Plantar fasciitis is a common orthopedic condition characterized by sharp or stabbing pain in the heel and arch of the foot, often felt with the first steps after rest. This pain originates from the inflammation or damage of the plantar fascia, a thick band of tissue running along the bottom of the foot. Transcutaneous Electrical Nerve Stimulation (TENS) is a small, battery-operated device used at home to manage various types of pain. A TENS unit delivers low-voltage electrical impulses through adhesive electrode pads placed on the skin, offering a non-pharmacological pain relief option.
How TENS Works to Manage Pain
TENS therapy uses electrical currents to interfere with the body’s transmission of pain signals to the brain. This is primarily explained by the Gate Control Theory of pain, where non-painful electrical impulses stimulate large nerve fibers. These impulses effectively close a “gate” in the spinal cord, preventing slower, painful signals from reaching the central nervous system. This replaces the sensation of pain with a mild, tingling feeling while the device is active.
A second mechanism involves stimulating the body’s internal pain-management systems. The electrical current triggers the release of endorphins, which are naturally occurring pain relievers. These endorphins provide a generalized analgesic effect, potentially extending pain relief after the TENS unit is turned off. Different TENS settings, such as high-frequency or low-frequency, can engage these two pain-relieving pathways.
Clinical Evidence for Plantar Fasciitis Relief
Research suggests TENS functions primarily as a temporary symptomatic treatment for plantar fasciitis. Electrical stimulation suppresses the perception of pain while the device is active, providing immediate, drug-free relief. However, TENS does not directly address the underlying inflammation or tissue damage, so it is not considered a cure.
The relief provided is often short-lived, with pain sometimes returning shortly after the session concludes. TENS is most beneficial when used as part of a broader, conservative treatment plan, rather than as a standalone therapy. Combining TENS with established treatments like stretching, physical therapy, and supportive orthotics can lead to greater overall improvement in pain and function.
By alleviating discomfort, TENS allows individuals to perform necessary physical therapy and stretching exercises more comfortably and consistently. This ability to maintain an active rehabilitation schedule facilitates adherence to a comprehensive recovery program.
Practical Guide to TENS Application
Effective TENS use requires proper electrode placement to target the affected area. One common method involves placing one pad directly on the heel, where pain is most intense, and the second pad at the base of the toes or on the mid-arch. This configuration directs the current path through the plantar fascia tissue. Alternatively, one pad can be placed on the bottom of the foot and the other higher up on the calf muscle.
The electrode pads should be positioned at least one inch apart to ensure the current flows across the treatment area. Users should select a setting that produces a strong tingling sensation without causing muscle contraction or discomfort. High-frequency settings (50-100 Hz) are used for immediate pain relief, while low-frequency settings (2-10 Hz) stimulate the release of endorphins.
A typical TENS session lasts between 20 and 30 minutes and can be repeated multiple times daily for pain management. Using the unit before activities that aggravate symptoms or prior to stretching exercises maximizes comfort and therapeutic benefit. Users should start with the lowest intensity setting and slowly increase it until an effective level is reached.
Safety Considerations and Contraindications
TENS is a low-risk treatment, but several absolute contraindications must be respected to ensure safety. Individuals with implanted electronic devices, such as cardiac pacemakers or defibrillators, should never use a TENS unit, as the electrical currents can interfere with device function. TENS should also not be applied over metallic implants, tumors, or areas with broken or irritated skin.
Pregnant individuals should avoid using TENS, particularly in the abdominal and pelvic regions, due to a lack of established safety data. Electrode placement must never occur over the front of the neck, as this can cause muscle spasms or disrupt the carotid sinus. Potential side effects are minimal but may include skin irritation or redness at the electrode site, which can be resolved by using hypoallergenic pads or repositioning. Consult a physical therapist or physician before beginning TENS therapy to confirm proper usage and rule out personal risk factors.