Source: BBC News
Concussion is a common brain injury. Sports stars suffer from this condition on a weekly basis. But what actually happens to the brain when we are concussed?
Concussions happen often, especially in contact sports such as rugby and American football.
Our video explores what happens in the brain after a bang on the head.
Body of Evidence is a video series from BBC Future unravelling medical myths and curious health conditions.
Video script: Ed Barrett, from the Department of Science and Technology Studies, University College London