Then, on occasion, there are two guys attempting to concuss one another.
From the ocregister.com
The incredible shrinking man Anthony Johnson and Dan Hardy were supposed to concuss each other with great relish for 15 minutes to the exclusion of jiu-jitsu and wrestling.
From the sportsillustrated.cnn.com
In an intermediate zone between solid and liquid, gas can make you laugh or lift you off the ground or concuss you or kill you, even though you can't see it.
From the guardian.co.uk
More examples
Shake violently
Injure the brain; sustain a concussion
(concussion) injury to the brain caused by a blow; usually resulting in loss of consciousness
(concussion) any violent blow
(Concussion (album)) Concussion is Matthew Ryan's third album. It was released in 2001 on WaxySilver.
To injure the brain, usually temporarily, by violent impact
(Concussion) Jarring injury of the brain resulting in dysfunction. It can be graded as mild, moderate or severe depending on loss of consciousness, amnesia and loss of equilibrium.
(Concussion) A mild injury to the brain. These injuries are often caused by a blow to the head or a sudden violent motion that causes the brain to bump up against the skull. Also called a traumatic brain injury or closed head injury.
(Concussion) A temporary loss of consciousness from traumatic brain injury.