Introduction: Osteoarthritis is an age-related disease affecting synovial joints. Its main symptoms are pain and morning stiffness. Transcutaneous electrical nerve stimulation (TENS) and interferential currents are primarily used to treat pain. The purpose of literature review was to find the effectiveness of TENS and interferential currents in knee osteoarthritis pain. Methods: Literature review of randomized controlled trials using databases CINAHL, Cochrane Library, MEDLINE, ProQuest, PubMed and Wiley Online Library. Results: Four randomized controlled trials have been found. Three have examined TENS effectiveness, one has compared the effectiveness of different amplitude-modulated frequencies of interferential currents in knee osteoarthritis. Studies on TENS and interferential currents effectiveness have shown comparable effects on pain intensity in knee osteoarthritis, all trial groups resulting in reduced pain. Among stimulated groups a lesser difference in percentage of pain decrease has been observed than with stimulated and placebo groups. However, analgesic effects in active groups had longer carryover effects when compared to sham groups. Conclusions: Randomized controlled trials with higher number of study participants and unified protocols should be made. Carry-over effects of interventions should be observed for a longer period of time after treatment.
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