June 2014 - Parks & Recreation - 76

Operations
Turf and Concussions:
Maintenance for Safety's Sake
By David Nardone

s we all know, concussions have become a major - if not THE major - issue in competitive contact sports, from the pros down to the
peewees. And concussions aren't limited to football, of course - just
about every contact sport is dealing with the increase, including other field
sports like rugby, lacrosse and soccer.
" Research using sensor devices has revealed that each year in the United
States, there are over 1.5 billion impacts to the heads of youth and high-school
football players, " says Chris Nowinski, founding executive director of the
Sports Legacy Institute (SLI), who launched the Hit Count initiative in 2012
with SLI medical director Dr. Robert Cantu.
While a number of factors come
into play when it comes to concussions, one that we have some control
over as field designers and owners is
the field surface itself. By properly
maintaining and monitoring a field's
turf, we can at least minimize any
concerns the playing surface could
pose for player safety.

Putting Turf to the Test
Turf safety is measured by what's
called a G-max test, which measures
the shock attenuation of a surface by
dropping the equipment's " missile "
onto the turf and measuring the resistance and absorption rate. The resulting G-max value represents the
ratio of deceleration upon impact to

Maintenance crews groom the infill at a stadium to ensure a safe playing field that helps
prevent concussions and other injuries.
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acceleration due to gravity. In other
words, it measures how well the turf
absorbs and slows the impact.
Right now, the American Society for
Testing and Materials (ATSM) recommends keeping the G-max level below
200, with a vote scheduled in May to
lower that standard to 165 - the maximum also recommended by the Synthetic Turf Council (STC). [Ed. Note:
Results of the vote had not been published
as of press time.] The NFL is requiring
teams to maintain their fields below
165 as well. These lower numbers stem
from growing research on concussions
showing that any safety enhancements
can help. So the lower the turf 's G-max
value, the greater safety buffer the surface can help provide.
Typical native topsoil and natural
grass turf systems, whether they're
USGA or ASTM sand, Kentucky
bluegrass or Bermuda grass, inherently have a lower G-max value - usually in the 80-110 range. As such, synthetic turf manufacturers are trying
to create turf systems that get closer
to those naturally lower levels, which
typically involves designing a field
with a padded turf system.
Historically, however, natural grass
fields have not been tested. While,
again, their numbers will be lower by
nature, the variety of soil profiles in a
field area, particularly in a city, make
the safety level of natural grass fields
harder to predict. While the NFL
now tests its fields before every game
- synthetic or natural - lower levels

June 2014 - Parks & Recreation

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