Internationally-recognised independent testing
The testing for Halos® utilises the internationally-recognised and independent Virginia Tech STAR system testing methodology [3]. Additionally, we have completed head-to-ground testing that simulates an extreme impact scenario in which frictional contact forces are high and can initiate greater rotational acceleration, such as striking a tarmac or concrete floor [4].
Independent testing in the UK and US, together with CE conformity documentation in Europe, supports Rezon Halos® as protective headwear designed to reduce linear and rotational acceleration in concussive and sub-concussive head impacts [1, 2, 4, 5].
What is the Virginia Tech STAR system?
The Virginia Tech STAR system is a peer-reviewed methodology that allows a biomechanical evaluation of the relative performance of headgear in its ability to reduce the probability of concussion. In protective headgear testing, this is widely regarded as one of the most respected independent methodologies [3].
STAR stands for the Summation of Tests for the Analysis of Risk, and the STAR score is calculated based on a headgear’s performance in a series of impact tests.
STAR is based on two fundamental concepts:
The Virginia Tech STAR system uses a bivariate risk function developed from more than 2 million head impacts, supporting the finding that headgear which better reduces linear and rotational head kinematics can reduce concussion risk. A higher star rating indicates better performance within the Virginia Tech system, with 5 stars representing the highest available rating.
What rating did Rezon Halos® achieve?
Virginia Tech awarded Rezon Halos® a 5-star rating. Under the STAR methodology, Halos® achieved a score of 0.26, corresponding to a published 74% reduction in concussion risk for the impacts tested [5].
As with any laboratory testing methodology, there is a trade-off between repeatability and realism. However, Virginia Tech’s testing is globally recognised and is widely regarded as one of the most respected publicly available independent methodologies [3].
| Head impact area | Speed (m/s) |
Reduced peak linear acceleration achieved by Halos® | Reduced peak rotational acceleration achieved by Halos® |
|---|---|---|---|
| Back | 2 | 64% | 61% |
| Back | 3 | 50% | 49% |
| Back | 4 | 37% | 36% |
| Side | 2 | 60% | 61% |
| Side | 3 | 49% | 46% |
| Side | 4 | 35% | 40% |
Extreme Head-to-Ground Testing
Based on independent lab testing at the Centre of Excellence for Sports Engineering and Research in the UK, the Rezon Halos® product:
Greater acceleration is associated with greater force transmission during head impact. This means that impacts with higher acceleration can produce greater linear and rotational loading. Halos® reduces linear and rotational acceleration, and therefore reduces the transfer of energy to the brain following a head impact. Reducing rotational acceleration is particularly important because rotational forces are strongly associated with the brain deformation mechanisms involved in concussive and sub-concussive impacts.
| Peak linear acceleration (g) |
Peak rotational acceleration (rad/s2) |
Impact duration (Ms) |
||||
|---|---|---|---|---|---|---|
| Average | Standard Deviation | Average | Standard Deviation | Average | Standard Deviation | |
| Naked Head | 133.7 | 3.4 | 4,798.4 | 241.8 | 14.1 | 0.2 |
| Rezon Halos® | 79.3 | 3.5 | 3,510.2 | 128.8 | 17.4 | 0.2 |
Why does this testing matter?
Minimum certification and comparative performance testing answer different questions. Virginia Tech states that its ratings help identify which products best reduce concussion risk and that the ratings are independent of manufacturer influence. That gives families, clinicians and organisations a more useful performance signal than certification alone [3].