The 49ers will take the field Saturday night against the Seahawks without star tight end George Kittle, who went down with an Achilles tear in the second quarter of the team’s playoff win over the Eagles on Sunday.

In the aftermath of his injury, a dizzying theory caught fire on social media.

A user named Peter Cowan, who identifies as “board-certified,” had posted on X/Twitter earlier in the week a map of the Niners’ stadium and practice facility located next to an electrical substation. “Low-frequency electromagnetic fields can degrade collagen, weaken tendons, and cause soft-tissue damage at levels regulators call ‘safe,’” Cowan wrote.

Cowan, who is not a doctor, went on in a series of posts and Substack articles to link the 49ers’ injuries in the past decade to the proximity of the substation. Star players including Brock Purdy, Christian McCaffrey, Nick Bosa, Brandon Aiyuk, and Fred Warner have all struggled with injuries, many of them major tendon and ligament tears.

The post picked up traction in the days before the game, but Kittle’s injury was gasoline on the fire. Niners wide receiver Kendrick Bourne joked “that power plant” is the source of the team’s injuries. Former NFL players promoted the theory on the Bussin’ With The Boys podcast. “We don’t know enough about it, but we know it’s 100% fact,” said cohost Will Compton. Other former NFLers like Taybor Pepper and Kurt Benkert also posted about the theory online. (Pepper was the 49ers’ long snapper from 2020 to 2024, and Benkert was briefly on the practice squad in 2022.) Cowan’s original post has around 22 million views on X.

Where It Breaks Down

Though the Kyle Shanahan–era 49ers have consistently been among the most injured teams in the NFL, there are two major problems with the substation theory. 

First, 49ers players have been exposed to the substation for far longer than the decade since the team moved to Levi’s Stadium. The plant has been operating since 1986. The 49ers opened a new practice facility next door in 1988, and they won three Super Bowls in the next seven years. The team moved into Levi’s Stadium in 2014, something Cowan presents as an important development when in fact the team had been practicing near the plant for nearly 40 years.

Second, according to a bevy of medical experts, the research doesn’t back it up.

Cowan’s theory targets extremely low-frequency radiation, or ELF, the kind produced by power lines and electrical equipment operating at frequencies around 60 hertz. He also suggests the guidelines for acceptable exposure are outdated.

Jerrold Bushberg, a radiology professor at UC Davis who chairs the board of directors for the National Council on Radiation Protection and Measurements, tells Front Office Sports that “there is no firmly established evidence” that these types of low-level exposures have any biological impacts on humans.

“These so-called ‘mechanisms’ have not been established, and many of the experiments are contradictory, and many of the experiments have exposures that either don’t relate specifically to 50-, 60-hertz magnetic fields, or are at much, much higher levels than what would be experienced at a practice level,” Bushberg, a 49ers fan himself, says of the science behind the injury theory.

The NFL is declining to comment on the matter. A spokesperson for the 49ers did not respond to multiple requests for comment.

The electrical substation is operated by Silicon Valley Power, the city of Santa Clara’s municipal electric utility. The city did not respond to requests for comment.

When thinking about players’ long-term exposure, Bushberg uses light as an analogy. Light is also a type of non-ionizing (lower-energy) electromagnetic radiation, and while it can be harmful when it’s very bright, a person can be exposed to normal levels of light for their whole life and never have a problem. “There’s no accumulation of damage that occurs over time like would be the case with potential for higher levels of ionizing radiation,” he says.

Stanford medical professor and ABC7 contributor Alok Patel told the local Bay Area station it’s a “massive leap” to take lab data about high levels of exposure being harmful and apply that to the 49ers situation. Gayle Woloschak, a Northwestern radiology oncology professor, told SF Gate: “In the huge number of studies that have tried to look at the effects of non-ionizing radiation on cells, there’s been no reported damage to DNA, proteins or other molecules that’s been identified.”

Additionally, multiple studies are looking into whether EMF exposure can actually help body parts like quadriceps and rotator cuffs heal after injury or surgery, and another has seen positive results with wound repair.

Cowan’s website and social media profiles show he is a former software developer who now runs a wellness center in Portland that offers services like cold plunge and red light therapy, and “harmonizing your electromagnetic environment.”

Cowan cited a post from this fall that also went viral, picking up 4 million views on X. A creator named Chase Senior cited former 49ers player Jon Feliciano saying players have joked about the substation causing injuries in the past. Last week, Feliciano shared Cowan’s post and a more recent one from Senior about the substation on his X page.

In an interview with FOS on Friday, Cowan said he wants to continue digging and writing about the theory, and is particularly curious about whether operations have changed or increased at the substation over the years. “This has kind of taken over my life and I’m running with it,” he said.

Nicholas Strasser, an orthopedic surgery professor at Vanderbilt, tells FOS that research is “just starting to scratch the surface” of factors that can impact common tendon injuries like Achilles ruptures, such as hydration and hormones. But, he says correlation doesn’t equal causation, and he hasn’t seen anything scientifically to back up the substation injury theory.

“I think you’re starting to see people question [tendon injuries] and look into that, which I think is good,” Strasser says, but “it’s hard to know if what you’re seeing here is, actually there is some causation from it, or if it’s a conspiracy theory.”