June 8, 2015
A Look At TENS
By Michael D. Shaw
Transcutaneous electrical nerve stimulation is a non-invasive, non-pharmaceutical peripheral stimulation technique used to relieve pain. TENS delivers pulsed electrical currents across intact skin surfaces, to activate underlying nerves, and can be self-administered by the patient. With virtually no side effects, and a growing body of positive clinical literature, TENS is becoming widely accepted as an effective tool in pain management.
While the first wearable TENS unit is relatively recent (patented in 1974), the technique in more primitive form dates back to dim antiquity. Ancient Egyptians (2500 BC) are said to have applied electrogenic fish to painful body parts. The first real documentation of such treatment seems to be in the work Compositiones, a compendium of pharmacological therapeutics, written by Scribonius Largus (mid-first century AD), a physician who practiced at the court of the emperor Claudius.
A few more historical tidbits…
The 18th century saw increased use of electrical therapy for numerous conditions—especially in Europe. During that same period, America’s own Benjamin Franklin documented the administration of electric shocks to his neighbor John Pringle, to relieve a case of frozen shoulder.
Around 100 years later (1863), a true precursor to our modern day TENS units was introduced by G. Gaiffe in Paris. While limited by very low electrical output (3 mA compared to the 90mA of today’s devices) it did have removable batteries, an inductorium, lead wires, and electrodes.
By the early 20th century, over-hype of the therapeutic benefits of TENS beyond the realm of pain relief, along with the introduction of many analgesic pharmaceuticals, slowed interest in the technique. The 1974 patent, assigned to Medtronic, took advantage of more advanced electronics and skin electrode design, and brought TENS back into the mainstream.
TENS is thought to provide pain relief by activating cutaneous afferent fibers—which carry nerve impulses toward the central nervous system—at the site of application. There is also involvement of deep tissue afferents, and this may even be the primary factor, as shown by clever experiments from Radhakrishnan and Sluka in 2005.
With more than 7000 papers cataloged by PubMed under a search for “Transcutaneous Electrical Nerve Stimulation,” there is certainly no shortage of scientific information on the technique. Here are a few recent findings:
1. TENS therapy holds promise as a palliative, alternative, safe, and inexpensive treatment for patients with some chronic pruritic (itching) conditions.
2. Efficacy against phantom limb pain in amputees.
3. Dental applications, including analgesia in pediatric and adult patients; treatment of chronic pain of maxillofacial region; treatment of acute orofacial pain; and increasing salivary flow in patients with xerostomia (dry mouth).
4. Application of TENS can potentially increase exercise tolerance and oxygen supply in healthy subjects.
5. Combining therapeutic exercise and TENS may reduce spasticity and improve balance, gait, and functional activity in chronic stroke patients.
A leading company in the field of TENS units and related products is JUSCO Medical, LLC. Let’s hear from their president, Jason Ridgel…
“Pain management is an important element of healing, recovery, and physical therapy. JUSCO prides itself on high-quality, pill-free solutions to aid in pain management for a variety of people and issues. Our FDA-approved TENS unit is an example of that. This product is excellently engineered with adjustable settings and an automatic shut-off timer. We give patients many options which include several ways to stimulate muscles and relieve pain. Portable, durable, and affordable, these items are at the forefront of positive change for millions of patients nationwide. In many cases, insurance is accepted.”
Also of interest is the company’s PH9 Generator, a unique portable unit for producing alkaline water without expensive filters.
Few things are more universal to the human experience than pain, and few methods of pain relief are as risk-free and effective as TENS. Give it a try!