A player gets nailed. He lies on the field motionless for a few moments.

Undoubtedly a scary sight, but also the most common misconception about concussions: Severity, in fact, is not determined by a loss of consciousness, known as LOC.

Unless LOC is unusually long, lasting more than a minute, the effect isn’t what most people believe, according to Jaime Pardini, a neuropsychologist at the University of Pittsburgh Center for Sports Medicine’s Concussion Program.

In fact, LOC only occurs in about 10 percent of cases; it turns out that the biggest indicator of impairment is amnesia, which also turned out to be Arizona quarterback Willie Tuitama’s biggest symptom.

“”I don’t remember all that much against LSU,”” he said. “”I was just really out of it, just in a daze.””

Most of the misconception comes from common grading scales with which the public is familiar. Although these scales are good as a way of communicating how severe a concussion is, it’s no way to go about treating them, Pardini said.

These scales typically break concussions down into three grades, based on how long symptoms last and the absence or presence of LOC.

Put simply, a Grade 1 concussion involves symptoms that last less than 15 minutes, a Grade 2’s symptoms last more than 15 minutes and a Grade 3 involves any LOC.

The simplicity of the scales becomes a problem when considering how they are accompanied with broad-reaching, return-to-play guidelines.

These scales also recommend that athletes who suffer a Grade 1 concussion can return the same day, those with Grade 2s should return a full week after all their symptoms have resided and athletes sustaining Grade 3s should wait two weeks after symptoms resolve.

When also considering all the variables that come along with the human brain, medical centers such as UPMC’s Center for Sports Medicine – and Arizona – now treat cases on a more individual level.

And as such, new scientific and research-based guidelines emerged from two international conferences of professionals involved in the brain-function impairment field – from physicians and athletic trainers to neurologists and neuropsychologists.

Now, in order to be cleared according to the new standards, Pardini said, athletes must be “”symptom-free at rest, symptom-free with gradually increasing levels of exertion and then normal on cognitive testing.””

“”There are people who have those one- to two-second loss of consciousness who recover very quickly,”” Pardini said. “”Why would you sit them out a month if their symptoms are gone and they’re symptom-free at rest, symptom-free at exertion, normal at cognitive testing?

“”Why do we sit them out a month?””