A case series of YouTube sporting injuries has identified what could be a useful clinical sign for sports coaches. The ‘fencing response’ (tonic posturing) is an immediate sign and is associated with moderate head injury. It seems to be a separate entity from convulsions, which may also occur, and since it is a clinical sign that is quite easily recognised, it can help direct care after the injury.

Hosseini, AH. Lifshitz, J. Brain Injury Forces of Moderate Magnitude Elicit the Fencing Response. Medicine & Science in Sports & Exercise: September 2009 - Volume 41 - Issue 9 - pp 1687-1697