Whatever the sport and level of play, impacts to the head from a ball, head, elbow, shoulder, knee and the ground all create rotational forces to the brain.
Rotational forces cause the brain to rotate inside the skull, brain cells to shear, tiny blood vessels in the brain to be torn and the protective ‘blood brain’ barrier to be disrupted. This results in an abnormal and harmful uncontrolled inflammation which damages the brain. Repeated inflammations increase the risk of longer-term neurodegenerative consequences, including the triggering of Chronic Traumatic Encephalopathy (CTE).
The brain is vulnerable to rotational forces from a single impact concussion and multiple sub-concussions received in sport. Sub-concussions are impacts that damage brain cell function, but do not produce evident signs or symptoms, so they go unnoticed by players and those around. The force to the brain to cause a concussion is 2-4 times greater than for a sub-concussion, but sub-concussions are over 500 times more frequent.
For children experiencing head impacts prior to age 12, they have been found to have demonstrated worse cognitive, executive and new learning ability as adults, compared to those who were at least 12 years old when they were first exposed to impacts.
For every sports person and especially youth players, it is rotational forces and sub-concussive impacts that present the greatest risk and damage to the brain.