title: Evaluation of a training program for persons with SCI paraplegia using the Parastep 1 ambulation system: part 5. Lower extremity blood flow and hyperemic responses to occlusion are augmented by ambulation training.
abstract: OBJECTIVE
  To test whether 12 weeks of exercise conditioning using functional neuromuscular stimulation (FNS) ambulation alters the resting lower extremity blood flow and hyperemic responses to vascular occlusion in subjects with paraplegia, and to determine whether an association exists between limb flow and lower extremity fat-free mass.
  
  
  METHODS
  Pretest, posttest.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Subjects with chronic neurologically complete paraplegia.
  
  
  METHODS
  Thirty-two sessions of microprocessor-controlled ambulation using electrically stimulated contractions of lower extremity muscles and a rolling walker.
  
  
  METHODS
  Subjects underwent quantitative Doppler ultrasound examination of the common femoral artery (CFA) before and after training. End-diastolic arterial images and arterial flow-velocity profiles obtained at rest and after 5 minutes of suprasystolic thigh occlusion were computer-digitized for analysis of heart rate (HR), CFA peak systolic velocity (PSV), CFA cross-sectional area (CSA), flow velocity integral (FVI), pulse volume (PV), and CFA (arterial) inflow volume (AIV).
  
  
  RESULTS
  Significant effects of training on CSA (p < .0001), FVI (p < .05), computed PV (p < .001), and computed AIV (p < .01) were observed. Resting HR was lower following training (p < .05). The change for resting PSV approached but did not reach significance (p = .083). Analysis of postocclusion PV and AIV showed significant effects for conditioning status (p values < .01), postcompression time (p values < .0001), and their interaction (p values < .01). At 1 minute after occlusion, the posttraining AIV response was 78.2% greater in absolute magnitude and 17.4% more robust when expressed as a percentage change from its resting value than before training. Significant correlations were found between thigh fat free mass and both AIV and PV (p values < .05).
  
  
  CONCLUSIONS
  Exercise training using FNS ambulation increases the resting lower extremity AIV in individuals with paraplegia and augments the hyperemic response to vascular occlusion. Improved posttraining blood flow is attributable both to vascular structural changes and upregulation of vascular flow control mechanisms. Limb mass is associated with the volume of arterial blood flow.
authors.affiliation: Department of Orthopaedics & Rehabilitation, The Miami Project to Cure Paralysis, University of Miami School of Medicine, FL 33146, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Nash
authors.forename: P L
authors.initials: PL
authors.lastname: Jacobs
authors.forename: B M
authors.initials: BM
authors.lastname: Montalvo
authors.forename: K J
authors.initials: KJ
authors.lastname: Klose
authors.forename: R S
authors.initials: RS
authors.lastname: Guest
authors.forename: B M
authors.initials: BM
authors.lastname: Needham-Shropshire
mesh_terms: D000328:Adult; D003251:Constriction, Pathologic; D004599:Electric Stimulation Therapy / Q000592:standards*; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D010264:Paraplegia / Q000209:etiology / Q000534:rehabilitation*; D015397:Program Evaluation; D013119:Spinal Cord Injuries / Q000150:complications*; D013813:Therapy, Computer-Assisted / Q000592:standards*; D013997:Time Factors; D014463:Ultrasonography; D016138:Walking