17
had diagnosed concussions but 17 others showed changes in the brain even though they never had a concussion. The researchers also determined that concussions "are likely caused by many hits over time and not from a single blow to the head, as commonly believed."
What these two studies have indicated is that the accumulation of smaller hits can be just as damaging as one “Big Hit”. They can also make a player more susceptible to a concussion from a hit that doesn't have extreme force. This throws concern to younger athletes too because their brains are still developing.
What Does It Matter (White Matter That Is)
The human brain consists of gray matter and
white matter. Grey matter is on top and
white matter is underneath. The importance
of white matter is that it connects different
regions of grey matter in the cerebrum to
one another. The white matter of the brain
is composed of nerve fibers and myelin. The
nerve fibers form the connections between
the nerve cells. Myelin is a fatty sheath
wrapped around nerve fibers. Myelin has
two functions: insulation (to prevent short-
circuits) and acceleration (accelerates the
proliferation of impulses along nerve fibers).
Myelin is an essential part of the white
matter. When the myelin sheath is damaged
or gets destroyed, the conduction of impulses
along nerve fibers slows down or fails completely. Consequently, brain functions become impaired or lost. It is theorized that when there is trauma to the brain – even non-concussion producing trauma, that it damages the myelin. Repeted damage to the myelin (even the "small hits") eventually deteriorates its integrity
or destroys it.
Summary
The research on the effects of "little hits" on the brain is still being studied but the initial data collected indicates that multiple non-concussion causing "small hits" over time can be problematic for athletes. There is no "magic" number of how many little hits will cause problems. The main thing to remember is to take every hit to the head serious – no matter how insignificant it seems to be.