Why does rotational force matter?
Head impacts create both linear and rotational forces. Rotational forces are strongly associated with brain deformation mechanisms such as shear strain, which is why rotational head kinematics are considered a primary biomechanical driver of brain injury in modern traumatic brain injury research and helmet-rating methods [2, 3, 4].
What is Rotection® technology?
Rotection® technology within Rezon Halos® is made up of nine independent protective layers that reduce the transmission of rotational forces during head impacts.
When the layers move over each other, they are designed to reduce the transmission of rotational forces during impact. Rotational forces can deform brain tissue and are associated with injury mechanisms such as shear strain, vascular stress, blood-brain barrier disruption and neuroinflammatory responses. Linear forces are also reduced.
A rotational head impact can place stress on the brain at multiple stages of the impact event:
- the point of impact;
- the opposite side of the brain; and
- when the brain comes to a final stop and rotates.
The result is a system designed to reduce rotational and linear forces rather than simply add padding alone [5].
What has testing shown?
Our published Virginia Tech testing summary shows reductions in both peak linear acceleration and peak rotational acceleration across side and back impacts at 2 m/s, 3 m/s and 4 m/s. In the published results, the largest listed reduction in peak rotational acceleration is 61%, and the largest listed reduction in peak linear acceleration is 64% [6].
Virginia Tech’s Helmet Lab awarded Rezon Halos® a 5-star rating with a STAR methodology value of 0.26 [1, 3]. Virginia Tech explains that its ratings are an independent and objective assessment of helmet performance, that lower STAR scores indicate better performance, and that a STAR value of 0.5 represents a 50% reduction in concussion incidence for the impacts tested. Rezon Halos® STAR score represents a 74% reduction in concussion risk [1].
Our published extreme head-to-ground testing summary also reports an average 41% reduction in peak linear acceleration and an average 27% reduction in peak rotational acceleration in independent testing conducted at Sheffield Hallam University’s Centre of Excellence for Sports Engineering Research [6].
Why is this relevant for everyday and medical use?
Falls, seizures, involuntary movements and repetitive self-injurious behaviour can all involve head impacts where rotational forces are transmitted to the brain. Reducing the transmission of rotational forces is an important part of reducing head-impact severity in everyday situations where head impacts may occur [7, 8].
Conditions including epilepsy and autism can increase the risk of head impacts in everyday life. Increased fall risk and higher exposure to head impacts are also common concerns in some older adults and elderly care settings.
