4 February 2014 Last updated at 13:11

Andy Hazell: Concussion issue in rugby is growing

Gloucester and former England flanker Andy Hazell tells BBC Points West that the number of concussions in rugby will only increase because of the size and speed of modern-day players.

The 35-year-old, who made 226 appearances over 17 seasons with Gloucester, has been forced to retire after failing to recover from a pre-season concussion injury.