Gardner Et Al. a Systematic Review and Meta-Analysis of Concussion in Rugby Union

Gardner et al. A Systematic Review and Meta-Analysis of Concussion in Rugby Union

Electronic Supplementary Material Table S1. Studies Examining Concussion in Rugby Union Players

Reference / Aims / Purpose / Study Findings
Fuller et al. (2014) (70) / To determine the incidence, nature, and causes of concussions sustained during men’s elite professional Rugby-7s and Rugby-15s / Overall incidence of concussion in Rugby-7s: 8.3 concussions per 1,000 player match hours, compared to Rugby-15s: 4.5 concussions per 1,000 player match hours.
Concussion incidence in Rugby-7s was significantly higher than that in Rugby-15s (risk ratio= 1.84).
The severity of concussions was significantly higher in Rugby-7s than Rugby-15s.
The main cause of concussion in Rugby-7s was tackling (44.1%); in Rugby-15s it was collisions (43.6%).
Significantly more concussed players were removed immediately from the game in Rugby-7s (69.7%) than in Rugby-15s (46.7%).
Coughlan et al (2014) (108) / To evaluate the current status of medical personnel, facilities, and equipment in Rugby Union clubs in Ireland / Approximately two-thirds of responding clubs reported having a dedicated medical room, most clubs also had a medical doctor, physiotherapist, or first-aiders attend games, and one-fifth of clubs reported having an anti-doping officer.
Two-thirds of clubs had organised first aid training for members.
In terms of safety equipment (i.e. stretcher, scoop board, spinal board, first aid kit and automated electric defibrillator), there was a positive association between having a club doctor and/or physiotherapist and possessing all five pieces of equipment.
93.4% of clubs reported that they followed the IRB guidelines on concussion, with 86.2% of these clubs obtaining medical advice and 5.5% of clubs using online concussion assessment tools (e.g. ImPACT®, CogSport) to assist with concussion management.
Fuller at al. (2013) (71) / To determine the frequency and the nature of injuries sustained during the IRB 2011 Rugby World Cup / The incidence of concussion match injuries was 7.8 (4.7 to 13.0) per 1,000 player match hours.
The mean severity (expressed as days to recover/return-to-play) of concussion injuries was 10.1 (2.5 to 17.8) days.
Concussion injuries were the second most common match injury (n=15), but resulted in the sixth greatest overall loss of time (n=152 days).
Of the 15 concussions; 7 were removed from play immediately; 6 were removed later in the game; and 2 remained in play.
Although higher, the difference in the number of concussions reported at the 2011 RWC (n=15) compared to the 2007 RWC (n=5) was not statistically significant.
Overall injury incidence was 89.1 per 1,000 player match hours and 2.2 per 1,000 player training hours, with player position incidence for forwards 85.0 and 2.7 respectively, and backs 93.8 and 1.7 respectively.
Baker et al. (2013) (105) / To determine the incidence of concussion among a cohort of male under 20 rugby players and assess basic knowledge and attitudes / 48% of players reported a history of at least one previous concussion, with a mean of 2.25 injuries.
56% of concussed players sought medical attention and were stood down from activity for a mean of 2.2 weeks
The back row position was concussed more often than outside backs; age, number of seasons played, or level of participation did not predict any increase in the number of reported concussions.
The mean number of symptoms reported was 2.6 [most common was headache (reported by 46% of players), memory disturbance (37%), nausea/vomiting (32%), dizziness (12%) and confusion (11%)]. No player reported the symptoms: feeling more emotional, irritability, sadness, nervousness, or sensitivity to light or noise.
A positive correlation was found between the number of concussions and the number of symptoms listed.
86% believed that a concussion could affect their ability to make decisions in play and 75% believed that concussion can lead to serious health consequences.
85% reported they would inform someone if they were concussed and 83% would do the same if they thought a teammate was concussed; however, 25% reported having previously continued to play whilst knowingly concussed.
45% believed that headgear and 40% believed that mouthguards reduced the risk of being concussed.
Players believed thaton average the appropriate stand down period from play after suffering concussion was 3.1 weeks.
Cusimano et al. (2013) (121) / To determine the mechanism of brain injuries among children and youth participating in team sports. / 721 brain injuries in rugby were reported; 2 (5-9 years age range), 175 (10-14 years age range), 541 (15-19 years age range).
Being struck by another player was the most common mechanism of injury overall and within each age grouping.
Specifically, the mechanism of injury ‘being tackled or tackling another player’ represented 48.5% of male head injuries, and 51.7% of female head injuries; ‘head-to-head collision’ 10.2% of male, and 7.3% of female injuries; ‘head-to-knee contact’ 9.1% male, and 5.1% of female head injuries.
Peck et al. (2013) (82) / To examine incidence rates and injury patterns between men and women competing in collegiate rugby at a single institution. / Injury rates among women and men rugby players were similar but the patterns of injury differed, suggesting that different style of play may be a factor for certain injury risks.
71 members of the women’s team sustained 200 injuries during 68,633 athletic exposures (practice and game play; this included 5 seasons of both Rugby-15s and Rugby-7s); 151 members of the men’s team sustained 459 injuries during 121,624 athletic exposures.
The overall injury rate was 30% higher for men than women.
Men sustained 40 concussions compared to 30 concussions sustained by women during the study period (a statistically non-significant difference).
There were gender differences in the rate of injuries to the head (other than concussion); men were 6.6 times more likely to have an open wound, lacerations, or fractures.
King et al. (2013) (129) / To use the King-Devick (KD) test and the Sports Concussion Assessment Tool 2 (SCAT2) in amateur rugby union players to identify witnessed and unrecognised episodes of concussion that occurred from match participation. / 22 concussions were recorded during a single season of a premier level amateur rugby competition, and five were witnessed and reported.However, there were allegedly 17 injuries that went unrecognised until the results of the KD test reportedly identified them.
Players who experienced a ‘witnessed concussion’ recorded a longer KD (5.5 ± 2.4s) than the players who experienced an ‘unrecognised’ concussion (4.4 ± 0.9s) when compared with their baseline KD performance.
Hollis et al. (2012) (104) / To describe the proportion of rugby union players who comply with the sports body’s regulations on returning to play post-concussion / 187 players (10% of the cohort) sustain one or more concussions throughout the follow up period, with a total of 215 concussions reported (one concussion, n = 163; 2 concussions, n = 24; three concussions, n = 3; four concussions n = 1).
48% of concussed players returned to play in the same game and 34% of players did not leave the field of play and remained in play.
The median number of days before return to play after the player’s first concussion was 3 days (range 1-84), 87% returned within one week, 91% with two weeks, and 95% by the third week.
The median number of days before return to play after the player’s second concussion was 7 (range 0-120), and 95% of players had returned within three weeks.
Of the players who had sustained either a third or fourth concussion, 67% returned within three weeks.
Players typically returned to training before match play, as evidenced by the longer period of return to match play (e.g. 56% of players who sustained one concussion returned to competition within one week, 81% by the second week, and 88% by the third week).
A significant association was observed between the number of concussion sustained by players throughout the study and player compliance with the three week stand-down regulation.
78% of concussed players did not receive any return to play advice.
Of those concussed players who received correct return to play advice, not one of them complied with the mandatory stand-down period of three weeks, suggesting greater dissemination and implementation of the return to play regulations are required at the community rugby union level of play.
Only 2 of 23 players who received advice complied with the return to play regulation, if ‘return to play’ was defined as returning to competition game play only (not training).
Players aged 21-26 years were more likely to receive return to play advice post-concussion compared with the 15-20 or the 27+ year age groups.
Players who trained ≥ 3 h were also more likely to receive return to play advice compared with players who trained < 3 h.
Hollis et al. (2011) (106) / To investigate whether mild traumatic brain injury occurs at a particular time in the playing season among community rugby players and whether there are factors that shorten the injury-free period. / The mean game time to first concussion was 8 h (SD: 6.2 h, median 6.8 h).
After adjustment for censoring, within 10 h (just less than the average number of game hours per player season), 7% of the cohort had sustained a first concussion and within 20 h (approximate length of one season for adults), 14% had sustained a concussion.
Players who had sustained a recent concussion, had a lower BMI, trained less, or played adult rugby were most at risk for sustaining a concussion.
Gardner et al. (2012) (124) / To examine the diagnostic efficiency of CogSport and ImPACT in rugby union players without individual baseline data / Considerable variability in the sensitivity and specificity of CogSport and ImPACT scores were observed.
Overall group (concussed versus control) classification accuracy: demographic information alone (age, predicted FSIQ, number of previous concussions) accurately classified 83.9% and was not significantly improved with the addition of either the CogSport or ImPACT composite scores (a modest improvement of 3.5% was observed).
Boffano et al. (2011) (101) / To survey the knowledge and beliefs concerning concussion in a sample of young rugby players / 38.5% (n = 25) of athletes reported that they had not been informed by anyone about symptoms of concussion and its consequences.
Among these 25 athletes, 7 players thought they could return to play immediately after a concussion during the very same match, whereas the remaining 18 players knew that an immediate return-to-play is not advised.
Three of the 40 athletes who reported that they had been informed about the signs and symptoms of concussion indicated that they could return to play immediately after a concussion during the very same match.
The most common source of information was provided by physicians, followed by school/university and trainers.
The most frequently listed post-concussion symptoms was nausea, followed by vomiting, loss of memory and dizziness.
Taylor et al. (2011) (79) / Surveillance of all injuries sustained during the 2010 Women’s Rugby World Cup / Incidence of match play injury was 35.5 per 1,000 player match hours.
Mean severity of injury was 55.0 days (with a median severity of 9 days).
Only one training injury was recorded.
The tackle was the most common cause of injury.
Knee ligament injuries were the most common (15%) and resulted in the most days lost (43%).
Concussion represented 10% of all injuries and ranked as the 4th most frequent injury incurred by players.
Hollis et al. (2011) (106) / To examine if concussions are sustained at a particular time within a playing season and if key factors exist that shorten the injury-free period or time to injury. / Of the 1958 players, 10% (n = 187) sustained ≥1 mTBI throughout the study with a total of 215 mTBIs sustained overall.
Of the 187 concussed players; 163 (87%) sustained one mTBI, 24 (13%) sustained ≥2 mTBIs.
After adjustment for censoring, 7% of the cohort sustained an mTBI within 10 hours of game time, which increased to 14% within 20 hours of game time.
The mean time to first mTBI was 8 hours.
Players reporting a recent history of concussion (within the previous 12 months) were 20% more likely to sustain an mTBI after 20 hours of game time compared to players with no recent history of concussion.
Players were more likely to sustain an mTBI in shorter time if they trained < 3 hours per week or had a body mass index < 27.
Competition level was a significant risk factor for mTBI, with schoolboys at a lower risk compared to adult levels of competition.
Haseler et al. (2010) (89) / Examine the epidemiology of injuries in English youth community rugby union / The overall incidence of injury was reported to be 24.0 per 1,000 player hours.
Injury rates were found to increase significantly with age.
The injury rate for u/17s was 49.3 injuries per 1,000 player hours.
59% of injuries occurred in the tackle, the knee (4.9 per 1,000 player hours), shoulder (4.9) and head (4.3) were the most commonly affected regions.
The incidence of concussive injury during match play was 1.8 per 1,000 player hours, with the head and neck region recording an overall match play injury incidence of 6.1 per 1,000 player hours.
Fuller and Molloy (2011) (99) / Examine the epidemiology of injuries in men’s international under-20s rugby union tournaments / The overall incidence of injury was reported to be 57.2 per 1,000 player match hours (forwards 55.3; backs 59.4).
The mean days of time lost was 22.4 days (forwards 27.7; backs 16.9).
Most injuries were sustained during tackles (45.1%) and collisions (17.7%).
Head/neck match play injury incidence was 12.1 per 1,000 player hours (forwards: 12.5; backs: 11.6), while the overall central/peripheral nervous system match play injury incidence was 6.9 per 1,000 player hours (forwards: 5.7; backs: 8.1).
Fuller et al. (2010) (95) / Examine the epidemiology of injuries in international rugby sevens / The overall incidence of injury was reported to be 106.2 per 1,000 player match hours.
The mean days of time lost was 45.
The incidence of match play concussion injury was 2.0 per 1,000 player hours.
Head/neck match play injury incidence was 4.9 per 1,000 player hours (forwards: 7.3; backs: 3.3), while the overall central and peripheral nervous system match play injury incidence was 4.9 per 1,000 player hours (forwards: 4.9; backs: 5.0).
Fuller et al. (2010) (94) / To compare the incidence, nature, and cause of injuries sustained in rugby union played on artificial turf and grass / There were no significant differences in overall incidence or severity of training injuries sustained on artificial turf and grass. Incidence of match injuries per 1,000 player hours: artificial turf: 38.2; grass: 26.9.
The lower limb and muscle/tendon injuries were the most common location and type of training injury on both surfaces.
Only three concussions were recorded: artificial turf: 1; grass: 2.
Head/neck injury on grass: 25.0; artificial turf: 19.2;
Central & Peripheral Nervous System injury on grass: 10.7; artificial turf: 1.9
Training injuries: head/neck injury on grass: 4.6; artificial turf: 3.7
Training injuries: Central & Peripheral Nervous System injury on grass: 3.0; artificial turf: 0.0
Gardner et al. (2010) (123) / To examine the potential cognitive effects of multiple self-reported concussions in a sample of rugby union players / Players with a self-reported history of three or more concussions performed significantly slower across both pencil and paper and computerised measures of processing speed as a group, than those players who had no self-reported history of concussion.
No player from either group performed below -1.5 SD on the measures that demonstrated significant differences between groups, suggesting these measures are particularly sensitive to the residual effects of concussion.
Fuller et al. (2010) (122) / Examine the injury risk associated with tackling in rugby union / High-speed going into the tackle, high impact force, collisions and contact with a player’s head/neck were identified as significant risk factors for ball carriers and tacklers.
Midfield backs were significantly more prone to injury when tackling than other players.
Relatively few tacklers were penalised by referees for collision tackles (general play: 2.0%; injured players 3.3%) and tackles above the line of the shoulder (general play: 5.9%; injured players 16.7%).
In terms of injury, BC was significantly (p=0.006) more likely to be a back, but there were no significant differences between forwards and backs.
There was no indication that double-tackles from opposing directions were significantly more likely to result in injury to ball carriers than double-tackles from the same direction.
In over 98% of tackle events, the ball carrier, tackler number 1 and tackler number 2, went into the tackle with their head/neck in the ‘head-up’ position; only three players (all BCs) sustained an injury when their head was in the ‘chin-on-chest’ position, and none of these involved injuries to the players’ head/necks.
Tacklers were more likely to be injured in a tackle if their heads were in front, and less likely to be injured if above the ball carrier.
Ball carriers and tacklers were all significantly more likely to sustain an injury if they were struck on the head/neck during a tackle; the majority of these injuries were concussions or cervical nerve root injuries.
For BC, 70.0% of the head/neck injuries were sustained during tackles from the front.
Of 13 concussion and cervical nerve root injuries sustained by tackler number 1, significantly more (eight injuries, 61.5%) were experienced by midfield backs.
The risk ratio associated with head/neck injuries sustained by ball carriers and tackler number 1 in all tackles; of the eight head/neck injuries sustained by tackler number 1 following contact with the ball carrier’s lower limb, four (50.0%) were a result of direct contact with the tackler’s head/neck.
McIntosh et al. (2010) (93) / Incidence of head, neck and facial injuries in youth rugby and associated risk factors / 554 head, face and neck injuries were recorded within a total of 28 902 hours of rugby game exposure, equating to 19.2 injuries per 1,000 player hours.
Level of play and player position were related to injury risk.
Younger players had the lowest rates of injury.
Forwards, especially the front row had the highest rate of neck injury; and inside backs had the highest rate of injuries causing the player to miss a game.
Contact events, including the scrum and tackle, were the main events leading to injury.
Shuttleworth-Edwards et al. (2009) (125) / Investigate baseline neuropsychological test profiles on ImPACT in English and South African rugby union players versus US football players / An overall equivalence was observed between South African and US athletes on the neurocognitive measures, suggesting that US normative data on the ImPACT test are appropriate for use on English first language South African athletes.