A randomized trial to determine the duration of analgesia following a 15- and a 30-minute application of acupuncture-like TENS on patients with chronic low back pain

Background: Acupuncture-like TENS (AL-TENS) has been shown to produce prolonged pain relief, but no study has yet investigated its duration on a population suffering from chronic low back pain (CLPB). Objective: Our objective was to quantify the duration and magnitude of analgesia induced by a 15- or 30-minute application of AL-TENS. Methodology: We recruited a sample of 11 participants presenting with CLBP and conducted a randomized, crossover study, where participants were given AL-TENS for 15 and 30 minutes on two separate occasions. The pain intensity of their CLBP was assessed with a visual analogue scale before, during, and after AL-TENS applications. Magnitude and duration of analgesia were determined for each subject and for both AL-TENS application times. Results: The AL-TENS applications induced a clinically and statistically significant (p = 0.003) analgesia in all participants. Median duration of analgesia was 9 hours and 10 hours 30 minutes following the 15- and 30-minute AL-TENS applications, respectively; this 1.5-hour difference was not statistically significant (p = 0.55). Furthermore, we observed no significant difference in the magnitude of analgesia between both applications of AL-TENS (p > 0.56), suggesting that the duration of application of AL-TENS does not influence the magnitude of analgesia. Conclusion: Our results suggest that clinicians could use a 15-minute AL-TENS application to provide significant analgesia in patients presenting with low back pain since if provides a comparable analgesia versus a 30-minute application.