My first lesson in ice hockey was at the age of five when my dad dragged me down to the ice rink for the first time. It was on the importance of wearing a helmet at all times. Over the last 22 years playing ice hockey at both a junior and semi-professional level, I have witnessed too many teammates suffer concussions. I, have missed exams and even vacations due to taking a concussive knock to the head. It is an accepted fact amongst players that although we wear helmets, we may still suffer concussions, as head injury is common. This is how it is, but is it how it should be?

In my third year at university I learnt that, on average, a professional player will suffer at least one head injury every other season (German Professional League [1]). It is apparent that the helmets in which the players put so much trust provide limited protection against concussion, this is recognised anecdotally by the players. Helmets are certified and designed to prevent the most catastrophic of head injuries, i.e. a skull fracture. The underlying reasons for this limitation are varied and complex. Issues range from simplified standards that do not represent typical head impact scenarios, to difficulties in assessing the risk of concussions and brain injury [2].

There is a push to reduce concussion within the sport, with extensive research within American football, ice hockey, soccer (particularly the junior game), and combat sports [3], to name a few. Despite this research and investment, the best ways to prevent concussion within sports are still not fully understood. With my new found awareness of the severity of concussion, and from personal experience of having received one too many blows to the head in the sport I love, I decided to focus my undergraduate and subsequent Master’s thesis project on investigating helmet performance. I have now commenced a PhD at Sheffield Hallam University. Driven to improve player safety, I am conducting research with the primary aim of reducing brain injury occurrences in ice hockey.

Typically, helmets have two functional layers; a hard and durable outer shell to distribute impact, and an energy absorbing inner liner. Traditionally liners are made of expanded foam, that crushes under load, absorbing the energy that would otherwise be transferred to the head and brain [4]. Most sports helmets are developed and tested to pass standard tests; featuring impacts against rigid surfaces; similar to the ice or the boards. However, 88% of concussions within the sport are as of a result of player-player collision, where the (helmeted) player’s head impacts a softer or more compliant surface [5].

High concussion rates may therefore not seem surprising; the typical helmet is not designed for the most common injury scenario. The statistics highlight the huge potential for further helmet development, and to increase awareness of concussions in ice hockey.

To date, solutions designed to improve the performance of sports helmets have focussed on new materials, structures, and inserts. Most cyclists will be aware of MIPS (MIPS AB, Täby, Sweden), and in ice hockey we have seen Bauer Suspend-Tech (BAUER Hockey, Kitchener, Canada); both are low friction technologies that claim to reduce injury risk. Other approaches seen in helmets include the use of engineering structures such as WaveCel (Trek Bicycle Corporation Ltd., Waterloo, USA), and Koroyd (Koroyd SARL, Monaco), or the use of shear thickening polymers such as D3O (Croydon, UK). MIPS and D3O currently appear to be the most widely adopted solutions, but the effectiveness of all of these approaches still remains widely unknown and hotly debated.

As I start out on my PhD journey my first task is to design a representative test method that is appropriate to impact scenarios seen in ice hockey. I then intend to use this test to benchmark the performance of current helmets, and to investigate promising liner systems, before I then turn my attention to developing some new solutions. It is clear that this work could benefit other areas of life where helmets are required, such as in the emergency services and the construction industry.

References

1.        VBG-Sportreport 2019, Analyse des Unfallgeschehens in den zwei höchsten Ligen der Männer: Basketball, Eishockey, Fußball, Handball. 2019.

2.        Whyte T, Stuart CA, Mallory A, Ghajari M, Plant DJ, Siegmund GP, et al. A review of impact testing methods for headgear in sports: Considerations for improved prevention of head injury through research and standards. J Biomech Eng. 2019;141(7).

3.        Mizobuchi Y, Nagahiro S. A Review of Sport-Related Head Injuries. Korean J Neurotrauma. 2016;12(1):1.

4.        Hoshizaki TB, Post A, Oeur RA, Brien SE. Current and future concepts in helmet and sports injury prevention. Neurosurgery. 2014;75(4):S136–48.

5.        Hutchison MG, Comper P, Meeuwisse WH, Echemendia RJ. A systematic video analysis of National Hockey League (NHL) concussions, part I: Who, when, where and what? Br J Sports Med. 2015;49(8):547–51.

6.        Rousseau P, Hoshizaki TB. Defining the effective impact mass of elbow and shoulder strikes in ice hockey. Sport Biomech. 2015;14(1):57–67.

7.        Pauelsen M, Nyberg G, Tegner C, Tegner Y. Concussion in ice hockey – A cohort study across 29 seasons. Clin J Sport Med. 2017;27(3):283–7.