Webbe, who has studied the effects of heading since the early 1990s, recently published two studies with different collaborators. Both studies researched the effects of frequent headings over time, while one focused further on the short-term effects of recent soccer heading. In the research, brain function among soccer players who had played for varying number of years was compared with the brain function of subjects who had never played. In his study with Shelly Ochs, Webbe also compared the functionality of players who had recently played soccer with those who had not.
The results of both studies should further fuel the debate on the safety of this common soccer practice. The results of his recency study were the most clearly defined.
Webbe found that recent heading by players who headed with "moderate-to-high frequency" led in some cases to weaker neurocognitive performance. This lessened performance includes a decline in cognitive function, difficulty in verbal learning, in planning and maintaining attention and a reduced information processing speed.
"What we found is that if Bill plays soccer on a Thursday night, and is a frequent header, he's more likely to score lower on a neurocognitive test Friday morning than a similar player who heads the ball only occasionally," said Webbe.
While recent heading is not guaranteed to decrease functionality, Webbe said it presents a strong enough risk factor to warrant further study.
The two studies seem to contradict each other on the long-term effects of soccer heading. Webbe's work with Ochs reports that, "no significant or strong effect was found for lifetime heading on neuropsychological performance." But, his study with Adrienne D. Witol reached an opposite conclusion, noting "players with the highest lifetime estimates of heading had poorer scores on scales measuring attention, concentration, cognitive flexibility and general intellectual functioning."
Webbe acknowledged the apparent contradiction, but said that the research with Ochs does support the concept of long-term harm.
"Inside the groups of testers, we found that more individuals were likely to be impaired in the frequent heading groups than in the less frequent heading and control groups," he said. "The difference was three or five out of 20 impaired among the lifelong frequent headers as opposed to one or zero out of 20 in the control groups."
After these studies, Webbe is more convinced than ever that soccer heading affects brain function. He has an idea of why this activity can be so damaging.
"Generally, we accept the premise that if you head the ball with proper technique, then your risk for brain injury is lower. However, we have to acknowledge that during a game things happen to make the heading situation less than ideal," said Webbe. "If you leave your feet, or are challenged by an opponent, you may not be able to head the ball correctly. As a result, when you head the ball you are putting yourself in a position to sustain an insult to the brain."