title: Conventional versus acupuncture-like transcutaneous electrical nerve stimulation on cold-induced pain in healthy human participants: effects during stimulation.
abstract: OBJECTIVE
  To compare the hypoalgesic effects of conventional transcutaneous electrical nerve stimulation (TENS) (high frequency, low intensity) and acupuncture-like TENS (AL-TENS, low frequency, high intensity) on cold-induced pain.
  
  
  METHODS
  Randomized controlled parallel group study comparing the effects of strong non-painful AL-TENS, conventional TENS and placebo (no current) TENS on cold-pressor pain threshold (CPT) and pain intensity. Two baseline (pre-intervention) measures and three during intervention measures of CPT and cold pain intensity (four point category scale) were recorded.
  
  
  METHODS
  Physiology laboratory in Leeds Metropolitan University.
  
  
  METHODS
  One hundred and twenty-one healthy participants.
  
  
  METHODS
  Each participant received one of three TENS interventions over their flexor digitorum profundus: (i) high pulse rate TENS with a strong non-painful paraesthesia (conventional), (ii) low-rate burst mode TENS that caused strong non-painful phasic muscle twitching (acupuncture like) or (iii) no current (placebo) TENS.
  
  
  METHODS
  Difference between conventional TENS and AL-TENS in cold pain threshold relative to pre-TENS baseline after 25 min of stimulation.
  
  
  RESULTS
  No differences were detected for CPT or cold pain intensity during conventional TENS compared with AL-TENS. When compared with placebo TENS, the confidence intervals for the ratio of intervention CPT to baseline CPT, for both AL-TENS (0·966, 1·424) and conventional TENS (0·948, 1·401), were close to the positive side of one, although neither reached statistical significance.
  
  
  CONCLUSIONS
  Unlike some previous studies, the present study detected no differences in hypoalgesia between AL-TENS, conventional TENS and placebo (no current) TENS during stimulation.
authors.affiliation: Centre for Pain Research, Faculty of Health, Leeds Metropolitan University, Leeds, UK. richard2506@hotmail.com
authors.forename: Richard P
authors.initials: RP
authors.lastname: Francis
authors.forename: Paul
authors.initials: P
authors.lastname: Marchant
authors.forename: Mark I
authors.initials: MI
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003080:Cold Temperature / Q000009:adverse effects*; D015671:Electroacupuncture; D004739:England; D005260:Female; D006225:Hand / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D010147:Pain Measurement; D017288:Pain Threshold; D004561:Transcutaneous Electric Nerve Stimulation; D016896:Treatment Outcome; D055815:Young Adult