title: Electromyographic analysis of anterior cruciate deficient knees with and without functional bracing during lunge exercise.
abstract: BACKGROUND
  The use of functional knee braces for returning to sports or during demanding activities following anterior cruciate ligament rupture is common; yet despite being commonly prescribed, its mechanism of action remains unknown.
  
  
  OBJECTIVE
  To examine the effect of functional knee braces on mean muscle activity when performing lunge exercises.
  
  
  METHODS
  Pre-/post-test (within-subject research design).
  
  
  METHODS
  A total of 10 male participants with unilateral isolated anterior cruciate ligament deficiency participated. Electromyographic activities of six muscles around the knee were recorded during lunge exercises, with and without wearing a custom functional knee brace. The lunge cycle movement was subdivided into three phases: eccentric, isometric, and concentric.
  
  
  RESULTS
  The quadriceps and hamstrings were no different in the braced and unbraced conditions. When braced, the mean amplitude of the medial gastrocnemius was significantly lower throughout the whole movement (p = 0.01) and during the concentric (p = 0.006) and eccentric (p = 0.028) phases, but not within the isometric phase. The lateral gastrocnemius was found to have lower mean amplitude in the isometric phase (p = 0.044).
  
  
  CONCLUSIONS
  With its origin on the medial femoral condyle, perhaps reduced medial gastrocnemius activity may better guide knee rotation and assist the joint achieving a healthier kinematic pattern.
  
  
  CONCLUSIONS
  Lower medial gastrocnemius activity may facilitate lower medial compartment contact pressure, for which greater loading is known to increase the risk of osteoarthritis in anterior cruciate ligament-deficient (ACLD) knees. However, further research is needed.
authors.affiliation: Iran-Helal Institute of Applied Sciences and Technology, Tehran, Islamic Republic of Iran marjalali@gmail.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Jalali
authors.affiliation: Department of Mechanical Engineering, Sharif University of Technology, Tehran, Islamic Republic of Iran.
authors.forename: Farzam
authors.initials: F
authors.lastname: Farahmand
authors.affiliation: University of Leeds, Leeds, UK.
authors.forename: Tahmineh
authors.initials: T
authors.lastname: Rezaeian
authors.affiliation: Department of Health Professions Education, D'Youville College, Buffalo, NY, USA.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Ramsey
authors.affiliation: Department of Orthotics and Prosthetics, University of Social Welfare and Rehabilitation Sciences, Tehran, Islamic Republic of Iran.
authors.forename: Seyed Mohammad Ebrahim
authors.initials: SM
authors.lastname: Mousavi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000070598:Anterior Cruciate Ligament Injuries / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D001915:Braces; D015331:Cohort Studies; D004576:Electromyography; D004867:Equipment Design; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology; D011187:Posture / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: Electromyography; anterior cruciate ligament; brace