The NFL\u2019s chief medical officer became the latest expert to downplay the notion that the rash of injuries suffered by the San Francisco 49ers over the past two seasons is due to the team\u2019s practice fields being close to an electrical substation.<\/p>\n
\u201cListen, I would say we look at injury causation across the board,\u201d Dr. Allen Sills said Friday during the league\u2019s health and safety call. \u201cWe consult with experts throughout sports medicine and other industries to try to understand and gain as comprehensive an understanding of injury causation as we can.\u201d<\/p>\n
He continued, \u201cI would tell you that I\u2019m not familiar with anything in the sports medicine literature that supports those associations, but I would also tell you that injury causation is really complex.\u201d<\/p>\n
The 49ers have been practicing at the same facility in Santa Clara, Calif., since 1988. It is next to Levi\u2019s Stadium and adjacent to the Silicon Valley Power Mission Substation. The team has struggled with injuries in recent seasons, with fantasy football website Rotowire ranking them fourth worst in the league in injuries in both 2024 and 2025, and a viral conspiracy theory posits the injuries could be linked to excessive exposure to electromotive force (EMF),\u00a0the invisible electricity from power lines and other electrical equipment.<\/p>\n
\u201cIf you think about biology and medicine, you don\u2019t have usually one single factor that drives biological systems. And so when we think about injury causation, whether it\u2019s lower extremity strains or ACL or concussion, you know, as we\u2019ve already talked about on this call today, it\u2019s equipment, it\u2019s training, it\u2019s prior injury history, it\u2019s exposure, it\u2019s play type. There\u2019s so many things that go into that. And so, I think it\u2019s very rare in a biological system that you\u2019ll see one factor that really drives an injury risk,\u201d Dr. Sills said.<\/p>\n
\u201cSo with that being said, we look at all factors. We look at it very comprehensively. I think it\u2019s also important \u2026 to say that we have seen significant erroneous conclusions drawn from people using publicly available data sources. And what I mean by that is there\u2019s research that often gets published where people take injury reports that are distributed media and use that to try to assess an injury burden. And those are almost universally wrong because they\u2019re just not complete, and they\u2019re not complete because they don\u2019t have all the data because not everything gets put into those disclosure systems.\u201d<\/p>\n