Much of the research into traumatic brain injury, or TBI, in recent years has focused on concussions, as readers in Los Angeles who have been following the issue know. But some studies have suggested that sub-concussion blows can have a cumulative effect similar to brain injuries caused by concussion. A new study adds ammunition to that contention by focusing on a seemingly innocuous soccer move.

Even the most casual soccer fans know that players may use their heads as well as their legs to advance the ball. For example “headers” are often used as shot attempts near the goal. Leaving aside the professionals, a recreational soccer player may head the ball hundreds of times per year.

One researcher, a former soccer player himself, saw an opportunity to study a common type of sub-concussion blow to the head for possible effects on the brain. He interviewed 37 rec league soccer players, asking them about how often they played and how many times they headed the ball. Then he tested the volunteers memory, focus, vision and cognition.

While there were no significant differences among the volunteers on the latter three brain functions, it appears that there is a tipping point at which heading a soccer ball begins to affect memory. Those who headed the ball most often out of the group — more than 1,800 times per year — did worse on memory tests than the rest. They also tended to have the lowest fractional anistropy scores, a test which measures the health of the white matter that connects different parts of the brain together.

The researcher concluded that keeping a player’s number of headers below a certain threshold may minimize his risk of developing memory problems. He said it would be similar to the pitch count used in baseball to keep pitchers from injuring themselves from overuse.

Source: Los Angeles Times, “To prevent brain damage, soccer players should keep ‘heat counts’,” Brad Balukjian, June 11, 2013