title: Neuromuscular properties of the thigh muscles in patients with Ehlers-Danlos syndrome.
abstract: BACKGROUND
  Ehlers-Danlos syndrome (EDS), a connective tissue disorder, may lead to impaired contractile function of lower limb muscles.
  
  
  METHODS
  To test this hypothesis and to understand the possible mechanisms involved, isometric function of the thigh muscles was investigated at different joint angles (30°, 60°, and 90° of knee flexion) in 7 tenascin-X (TNX)-deficient EDS patients.
  
  
  RESULTS
  There was reduced maximal voluntary torque of the knee extensors (but not knee flexors) across all joint angles in the patients. Time to reach maximal rate of torque development was delayed, and voluntary activation capacity was reduced in patients compared with controls, particularly at 30°.
  
  
  CONCLUSIONS
  EDS is associated with muscle weakness, most likely due to increased compliance of the series-elastic component of muscle tissue and failure of maximal voluntary muscle activation. Further research is required to understand the influence of reduced voluntary activation on the severe fatigue reported by EDS patients.
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands. h.l.gerrits@vu.nl
authors.forename: Karin H L
authors.initials: KH
authors.lastname: Gerrits
authors.forename: Nicol C
authors.initials: NC
authors.lastname: Voermans
authors.forename: Arnold
authors.initials: A
authors.lastname: de Haan
authors.forename: Baziel G
authors.initials: BG
authors.lastname: van Engelen
mesh_terms: D000328:Adult; D004535:Ehlers-Danlos Syndrome / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology*; D018908:Muscle Weakness / Q000503:physiopathology*; D052097:Quadriceps Muscle / Q000503:physiopathology*; D013848:Thigh / Q000503:physiopathology; D019415:Torque