Protecting Athletes: The Truth About Concussion-Reducing Devices

In the past few years, there has been a significant emphasis (and rightly so) on concussion prevention in sports at both professional and amateur levels. Professional sports organizations such as the NFL and NHL have implemented rule changes and introduced new equipment to try to reduce concussion risk and improve overall player safety.

While we love to see the increasing awareness around concussion prevention and the rule changes to increase player safety, do any of the new concussion-prevention devices actually work?

In this article, we’re going to review some of the most recent developments in equipment designed to reduce concussion risk in sport and determine if they truly lead to a reduction in concussion risk.

NOTE: CCMI is not involved or associated with any of the companies or products that will be discussed. We do not have financial or personal interests in the validity of any of the products mentioned. This review is based purely on the currently available data.

Pathophysiology of Concussions.

To better understand how these products are trying to prevent concussions, we first need to understand how concussions occur.

A concussion is a brain injury that happens when there’s an acceleration-deceleration event of the brain inside the skull cavity. These alternating forces create a shearing effect on brain tissues, leading to the functional neuron damage we associate with concussions.

The main point to remember is that any force translated from the body or head to the brain has the potential to cause a concussion. Therefore, to prevent a concussion, we need to reduce the amount of linear and rotational acceleration on the brain during sports-related impacts.

Understanding this concept also highlights that no device or rule change can eliminate concussions 100%. Because concussions are acceleration-deceleration injuries, you’d have to remove all head movement and any source of force (e.g., gravity, other players, equipment)—which isn’t possible.

However, protective devices that reduce the peak force transmitted to the brain or dampen the brain’s acceleration-deceleration might reduce concussion risk.

Here’s the list of the concussion-prevention equipment we’re going to discuss:

• Helmets (American football, ice hockey, and bicycle)
• Guardian Cap
• Q-Collar
• Mouthguards

Helmets.

 A Brief History of Helmets

Before we dive into specific helmet technologies, it’s important to note that helmets were initially designed to prevent skull fractures and other catastrophic head injuries—not concussions. Historically, helmets have been very effective at preventing fractures and lacerations, but the forces from impacts (linear and rotational acceleration) can still be transmitted to the brain, causing concussions.

For a helmet to reduce concussion risk, it needs to effectively absorb and redistribute these forces before they reach the brain.

Please see our other blog post here for a further deep dive into helmets and concussion risk.

The Guardian Cap.

The Guardian Cap is one of the most recent introductions into the concussion prevention space. It has gained attention over the last few NFL seasons as an over-the-helmet padding designed to reduce the force of repetitive helmet-to-helmet impacts during American football.

The cap aims to achieve this by:

1. Adding additional, compressible padding to the helmet’s exterior.
2. Lowering the surface friction of the helmet’s outer shell.
3. Redirecting impact energy through independent motion of the padded shell along the helmet’s surface.

These mechanisms are intended to reduce the amount of force transferred to the brain, theoretically lowering the risk of concussion.

What the NFL Says

According to the NFL’s internal data:

• Guardian Caps reduce peak force impacts by 8-10% when one player wears the cap and up to 20% when both players are wearing them.
• A 50% reduction in reported concussions was observed during the 2022 preseason for positions required to wear the Guardian Cap.
• Other brands of helmet covers showed peak force reductions of up to 5%, depending on the design.

While these results sound promising, it’s important to note that the NFL’s testing remains unpublished and unverified by independent peer-reviewed studies, which raises questions about the reliability of their findings.

What Peer-Reviewed Research Says

When tested in controlled laboratory settings, the Guardian Cap has shown more modest results:

• Laboratory tests revealed significant reductions in head impact severity in only 2 of 6 helmet locations at high speeds (Breedlove et al., 2017).
• No reductions were observed during low- or medium-speed impacts, and the locations where forces were reduced (rear and right-rear) are not the most common points of impact for concussion injuries.

In practice conditions, the results are even less encouraging. A study by Quigley et al. (2024) measured linear and rotational forces during full-contact football practices using data-capturing mouthguards. The study found no significant differences in head impact forces (or head impact number) between players wearing the Guardian Cap and those not.

Possible Explanations for Mixed Results

There are several theories as to why the Guardian Cap might not perform as effectively in real-world scenarios:

1. Concussion Education in Training Camps: The observed reduction in concussions during NFL training camps may have been due to increased awareness and an emphasis on reducing head impacts during that period, rather than the Guardian Cap itself.
2. Cushion “Bottoming Out”: The Guardian Cap may compress to its limit during high-impact collisions, reducing its ability to absorb additional force.
3. Reduced Force Redistribution: The cap might prevent the helmet from spreading the force of an impact as effectively as it would without the cap.
4. Perceived Invincibility: Players wearing the Guardian Cap might feel more protected and play more aggressively, offsetting any potential benefit the cap provides.

Conclusion on the Guardian Cap: The Guardian Cap has generated excitement, but the data supporting its effectiveness is mixed. While the NFL’s internal testing suggests promise, independent studies show limited lab and real-world performance. More research is needed before any firm conclusions can be drawn.

Q-Collar.

The Q-Collar is a wearable device designed to decrease concussion risk by compressing the jugular vein. By applying this gentle pressure, the collar increases the amount of blood retained in the skull, which is thought to create a “padding” effect for the brain during impacts.

This concept stems from the idea that increased intracranial blood volume could reduce the brain’s ability to move within the skull during an acceleration-deceleration event, potentially reducing damage from impacts.

Animal Research

The underlying mechanism has shown some validity in animal studies. For example, rat models demonstrated reduced white matter damage after head impacts when jugular compression was applied (Myer et al., 2016). However, it’s worth noting that these studies didn’t involve the Q-Collar specifically. Instead, they focused on the general effects of increased jugular pressure.

Human Research

Human studies have produced mixed results. One study on adolescent football players found that those wearing the Q-Collar showed reduced changes in white matter throughout a season compared to those who didn’t wear the collar (Diekfuss et al., 2021). However, there are important caveats:

• The study was funded by the Q-Collar’s manufacturer, raising potential bias concerns.
• Results were inconsistent, with some players wearing the collar showing increased white matter changes and some not wearing the collar showing reduced white matter changes.
• The study didn’t assess actual concussion rates, leaving it unclear whether the Q-Collar impacts concussion incidence.
• The white matter changes were identified using brain scans, but their clinical significance remains uncertain.

FDA Approval

The Q-Collar has been approved by the FDA for use in sports, with the agency stating that the “potential benefits outweigh the potential risks.” However, FDA approval does not confirm the device’s effectiveness; rather, it allows the device to be marketed for specific uses based on limited data.

Outstanding Questions

While the Q-Collar’s concept is intriguing, many researchers remain skeptical about whether it translates effectively from animal studies to human applications. Key questions remain:

• Can increased jugular pressure consistently reduce concussion risk?
• Is the device safe for long-term use, especially in high-contact sports?
• How significant are the observed white matter changes, and do they translate to meaningful protection?

Conclusion on the Q-Collar: The Q-Collar is an innovative idea with some support from animal studies, but human research is still in its early stages. The device shows potential, but more third-party testing and longitudinal studies are needed before its effectiveness can be confirmed.

Mouthguards.

Mouthguards are among the most supported pieces of equipment for concussion prevention—and for good reason. They appear to work.

Mouthguards are the only piece of protective equipment included in the list of recommended protective equipment for concussions at the 2022 Amsterdam International Conference on Concussion in Sport (Patricios et al., 2022).

In ice hockey, wearing a mouthguard has been shown to reduce concussion risk by 28% across all age groups (Chisholm et al., 2020). This finding supports the recommendation that all players, even those in non-contact leagues, should wear mouthguards to minimize concussion risk.

Furthermore, a meta-analysis of 39 studies found a significant reduction in concussion incidence among athletes who wore mouthguards in contact sports, including hockey, football, and rugby (Knapik et al., 2019).

How Do They Work?

The exact mechanism by which mouthguards reduce concussion risk is not fully understood. However, it is thought that they may:

• Reduce the force transmitted to the head and jaw during an impact.
• Alter jaw mechanics to minimize force transfer to the brain.
• Improve neck stability or muscular activation, reducing the acceleration-deceleration forces that lead to concussion.

Notably, both off-the-shelf mouthguards and custom dental mouthguards are effective options for reducing concussion risk.

Conclusion on Mouthguards: Mouthguards work (at least in hockey). However, if you play any contact sport, wear one!

Take-Home Points

• Helmets prevent severe head injuries, traumatic brain injuries (TBI), and skull fractures better than they reduce concussions.
• Mouthguards have been shown to work in ice hockey and should be worn at every level, even if contact isn’t part of the game yet.
• Bicycle helmets are one of the best things (in cycling) you can do to protect your head, and modern helmets with MIPS or other force-reducing technologies make them even better.
• Other safety devices like the Q-Collar and Guardian Cap are exciting experiments in the lab but haven’t yet been proven to reduce concussions significantly in real-world settings.

In this blog, we’ve covered “all things wearable devices” for preventing concussions in sports. While these technologies represent steps toward reducing brain trauma, we’re still in the early stages. Some of these devices show promise and could lead to further advancements in the future, but for now, most are still just that—promising ideas.

As it turns out, the tried-and-true concussion prevention strategies still reign supreme:

• Reduce contact during sporting activities.
• Advocate for rule changes to reduce head impacts during practice and at younger ages.
• Educate players and coaches on the mechanisms, signs, and symptoms of concussions, and emphasize the importance of removing players from play when necessary.

Have fun and stay safe!