Why would somebody wear neck brace on a road bike? The answer is simple, to limit head movement in an accident, preventing hyperextension, lateral hyperflexion and hyperflexion of the neck.
There's a good reason why the neck brace's popularity is growing so quickly: it saves lives. Designed to prevent serious injuries, the Leatt STX Road brace helps to bring the head and helmet to a controlled stop during an accident. It locates around a rider's neck and uses four wings – two front, two rear – to locate on the user's chest and back. The thinking behind these carbon fiber extensions is to redirect and dissipate the pressure created in a crash, absorbed and collected by the unit's outer lip when the helmet makes contact.
Essentially, the wings work like collarbones and are designed to snap if overwhelming force is applied. The product is easily adjusted to offer a best fit and is supported by underarm straps.