Acute presentation of vomiting after an injury should raise suspicion for concussion.
For additional information on concussion, see the Canadian Paediatric Society Position Statement on Sport-related concussion (2014).
http://www.cps.ca/documents/position/sport-related-concussion-evaluation-management
http://www.cps.ca/fr/documents/position/commotion-cerebrales-liees-au-sport
See also the Canadian Paediatric Society Position Statement on Management of the paediatric patient with acute head trauma (2013)
http://www.cps.ca/documents/position/paediatric-patient-with-acute-head-trauma
http://www.cps.ca/fr/documents/position/patient-age-pediatrique-victime-traumatisme-cranien-aigu