Recently football teams have made headlines for investing in smart helmets that detect concussions and measure hits. But are these helmets as effective at detecting concussions as they are made out to be?

Concussion is due to acceleration and deceleration of the brain. The idea is to fit these helmets with accelerometers, so that if the sensor hits a certain acceleration or deceleration threshold it can help to detect whether or not that player may have suffered from a concussion. Generally, the helmets are calibrated to measure accelerations over 10 G’s, and send that data to a computer device on the sidelines.

In a sport like football, where there is lots of action happening simultaneously at the line of scrimmage, it can be challenging for sideline spectators or medical personnel to see every hit. The idea is that amongst all the action, this technology can help to evaluate impacts and provide more insight as to what’s happening on the field.

Pretty genius, right? But is it as good as it sounds?

These types of sensors first came out in a program called the HIT system (Head Impact Telemetry). The HIT system is a series of six triaxial accelerometers positioned around the inside of the helmet to measure impacts in all directions. This program has been used in research for years and has established threshold ranges for when concussions occur.

Over millions of impacts, research using these helmets in football players found a range that concussion is thought to occur is between 70 to 120 G’s of linear acceleration and 5,000 to 10,000 rad/s2 of rotational acceleration.

Here’s the problem – these ranges are pretty wide! Everyone has a different threshold for concussion injury. We don’t know yet if there are directional, or location, issues. For example, is a lighter hit to the top of the head worse than a bigger hit to the front? We don’t know. So, relying on these threshold ranges as a benchmark, sets up the potential to miss important and relevant impacts that may be significant but fall outside of the range. Important examples of this are a player with a high threshold for injury constantly being removed for unnecessary concussion evaluation, and even worse, a player with a low threshold for concussion injury being dismissed as “fine” because his/her sensor says that the hit was pretty minor.

These sensor helmets can detect acceleration, but they do not detect concussion.

The helmet is not the head!

The helmet may move around during an impact – it could spin around or pop off – but this does not mean the head has moved to the same degree. A better point of measurement would likely be through a mouthguard, as it is fixed to the head, however it is difficult to get the same number of accelerometers into a mouthguard.

At this time, helmet and mouthguard sensors should be utilized as research tools only. Just because a sensor has gone off, or not gone off, does not indicate that a concussion has, or has not occurred. Concussion is still a clinical diagnosis and requires a healthcare professional to assess anyone suspected of having one. This technology is not ready for commercial use, unless used as one component of a larger strategy – i.e., medical staff present to confirm the diagnosis, objective testing (baselines and post-injury testing), etc.

Here is a recent systematic review that looked at the state of concussion sensors.

Have you suffered from a concussion? Are you looking for a concussion-trained practitioner? Complete Concussion Management is a network of clinics and trained practitioners that provide evidence-informed concussion care for all those impacted by concussion. We may have a clinic near you.