title: A comparison of true and premodulated interferential currents.
abstract: OBJECTIVE
  To compare true and premodulated interferential currents (IFCs) in terms of sensory, motor, and pain thresholds; maximum electrically induced torque (MEIT); and comfort.
  
  
  METHODS
  Repeated-measures design.
  
  
  METHODS
  Laboratory setting.
  
  
  METHODS
  University student and staff volunteers.
  
  
  METHODS
  Participants were exposed to 4 different conditions, chosen to evaluate 2 fundamental differences between true and premodulated IFCs. The conditions were different combinations of (1) premodulated or constant-amplitude currents applied at the skin and (2) crossed or parallel current paths.
  
  
  METHODS
  Sensory, motor, and pain thresholds; MEIT; and subjective reports of relative discomfort were recorded for each of the 4 conditions. Motor to sensory threshold ratios were subsequently calculated to assess depth efficiency of stimulation.
  
  
  RESULTS
  The major findings were that crossed currents (true IFC) had no advantage over parallel currents (premodulated IFC) in terms of motor to sensory threshold ratio, MEIT, or comfort, and that premodulated currents produced higher torque values and less discomfort than constant-amplitude currents (true IFC). These results contradict the claimed superiority of true IFC.
  
  
  CONCLUSIONS
  The findings indicate that premodulated IFC, delivered via 2 large electrodes, may be clinically more effective than the traditional true IFC arrangement in terms of depth efficiency, torque production, and patient comfort.
authors.affiliation: School of Physiotherapy, La Trobe University, Victoria, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Ozcan
authors.forename: Alex R
authors.initials: AR
authors.lastname: Ward
authors.forename: Valma J
authors.initials: VJ
authors.lastname: Robertson
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D017288:Pain Threshold / Q000502:physiology*; D012016:Reference Values; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*