Problem is not “just” the concussion

Frequent head impacts occur in multiple sports. These impacts may cause:

1. Traumatic Brain Injury (TBI), or contribute to brain diseases. Traumatic Brain Injuries range from mild concussions to severe permanent brain damage, and can result in physical, cognitive, social, emotional, and behavioral symptoms, and outcome can range from complete recovery to permanent disability or death. Childhood Traumatic Brain Injuries indirectly affect on psycho-social development dysfunctionalities, learning difficulties, late-onset epilepsy, ADHD, asocial behavior, substance abuse, and mental disorders.

2. Head impacts may also contribute to the development of brain diseases, such as dementia, Alzheimer’s disease and Parkinson’s disease.

3. Performance aspect is more rarely being discussed (rightly so), but clearly there are multiple critical elements to the performance, which may be severely compromised due to head impacts and concussion, such as alertness, memory, focus, fast thinking, ability to solve problems, balance and coordination.

There is very little the modern medicine can do to brain injuries, or brain diseases they may contribute to.

Prevention is the key.

And it all starts with data.

That’s why we created ACT Head Impact Tracker.

The more violent the forces, the bigger the chance that damage occurs

ACT Head Impact Tracker measures head impacts by maximum linear acceleration (g-force) in all sensor versions and types, and by rotational movement (maximum angular speed, rad/s) in head sensor version 2.0 and PRO helmet sensor (introduced in the 2nd half of 2023). New measurement Impact g-load will also be introduced in 2023. Typically head injury results from the combination of angular and linear forces. There is no clear consensus of a clear-cut danger limit as expressed in linear acceleration (g-force), or that of angular speed (rad/s) nor Impact g-load. However, in many studies acceleration/deceleration under 40g have been considered likely not to cause permanent damage, but it can be extrapolated that the probability of permanent damage starts to increase in impacts within the range of 40-60g and higher. This when considering individual and infrequent impacts.

We believe that today there is not sufficient medical research to reliably, simply and safely classify the individual impacts to “small-medium-hard” or “green-yellow-red” on the basis of g-force, angular speed (rad/s) or Impact g-load. In the absence of proven, reliable, scientific results ACT Head Impact Tracker is not telling you “when the impact is too hard, or when it is not”, nor will it tell you “when you have to seek medical help, or when not”. There simply is no safe way for a head impact measuring device way to do so. Not yet. That’s why more data and research is needed.

One rule of thumb applies tho: the more violent the forces acting on a head, the bigger the chance damage may occur.


ACT Head Impact Tracker is not a medical device and it is not intended for diagnosis or treatment evaluation of traumatic brain injury. ACT Head Impact Tracker is not a protective device, it does not prevent incidents from happening and it does not protect against injuries or any kind. In case of a head impact, or when suspecting one or a concussion, immediately and safely leave the activity and seek help from licensed medical professional. It is advisable to have an accompanying person if concussion is possible.