Innovative Approach: Using Ear Stimulation to Alleviate Knee Pain via Vagus Nerve Activation

Knee pain can significantly impact daily activities such as tying shoelaces, entering a car, or walking downstairs, making life much more challenging for those affected. Traditional treatments for osteoarthritis-related knee pain often offer limited relief and may come with undesirable side effects. Recent research from the University of Texas at El Paso explores a novel method that targets central pain mechanisms rather than just the affected tissue.

In collaboration with Harvard Medical School and Boston University, the team conducted a pilot study on stimulating the vagus nerve through the ear to reduce knee pain. The vagus nerve, a key component of the parasympathetic nervous system, plays an essential role in regulating the body's rest-and-digest functions and maintaining balance against stress-related responses. Imbalances between sympathetic and parasympathetic activity have been linked to chronic pain in osteoarthritis patients.

The treatment, known as transcutaneous auricular vagus nerve stimulation (tVNS), involves placing a device on the ear that sends pulses to activate the auricular branch of the vagus nerve. In this study, 30 individuals with knee osteoarthritis received 60-minute sessions of tVNS. Results showed that 11 participants experienced a noticeable reduction in pain, highlighting the potential of this non-invasive therapy.

As Dr. Kosaku Aoyagi explains, this approach aims at correcting autonomic nervous system imbalance, which may be a contributing factor to chronic knee pain. Although tVNS is currently approved for conditions like epilepsy and depression, this trial is the first in the U.S. to evaluate its efficacy for knee osteoarthritis.

Future research will involve larger, randomized controlled trials to verify the effectiveness of ear stimulation in managing knee pain. The goal is to develop an alternative, safe, and drug-free treatment option that addresses the underlying neural mechanisms of pain.

This promising research underscores the importance of central nervous system modulation in pain management and could lead to innovative therapies for those suffering from chronic knee conditions.

source: https://medicalxpress.com/news/2025-05-knee-pain-vagus-nerve-ear.html