after aerobic exercise.
authors.affiliation: Crest High School, Shelby, NC, USA.
authors.forename: Alexis G
authors.initials: AG
authors.lastname: Davis
authors.forename: Brian G
authors.initials: BG
authors.lastname: Pietrosimone
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Ingersoll
authors.forename: Kelli
authors.initials: K
authors.lastname: Pugh
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Hart
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D001915:Braces; D018592:Cross-Over Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007717:Knee; D008297:Male; D009387:Neoprene; D052097:Quadriceps Muscle / Q000502:physiology*
chemical_list: D009387:Neoprene