If you shuddered a little after watching Stevan Ridley take a brutal hit from Bernard Pollard and immediately lose consciousness on Sunday night, you probably weren’t alone. However, the realities of the injury are much more cringe-worthy than even the image of watching Ridley suddenly go limp.
According to Bleacher Report, Ridley immediately exhibited what is known as the “fencing response” after taking the hit. Upon hitting the ground, Ridley’s left arm went straight out and above him, while his right arm curled back into his chest. These actions were completely involuntary, but are common when sudden pressure is applied to the brain stem.
In short, when babies are born they eventually develop the ability to have certain reflexive muscle responses. One of these is the “Moro reflex,” which occurs when, for instance, a baby is put down or isn’t being held anymore. This response is believed to have evolved so that a baby can reach out for physical support, and the fencing response is said to be a reactivation of sorts of the Moro reflex.
In Ridley’s case, the hit from Pollard not only compressed his brain stem, but exhibited rotational forces since the hit wasn’t straight on. The brain stem is particularly sensitive to rotational force, and that is why Ridley lost consciousness so easily. The hit stunned the running back’s reticular activating system, which is located in the brain stem and is responsible for maintaining consciousness.
Of course, Ridley also sustained a concussion, as well. Now better understood, concussions are no longer believed to be “brain bruises” but are now known to occur when the brain moves inside the skull as little as seven millimeters.
One obvious sign of just how badly Ridley was doing was overlooked, as he bumped into the wall on his way to the locker room.