Children 'at risk' from heading footballs, warns neuropathologist

Dr Ann McKee, a neuropathologist at Boston University, warns that children's brains can be damaged by heading footballs at an early age.

In the United States, a study of 24 American football players aged between 16 and 18 found abnormalities similar to the effects of mild traumatic brain injury after one season.

And McKee told BBC World Service there are dangers to the adolescent brain being exposed to these injuries.