Reviewed by Kirsten Hales, SPT
Transcutaneous Electrical Nerve Stimulation (TENS) has long been used as a method of pain management, particularly in clinical settings for conditions like musculoskeletal pain and post-surgical discomfort. What many may not realize is that while TENS is commonly used for pain relief, the underlying mechanisms and its clinical efficacy remain complex and inconsistent. In the article “Using TENS for Pain Control: The State of the Evidence,” Vance et al. (2014) delve into the scientific evidence, reviewing the two primary theories behind its function and highlighting the need for further research to establish more conclusive results on its use and effectiveness in both acute and chronic pain management.
Methods
The authors conducted a systematic search of multiple databases, including PubMed, CINAHL, and Cochrane Library, for studies published up to 2013. The review included randomized controlled trials (RCTs), cohort studies, and case series that investigated the efficacy of TENS for a variety of pain conditions, including musculoskeletal, neuropathic, and postoperative pain. The focus was on evaluating the effectiveness of TENS in reducing pain intensity, improving functional outcomes, and providing long-term relief. The review aimed to assess both the clinical outcomes and the mechanisms underlying the effects of TENS.
Results
The review identified a total of 23 studies meeting the inclusion criteria, with results showing mixed outcomes for TENS use in pain control. The authors found moderate evidence supporting the use of TENS for musculoskeletal pain, particularly in conditions such as osteoarthritis and lower back pain. In contrast, the effectiveness of TENS for neuropathic pain was less consistent, with some studies showing positive effects while others found no significant benefit. For postoperative pain, the evidence was inconclusive, with studies reporting both positive and negative outcomes. The authors also noted that optimal TENS parameters (e.g., frequency, intensity, and duration) varied significantly across studies, which could account for the inconsistencies in the findings.
Discussion
The authors concluded that while TENS shows promise as a non-invasive and relatively safe option for pain management, the evidence is still inconclusive regarding its overall effectiveness. The authors highlight the need for further high-quality, large-scale RCTs to determine the most effective TENS protocols for specific pain conditions. They also emphasize that while TENS may be a valuable adjunct therapy, it should not be considered a standalone treatment for chronic pain. The review also addresses the potential mechanisms of action for TENS, such as the gate control theory and the release of endogenous opioids, although further research is needed to confirm these hypotheses. Finally, the authors note the importance of individualized treatment plans, as the response to TENS can vary significantly between patients.
Conclusion
Based on my experience in outpatient clinics during my first two rotations, I observed significant improvements in patients using TENS, particularly those with chronic back or neck pain. While the article highlights inconsistencies in the evidence for TENS efficacy, my clinical observations align with the moderate support for its use in musculoskeletal pain management. Whether TENS functions through mechanisms like gate control theory or endogenous opioid release, or even as a placebo, the reduction in pain levels was undeniable among the patients I treated. Although I have not used TENS for my own pain management, I believe it holds potential as a non-invasive, adjunct therapy that can enhance a patient’s overall pain management plan. My experience suggests that TENS, when applied thoughtfully and in conjunction with other therapies, can contribute meaningfully to improved functional outcomes and quality of life.