• Carol Grace T Vance, Barbara A Rakel, Nicole P Blodgett, Josimari Melo DeSantana, Annunziato Amendola, Miriam Bridget Zimmerman, Deirdre M Walsh, and Kathleen A Sluka.
• Graduate Program in Physical Therapy and Rehabilitation Science, The University of Iowa, Iowa City, Iowa 52242, USA.
• Phys Ther. 2012 Jul 1;92(7):898-910.

BackgroundTranscutaneous electrical nerve stimulation (TENS) is commonly used for the management of pain; however, its effects on several pain and function measures are unclear.ObjectiveThe purpose of this study was to determine the effects of high-frequency TENS (HF-TENS) and low-frequency TENS (LF-TENS) on several outcome measures (pain at rest, movement-evoked pain, and pain sensitivity) in people with knee osteoarthritis.DesignThe study was a double-blind, randomized clinical trial.SettingThe setting was a tertiary care center.ParticipantsSeventy-five participants with knee osteoarthritis (29 men and 46 women; 31-94 years of age) were assessed.InterventionParticipants were randomly assigned to receive HF-TENS (100 Hz) (n=25), LF-TENS (4 Hz) (n=25), or placebo TENS (n=25) (pulse duration=100 microseconds; intensity=10% below motor threshold).MeasurementsThe following measures were assessed before and after a single TENS treatment: cutaneous mechanical pain threshold, pressure pain threshold (PPT), heat pain threshold, heat temporal summation, Timed "Up & Go" Test (TUG), and pain intensity at rest and during the TUG. A linear mixed-model analysis of variance was used to compare differences before and after TENS and among groups (HF-TENS, LF-TENS, and placebo TENS).ResultsCompared with placebo TENS, HF-TENS and LF-TENS increased PPT at the knee; HF-TENS also increased PPT over the tibialis anterior muscle. There was no effect on the cutaneous mechanical pain threshold, heat pain threshold, or heat temporal summation. Pain at rest and during the TUG was significantly reduced by HF-TENS, LF-TENS, and placebo TENS.LimitationsThis study tested only a single TENS treatment.ConclusionsBoth HF-TENS and LF-TENS increased PPT in people with knee osteoarthritis; placebo TENS had no significant effect on PPT. Cutaneous pain measures were unaffected by TENS. Subjective pain ratings at rest and during movement were similarly reduced by active TENS and placebo TENS, suggesting a strong placebo component of the effect of TENS.

18 keywords...

hide…