Collision and the effects of head injuries

The professionalisation of rugby union has seen significant advances in player size, strength and speed to maintain competitive advantages. Concussion is a traumatic brain injury induced by biomechanical forces resulting from head-to-head collision, contact between the head and limbs of two players, or contact between the head and the ground. Concussion induces diffuse axonal injury and is accompanied by a constellation of short-lived neurological sequelae, including headache, amnesia, blurred vision and difficulty concentrating. The professionalisation of rugby in 1995 and formation of the Rugby Injury Consensus Group in 2007 has ensured an improved means of injury reporting, while concussion awareness among players and coaches has improved, leading to a dramatic rise in reported injuries. Concussion is often associated with neurological disorders, including mild cognitive impairment, particularly in ageing athletes with a history of multiple concussions. There is a need for more research to elucidate the integrated molecular-haemodynamic-structural mechanisms and associated biomarkers underpinning neurodegeneration, to better inform clinical management of players.