Transcutaneous electrical nerve stimulation [TENS] for chronic low back pain

Transcutaneous electrical nerve stimulation [TENS] has been in use for four decades for the treatment of pain. The study of this pain control modality has been limited. There have been small randomized studies which have tested older TENS modalities. These studies have had difficulty obtaining adequate results due to unreported drop out rates, small sample sizes, selection bias and study design. A large study with conventional, nu-waveform and acupuncture-type TENS as compared to sham treatment has been lacking. In this study, 324 patients with chronic lower back pain were randomly allocated to receive daily treatment of sham TENS [N = 83], conventional TENS [N = 84], acupuncture TENS [N = 78], or nu-wave TENS [N = 79]. After one month no significant effect of TENS treatment was detected on any of nine indicators of outcome measuring function, motion, or depression. There was a significant omnibus time effect [P < 0.0001] indicating improvement of all patients with time over the first month. There was no significant interactive effects of TENS treatment with time [P < 0.1180]. In this study, 324 patients with chronic low back pain with blinded randomization to one of four treatment groups revealed that TENS therapy is no more effective than placebo.