2. General information

It is a measuring device for forces and impacts acting on a head while doing sports. The system consist of: a sensor, mobile application and cloud service.

In everyday use, every athlete, coach, trainer and parent can use ACT Head Impact Tracker to:

1. Track down the impacts occurring. High numerical values indicate more violent impacts.
   There is no clear consensus of a clear-cut danger limit of acceleration as expressed in g-force. 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.
2. Keep an eye on the impact history and load. When the previous impact occurred? How many and what kind of impacts has happened in last days / weeks / months / season / year / 3 years / career?
3. Track down the athlete/-s getting more impacts than their peers, address the issue and reduce the impact load for the individual athlete/-s.
4. Identify the trainings and drills with most head impacts, modify them or lower their frequency in the training plan to reduce the impact load for all the athletes.
5. Identify the positions more prone to head impacts, keep an eye on the players in those positions and modify the training plans to reduce the impact load for the athletes involved.
6. Demonstrating how hard the impacts are with objective measures can contribute to better awareness and understanding of the head impacts, increase mutual respect of players and athletes, and minimize unnecessary risk taking.
7. Demonstrating objectively that impacts are occurring may encourage the coaches, trainers and team personnel to introduce and apply suitable sideline procedures, like CRT.
8. Share with those who care and can help to reduce your impact load. Users can share their impact data with those who should know too. These can be for example coaches, trainers, parents and co-athletes.
9. Trained eye of a coach may detect poor techniques from the force and direction graphical illustrations.
10. Teams and clubs tracking the head impacts can tell the parents of junior athletes that they do everything they can to monitor their children on the pitch.

Regarding point 7. we highly recommend including to your “head impact protocol” a side line assessment tool such as BMSJ’s Concussion Recognition Tool®s (CRT). You can download the English version of CRT 5 here: https://bjsm.bmj.com/content/51/11/872 and English Pocket CRT in here: https://bjsm.bmj.com/content/47/5/267. They are also available in several other languages, go and look them up in the web.
If licensed medical professionals are unavailable on site, and you do not have an assessment tool available at hand, you can also see “In case of a sport incident” text in the App. You will find it in the App’s Menu. There is useful information for non-medical first responders to help deal with the situation in a calm and structured manner.

ACT Head Impact Tracker consists of three parts, a head sensor (in the following called “the sensor”), a smartphone mobile App and a Cloud service. When the head sensor detects linear impact of 10g or more, it sends the impact information to a Cloud server via ACT Head Impact Tracker smartphone mobile App. The Cloud server saves the information and sends the information back to the assigned App(s). There are also additional service features and functionalities available and in development, which might differ from or add to this flow, but the basic functionality is this.

Every athlete, coach, trainer, relevant team personnel, and parent can:
1. Track the impacts occurring.
High numerical values indicate more violent impacts.
2. When an impact occurs, act on it.
If no medical professionals are available on site to do the assessment, we recommend using well-established assessment tools, such as Pocket Concussion Recognition Tool 5®.
3. Keep an eye on the impact history.
When did the previous impact occur? How frequently the impacts occur? How many impacts have you had today/this week/this month/…?
4. Increase awareness and understanding, Advocate the change in attitudes and behavior.
Create awareness and understanding by bringing the forces acting on a head visible with objective
measures. Educate when and why they occur and what they may cause. Aim for a good sportsmanship
and increased respect, less risk-taking, using excessive force and foul play.
5. Take a stand and send a message.
Measuring the impacts and acting on them, signals to everyone involved that this matter is with very high significance and closely observed. Incidents will not go unnoticed and will be acted upon. No-one should fear for their life, health or well-being when doing sports. You are riding on the 1st wave to make this change.

Every coach, trainer and relevant team personnel can:
6. Track down the athlete/athletes getting more impacts than their peers.
Address the issue with athletes at risk, reduce the impact load of the individual athlete/-s.
7. Identify the trainings and drills with most head impacts and/or load.
Modify them or lower their frequency in the training plan to decrease the impact load of all the athletes.
8. Identify the playing positions more prone to head impacts.
Keep an eye on the players in those playing positions and modify the training plans to reduce the impact load of the athletes in those positions.
9. Trained eye of a coach may detect technique with need of improvement.
Headings, giving and receiving a tackle for example usually show on the graphical illustrations on the forces. Compare the graphs to detect gaps in techniques.
10. Introduce and apply a suitable sideline procedure.
Demonstrating objectively that impacts are occurring should encourage coaches, trainers and team personnel to introduce and apply suitable sideline procedures.
11. Share with those who care and can help to reduce impact load.
Users can share their impact data with those who should know too. These can be for example parents, coaches, trainers, or co-athletes.
12. Lead the way.
Teams and clubs tracking the head impacts truly aim to do everything they can to monitor athletes on the pitch. Towards safer, healthier and happier sports for everyone.

Last updated: 19th of December 2022

LIST OF MOBILE DEVICES’ FUNCTIONALITY WITH ACT HEAD IMPACT TRACKER

Tested and found working brands (models, Android OS)
1. Samsung Galaxy A21s (AOS 12)
2. Samsung Galaxy A41 (AOS 11)
3. Samsung 9+ (AOS 10)
4. Samsung A40 (AOS 11)
5. Samsung S21 Ultra 5G (A13)
6. Motorola e20 (AOS 11)
7. OnePlus8 (AOS12)
Please note: occasional problems with establishing and maintaining connection between the head sensors and mobile devices (no notification to the App regarding) were recorded:
Samsung phones: a.) in some models Bluetooth® wireless connection was slow or even disconnected if the mobile phone’s screen is switched off (= not lighted). The connection should be re-established and information from the sensors delivered when the screen is switched back on (=lighted) – if the sensor(s) are in the reach of Bluetooth® wireless technology. b.) In all models pop-up window with list of devices for paring appears when Bluetooth® wireless technology is switched on. When this happens, just click “Continue” to close the window. No paring is needed, nor appearing nor choosing it on the list.

Tested and found not working as intended (models, Android OS)
8. Xiaomi Redmi 9a (AOS 10)
Frequent problems with establishing and maintaining connection between the head sensors and mobile devices (no notification to the App regarding) were recorded:
The connection between the sensors and the mobile phone was disconnected when the App was not on, on top of the open Apps and/or screen was switched off (not lighted).

Tested and found not working (models, Android OS)
9. OnePlus Nord N100 (AOS 11)
10. OnePlus8 (AOS13)
ACT Head Impact Tracker does not function with these mobile devices.

Other brands and models have not been tested, and cannot be granted to work, or work as intended with ACT Head Impact Tracker. (If your device is not on the list, it does not guarantee it is functional, or that is not. We just have not tested it yet.)

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 acceleration. 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.

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

Regarding individual events above 10g, 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 (both introduced in the 2nd half of 2023). New highly relevant measurement Impact g-load will also be introduced in 2023. Users’ impact history is saved to the Profile and can be accessed and revied also in the later occasions.

When an impact occurs the head sensor is trying to send the impact information via Bluetooth® wireless connection to the mobile smartphone with ACT Head Impact Tracker App. If the mobile device and App are not at Bluetooth® wireless connection reach, the head sensor saves the impact data in it. The saved impact information can be transmitted when the sensor is at Bluetooth® wireless connection reach and multiple impact information can be transferred on one go.

There is not sufficient information or scientific research to reliably, simply and safely classify 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 and correlation 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.

That is a question you have to ask them.

There is a set of great sideline tools available for anyone which you can download for free. They are BMSJ’s Concussion Recognition Tool®s (CRT). You can download the English version of CRT 5 here: https://bjsm.bmj.com/content/51/11/872 and English Pocket CRT here: https://bjsm.bmj.com/content/47/5/267. It is also available translated to many other languages, look them up in the web, print out and include it into your training kit! When an impact occurs, take out your CRT and run through it to get more information on the situation and what to do next, do’s and don’ts.
It is always recommended to seek immediate medical attention, if there is any reason to suspect a brain injury.