Long-COVID, a complex and lingering condition following COVID-19 recovery, affects approximately 1 in 13 adults in the U.S. Symptoms such as widespread pain, fatigue, and muscle weakness often continue to disrupt daily activities, including walking and basic tasks.

The study, published in the peer-reviewed Nature Scientific Reports, focused on a wearable Transcutaneous Electrical Nerve Stimulation (TENS) device, which uses low-voltage electrical currents to reduce pain, fatigue, and mobility issues associated with long-COVID.

The project was co-led by Dr. Bijan Najafi, research director of the Center for Advanced Surgical & Interventional Technology at UCLA Health and co-director of NSF IUCRC Center to Stream HealthCare in Place (C2SHIP), who said the device could have wider applications.

“While this study focused on managing pain and fatigue caused by long COVID, it may also have potential applications for addressing similar symptoms in individuals with other respiratory diseases, those who have experienced extended ICU stays and developed post-hospitalization weaknesses, and conditions involving chronic fatigue and pain, such as fibromyalgia or chemotherapy-related side effects,” Najafi said. “But further studies are needed to confirm these potential uses.”

In the study, 25 participants with chronic musculoskeletal pain, fatigue, and gait difficulties were assigned either a high-dose (active) TENS device or a low-dose (placebo) device. Both groups used the TENS device for three to five hours daily over a four-week period.

Researchers measured participants’ pain levels, fatigue, and walking performance before and after the therapy period. Findings indicated that the high-dose TENS group experienced notable improvements in pain relief (26.1% more relief compared to placebo) and walking ability (8% during fast walking), suggesting that wearable TENS therapy may help reduce long-COVID’s impact on daily life.

The high-dose TENS group also reported a slightly higher perceived benefit (71.2%) compared to the low-dose group (61.4%), underscoring the potential of wearable TENS technology to support long-COVID recovery.

One factor in the study’s success was likely the high rate of daily device usage, Najafi said. The wearable nature of the TENS device allowed participants to use it seamlessly throughout the day, without disrupting their routines.

“This wearable TENS system offered immediate, on-demand relief from pain and fatigue, making it easy to integrate into daily activities,” Najafi said.

He also cautioned that more research is needed. This study provides some hope for finding an effective, non-invasive solution for managing lingering COVID-19 symptoms that continue to affect millions,” he said. “But our sample size was limited, so further research is needed to confirm these findings.”

Study co-authors are Alejandro Zulbaran-Rojas, Rasha Bara, Myeounggon Lee, Miguel Bargas-Ochoa, Tina Phan, Manuel Pacheco, Areli Flores Camargo, Syed Murtaza Kazmi, Mohammad Dehghan Rouzi, Dipaben Modi, and Fidaa Shaib of Baylor College of Medicine.

This study was funded by the National Science Foundation’s Industry-University Cooperative Research Centers (IUCRC), specifically from the Center to Stream HealthCare in Place (C2SHIP), with award numbers NSF 2052514 and C2SHIP Y01-BCM-008. There was also in-kind support provided by Neurometrix Inc., which manufactured the Quell^® TENS device.