The Wall Street Journal published a story in November 2009 questioning the potential increased risk of head injury stemming from grid-iron helmet use in the NFL.
American Heritage invention and technology magazine provides a detailed history of all types of helmets.
On football helmets introduced in the 1950s, the magazine notes: "However, it had a paradoxically catastrophic effect on injuries. It reduced some head damage but was held responsible for a tripling of neck injuries and a doubling of deaths from cervical spine injuries."
On bicycle helmets which began to enter the market from the 1970s, the magazine notes: "By 2001, the CPSC reported, 69 percent of child cyclists and 43 percent of adults in the United States wore helmets. Yet this apparent success has turned up a paradox. In the decade from 1991 to 2001 the surge in helmets was accompanied by a decline in ridership and an increase in cyclist accidents, resulting in 51 percent more head injuries per bicyclist."
In a February 2009 study titled Does Padded Headgear Prevent Head Injury in Rugby Union Football? published by Medicine and Science in Sports and Exercise, authors from various Australian and New Zealand universities conclude: Padded headgear does not reduce the rate of head injury or concussion. The low compliance rates are a limitation. Although individuals may choose to wear padded headgear, the routine or mandatory use of protective headgear cannot be recommended.
Below is a media release issued on March 8 2000 in which internationally recognised neurologist Dr Paul McCrory warns that football helmets are not only useless, but might actually lead to more severe injury.
His findings concerning increased risk compensation from football helmets leading to worse injury are in line with studies suggesting the same result for mandatory bicycle helmets.