title: Isometric muscle function of knee extensors and the relation with functional performance in patients with stroke.
abstract: OBJECTIVE
  (1) To examine the isometric strength, speed, and fatigue resistance of the knee extensors of the paretic limb and nonparetic limb in patients with stroke and compare these with able-bodied subjects. (2) To relate the contractile properties with different indices of functional performance.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Rehabilitation center research laboratory.
  
  
  METHODS
  Eighteen stroke patients and 10 able-bodied controls.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Maximal voluntary torque (MVT), maximal rate of torque development, time to maximal rate of torque development, half relaxation time ((1/2)RT), and fatigue index. Scores on the Functional Ambulation Category scale, Berg Balance Scale, and Rivermead Mobility Index as well as distance walked during the six-minute walk test were obtained.
  
  
  RESULTS
  MVT of the paretic leg was lower than of the nonparetic leg (P<.05), and both limbs had lower MVT than controls (P<.05). Both the paretic and the nonparetic leg showed longer (1/2)RT compared with controls (P<.05). The fatigue index was reduced in the paretic leg (P<.05) but not in the nonparetic leg compared with controls. MVT and fatigue index of the paretic leg were related to indices of functional performance (r=0.49-0.64; P<.05).
  
  
  CONCLUSIONS
  Apart from bilateral weakness, knee extensors in patients with stroke showed a lower rate of torque development and relaxation (both paretic and nonparetic leg) and lower fatigue resistance (paretic leg only) than controls, which in part may be a consequence of changes within the muscles. Strength and fatigue resistance relate to functional performance, indicating that these muscle properties should be addressed during rehabilitation. However, future research is needed to elucidate the efficacy of exercise programs.
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands. k_gerrits@fbw.vu.nl
authors.forename: Karin H
authors.initials: KH
authors.lastname: Gerrits
authors.forename: Marijke J
authors.initials: MJ
authors.lastname: Beltman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Koppe
authors.forename: Hermanna
authors.initials: H
authors.lastname: Konijnenbelt
authors.forename: Peter D
authors.initials: PD
authors.lastname: Elich
authors.forename: Arnold
authors.initials: A
authors.lastname: de Haan
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Janssen
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D007717:Knee / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009068:Movement; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D055815:Young Adult