Tackling concussions: Investigating the role of neck muscles in head impact safety
Reducing the acceleration of a player's head's movement and limiting the rotation could potentially reduce the severity of a head knock. Image: Jim Cox - stock.adobe.com
As the long-term effects of head injuries come into sharper focus, Federation University researchers are examining whether strengthening athletes' neck muscles and improving their ability to react to potential head impacts can lessen the effects of head knocks in sports.
The study is led by sport scientist Dr Ryan Worn, supported by established concussion researcher Dr Andrew Lavender and has been funded by the Early Career Research Seed Funding Program. The research team will look to get a better understanding of head motion, brain function and concussion risks in female team sport athletes.
Dr Worn says that heading the ball in soccer may not immediately result in a concussion, but the cumulative effects of subconcussive impacts — a series of very minor hits that don't lead to immediate symptoms — could lead to long-term consequences, including an increased risk of neurodegenerative disorders such as Chronic Traumatic Encephalopathy (CTE) or other conditions.
The research team will initially focus on female soccer players and will include the use of inertial measurement units – electronic devices that can measure the head movements of players.
"There's a push globally in sport to think about how we can reduce concussion risks through mechanical variables like neck strengthening, but on the other side of that, there's a push to think about how we deal with it in training because you don't want to take away the elements of the sport that are good," Dr Worn said.
“Using rugby as an example, concussion is caused by tackles, but rugby would not be rugby without tackling. We don't want to take away the intricacies of the sports, but we do need to understand how we can potentially reduce concussion risks.
"If you are about to be tackled, you look to either get out of the way or if you know you can't get out of the way, you brace towards the tackle and tense your muscles. But if you're unaware of that impending impact, you can do nothing to prepare for it. That means there may be an opportunity to develop that neck strength to shorten reaction times to better anticipate head impacts.
"In a lot of ways, the potential neck strengthening might look similar to what Formula One drivers need to train to deal with high G-forces. Heading a soccer ball won't generally result in a concussion but it's the cumulative effect of repeatedly heading that is becoming a concern."
Dr Worn says many sports concussions are caused by a contrecoup injury, where a hit on the side of the head results in the brain moving and impacting the opposite side of the skull, potentially resulting in bruising on the brain.
He says reducing the acceleration of the head's movement and limiting the head's rotation could potentially reduce the severity of the head knocks. In soccer, this could involve strengthening the player's neck muscles and training exercises where players react to external stimuli like flashing pop-up lights that require them to quickly react to moving targets. The hope is that the exercises will help the athletes react more rapidly to on-field situations.
Dr Worn says research into women's sports is comparatively small compared with men's sports, but biological factors like neck strength mean that females may be at a higher risk of injury.
"Because these factors are under investigated, even if females are not at a higher risk, it is important to know that. There's not a lot of evidence to say that strengthening neck muscles will do anything about reducing concussion risk if you can't anticipate it, but we don't know enough about that yet."
The research team will assess neck strength qualities against specific forces, measure rotation strength, as well as the time it takes to react to a specific stimulus. They will also develop simulated soccer heading drills and put the athletes through other reaction, sensory and balance tests, as well as memory recall exercises.
The next arm of the project may also look at concussion from a genetic lens, with the researchers taking saliva swabs from the athletes to look for epigenetic changes – these modify gene activity in people's brains and may relate to concussion risk factors and potentially indicate if certain types of common sports drills, for instance heading a soccer ball are damaging.
Dr Worn also has a personal interest in concussion research. As a former track cyclist, he witnessed many concussions in serious falls that, at the time, were largely dismissed.
"The concussion incidence in cycling is quite low, but the severity is really high when you come off a bike. You don't have gears or brakes in track cycling, and you're strapped in, so it really is dominoes – one falls, and you all fall, and you're moving at 60-70 km/h," Dr Worn said.
"If someone, now, has a head impact in cycling and most sports, they are taken to hospital for assessment. We are getting better at concussion protocols around returning to sport. When I was a junior, it was a point of pride about how quickly you could get someone back on their bike.
"Now we know that the very worst thing you can do is put someone back on. If you increase the blood flow, you increase swelling, and the greatest concussion risk factor is a previous concussion.
"Many cyclists had symptoms of serious concussions including headaches, blurred vision, memory loss, balance problems etcetera on many instances, but at the time, the sporting and medical community wasn't very good at recognising or treating concussion symptoms."