title: Stroke-related changes in neuromuscular fatigue of the hip flexors and functional implications.
abstract: OBJECTIVE
  The aim of this study was to compare stroke-related changes in hip flexor neuromuscular fatigue of the paretic leg during a sustained isometric submaximal contraction with those of the nonparetic leg and controls and to correlate fatigue with clinical measures of function.
  
  
  METHODS
  Hip torques were measured during a fatiguing hip flexion contraction at 20% of the hip flexion maximal voluntary contraction in the paretic and nonparetic legs of 13 people with chronic stroke and 10 age-matched controls. In addition, the participants with stroke performed a fatiguing contraction of the paretic leg at the absolute torque equivalent to 20% maximal voluntary contraction of the nonparetic leg and were tested for self-selected walking speed (10-m Walk Test) and balance (Berg).
  
  
  RESULTS
  When matching the nonparetic target torque, the paretic hip flexors had a shorter time to task failure compared with the nonparetic leg and controls (P < 0.05). The time to failure of the paretic leg was inversely correlated with the reduction of hip flexion maximal voluntary contraction torque. Self-selected walking speed was correlated with declines in torque and steadiness. Berg-Balance scores were inversely correlated with the force fluctuation amplitude.
  
  
  CONCLUSIONS
  Fatigue and precision of contraction are correlated with walking function and balance after stroke.
authors.affiliation: Departments of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA.
authors.forename: Allison S
authors.initials: AS
authors.lastname: Hyngstrom
authors.forename: Tanya
authors.initials: T
authors.lastname: Onushko
authors.forename: Robert P
authors.initials: RP
authors.lastname: Heitz
authors.forename: Anthony
authors.initials: A
authors.lastname: Rutkowski
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Hunter
authors.forename: Brian D
authors.initials: BD
authors.lastname: Schmit
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D006429:Hemiplegia / Q000175:diagnosis / Q000209:etiology / Q000534:rehabilitation*; D006621:Hip Joint; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D020521:Stroke / Q000150:complications / Q000175:diagnosis*; D000071939:Stroke Rehabilitation; D019415:Torque