Professionals and amateurs wear football helmets to reduce chances of head injuries while playing American football games. A plastic helmet was introduced in 1940 by Riddell. In the same year, Riddell also developed a first chin strap to engage with a user's chin instead of the user's neck. In 1955, G. E. Morgan, a consultant to Riddell, and Paul Brown, the coach of the Cleveland Browns, invented the BT-5 face mask which is a single-bar design. In the late 1976, because of requirement for safety, four chin straps were required in college football games.
The football helmet of the present disclosure includes two shells (an rotatable outer shell engaging with an inner shell) and a bolt in a top crown area connecting the two shells. An advantage of the football helmet of the present disclosure is to significantly reduce impact forces at the rotatable outer shell being transferred to the inner shell.