title: Lower limb neuromuscular function and blood flow characteristics in AFO-using survivors of stroke.
abstract: OBJECTIVE
  Ankle-foot orthoses (AFOs) and gait aids are commonly used by survivors of stroke to ambulate, but they have not been used as inclusion or exclusion criteria for physiological studies. The purpose of this study was to examine differences in neuromuscular function and blood flow characteristics between the lower limbs of ambulatory, AFO-using survivors of stroke (n = 9).
  
  
  METHODS
  The subjects were, on average, 14 years poststroke and had used an AFO for about 7 years. We used the following measures to assess both lower limbs: quadriceps muscular strength (manual muscle testing, 1RM), calf muscular endurance (single-leg heel raises), lower limb soft tissue composition and muscle cross-sectional area, calf resting blood flow (strain gauge plethysmography), and central neural drive of the plantar flexors (nerve stimulation). The sound limb was defined as the control.
  
  
  RESULTS
  Quadriceps strength, triceps surae endurance, and calf cross-sectional area all were greater in the sound limb than in the affected limb (relative differences: 76.3% ± 16.6%, 146.4% ± 24.6%, and 25.6% ± 5.7%, respectively). In addition, resting blood flow, peak torque, and central neural drive of the plantar flexors were significantly greater (relative differences: 38.7% ± 5.9%, 94.4% ± 17.9%, and 43.6% ± 12.0%, respectively) in the sound calf.
  
  
  CONCLUSIONS
  Our findings confirm that significant decrements in muscle performance, size, and blood flow persist in the affected limb many years after stroke despite a resumption of ambulation.
  
  
  CONCLUSIONS
  This cohort of ambulatory AFO users exhibited large variations in functional abilities. We recommend that future studies in stroke survivors consider AFO use in their research designs.
authors.affiliation: 1Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma. 2Hanger Orthotics and Prosthetics, Oklahoma City, Oklahoma. 3Health Science Center, University of Oklahoma, Oklahoma City, Oklahoma.
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Sherk
authors.forename: Vanessa D
authors.initials: VD
authors.lastname: Sherk
authors.forename: Mark A
authors.initials: MA
authors.lastname: Anderson
authors.forename: Debra A
authors.initials: DA
authors.lastname: Bemben
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bemben
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000503:physiopathology*; D052097:Quadriceps Muscle; D012039:Regional Blood Flow; D020521:Stroke / Q000503:physiopathology*