Effects of trancutaneous electrical nerve stimulation and interferential current on pain threshold in cold induced pain among apparently healthy subjects

Purpose: Studies on the relative efficacy of Interferential Current (IFC) and Transcutaneous Electrical Nerve Stimulation (TENS) is still inconclusive. This study compared the pain threshold of IFC and TENS on experimental cold induced pain among apparently healthy volunteers. Materials and methods: The subjects were 60 consented apparently healthy individuals (30 males, 30 females). Their age ranged between 20 and 25 years with mean age of 23.1 +/- 1.49. Subjects were randomly assigned into any of the 3 groups (IFC, TENS or Placebo). An Enraf-Nonius Endomed 582 ID electrical stimulator was used to generate TENS or IFC. The placebo group did not receive stimulation via a connected dummy stimulator. Stimulation was done on the forearm of the subjects while the hand was deep into cold water maintained at 0 degrees C. The duration of time that the subjects could tolerate the pain and self reported pain intensity were outcome measures. Results: The results revealed no statistical significance in pain intensity among the three groups (F=1.18; p>0.05). Similarly, the pain threshold among the three groups showed no significant difference (F=1.36; p>0.05). Conclusion: No significant difference was found in the pain threshold and pain intensity using either TENS or IFC or placebo on cold induced pain among apparently normal volunteers.