title: Effects of carrier frequency of interferential current on pressure pain threshold and sensory comfort in humans.
abstract: OBJECTIVE
  To assess the effect of carrier frequency of interferential current (IFC) on pressure pain threshold (PPT) and sensory comfort in healthy subjects.
  
  
  METHODS
  A double-blind randomized trial.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Healthy subjects (N=150).
  
  
  METHODS
  Application of the IFC for 20 minutes and measures of PPT collected in the regions of the nondominant hand and forearm.
  
  
  METHODS
  We measured PPT and comfort at frequencies of 1kHz, 2kHz, 4kHz, 8kHz, and 10kHz.
  
  
  RESULTS
  There was a significant increase in PPT in the 1-kHz group when compared with the 8-kHz and 10-kHz groups. There was a greater discomfort in the 1-kHz and 2-kHz groups.
  
  
  CONCLUSIONS
  IFC with a carrier frequency of 1kHz promotes a higher hypoalgesic response during and after stimulation than IFC with carrier frequencies of 8kHz and 10kHz. Carrier frequencies of 1kHz and 2kHz are perceived as more uncomfortable than carrier frequencies of 4kHz, 8kHz, and 10kHz.
authors.affiliation: Physical Therapy Department, University of the City of São Paulo (UNICID), São Paulo, Brazil.
authors.forename: Roberta Ceila
authors.initials: RC
authors.lastname: Venancio
authors.forename: Stella
authors.initials: S
authors.lastname: Pelegrini
authors.forename: Daiane Queiroz
authors.initials: DQ
authors.lastname: Gomes
authors.forename: Eduardo Yoshio
authors.initials: EY
authors.lastname: Nakano
authors.forename: Richard Eloin
authors.initials: RE
authors.lastname: Liebano
mesh_terms: D000293:Adolescent; D000328:Adult; D001132:Arm; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*