CHAPEL HILL --Football players and other athletes who suffer mild head injuries should wait at least three days after symptoms disappear before playing again, according to a new University of North Carolina at Chapel Hill study.
The study, published as a special supplement to the current issue of Medicine and Science in Sports and Exercise, shows it takes a minimum of three days, on average, for athletes' balance to recover enough from concussions and other head trauma to avoid further injury. Healing continues for more than a week following minor blows to the head, researchers say, but the first few days can be critical. The publication is the journal of the American College of Sports Medicine.
"There appears to be sensory interaction problems during the first few days following a concussion and athletes who start back earlier may still have balance deficits which could predispose them to further injury," said Dr. Kevin M. Guskiewicz, assistant professor of physical education, exercise and sport science at UNC-CH and study leader. "Records exist of young people dying from a second injury within a week or so of a head injury not thought to be serious at the time.
"We believe our study is important because it is the first to look at balance in athletes with acute mild head injuries and the first to show that balance can be impaired even when tests of cognition, or thinking, appear normal."
Using a $70,000 device known as the NeuroCom Smart Balance System, researchers could tell if and how long head injuries affected athletes' balance, impairment of which is a sign of lingering neurological effects. Athletes whose more severe injuries could be detected by X-rays or MRI scans, or who were hospitalized more than 48 hours, were excluded from the project.
Twenty-two subjects, half of whom had suffered blows to their head and half of whom had not, stood on a computer-linked force plate connected to the device, which resembles a large telephone booth. The machine recorded how well or poorly they balanced with their eyes open and closed, with changing and sometimes confusing visual cues and when the plate tilted beneath them.
Besides football players, athletes tested on the first, third, fifth and 10th days after their accidents included wrestlers, lacrosse players and soccer players. Researchers also evaluated their ability to think, concentrate and remember using various written and visual tests.
"To our surprise, we found little difference between our mildly injured athletes and the uninjured volunteers who served as controls in how well they could think," Guskiewicz said. "At the same time, the healthy volunteers were significantly more stable through day three, and differences didn't disappear entirely for more than a week."
Usually, the biggest problem with head injuries is that team physicians and athletic trainers must decide when athletes can safely return to competition based on subjective information, said Guskiewicz, also an athletic trainer with the UNC-CH women's lacrosse team. Athletes sustaining head injuries should never be permitted to play until all symptoms have disappeared.
"That's often very difficult because athletes, especially young ones, sometimes deny they have headaches and blurred vision or feel dizzy just to get back in the game," he said. "Now we have a way of obtaining sound objective information rather than relying on gut feeling. We can say, even in the absence of this sophisticated equipment, that they should be kept out of competition for at least three days regardless of what they tell the physician or athletic trainer."
A head injury is considered mild if the patient is not unconscious longer than 20 minutes, no damage shows up through X-rays or other imaging and amnesia does not exceed 24 hours.
Grants from the National Operating Committee on Standards for Athletic Equipment and the National Athletic Trainers' Association Research and Education Foundation paid for part of the research. The former, known informally as "NOCSAE," standardizes football and other athletic gear, such as helmets and shoulder pads, through testing to ensure that the equipment is as safe as possible. NASA supported Dr. Lewis M. Nashner's early development of the NeuroCom Smart Balance System as a way to study how astronauts adapted to weightlessness.
Report authors also include Dr. David H. Perrin, director of sports medicine research at the University of Virginia; Nashner, a University of Oregon faculty member; and Bryan L. Riemann, a doctoral student at the University of Pittsburgh.
Guskiewicz directs the Sports Medicine Research Laboratory and the Undergraduate Athletic Training Education Program, both at UNC-CH.
Note: Guskiewicz can be reached at (919) 962-7187 or 962-5175 (w) or (919) 403-1321 (h). Contact: David Williamson
Journal
Medicine & Science in Sports & Exercise