"In all cases the rider was wearing some form
of body protector, yet 24 chest injuries were
recorded, one fatal. The protector is still in the
developmental phase and has been improved
every year. It is designed to reduce soft tissue
injury and possibly provide some protection to
the chest and spine from a fall or kick. It may
also reduce the severity of injury from a kick to
the upper abdomen. No rider who sustained a
chest or spinal injury was wearing a protector
that conformed to the BETA Class 3 or prEN
13158 standard. It is only when riders wear
such garments that an accurate evaluation will
be possible. Shoulder protectors have only
been recently introduced as part of the
standard. There have, however, been 20
witnessed falls where a shoulder injury was
expected and the rider was wearing a shoulder
protector. In all instances the rider was able to
continue the competition. None of the riders
who sustained a fracture to the shoulder girdle
was wearing any form of protection to that
area."
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1756171/pdf/v033p00212.pdf