By Christian Radnedge LONDON (Reuters) – Mouthguards are usually used as protective kits in sports such as rugby and boxing but in football a similar custom-made device is being used to collect data on the frequency and intensity of impacts a player receives to their head. English football expanded its study into the risks of heading the ball on Tuesday with the instrumented PROTECHT mouthguard, developed by Sports & Wellbeing Analytics (SWA), being worn by players in training until the end of the season. Twelve clubs across the Premier League, English Football League (EFL) and FA Women’s Supe…