Concussions and sub-concussive events are caused by rapid head movements, acceleration and deacceleration. These invisible injuring forces must be made visible, objectively measured, tracked, and actionable.
ACT Head Impact Tracker.
Because you should know. Protect your assets.
#youshouldbeACTingonit
Pathophysiology of Rapid Head Movements and Brain Injury
Rapid head movements—particularly those involving abrupt acceleration or deceleration—expose the brain to inertial forces capable of disrupting normal neurophysiological function. Because the brain is suspended in cerebrospinal fluid and not rigidly fixed within the skull, sudden rotational or linear motion causes differential movement between brain tissues of varying densities. This mechanical shear strain is the primary driver of both concussive and sub-concussive injury.
During rapid rotational acceleration, axons experience stretching and deformation that can transiently impair axonal transport and depolarization. When these forces exceed the tissue’s tolerance, diffuse axonal injury (DAI) can occur, characterized by microstructural axonal disruption, ionic imbalance, glutamatergic excitotoxicity, and metabolic dysfunction. Even in the absence of overt symptoms, repetitive low-magnitude shear forces can produce cumulative microtrauma, neuroinflammation, and alterations in white-matter integrity detectable through advanced neuroimaging.
These biomechanical and cellular cascades contribute to the acute clinical manifestations of concussion and may play a role in the long-term neurodegenerative consequences associated with repeated events. Understanding these mechanisms is essential for accurate risk assessment, early detection, and mitigation of brain injury in high-exposure populations.
Frequent impacts, bumps, knocks and jolts on a head or on a torso occur in multiple sports, across all levels, genders and age groups
Impacts and forces acting on a head or a torso may make head rapidly move, accelerate and deaccelerate. This makes brain inside the skull to move as well, and potentially causing damage to it, which might cause and contributing to:
1. Traumatic Brain Injury (TBI)
TBIs 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. Degenerative brain diseases
(CTE, early onset dementia, Alzheimer’s and Parkinson’s diseases), and neurodegenerative disorders (such as MS and ALS) The connection of these diseases and disorders to cumulative effect of Traumatic Brain Injuries and so-called sub-concussive events has been established in multiple researches.
3. Second Impact Syndrome (SIS)
Second impact syndrome is a condition in which an individual experiences a second brain injury before completely recovering from a previous one. Athletes who sustain a concussion and return to sport early are considered being at exceptionally high risk. The second event does not have to be high in magnitude, a small skale blow to the head, chest or back might be enough to cause the brain to move inside the skull and trigger the SIS, and lead to death or being severely disabled for life.
4. Impaired Performance is more rarely being discussed (rightly so), but clearly there are multiple critical elements to the performance, which may be severely compromised due to sub-concussive events or concussions, such as alertness, memory, focus, fast thinking, ability to solve problems, balance and coordination. Tere is very little the modern medicine can do to brain injuries, brain diseases and disorders they may contribute to.
Prevention is the key.
And it all starts with data.
That’s why we created ACT Head Impact Tracker.
Addressing the issue has been slow probably due to the difficulties in understanding the injury mechanism, leading to poor recognition of the hazarduous events, and not understanding the scope of the events
1. Injury mechanism is rapid movement of a head.
2. Impact is not needed. A blow or a jolt on a torso making head rapidly move can be just as devastating.
Wearing helmets and mouthguards are not preventing concussions, nor sub-concussive events, nor physical brain load (cumulative effect).
3. Concussion symptoms may take up to 2 days to manifest.
The bigger the forces in head movement, the more violent the event, and higher the risk of damage.
4. There are no pain receptors in brain tissue.
Athletes do not know when something is wrong.
5. Susceptibility to injury varies.
Gender, age and concussion history are some of the variables in the equation.
6. Cumulative effect usually become visible only later in career, or life.
The events occur,and the damage is done out there, today. But in the absence of acute injury, sub-concussive events and cumulative effect are not intervened, and the preventive action which should be taken today, is not.
ACT Head Impact Tracker is making these damaging forces acting on a head visible, objectively measured and actionable
1. Initial and maximum linear acceleration/deceleration (g-force) in all sensor types
2. Impact g-load in all sensor types
3. Initial and maximum angular velocity (rad/s) in ACT Head Impact Tracker head sensor Pro
4. Initial and maximum angular acceleration (rad/s2) in ACT Head Impact Tracker head sensor Pro
5. Accumulation of angular velocity in ACT Head Impact Tracker head sensor Pro
6. Accumulation of angular acceleration in ACT Head Impact Tracker head sensor Pro
Typically brain 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 velocity (rad/s). 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. Some research studies on adult male athletes have suggested that exceeding 70-100g or more, is associated with an increased risk of concussion.
WARNING! These thresholds are not universally agreed upon within the medical and scientific communities and can vary depending on multiple factors (such as age, gender, event history, brain injury history, and many more). These thresholds must not be used as general guidance.
Why electronically measuring and tracking the events is a must
1. We do not know what is happening on the pitches today
It is virtually impossible to know how many potentially harmful events there are, how violent they are, and when they occur.
2. We do not know who will be affected
For the athletes’ health, safety and legal protection, it is crucial to be able to recognize the incidents on the pitch/path/track/…
3. We do not know how they would be affected
Knowing the event history may help to trace possible causes or contributors and can help to manage the load on a head.
4. We do not know when they would be affected What magnitude is too high?
How many events is too many? How big of a cumulative load is too big? Who will be affected, how and when? We do not know these things today. And we never will know these things, unless the data is gathered and far more research is made. Cumulative effect of events from today may take tens of years to manifest, not one more day without knowing what is happening should go by – the data collection must start now.