I came across this study on Facebook and thought it was woryh a read for people in many arts. There is increasing awareness of the effects of repeated blows to the head over time, with much work being done on NFL players for example. Other sports, such as rugby, are radically changing the way they deal with players who suffer a concussion. As martial artists, those of us involved in sports where knockouts and head trauma are a possibility should keep ourselves up to date on these issues. http://www.medscape.com/viewarticle/883079?src=wnl_edit_tpal&uac=116586PG
More on the work being done on this in the NFL. Brain Trauma Discovered in 99% of Deceased NFL Players in Post-Mortem Study