Transcutaneous Electrical Nerve Stimulation (TENS) offers a non-invasive method for temporary pain relief, utilizing low-voltage electrical impulses delivered through adhesive electrode pads placed on the skin. The TENS unit produces this current to stimulate the nerves. For individuals experiencing the discomfort of Tennis Elbow, medically known as Lateral Epicondylitis, this therapy can be a valuable tool. This guide provides specific instructions focusing on correct TENS pad placement and appropriate machine settings for this condition.
Understanding the Affected Anatomy
Tennis Elbow is primarily associated with the tendons connecting the forearm muscles to the bone on the outer side of the elbow. The pain centers around the lateral epicondyle, the bony bump felt on the outside of the elbow. This area serves as the common origin point for the wrist extensor muscles. The muscle most commonly involved in this condition is the Extensor Carpi Radialis Brevis (ECRB). Repetitive strain, such as from gripping or wrist extension, can cause microscopic tears or degeneration in the ECRB tendon. Consequently, the pain often radiates down the forearm muscle belly below the elbow.
Key Strategies for Pad Placement
Effective TENS therapy requires strategic pad placement to intercept pain signals and target affected muscle tissue. A primary strategy uses a two-pad setup, positioning one pad proximal and one pad distal to the center of the painful area. This configuration ensures the electrical current encompasses the region of discomfort without placing pads directly over the bony prominence of the joint itself.
Two-Pad Placement
One common method involves placing the first pad directly over the lateral epicondyle, which is often the point of most tenderness. The second pad is then placed several inches down the forearm over the muscle belly of the wrist extensors. This alignment allows the current to flow along the length of the damaged tendon and muscle. A second effective approach uses the “surrounding the pain” strategy, where the pads are placed on either side of the lateral epicondyle, ensuring they are at least one inch apart.
Four-Pad Placement
For more comprehensive coverage, a four-pad setup using two channels can be employed to create a cross-current that thoroughly covers the elbow area. In this arrangement, two pads are positioned above the elbow and two pads are positioned below it. The pads from different channels are placed to intersect the current paths, stimulating the radial nerve pathway which supplies the extensor muscles. Correct pad placement aims for a strong, comfortable tingling sensation without causing an unwanted muscle contraction.
Recommended Unit Settings for Relief
The settings on a TENS unit determine the type of pain relief achieved, generally falling into two categories based on frequency.
High-Frequency (Conventional TENS)
For immediate, acute pain relief, the Conventional TENS mode, or high-frequency setting, is recommended. This mode uses a high pulse rate, often set between 80 and 120 Hertz (Hz). It works by engaging the Gate Control Theory of pain, which effectively blocks pain signals from reaching the brain.
Low-Frequency (Acupuncture-like TENS)
For longer-lasting relief, particularly for chronic pain, a Low-Frequency TENS or Acupuncture-like TENS mode is suggested. These settings utilize a much lower frequency, usually in the range of 2 to 10 Hz, which encourages the body to release natural pain-relieving chemicals called endorphins. A common pulse width setting for pain relief across both modes is around 200 microseconds (μs).
The intensity setting controls the strength of the electrical impulse and should be adjusted to produce a strong but comfortable tingling sensation. The current must be perceptible but must not be high enough to cause an uncomfortable muscle twitch or contraction. Sessions typically last for 30 to 60 minutes and can be repeated up to four times daily, with the unit providing pain relief that can last for several hours after use.