title: Does wearing a functional knee brace affect hamstring reflex time in subjects with anterior cruciate ligament deficiency during muscle fatigue?
abstract: OBJECTIVE
  To evaluate the effects of wearing a functional knee brace and muscle fatigue on hamstring reflex time in subjects with anterior cruciate ligament (ACL) deficiency.
  
  
  METHODS
  Repeated-measures clinical trial.
  
  
  METHODS
  Outpatient physical therapy department.
  
  
  METHODS
  Sixteen subjects with ACL deficiency.
  
  
  METHODS
  Subjects tested with and without a functional knee brace before and after an exercise protocol designed to fatigue the knee muscles.
  
  
  METHODS
  Latency of hamstring reflex muscle activity after sudden perturbation of the knee.
  
  
  RESULTS
  Wearing a knee brace shortened the hamstring reflex latency regardless of fatigue (F(1,15)=20.62, P<.001). Muscle fatigue lengthened the hamstring reflex time regardless of the bracing condition (F(1,15)=7.57, P<.015).
  
  
  CONCLUSIONS
  Wearing a functional knee brace facilitated hamstring muscle reflex, but muscle fatigue lengthened the hamstring reflex latency. Subjects with ACL deficiency should not rely on the knee brace to facilitate hamstring reflex for joint protection during prolonged sporting activities when muscles are fatigued.
authors.affiliation: Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong.
authors.forename: Rita Y
authors.initials: RY
authors.lastname: Lam
authors.forename: Gabriel Y
authors.initials: GY
authors.lastname: Ng
authors.forename: Eric P
authors.initials: EP
authors.lastname: Chien
mesh_terms: D000125:Achilles Tendon / Q000503:physiopathology; D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology*; D001915:Braces; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology* / Q000534:rehabilitation*; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D018763:Muscle Fatigue; D011930:Reaction Time; D012026:Reflex, Stretch