The Influence of Tens Treatment Parameters upon Experimental Pain Perception in Healthy, Pain-Free Subjects

Transcutaneous electrical nerve stimulation (TENS) has been the subject of extensive research, yet relatively little consensus exists regarding optimal analgesic stimulation parameters. A high degree of TENS response variability has led to the institution of different modes of treatment, which vary in their featured operating parameters and efficacy. Much attention has focused on the frequency of stimulation and, to date, little attempt has been made to compare alternative modes of TENS systematically, especially high-intensity applications using experimental pain protocols and healthy, pain-free subjects. Moreover, the lack of a well-circumscribed set of effective analgesic parameters has made it difficult to devise suitable placebo protocols. This review attempts to explore the possibility that stimulation intensity may be the most important parameter consideration for TENS modulation of experimentally induced pain and the implication this may have for the creation of more appropriate TENS placebo techniques.