title: A single-blind investigation into the hypoalgesic effects of different swing patterns of interferential currents on cold-induced pain in healthy volunteers.
abstract: OBJECTIVE
  To compare the analgesic effects of differing swing patterns of interferential current (IFC) on cold-induced pain.
  
  
  METHODS
  Single-blind intervention study in which subjects completed 6 cycles of the cold-induced pain test-2 pretreatment, 2 during treatment, and 2 posttreatment.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Forty healthy volunteers.
  
  
  METHODS
  Subjects were randomly allocated to receive 1 of 4 IFC treatment interventions: 1 integral 1, 6 integral 6, 6 wedge 6, or burst. IFC was administered for 20 minutes via 4 electrodes attached to the forearm (quadripolar application) at a strong but comfortable intensity using amplitude-modulated frequencies of 1 to 100 Hz.
  
  
  METHODS
  Change in pain threshold and self-report of pain intensity and unpleasantness from pretreatment baseline.
  
  
  RESULTS
  Two-way repeated-measure analysis of variance found significant effects for time and group by time interaction (P<.01), but effects for groups failed to reach statistical significance (P=0.1). This suggests that when all groups are considered together, subjects experience a rise in pain threshold when IFC devices are switched on but not when they are switched off. However, the rise in pain threshold was not dependent on the swing pattern employed. Analysis of pain intensity and unpleasantness ratings found no effects for group or group by time interaction.
  
  
  CONCLUSIONS
  There were no differences in the hypoalgesic effects of different swing patterns.
authors.affiliation: School of Health Sciences, Faculty of Health and Environment, Leeds Metropolitan University, Leeds, UK. M.Johnson@LMU.ac.uk
authors.forename: Mark I
authors.initials: MI
authors.lastname: Johnson
authors.forename: Ghazala
authors.initials: G
authors.lastname: Tabasam
mesh_terms: D000328:Adult; D001132:Arm; D003080:Cold Temperature / Q000009:adverse effects*; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008297:Male; D010146:Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D059408:Pain Management; D010147:Pain Measurement; D017288:Pain Threshold; D012016:Reference Values; D016037:Single-Blind Method; D016896:Treatment Outcome