Mountain bike helmets are focussed on how to reduce a compressional impact. They work by increasing the time it takes for your head to stop moving in a crash and therefore lessening the linear force on it. However, research has suggested that your head can take just as much damage from rotational forces as well. That’s where Brain Shield comes in

For a few years now Bell helmets have used MIPS (Multi-Directional Impact Protection System) technology that allows the inside of the helmet to move separately from the outside. Brain Shield is a sticker that performs a similar function but on the outside of the helmet – making it compatible with any helmet brand.

The Brain Shield is made up of four layers that slide over each other and is claimed to reduce the gripping friction that can twist your head in an impact.

On the right you can see the helmet slides off the angled surface, leading to less rotational force

The application process looks really easy and you needn’t worry about it ruining your style as you can choose a number of custom designs.The are protoype, bike-specific Brain Shields in the making but until then it looks like it will cover up vents in your helmet though so be prepared for a sweaty head.

At the moment a pair of Brain Shield stickers (one for each side of the helmet) will cost $23.99 (roughly £16) with unlimited replacement for a further $11.99 (£8).