Plantar fasciitis is a common and often debilitating condition that causes pain in the heel and along the arch of the foot. It occurs when the plantar fascia, the thick band of tissue running across the bottom of the foot, becomes inflamed or sustains small tears due to excessive strain or repetitive stress. Transcutaneous Electrical Nerve Stimulation (TENS) offers a non-pharmacological method for managing this discomfort by delivering low-voltage electrical currents through electrodes placed on the skin. This guide provides detailed instructions on how to effectively use a TENS unit for plantar fasciitis pain relief.
Mechanism of Action and Safety Precautions
The pain-relieving effect of TENS therapy is attributed to two distinct physiological mechanisms. The first is the Gate Control Theory, which suggests that electrical impulses activate large, non-pain-carrying nerve fibers, effectively “closing a gate” in the spinal cord. This action inhibits the transmission of pain signals to the brain, providing immediate relief during the treatment session.
The second mechanism involves the release of the body’s natural painkillers, known as endogenous opioids. Low-frequency TENS stimulation triggers the production of these substances, which then bind to opioid receptors in the central nervous system, offering a sustained analgesic effect that can last even after the device is turned off. The electrical impulses also promote local blood flow, which may help reduce inflammation and facilitate the delivery of oxygen and nutrients to the affected tissue.
Before beginning TENS therapy, be aware of several safety precautions and contraindications. TENS should not be used if you have an implanted electronic device, such as a pacemaker, as the electrical current could interfere with its operation. Pregnant individuals should avoid using TENS, especially over the abdominal or pelvic area, as the safety of the device during pregnancy has not been established.
Electrodes must never be placed over broken skin, infected tissue, or areas of nerve damage where sensation is impaired. Placement over the front or side of the neck, eyes, or head is strictly prohibited. If you have epilepsy, deep vein thrombosis (DVT), or a known heart condition, consult a healthcare professional before using TENS.
Precise Electrode Placement for the Foot and Calf
Correct electrode placement is crucial for effective TENS therapy for plantar fasciitis pain. Standard self-adhesive electrode pads, typically 2×2 inches, are commonly used. Prior to application, the skin must be clean and dry, free of lotions or oils, to ensure optimal conductivity and adhesion.
One effective method involves placing the pads directly on the site of pain, specifically the sole and heel. Place one electrode pad on the bottom of the foot, near the heel where the pain is most often concentrated, and the second pad toward the base of the toes or on the mid-arch. This positioning ensures the electrical current flows directly through the inflamed plantar fascia tissue.
Alternatively, placement can target the nerve pathway that supplies the foot. This involves placing one pad on the sole of the foot, near the arch or heel, and the second pad on the calf muscle of the same leg. Targeting the calf can help address referred pain and muscle tightness associated with plantar fasciitis, providing a broader therapeutic effect. Always ensure the TENS unit is turned off before you apply, adjust, or remove the electrode pads to prevent sudden, uncomfortable shocks.
Optimal TENS Settings and Intensity Adjustment
Selecting the appropriate technical parameters for the TENS unit is necessary for achieving targeted pain relief. For chronic pain conditions like plantar fasciitis, two main frequency ranges are commonly employed: high-frequency (conventional TENS) and low-frequency (acupuncture-like TENS).
High-frequency TENS, typically set between 80 and 120 Hertz (Hz), is used to activate the Gate Control mechanism for immediate pain blocking. Low-frequency TENS, usually between 2 and 10 Hz, is intended to stimulate the release of endogenous opioids for longer-lasting relief. A pulse width, which determines the duration of each electrical pulse, is often set within the range of 150 to 250 microseconds (us) for effective pain relief.
Intensity is the most user-dependent setting and should be adjusted carefully after the pads are in place and the unit is turned on. The goal is to gradually increase the intensity until a strong but comfortable tingling or buzzing sensation is felt, known as paresthesia. The intensity should never be high enough to cause muscle contraction or discomfort, as this indicates overstimulation.
Recommended Treatment Duration and Frequency
Once the electrodes are secured and the settings are optimized, establish the treatment session duration. A typical session length ranges from 20 to 45 minutes. Using the TENS unit for this time frame is sufficient to provide pain relief that can last for a few hours after the stimulation ends.
The frequency of treatment can be adjusted based on the level of pain experienced. It is recommended to use the TENS unit one to three times per day, as needed, to manage symptoms. Some users find it beneficial to apply TENS before taking their first steps in the morning or after activities that aggravate the pain.
Regular, consistent use over several days or weeks is required to see sustained improvement in chronic pain symptoms. If the pain sensation increases during the session or if the device’s effectiveness seems to diminish over time, change the electrode placement or slightly adjust the frequency and intensity settings. If pain persists or the treatment becomes unpleasant, discontinue use and consult with a medical professional.