Graphic footage from 2014 has emerged showing the moment an aspiring Olympic sprinter kicked a defenseless man tending to a stranger in the head - leaving him with brain damageMichael Kerry Norman Brusnahan, 23, will spend a minimum one year behind bars after being found guilty of assaulting two men in a drunken rage outside an Adelaide hotelBrusnahan faced up to 15 years in jail after he admitted to recklessly causing harm, but instead received a three and a half year sentence due to his age and 'rehabilitation prospects'