Chapter 24 - Transcutaneous Electrical Nerve Stimulation (TENS): A Review

Abstract

This chapter focuses on the transcutaneous electrical nerve stimulation (TENS), which involves the application of electrical currents to the skin primarily for the purposes of pain relief. It is a safe, noninvasive treatment that can be self-administered and can be used to treat both acute and chronic pain. A TENS unit may be considered as any device that generates appropriate cutaneously applied pulsed current through surface electrodes to overcome the impedance of the skin's conductive barrier and result in excitation of peripheral nerves. The clinical application of TENS involves the delivery of a low voltage electrical current from a small battery-operated device to the skin via surface electrodes. It involves a degree of trial and error in determining the most appropriate stimulation parameters and electrode placement sites. Low frequency and high frequency TENS produce analgesia through various mechanisms that primarily involve central inhibitory mechanisms. The most common procedural interventions in physical therapy are therapeutic exercise and functional training. TENS, are utilized by physical therapists as an adjunct to modulate and reduce pain. Use of TENS in combination with other therapies can also allow the patient to increase activity level, reduce hospital stay and improve function. The treatment with TENS increases joint function in patients with arthritis and postoperative TENS treatment in patients following thoracic surgery reduces recovery room stay and improves their pulmonary function. However, research on TENS for pain relief has suffered from a lack of rigorous randomized controlled trials (RCTs), and thus further evidence is required on the efficacy, parameter specific effects, and indeed cost-effectiveness of TENS.