3 “if in doubt, sit them out” Recognising concussion is critical to correct management and prevention of further injury. The Concussion Recognition Tool (CRT5), developed by the Concussion in Sport Group to help those without medical training detect concussion, includes a list of these symptoms11,12 . When an athlete is suspected of having a concussion, first aid principles still apply, and a systematic approach to assessment of airway, breathing, circulation, disability and exposure applies in all situations. Cervical spine injuries should be suspected if there is any loss of consciousness, neck pain or a mechanism that could lead to spinal injury. Manual in-line stabilisation should be undertaken and a hard collar applied until a cervical spine injury is ruled out. A medical practitioner should review any athlete with suspected concussion. In a situation where there is no access to a medical practitioner, the athlete must not return to sport on the same day. If there is any doubt about whether an athlete is concussed that athlete should not be allowed to return to sport that day. An athlete with suspected concussion should be reassessed to look for developing symptoms and cleared by a medical practitioner before returning to sport12 . Due to the evolving nature of concussion, delayed symptom onset is not unusual3 . Therefore, any athlete cleared to return to sport after medical assessment for suspected concussion should be monitored closely during the game/competition for developing symptoms or signs. If symptoms develop, the athlete should be removed from sport. Sometimes there will be clear signs that an athlete has sustained a concussion. Medical practitioners covering sporting events should immediately remove from sport an athlete with any of the following clinical features: > > loss of consciousness > > no protective action taken by the athlete in a fall to ground, directly observed or on video > > impact seizure or tonic posturing > > confusion, disorientation > > memory impairment > > balance disturbance or motor incoordination (e.g. ataxia) > > athlete reports significant, new or progressive concussion symptoms > > dazed, blank/vacant stare or not their normal selves > > behaviour change atypical of the athlete. Athletes displaying any of these signs should be treated as concussed and not be returned to sport. Some features suggest more serious injury and athletes displaying any of these signs should be immediately referred to the nearest emergency department: > > neck pain > > increasing confusion, agitation or irritability > > repeated vomiting > > seizure or convulsion > > weakness or tingling/burning in the arms or legs > > deteriorating conscious state > > severe or increasing headache > > unusual behavioural change > > double vision.