For over 50 years, transcutaneous electrical nerve stimulation (TENS) therapy has been used to provide non-pharmacological pain relief. Traditionally, TENS was offered as a way to alleviate pain while the device was in use. Neither chronic nor acute pain, however, can be solved by intermittent periods of relief. At Sword Health, we understand that solving pain requires habit-forming and guided movement by licensed physical therapists, which is why we exclude TENS therapy from our practice.

What is TENS?

TENS therapy is conducted via non-invasive, wireless patches that deliver electric pulses to the skin. This stimulates sensory nerve roots and, by doing so, aims to reduce or distract the transmission of pain signals to the brain. Similar to opioids, TENS masks symptoms, giving people a temporary break from their pain. Despite its widespread use, there are significant limitations and drawbacks.

Does Sword Health’s MSK programs use TENS?

At Sword Health, we focus on evidence-based treatment to deliver meaningful improvement, which means we rely on clinical results and science to deliver only the most appropriate and effective care for our patients. We believe in a high-touch model of physical care, delivered by a team of licensed doctors of physical therapy. Their expertise, combined with sensor-based technology, is the best way to heal long-term. Because of our philosophy, we make the conscious choice to avoid TENS therapy in our approach — and this is why:

High vs Low Frequency TENS

Often, TENS therapy is applied at various frequencies, intensities and pulse durations to achieve different levels of relief. In the beginning, the devices were applied at low frequencies. More recently, however, musculoskeletal (MSK) providers have turned to high-frequency impulse therapy (HFIT), claiming superiority over low-frequency stimulation. While this may solve for immediate pain, there is currently not enough evidence to support this approach. While some studies on implantable spinal cord stimulators have shown high-frequency stimulation to be superior to low-frequency stimulation, the same has not been studied for transcutaneous stimulation. In fact, the only published study upon which solutions such as Enso have based their approach is exploratory. In this study, high-frequency stimulation was compared with no stimulation. Since the HFIT results in impulses that the member can feel (versus no stimulation), it is impossible to note placebo effects.

All studies around high versus low frequency TENS have focused solely on chronic low back pain, with no evidence on acute pain, or on pain affecting other areas of the body. MSK solutions should be validating their care models against clinical-grade studies and results, and with the lack of clinical validation around TENS, Sword has chosen to avoid incorporation into our care model.

The problems and limitations of TENS

Through the years, multiple efforts to conclude on the efficacy of TENS for acute or chronic pain have taken place, with over 160 systematic reviews and 50 meta-analyses conducted so far. With all of this, the efficacy of TENS remains unclear. While many studies show positive effects, others state negative effects, and several systematic reviews conclude that there is insufficient evidence.

When it comes to MSK conditions, TENS studies have focused on chronic low back pain and neck pain, but the question of its effectiveness still remains. There is currently no consensus on its clinical worthiness. As a result, TENS is not suggested by clinical guidelines for the management of chronic low back pain (most importantly, the American College of Physicians / American Pain Society guidelines and the NICE guidelines). Additionally, the Centers for Medicare and Medicaid CMS issued a Medicare National Coverage Determination (NCD) in 2012 that allowed for coverage of TENS for chronic low back pain, only in the context of clinical trials. Since then, this coverage has expired, which has led several health plans to stop reimbursing for TENS therapy.

Most importantly, TENS does not address the underlying root causes of MSK pain, nor has it been proven to produce long-term relief. Evidence-based MSK care stresses that non-pharmacological approaches should be the mainstay treatment in MSK conditions. For solutions with the best outcomes, education, therapeutic exercise and behavioral change are driving care.

Can TENS be harmful?

As with any electronic device, risks are evident. Side effects from TENS range from uncomfortable buzzing, to skin irritations, to spasms and possible injury. TENS is not recommended for people who are pregnant or have epilepsy, heart problems, or wear a pacemaker or other metal implants. Much like opioids, you can develop tolerance to TENS, rendering it ineffective when frequently used.

The most clinical solution on the market

At Sword Health, we believe the most clinically effective solution for MSK disorders is high-quality physical care delivered by licensed doctors of physical therapy combined with our FDA-listed, sensor-based technology. Unlike TENS, Sword’s program is designed to address the physical and mental barriers to long-term pain relief.