title: Fatigability in Patients With Multiple Sclerosis During Maximal Concentric Contractions.
abstract: To compare quadriceps fatigability during maximal concentric contractions in persons with multiple sclerosis (MS) and healthy subjects.
  
  
  
  Observational study.
  
  
  
  Hospital rehabilitation department.
  
  
  
  Persons with MS (n=38) and healthy subjects (n=14) were included (N=52). Torque of the knee flexor and extensor muscles and fatigability of the knee extensor muscles were evaluated using an isokinetic device. Surface electromyographic activity of the rectus femoris, vastus lateralis, biceps femoris, and semitendinosus muscles was recorded.
  
  
  
  None.
  
  
  
  Muscle fatigability (torque fatigue index).
  
  
  
  The torque fatigue index was lower in persons with MS than in healthy subjects, but when torque was normalized to maximal isometric peak torque, persons with MS and healthy subjects finished the fatigue protocol at exactly the same level of relative strength (50% of the maximal isometric peak torque). Moreover, the reduction in torque was primarily because of a reduction in neuromuscular efficiency, with no changes of coactivation of antagonist muscles.
  
  
  
  Although fatigue is a disabling symptom of MS, persons with MS develop less muscle fatigability than healthy subjects during repeated maximal concentric contractions, but they end up at the same level of relative strength.
authors.affiliation: Inserm Unit 1179, Team 3: Technology and Innovative Therapies Applied to Neuromuscular Diseases, University of Versailles Saint Quentin en Yvelines, Garches, France; Department of Physical Medicine and Rehabilitation, R. Poincaré Hospital, Garches, France. Electronic address: sophie.hameau@aphp.fr.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hameau
authors.affiliation: Inserm Unit 1179, Team 3: Technology and Innovative Therapies Applied to Neuromuscular Diseases, University of Versailles Saint Quentin en Yvelines, Garches, France; Department of Physical Medicine and Rehabilitation, R. Poincaré Hospital, Garches, France.
authors.forename: Djamel
authors.initials: D
authors.lastname: Bensmail
authors.affiliation: Inserm Unit 1179, Team 3: Technology and Innovative Therapies Applied to Neuromuscular Diseases, University of Versailles Saint Quentin en Yvelines, Garches, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Roche
authors.affiliation: Laboratory of Human Motricity, Education, Sport, and Health (LAMHESS), University of Côte d'Azur, Nice, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Zory
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D000070633:Hamstring Muscles / Q000503:physiopathology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009119:Muscle Contraction / Q000502:physiology*; D018763:Muscle Fatigue / Q000502:physiology*; D052097:Quadriceps Muscle / Q000503:physiopathology*; D019415:Torque
keywords: Electromyography; Muscle fatigue; Muscle strength; Quadriceps muscle; Rehabilitation