This photograph is often shared with a caption “Testing football helmets in 1912”

This photo has nothing to do with football. The picture is from 1912 and it shows a British inventor W.T. Warren demonstrating a protective flight helmet.

The picture was published in an aviation magazine called the Flight. Screenshot of the article is below:

Warren safety helmet was actually used by the pilots. Here is an advertisement from 1912. You can also see the helmet in the Imperial War Museum.

Spiegel Online debunked the football helmet story in 2016 (in German).