title: Muscle volume as a predictor of maximum force generating ability in the plantar flexors post-stroke.
abstract: BACKGROUND
  Post-stroke muscle weakness is commonly thought to be the result of a combination of decreased voluntary activation and decreased maximum force generating ability (MFGA). We assessed the ability of muscle volumes obtained using MRI to estimate the MFGA of the plantar flexor muscle group in individuals post-stroke.
  
  
  METHODS
  MRI was used to measure muscle volume of the plantar flexor muscle group in 17 individuals with post-stroke hemiparesis. A modified burst superimposition test was used to measure force of volitional contraction and predict the MFGA of the plantar flexors.
  
  
  RESULTS
  While muscle volume obtained by means of MRI provided information on the overall size of muscle, it overestimated the force generating ability of the paretic plantar flexors.
  
  
  CONCLUSIONS
  Results suggest that MRI-derived muscle volume underestimates the functional impairment in individuals post-stroke. Interestingly, the central activation ratio had a strong relationship with the maximum volitional force of contraction.
authors.affiliation: Biomechanics and Movement Science, University of Delaware, Newark, Delaware, 19716, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Knarr
authors.forename: John W
authors.initials: JW
authors.lastname: Ramsay
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Buchanan
authors.forename: Jill S
authors.initials: JS
authors.lastname: Higginson
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Binder-Macleod
mesh_terms: D000368:Aged; D004576:Electromyography; D005260:Female; D005528:Foot / Q000294:innervation*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D018908:Muscle Weakness / Q000175:diagnosis* / Q000209:etiology*; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D020521:Stroke / Q000150:complications*
keywords: electrical stimulation; magnetic resonance imaging; muscle strength; plantar flexors; stroke