The dangers of side impacts to the head such those from football headers or boxing hooks have been uncovered in a new Irish study.
The researchers found that impacts which cause a twisting motion can be just as dangerous as head-on impacts to the front of the head.
In the first study of its kind, the team from NUI Galway and UCD measured the effects of side impacts or rotational acceleration of the head on the brain.
The study called Mechanics of a Twisted Brain found pressure, stretching, shearing and twisting of the brain from side-on blows can impair neurons and lead to concussion, brain injury and even permanent damage.
The authors said this can have “grave implications for traumatic brain injury”.
Valentina Balbi led the study from NUI Galway, with co-authors Michel Destrade from NUIG and Aisling Ní Annaidh and Antonia Trotta from UCD. They measured the twisting properties of brain matter using advanced torsion techniques carried out on pig brains.
They then fed the data into computer simulations of a rotational acceleration of the head, typical of a punch.
While a lot of research has focused on frontal or head-on collisions such as car accidents or American football clashes, the Irish researchers found side blows or impact are just as likely to occur as frontal blows.
In a frontal collision car accident, the head rotates forward and backward in a whiplash motion, but in football headers or uppercuts in combat sports, the head rotates or tilts from one side to the other.
The study, which has just been published in the international scientific journal Soft Matter, said linear acceleration or frontal blows are expected to create large stresses and stretches in the direction of the impact.
However, the new research shows that rotational accelerations or side impacts create pressure and forces of the same magnitude in all directions, which could potentially lead to brain damage. They found stretches and stresses in the brain as high as those of head-on or frontal impacts such as whiplash.
They found large motions can occur in the brain when the human head is accelerated violently by an impact, be it accidental or even voluntary as in a football header.We found that large shear forces develop in the horizontal plane, as expected”, said Dr. Balbi, who is now a Lecturer of Industrial and Applied Mathematics at University of Limerick.
“But we also found that a high-pressure level and large vertical forces also develop in the brain, especially in the frontal cortex, as a result of the twisting motion.”
Mark Ganly, CEO of Contego Sports, a company that developed the N-Pro Rugby headguard, which is scientifically proven to provide impact protection, said they are keenly aware of the dangers of impacts in the game.He said:
This research confirms my intuition that it is crucial to protect rugby players from side impacts as well as from frontal impacts to the head.
“In my experience, they are just as likely to lead to concussion or mild traumatic brain injury.”