title: Surface-distributed low-frequency asynchronous stimulation delays fatigue of stimulated muscles.
abstract: BACKGROUND
  One important reason why functional electrical stimulation (FES) has not gained widespread clinical use is the limitation imposed by rapid muscle fatigue due to non-physiological activation of the stimulated muscles. We aimed to show that asynchronous low-pulse-rate (LPR) electrical stimulation applied by multipad surface electrodes greatly postpones the occurrence of muscle fatigue compared with conventional stimulation (high pulse rate, HPR).
  
  
  METHODS
  We compared the produced force vs. time of the forearm muscles responsible for finger flexion in 2 stimulation protocols, LPR (fL = 10 Hz) and HPR (fH = 40 Hz).
  
  
  RESULTS
  Surface-distributed low-frequency asynchronous stimulation (sDLFAS) doubles the time interval before the onset of fatigue (104 ± 80%) compared with conventional synchronous stimulation.
  
  
  CONCLUSIONS
  Combining the performance of multipad electrodes (increased selectivity and facilitated positioning) with sDLFAS (decreased fatigue) can improve many FES applications in both the lower and upper extremities.
authors.affiliation: State University of Novi Pazar, Novi Pazar, Serbia; Tecnalia Serbia, Ltd., Vladetina 13, Belgrade, 11000, Serbia.
authors.forename: Lana Z Popović
authors.initials: LZ
authors.lastname: Maneski
authors.forename: Nebojša M
authors.initials: NM
authors.lastname: Malešević
authors.forename: Andrej M
authors.initials: AM
authors.lastname: Savić
authors.forename: Thierry
authors.initials: T
authors.lastname: Keller
authors.forename: Dejan B
authors.initials: DB
authors.lastname: Popović
mesh_terms: D000328:Adult; D000368:Aged; D001703:Biophysics; D004558:Electric Stimulation / Q000379:methods; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005221:Fatigue / Q000209:etiology* / Q000628:therapy*; D005260:Female; D007839:Functional Laterality; D006429:Hemiplegia / Q000150:complications* / Q000209:etiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D020521:Stroke / Q000150:complications
keywords: functional electrical stimulation; grasp; multipad electrodes; muscle fatigue; upper extremities