Carpal Tunnel Syndrome (CTS) is a common condition that affects the wrist and hand, causing discomfort and limiting function. Transcutaneous Electrical Nerve Stimulation (TENS) is a non-invasive pain management technique that uses low-voltage electrical currents.
Understanding Carpal Tunnel Syndrome
Carpal Tunnel Syndrome arises from the compression of the median nerve as it passes through a narrow passageway in the wrist called the carpal tunnel. This tunnel is formed by bones and ligaments, and when swelling or irritation occurs within this space, it can put pressure on the median nerve.
Common symptoms of CTS include numbness, tingling, pain, and weakness in the hand and fingers, particularly the thumb, index, middle, and half of the ring finger. Factors contributing to CTS include repetitive hand movements, certain wrist positions, and underlying health conditions such as arthritis, diabetes, or thyroid imbalances.
How TENS Units Work
A TENS unit is a small, battery-operated device that delivers low-voltage electrical current through electrodes placed on the skin. These electrical impulses are thought to relieve pain through a couple of mechanisms. One theory, known as the Gate Control Theory, suggests that the electrical impulses interfere with and block pain messages from reaching the brain and spinal cord.
Another proposed mechanism is the stimulation of endorphin release. Endorphins are the body’s natural painkillers, and the electrical stimulation from a TENS unit can promote their production, leading to a reduction in pain perception. The unit’s settings can be adjusted to control the intensity, frequency, and duration of the electrical pulses.
TENS Unit for Carpal Tunnel Relief
A TENS unit may help with Carpal Tunnel Syndrome symptoms by delivering electrical impulses to the affected area, which can reduce pain and inflammation. It can also potentially improve blood flow and promote healing in the tissues around the median nerve. The electrical impulses work by interfering with pain signals and stimulating the body’s natural pain-relieving substances.
Research on the effectiveness of TENS for CTS shows varying results, and it is often considered an adjunctive therapy. A 2019 study indicated that TENS use for CTS led to improvements in pain, hand function, and grip strength. Another study from 2017 found that TENS combined with exercise therapy was more effective than exercise therapy alone. However, a 2019 meta-analysis noted that many studies on TENS for CTS, and other chronic pain, have been inconclusive due to insufficient data, though some patients do report short-term pain relief.
Proper Application and Considerations
Proper electrode placement is important for effective TENS unit use for Carpal Tunnel Syndrome. One common placement involves putting one electrode along the base of the palm and the other under the wrist line. Another approach is placing one electrode on the center of the back of the hand and the second on the forearm just below the wrist. Conductive hand glove garments are also available as an alternative to traditional pads, allowing for more complete coverage of the hand and wrist.
For settings, TENS mode is generally recommended. While there is not enough definitive research to confirm the difference between low-frequency (less than 10 Hz) and high-frequency (greater than 100 Hz) treatments for CTS, a higher frequency may provide a faster onset of pain relief by reducing pain signal transmission. Low frequency, on the other hand, can stimulate the release of natural opioids for potentially prolonged relief. The intensity should be adjusted to a comfortable tingling sensation, not pain. Treatment sessions often last 20 to 40 minutes and can be used daily.
Before using a TENS unit, it is important to consult a healthcare professional, especially if the cause of pain is unknown.
TENS devices should not be used by individuals with pacemakers or other implanted electronic devices due to potential interference. Pregnant individuals are generally advised against TENS use unless specifically recommended by a medical professional. Electrodes should not be placed over broken skin, open wounds, the front of the throat, the carotid sinus, or transcranially (through the head). While side effects are minimal when used correctly, isolated cases of skin irritation can occur at the electrode site. TENS is a symptomatic treatment and does not offer a cure for CTS.