Soccer Headgear Fails Impact Tests
ARLINGTON, Va., Jan. 10, 2003 – Foam helmets and padded
headbands do little to soften the impact of heading a soccer ball,
according to a new study.
Heading has recently been associated with diminished mental capacity
among professional soccer players and has spawned a new market for
manufacturers of athletic equipment.
The leading brands of headgear may reduce injury from collision
with a goal post or other hard object, but they fail to dampen the
impact of heading a soccer ball, according to Whitaker investigator
Phil Bayly, Ph.D., of Washington University in St. Louis.
Bayly and his colleagues tested four brands of headgear—
Soccer Docs, Kangaroo, Head Blast and Head'r—and reported
their results in the current issue of Academic Emergency Medicine.
Each head protector was placed on a metal mannequin head outfitted
with pressure sensors and attached to a flexible neck. A soccer
ball was propelled toward the metal forehead at 20 and 26 miles
per hour to simulate heading and at 34 miles per hour to mimic a
stronger collision, such as the impact from a blocked downfield
kick. The researchers measured peak acceleration, which is common
in impact studies, especially in auto crash testing. Only at the
fastest speed did the headgear ease the impact.
The problem is that both the soccer ball and the headgear are relatively
soft, so when they collide there is little change in force and acceleration.
A football helmet protects against hard objects, like the ground
or another helmet, because it dissipates energy, its size reduces
the velocity to the head, and its padding increases the time of
impact, softening the blow.
"This decreases the stress experienced by the brain,"
said Bayly, who played high school soccer and coaches his 6- and
9-year-old kids.
"In my opinion, if heading is shown to be a problem, the changes
should be made to the ball," Bayly said. "Lighter and
softer balls will unquestionably reduce accelerations. In youth
soccer, I think it's wise to avoid unnecessary heading—no
need for drills in practice—but this is opinion at this point."
The American Academy of Pediatrics has recommended against intentional
heading of the ball in youth soccer until more is known about the
associated risks.
This area of research bears on a potentially significant health
issue, since about 200 million people play soccer worldwide. Headgear
has not yet become popular in the United States, but there is some
concern that the growing market for this equipment may be based
on a false sense of security.
These cautionary notes come in the wake of European studies linking
soccer players with mental deficiencies similar to those afflicting
retired boxers.
A recent report in the Journal of Clinical and Experimental
Neuropsychology concluded that both heading the ball and soccer-related
concussions contribute to mental impairment.
The study conducted in the Netherlands examined 84 active professional
soccer players from top clubs. The researchers looked at the relationship
between the number of headers and the number of concussions and
mental performance.
The number of single-season headers was linked to diminished attention
and visual and verbal memory. Soccer-related concussions were associated
with inability to focus attention and impaired visual and perceptual
processing.
Bayly, Rosanne Naunheim, M.D., and a team of physicians and bioengineers
conducted their study as part of a larger project to evaluate the
risk of brain damage from repetitive blows to the head. The goal
is to determine what levels of mild impact have adverse effects
on the brain. The research includes studies of deformation of brain
matter and neurons and the effect of these deformations on brain
cells.
The current research did not examine how headbands and soft helmets
affect neck rotation caused by glancing blows and other such impacts.
Some aspects of headband design have been implicated in laboratory
studies of neck injuries.
Contact:
Phil Bayly, Washington University
Frank Blanchard, The Whitaker
Foundation
Photo: Bob Boston, Washington University, St. Louis
Caption: Phil Bayly heads a soccer ball.
|