title: Coactivation of Lower Limb Muscles during Gait in Patients with Multiple Sclerosis.
abstract: BACKGROUND
  Coactivation of agonist and antagonist lower limb muscles during gait stiffens joints and ensures stability. In patients with multiple sclerosis, coactivation of lower limb muscles might be a compensatory mechanism to cope with impairments of balance and gait.
  
  
  OBJECTIVE
  The aim of this study was to assess coactivation of agonist and antagonist muscles at the knee and ankle joints during gait in patients with multiple sclerosis, and to evaluate the relationship between muscle coactivation and disability, gait performance, dynamic ankle strength measured during gait, and postural stability.
  
  
  METHODS
  The magnitude and duration of coactivation of agonist-antagonist muscle pairs at the knee and ankle were determined for both lower limbs (more and less-affected) in 14 patients with multiple sclerosis and 11 healthy subjects walking at a spontaneous speed, using 3D-gait analysis.
  
  
  RESULTS
  In the patient group, coactivation was increased in the knee muscles during single support (proximal strategy) and in the ankle muscles during double support (distal strategy). The magnitude of coactivation was highest in the patients with the slowest gait, the greatest motor impairment and the most instability.
  
  
  CONCLUSIONS
  Increased muscle coactivation is likely a compensatory mechanism to limit the number of degrees of freedom during gait in patients with multiple sclerosis, particularly when postural stability is impaired.
authors.affiliation: INSERM 1179, CIC 1429, CHU Raymond Poincaré, APHP, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Boudarham
authors.affiliation: INSERM 1179, CIC 1429, CHU Raymond Poincaré, APHP, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hameau
authors.affiliation: LAMHESS, EA 6312, University of Nice Sophia Antipolis, Nice, France.
authors.forename: Raphael
authors.initials: R
authors.lastname: Zory
authors.affiliation: INSERM 1179, CIC 1429, CHU Raymond Poincaré, APHP, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hardy
authors.affiliation: INSERM 1179, CIC 1429, CHU Raymond Poincaré, APHP, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Djamel
authors.initials: D
authors.lastname: Bensmail
authors.affiliation: INSERM 1179, CIC 1429, CHU Raymond Poincaré, APHP, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Roche
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology; D004576:Electromyography; D005260:Female; D005684:Gait; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D035002:Lower Extremity / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000503:physiopathology*; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011597:Psychomotor Performance; D013035:Spasm