Introduction

Rugby union (hereafter referred to as rugby) has one of the highest incidences of concussion in sport, and rates are continuing to rise.1 The latest Injury Surveillance Project (2017) stated that for the sixth consecutive season the occurrence of match concussions within English rugby had increased, reaching a figure of 15.8 concussions per 1000 player-hours.2 Since rugby became a professional sport in 1995, full-time training has allowed players to increase their strength, power and fitness, as well as their body mass. This increased physicality is thought to be the cause of the rise in concussion figures.1 However, it has been argued that the dramatic increase could be a result of improved awareness of the condition, reflecting previous underdiagnoses rather than a real rise in incidence.3 Regardless of the cause of this trend, steps need to be taken to protect players from head impact injury.

In addition to the immediate dangers posed by concussion, research into long-term sequelae of concussion is proposing a link between recurrent head collisions in contact sports and fatal conditions such as second impact syndrome4–8 and chronic traumatic encephalopathy (CTE).9–11 The debate surrounding the long-term sequelae of concussion in contact sport is becoming a mainstream issue, with CTE even making it to Hollywood with the film, Concussion.12 However, research into both conditions is in its early stages, and some have disputed their existence due to a limited case number.13–15

It is estimated that between 1.6 million and 3.8 million sports-related concussions occur each year, but this figure may be an underestimate due to the large number that goes unrecognised and unreported.16 Raised awareness of sports-related concussion has sparked a wave of research into the field, primarily in the USA within the American football setting. However, in most contact sports, such as American football, ice hockey and cycling, players use hard-shelled helmets during play, which differ dramatically from the foam-padded headguards used in rugby. While the American studies may not be a useful comparison for headgear, there were some studies that attempted to determine a threshold force for concussion, which are useful for evaluating the effectiveness of rugby headgear.17–21 Studies within the field of rugby have investigated the epidemiology of head impacts and concussive injuries, such as King et al 17 and Gardner et al .1 Focusing more on rugby headguards, most of the limited on-pitch testing of headguards has revealed no change in concussion incidence,22–24 with the exception of Hollis et al , who demonstrated a decreased frequency of concussion in those who chose to wear a headguard.25 Despite this, one of the studies that demonstrated no change in the frequency of concussion while wearing a headguard did highlight a decrease in severity of concussive symptoms in those wearing a headguard.22 Taking this further, a laboratory study highlighted that small alterations to the headguards’ design could significantly improve their impact attenuation performance.26

In response to growing pressures, World Rugby have made reducing the incidence of concussion one of their main priorities. They have focused on education, creating many online resources providing information on recognising and managing concussion within the game of rugby.27 They have also changed the laws of the game to punish reckless head collisions.28 However, one area World Rugby have not used to prevent concussion is protective headgear. Their laws enforce tight limits on the thickness and density of the material used,29 emphasising their purpose is to prevent superficial head injuries which they have proven to do.24 30 World Rugby argue that wearing headgear would give players a ‘false sense of security’ and encourage ‘risk taking behaviour’, resulting in an increase rather than a decrease in head injuries.31 32 However, research into the effectiveness of headguards has shown the tackle style and frequency do not change when comparing players wearing a headguard with those who are not.23

The primary aim of this research was to investigate the efficiency of several branded rugby headguards at reducing the forces transferred to the head on impact. Headguards are the only form of head protection available to rugby players, and there is limited research comparing the efficiency of different brands which are approved by World Rugby. It was hoped the results would point towards a brand of headguard that provided the best protection for players.