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Review Article
Open Access Peer-reviewed

Concussion: A Growing Concern in the Rugby Fraternity

Wangui Anthony Muchiri , Oloo Micky Olutende, Issah W. Kweyu
American Journal of Sports Science and Medicine. 2019, 7(1), 10-15. DOI: 10.12691/ajssm-7-1-2
Received September 01, 2018; Revised October 10, 2018; Accepted January 24, 2019

Abstract

Rugby is a team contact sport that is popular in many countries. Concussion remains one of the inherent risks of participation in rugby union with Certain facets of play, as well as specific tactics and strategies in contact and collision predispose athletes to a greater chance of sustaining a concussion. While other injuries incurred by rugby players have been well studied, less focus and attention has been directed towards concussion. The Third International Conference on Concussion in Sport defined concussion as a complex pathophysiologic process induced by traumatic biomechanical forces. World Rugby (previously known as the International Rugby Board or IRB) has acknowledged that there is a significant risk associated with concussions, and have subsequently implemented a risk management strategy [1]. This systematic review aims to evaluate the available evidence on concussion in Rugby Union (here- after referred to as ‘rugby’) and to conduct an analysis of findings regarding the incidence of concussion and players knowledge on concussion. Data was collected through Library Research on Masinde Muliro university of science and technology, Kenya rugby union, Kenya rugby football clubs, internets and Hospitals and clinics affiliated to Rugby. A desk review was also conducted and a search done PsycINFO®, MEDLINE™, Embase, SPORTDiscus™, Crossref, British Journal of Medicine (BMJ) Genamics Journal Seek, Global impact factor.com, Google Scholar, Academic keys, Open Academic Journals Index, Sherpa/RoMEO (University of Nottingham), Chemical Abstracts (CAS) and Open-j-Gate. Precisely the pathophysiology of concussion is not well known but recent research show that moderate to severe brain injury causes intricate torrent of neurochemical changes in the brain. The assumption is that similar changes occur in concussion. Paucity of literature exists on player knowledge of concussion or the rate of reporting of this injury despite there now being over 20, 000 adult rugby players in Ireland only but other studies showed that participants displayed a relatively high level of knowledge with regard to what constitutes a concussion, the risk that a history of concussion holds with regard to future concussion, and the authority that should rest with medical doctors in clearing players to Return To Play following concussion. In future Biomechanical research should be done with other clinical based research to improve on sideline concussion recognition and treatment modalities. In conclusion more research on concussion education, sensitization and awareness on concussion to help reduce incidences of concussion.

1. Background

In 1823, the sport of Rugby Union or ‘rugby’ as it is colloquially known was conceptualized at the local high school in the small English town of Rugby. The sport closely resembled that of Rugby League, but forged its own identity as an independent sport following separation from rugby league 2. Rugby is a team contact sport that is popular in many countries. In France, there were more than 390, 000 licensed players in the French Rugby Union in 2010 including 4.5% women, with an increase in membership of 40% in the last five years 3. The Third International Conference on Concussion in Sport defined concussion as a complex pathophysiologic process induced by traumatic biomechanical forces 4. Concussion is an entity that can occur not only from direct head trauma, but also from a force transmitted to the head, even if seemingly mild 5. The incidence of concussion is the highest in sports that involve frequent high-impact collisions, for example those seen in rugby union, in comparison to other team sports such as soccer. 6. Certain facets of play, as well as specific tactics and strategies in contact and collision sports predispose athletes to a greater chance of sustaining a concussion. For example, the tackle phase of play in rugby union has a higher association with concussion events. Despite concussion being regarded as a common injury in rugby codes, paucity of literature exists into the chronic effects of head injuries. To date studies in retired elite rugby union players with a history of concussion have explored cognitive outcomes 7 Regional study in the Waikato region of New Zealand went beyond hospital data for Traumatic Brain Injury (TBI) and found 790 per 100, 000 8. The Feigin et al. (2013) study identified a sample of 1369 people with TBI in the Waikato region, and revealed peaks in TBI incidence occurred in 0 to 4 year old and 15 to 34 year old. Males were also more likely to experience TBI than females, with 69% of the sample being of male gender. In England Concussion is the most frequently reported injury in rugby union and rugby league and It is now the most commonly recorded injury in professional rugby union due to its increasing in incidence 9. In south Africa, the incidence of concussion in high-level under-18 rugby union players were calculated at 5.8 concussions per 1000 player-exposure hours and an incidence of 6.8 concussions per 1000 player - exposure hours was observed across four youth week rugby tournaments (under - 13, under - 16, and under - 18) 10. Interestingly, overall concussion rates (game and practice combined) in American collegiate rugby union players was recently shown to be significantly higher than that in collegiate football players 11.

World Rugby (previously known as the International Rugby Board or IRB) has acknowledged that there is a significant risk associated with concussions, and have subsequently implemented a risk management strategy, World Rugby used current scientific evidence and the 2012 international consensus statement for concussion in sport 12 to advise on concussion prevention, identification and management at various levels of play. but despite this the cases of concussion are still on the rise with the popularization of the game 13.

The Massey University researchers surveyed the tournament's 48 games and found that seven of the 13 players they deemed to have been concussed returned to the field or played in another match, against International Rugby Board guidelines 14. There is growing international attention towards understanding the relationship between repetitive concussions experienced in sport and the development of chronic neurological impairment later in life 5. The aim of the current review is to systematically evaluate the available evidence on concussion in Rugby Union (here- after referred to as ‘rugby’) and to conduct an analysis of findings regarding the incidence of concussion and knowledge of players on concussion. To examine and address this issue, observational, cohort, correlational, cross-sectional, and longitudinal studies were included in the review.

2. Methodology

The following methods were used to collect data.

Library research This was conducted in the following centers and libraries in Masinde Muliro university; 1. Kenya Rugby Union. 2. Kenya Rugby Football Clubs. 3. Internet. 4. Hospitals and clinics.

Desk review was done using the following descriptors ‘Rugby Union’, ‘rugby’, ‘union’, and ‘football’, in combination with the injury terms ‘athletic injuries’ ‘concussion’, ‘sports concussion’, ‘sports-related concussion’, ‘brain concussion’, ‘brain injury’, ‘brain injuries’, ‘mild traumatic brain injury’, ‘mTBI’, ‘traumatic brain injury’, ‘TBI’, ‘craniocerebral trauma’, ‘head injury’, and ‘brain damage’. The search was done in PsycINFO®, MEDLINE™, Embase, SPORTDiscus™, Crossref, British Journal of Medicine (BMJ) Genamics Journal Seek, Global impact factor.com, Google Scholar, Academic keys, Open Academic Journals Index, Sherpa / RoMEO (University of Nottingham), Chemical Abstracts (CAS) and Open-j-Gate.

3. Results

3.1. Epidemiology of Concussion

A number of published articles deliver sufficient detail (i.e., player exposure hours, number of concussions recorded, and/or the incidence of concussion per 1, 000 player hours) have been published. According to the RFU website, studies showed concussion has become the most common match injury, and for the first time, concussion incidence in the 2012-2013 season was above the expected variation during the 11-year study period of the English professional Rugby Survey 9. From the review by Koh et al, 15 the incidence of concussion in rugby seems to range between 1.03 and 9.05 per 1000 player- game hours. Moreover, concussions may occur during training (0.02/1000 player-hours), although their incidence is lower than that during match play 16. Further research shows that head injuries are common and account for about 25 % of injuries during play (this includes concussions, laceration, bruises, etc.). Professionally English Rugby has rates of approximately 3.9 per 1, 000 player match hours (i.e., one concussion in every six games amongst all the players involved) 9 whereas studies at the community/amateur adult level done by Roberts et al. suggest that concussion occurs at a rate of 1.2 per 1, 000 player match hours (i.e., one in every 21 games) 17. The incidence of match play ‘time-loss’ injuries reported in the men’s rugby-15s literature was 4.73 cases in 1, 000 player match hours ranging from 0.19 18 to 17.1 19. In other studies, Retired players self‐reported an average of 8.5 concussions (where they missed competing the following week), with their last concussion occurring a mean 18.7 years previously 7. In rugby 7s the incidence rates were 3.01 concussion per 1, 000 player match hours ranging from 2.0 20 to 8.3 21 the rates of injury in matches differ considerably from rates of injury during training. Holtzhausen et al found that it was quite rare (0.07 concussion per 1, 000 player practice hours), ranging between 0.0 23 and 1.5 22 concussions per 1, 000 player practice hours 16, 20, 22, 23, 24. This clearly shows that the incidences of concussiona are high in 15s rugby than in 7s due to the difference in physicality of the two types of games. The disparity in incidences of concussion between team Practice and matches is due to poor documentation during patcice and lack of trained persnnel in tarining sessions to document concussion cases hence the low incidences in training sessions this was also supported by a study done by Gardner and colleagues 2. The National Rugby League (NRL), did a survey of medically diagnosing concussions in three clubs from the 2013 season revealed an incidence rate of 14.8 concussions per 1000 player match hours 25. A survey of over 15-year period (1998-2012) on an NRL club revelead a rate of 28.3 concussion per 1000 player match 26. Since not all studies used the standardized method for presenting injury information (i.e. number of injuries per 1, 000 player-hours of exposure), that allows comparison between different groups with different number of matches, calculations were required to convert the data of some eligible studies.

3.2. Pathophysiology of Concussion

Concussion is a Trauma-induced change in mental state that may not always involve Loss in consciousness 27 it is the most common among traumatic brain injury (TBI) worldwide 28, 29. Precisely the pathophysiology of concussion is not well known but recent research show that moderate to severe brain injury causes intricate torrent of neurochemical changes in the brain. The assumption is that similar changes occur in concussion 30. The rapid onset of short of short-lived impaired of neurologic function which may resolve spontaneous is what is experts agreed unanimously as concussion 4. Concussive head injury causes the brain to experience a mechanical “shake,” by virtue of the action of the acceleration and deceleration forces transmitted to the head immediately after the impact, initiating a complex cascade of subsequent neurochemical and neurometabolic events 31. Brain injury causes a release of excitatory amino acids (EAA), induces ion flux resulting in decreased blood glucose, oxidative metabolism and blood flow 32, 33. This results in further changes of neuronal ionic homeostasis. Among the EAAs, glutamate plays the pivotal role by binding to the kainite, N-methyl-d-aspartate, and D-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ionic channels. N-methyl-d-aspartate receptor activation is responsible for a further depolarization, ultimately causing an influx of calcium ions into the cells. The essential point of this post-Traumatic ionic cellular derangement is mitochondrial calcium overloading 34, 35, 36 responsible for inducing changes of inner membrane permeability with consequent malfunctioning, uncoupling of oxidative phosphorylation, and finally, organelle swelling 37, 38. This mismatch in neurological changes may account for the symptoms and behavioral changes that are often associated with concussion. When this change resume to normal the symptoms usually disappear. The damage on the reticular activating system accounts for the loss of consciousness which recovers relatively fast and therefore consciousness is regained fairly soon after injury 39. Signs and symptoms of a concussion can be physical, emotional, postural, or cognitive. In particular, prospectively validated signs and symptoms include amnesia, loss of consciousness, headache, dizziness, blurred vision, attention deficit, memory, postural instability, and nausea 40, 41, 42 Furthermore, behavioral changes (e.g., irritability), cognitive impairment (e.g., slowed reaction times), and sleep disturbances (e.g., drowsiness) also may be observed 4.

3.3. Knowledge of Concussion

Little is known, on player knowledge of concussion or the rate of reporting of this injury despite there now being over 20, 000 adult rugby players in Ireland 43. The players Knowledge on concussion can be tested on their identification of concussion symptoms. A study done by Baker and colleagues on Ireland under 20 reported that on average, at least two symptoms (as listed on the SCAT-2) that could be experienced in the presence of concussion was identified by the players 44. Paolo Boffano et al researched on 4 rugby amateur clubs and identified that 38.5% of his population reported that they had not been informed by anyone about symptoms of concussion and its consequences. Among these, 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. 45 in other studies participants displayed a relatively high level of knowledge with regard to what constitutes a concussion, the risk that a history of concussion holds with regard to future concussion, and the authority that should rest with medical doctors in clearing players to RTP following concussion 46.

Considering the concussion knowledge differences in rugby playing experience and level of play of players a study done by Walker showed there is a discrepancy in knowledge between professional and amateur rugby players implying that there is a better chance of a player being exposed to concussion information at provincial level compared to club level or high school level where minimal medical assistance is available 46. Players knowledge on concussion can be bridged through education to players on Risks, signs and symptoms of concussion to their health. A study by Patricios exhibited that there was less adequate knowledge on the field-side management of players suspected of having a concussion and a low level of knowledge with respect to concussion-related RTP guidelines. In addition, concussion knowledge did not appear to be related to RTP attitudes. While current concussion education initiatives appear to have been partially successful, additional methods of facilitating attitudinal and behavioral changes need to be considered 47.

3.4. Diagnosis of Concussion

One of the first challenges in responding to sports-related concussions is to recognize that a player may have sustained a concussion and therefore should be removed from the activity for further evaluation. Current on-field detection methods rely heavily on sideline medical staff to identify if a player is exhibiting concussive symptoms on the field 48. The assessment of an injured player is facilitated by the presence of a certified athletic trainer, team physician, or other health care provider at the venue (e.g., field, gymnasium, or rink) where the injury occurred 49 a number of standardized tools have been agreed upon for the initial assessment of an individual for a possible concussion by qualified and certified personnel. The most accepted tool is the pocket concussion tool 50.

Others tools have been developed to diagnose the severity of concussion are the Teasdale and Jennett published Glasgow Coma Scale (GCS) in the Lancet in 1974 as an aid in the clinical assessment of post-traumatic unconsciousness 51. The GCS has three components: eye (E), verbal (V) and motor (M) response to external stimuli. The best or highest responses are recorded 51. The Standardized Assessment of Concussion (SAC) was developed to provide clinicians with a more objective and standardized method of immediately assessing an injured athlete's mental status on the sport sideline within minutes of having sustained a concussion. The instrument is intended as a supplement to other methods of concussion assessment (eg, neuropsychological evaluation, postural stability testing) but not meant to be a stand-alone measure to determine the severity of injury or an athlete's readiness to resume participation after concussion 52, 53.

3.5. Recovery (Return to Play (RTP)

A structured and well supervised by trained and certified personnel concussion rehabilitation protocol is conducive to optimal injury and safe return to play 27, 60. Walker & Psych not from their study that their participants displayed a relatively high level of knowledge with regard to what constitutes a concussion, the risk that a history of concussion holds with regard to future concussion, and the authority that should rest with medical doctors in clearing players to RTP following concussion 46. These findings were consistent with other studies in regards to RTP from concussion 61, 62, 63. In Sye et al. study coaches stated they would “keep the patient calm and responsive while medical attention was being sought”, “use the SCAT”, and “ensure an appropriate recovery period.” 62. this clearly shows that coaches have knowledge of Sports Concussion the RTP is a graded rehabilitation protocol that its end point is a return to play/match/competition. It is a stepwise process that entails;

1. No activity and complete rest until the player is asymptomatic.

2. Neuropsychological test parameters return to baseline values.

3. Exercise rehabilitation program: a) light aerobic exercise (walking and stationary bike); b sports specific training (running drills, ball handling skills); c) Non-contact drills; d) Full-contact practice; e) Game play.

The player has to proceed step by step in advance to the last level of recovery only if He / She is asymptomatic. 27 the above return to play protocol was also adopted by World Rugby (WR) after the Ist (Vienna) and 2nd [(prague) International Symposia on concussion in Sport 4.

3.6. Prevention of Concussion

There is no good clinical evidence that currently available protective equipment will prevent concussion although mouth-guards have a definite role in preventing dental and orofacial injury 4 studies in Biomechanics have shown a reduction in forces to the brain with the use of Head gear and helmets however these studies have not been translated to show a reduction in concussion incidences. 64. Tierney et al observed that certain techniques can help reduce the risk of head impacts occuring on players as the tackle was major cause of concussion players 65. Neurologically An acute injured brain may be capable of recovering after the fist blow, but a second blow during energy failure can lead to irreversible neuronal injury and massive cell death 66 this underpins the neeed for a conclusive Graduated Return to play Protocol before clearance for return to play. Educating players on sypmtoms and health effects of concussion assists players to recognize and advice pitchside medical officials to remove players whove concusssed from the field of play for further concussion tests.

4. Guidelines and Recommendations on Concussion

To gain a broader understanding of concussion and head impacts in rugby, future studies should combine biomechanical research with other clinical-based research such as medical imaging, blood testing, ocular micro-tremor, and genetic analysis. For on-field detection, approaches such as Model-Based Image-Matching (MBIM). Consensus documents on concussion should reflect on the current state of knowledge and needs to be modified according to the development of new knowledge. This provides an overview of issues that may be of importance to healthcare providers involved in the management of sports related concussion 4. Education should be an integral part in the management of concussion. Athletes, referees, administrators, parents, coaches and healthcare providers must be educated regarding the detection of concussion, its clinical features, assessment techniques and principles of safe return to play.

5. Conclusion

Concussion is a major issue in Rugby Union at present with high injury incidence and severity. Within the game, the tackle is the main cause of concussion with the tackler at highest risk. Currently detection of concussion depends highly on the sideline medical staff to identify a player exhibiting concussion symptoms with the Video review being used in more professional matches. The suggestion of using Biomechanical research using wearable head sensors can potentially improve this identification protocol by reliably measuring concussion injury thresholds and reduce effects of concussion. Extensive education programs through web-videos, social media, refresher courses to Athletes, referees, administrators, parents, coaches and healthcare providers should be intensified to grassroots/amateur rugby to increase awareness, knowledge and improve their attitude on concussion.

References

[1]  Raftery M. Concussion and chronic traumatic encephalopathy: International Rugby Board’s response. Br J Sports Med. 2014; 48(2): 79-80.
In article      View Article  PubMed
 
[2]  Gardner, A. J., Iverson, G. L., Williams, W. H., Baker, S., & Stanwell, P. (2014). A systematic review and meta-analysis of concussion in Rugby Union. Sports Medicine, 44(12), 1717-1731.
In article      View Article  PubMed
 
[3]  Chermann, J. F., Klouche, S., Savigny, A., Lefevre, N., Herman, S., & Bohu, Y. (2014). Return to rugby after brain concussion: A prospective study in 35 high level rugby players. Asian Journal of Sports Medicine, 5(4).
In article      View Article  PubMed  PubMed
 
[4]  McCrory, P., Meeuwisse, W., Johnston, K., Dvorak, J., Aubry, M., Molloy, M., & Cantu, R. (2009). Consensus statement on concussion in sport 3rd international conference on concussion in sport held in zurich, november 2008. Clinical Journal of Sport Medicine, 19(3), 185-200.
In article      View Article  PubMed
 
[5]  Guskiewicz, K. M., Marshall, S. W., Bailes, J., Mccrea, M., Harding, H. P., Matthews, A., ... Cantu, R. C. (2007). Recurrent concussion and risk of depression in retired professional football players. Medicine and Science in Sports and Exercise, 39(6), 903-909.
In article      View Article  PubMed
 
[6]  Burger, A. N., Abrahams, S., Brown, J., Hendricks, S., Mcfie, S., Patricios, J., & Burger, N. (n.d.). Long-term effects of concussion in rugby union versus other contact sports, 1-21.
In article      
 
[7]  Pearce, A. J., Rist, B., Cohen, A., & Maller, J. J. (n.d.). Neurophysiological and cognitive impairment following repeatedsports concussion injuries in retired professional rugby league players., 1-25.
In article      
 
[8]  Feigin, V. L et.al (2013) Incidence of traumatic brain injury in New Zealand: a population-based study, The Lancet Neurology, Volume 12, Issue 1, Pages 53-64, ISSN 1474-4422.
In article      
 
[9]  England Professional Rugby Injury Surveillance Project: 2015-2016 Season Report. http://www.irbplayerwelfare.com/ pdfs/RFU_Community_Rugby_Injury_Surveillance_Report_10 _11_EN.pdf. Accessed May 20, 2017.
In article      
 
[10]  Mc Fie S, et al. (2016) Incidence and Factors Associated With Concussion Injuries at the 2011 to 2014 South African Rugby Union Youth Week Tournaments. Clinical Journal of Sport Medicine.
In article      
 
[11]  Willigenburg N, W. et al (2016) Comparison of Injuries in American Collegiate Football and Club Rugby: A Prospective Cohort Study. m J Sports Med.44(3): 753-60.
In article      View Article  PubMed
 
[12]  McCrory P, Meeuwisse WH, Aubry M, et al (2012) Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012 Br J Sports Med 2013; 47: 250-258.
In article      
 
[13]  Patricios JS, Makdissi M. (2014) The sports concussion picture: fewer ‘pixels', more HD Br J Sports Med 2014; 48: 71-72.
In article      View Article  PubMed
 
[14]  Wadesportspin, B. A., Wadeemailprint, W., Adam, C., Cup, R. W., Black, A., Woodcock, T., … Cup, R. W. (n.d.). Rugby needs to get serious about concussions: Study.
In article      
 
[15]  Koh JO, Cassidy JD, Watkinson EJ. Incidence of concussion in contact sports: a systematic review of the evidence. Brain Inj 2003; 17: 901Y917.
In article      
 
[16]  Kemp SP, Hudson Z, Brooks JH, et al. The epidemiology of head injuries in English Professional Rugby Union. Clin J Sport Med 2008; 18: 227Y234.
In article      
 
[17]  Roberts SP, Trewartha G, England M, et al. Epidemiology of time-loss injuries in English community-level rugby union. Br Med J. 2013; 3(11): e003998.
In article      
 
[18]  Davidson RM. Schoolboy rugby injuries, 1969-1986. Med J Aust. 1987; 147(3): 119-20.
In article      PubMed
 
[19]  Lee AJ, Garraway WM. Epidemiological comparison of injuries in school and senior club rugby. Br J Sports Med. 1996; 30 (3): 213-7.
In article      View Article
 
[20]  Fuller C, Sheerin K, Targett S. Rugby World Cup 2011: Inter- national Rugby Board Injury Surveillance Study. Br J Sports Med. 2013; 47(18): 1184-91.
In article      View Article  PubMed
 
[21]  Fuller CW, Taylor A, Raftery M. Epidemiology of concussion in men’s elite Rugby-7s (Sevens World Series) and Rugby-15s (Rugby World Cup, Junior World Championship and Rugby Trophy, Pacific Nations Cup and English Premiership). Br J Sports Med.
In article      
 
[22]  Marshall SW, Spencer RJ. Concussion in rugby: the hidden epidemic. J Athlet Train. 2001; 36 (3): 334-8.
In article      PubMed  PubMed
 
[23]  Holtzhausen LJ, Schwellnus MP, Jakoet I, et al. The incidence and nature of injuries in South African rugby players in the rugby Super 12 competition. S Afr Med J. 2006; 96 (12): 1260-5.
In article      PubMed
 
[24]  Kerr ZY, DeFreese JD, Marshall SW. Current physical and mental health of former collegiate athletes. Orthop J Sport Med. 2014; 2: 1-9.
In article      View Article  PubMed  PubMed
 
[25]  Gardner AJ, Kohler RMN, Levi CR, Iverson GL. Usefulness of video review of possible concussions in National Youth Rugby League. Int J Sports Med. 2016.
In article      View Article
 
[26]  Savage J, Hooke C, Orchard J, Parkinson R. The incidence of concussion in a professional Australian rugby league team, 1998-2012. J Sports Med. 2013.
In article      View Article  PubMed  PubMed
 
[27]  Aubry M, Centu R, Dvorak J, et al Summary and agreement of the First International Conference on Concussion in Sport, Vienna 2001. Recommendations for the improvement of safety and health of athletes who may suffer concussive injuries, Br J Sports Med 2002; 36: 6-10.
In article      View Article  PubMed  PubMed
 
[28]  Bruns J Jr., Hauser WA. The epidemiology of traumatic brain injury: A review. Epilepsia 2003; 44(Suppl 10): 2-10.
In article      View Article  PubMed
 
[29]  Tagliaferri F, Compagnone C, Korsic M, Servadei F, Kraus J. A system- atic review of brain injury epidemiology in Europe. Acta Neurochir (Wien) 2006; 148: 255-268.
In article      View Article  PubMed
 
[30]  McCrory PR, should we treat concussion pharmacologically? BrJ Sports med 2002: 36: 3-5.
In article      View Article  PubMed  PubMed
 
[31]  Choe, M. C. (2016). The Pathophysiology of Concussion. Current Pain and Headache Reports, 20(6), S359-S368.
In article      View Article  PubMed
 
[32]  Hovda DA, Lee SM, Smith ML, et al. The neurochemical and metabolic cascade following brain injury, lancet 2004; 2: 605-9.
In article      
 
[33]  Katayama Y, Becker DP, Tamura T, et al. Massive increases in extracel- lular potassium and the indiscriminate release of glutamate following concussive brain injury. J Neurosurg 1990; 73: 889-900.
In article      View Article  PubMed
 
[34]  Xiong Y, Gu Q, Peterson PL, Muizelaar JP, Lee CP. Mitochondrial dysfunction and calcium perturbation induced by traumatic brain injury. J Neurotrauma 2007; 14: 23-34.
In article      View Article  PubMed
 
[35]  Nicholls DG, Budd SL. Mitochondria and neuronal glutamate excito- toxicity. Biochim Biophys Acta 1998; 1366: 97-112.
In article      View Article
 
[36]  Khodorov B, Pinelis V, Storozhevykh T, Vergun O, Vinskaya N. Dom- inant role of mitochondria in protection against a delayed neuronal Ca2 overload induced by endogenous excitatory amino acids follow- ing a glutamate pulse. FEBS Lett 1996; 393: 135-138.
In article      View Article
 
[37]  Zoratti M, Szabò I. The mitochondrial permeability transition. Biochim Biophys Acta 1995; 1241: 139-176.
In article      View Article
 
[38]  Schinder AF, Olson EC, Spitzer NC, Montal M. Mitochondrial dysfunc- tion is a primary event in glutamate neurotoxicity. J Neurosci 1996; 16: 6125-6133.
In article      View Article  PubMed
 
[39]  Noakes T, Du Plesis M, Common Rugby injuries, including anatomical sites and mechanisms of injury, in: Noakes T, du Plesis M, eds. Rugby Without Risk, Cape Town: J L van Schalk, 1996: 45-86.
In article      
 
[40]  Goldberg LD, Dimeff RJ. Sideline management of sport-related concussions. Sports Med Arthrosc 2006;14:199Y205.
In article      
 
[41]  Makdissi M, Darby D, Maruff P, et al. Natural history of concussion in sport : markers of severity and implications for management. Am J Sports Med 2010;38:464Y471.
In article      
 
[42]  Mansell JL, Tierney RT, Higgins M, et al. Concussive signs and symptoms following head impacts in collegiate athletes. Brain Inj 2010; 24: 1070Y1074.
In article      
 
[43]  IRFU (2007) Irish Rugby Football Union Annual Report 2006/2007.
In article      
 
[44]  Baker, J. F., Devitt, B. M., Green, J., & McCarthy, C. (2013). Concussion among under 20 rugby union players in Ireland: Incidence, attitudes and knowledge. Irish Journal of Medical Science, 182 (1), 121-125.
In article      View Article  PubMed
 
[45]  Boffano, P., Boffano, M., Gallesio, C., Roccia, F., Cignetti, R., & Piana, R. (2011). Rugby players’ awareness of concussion. Journal of Craniofacial Surgery, 22(6), 2053-2056.
In article      View Article  PubMed
 
[46]  Walker, S. P., & Psych, M. C. (2015). Concussion knowledge and return-to-play attitudes among subelite rugby union players. South African Journal of Sports Medicine, 27(2), 50-54.
In article      View Article
 
[47]  Patricios JS, Kohler RMN, Collins RM. Sports-related concussion relevant to the South African rugby environment: A review. S Afr J Sports Med 2010; 22(4): 88-94.
In article      View Article
 
[48]  Tierney, G. J., & Simms, C. K. (2017). Concussion in Rugby Union and the Role of Biomechanics. Res Medica, 24(1), 87-95.
In article      View Article
 
[49]  Graham R, Rivara FP, Ford MA, et al., editors Committee on Sports-Related Concussions in Youth; Board on Children, Youth, and Families; Institute of Medicine; National Research Council; . Washington (DC): National Academies Press (US); 2014 Feb 4.
In article      
 
[50]  Concussion in Sport Group. (2013). Pocket Concussion Recognition Tooltm. British Journal of Sports Medicine, 47 (5), 267.
In article      PubMed
 
[51]  Teasdale G, Jennett B. Assessment of coma and impaired consciousness: A practical scale. Lancet. 1974; 2(7872): 81-84.
In article      View Article
 
[52]  McCrea M, Kelly JP, Randolph C. Standardized Assessment of Concussion (SAC): Manual for Administration, Scoring and Interpretation. 2nd ed. Waukesha, WI: CNS Inc; 2000.
In article      
 
[53]  McCrea M. Standardized mental status assessment of sports concussion. Clin J Sport Med 2001; 11: 176-81.
In article      View Article  PubMed
 
[54]  DVBIC (Defense and Veterans Brain Injury Center). MACE: Military Acute Concussion Evaluation. 2012. [September 17, 2018]. https://www.jsomonline.org/TBI/MACE_Revised_2012.pdf.
In article      
 
[55]  Riemann BL, Guskiewicz KM, Shields E. Relationship between clinical and forceplate measures of postural stability. Journal of Sport Rehabilitation. 1999; 8 (2): 71-82.
In article      View Article
 
[56]  Neurocom. Sensory organizing test. 2013. [September 23, 2013]. http://resourcesonbalance.com/neurocom/protocols/sensoryImpairment/SOT.aspx.
In article      
 
[57]  Galetta KM, Brandes LE, Maki K, Dziemianowicz MS, Laudano E, Allen M, Lawler K, Sennett B, Wiebe D, Devick S, Messner LV, Galetta SL, Balcer LJ. The King-Devick test and sports-related concussion: Study of a rapid visual screening tool in a collegiate cohort. Journal of the Neurological Sciences. 2011; 309(1-2): 34-39.
In article      View Article  PubMed
 
[58]  Eckner JT, Kutcher JS, Richardson JK. Pilot evaluation of a novel clinical test of reaction time in National Collegiate Athletic Association Division I football players. Journal of Athletic Training. 2010; 45 (4): 327-332.
In article      View Article  PubMed  PubMed
 
[59]  Eckner JT, Kutcher JS, Broglio SP, Richardson JK. British Journal of Sports Medicine. 2013. Effect of sport-related concussion on clinically measured simple reaction time. (Published online first: January 11).
In article      
 
[60]  Johnston KM, McCory P, Mohtadi NG, Meeuwisse W, Evidence-Based review of sport-related concussion: clinical science. clin J Sport Med 2001; 11: 150-9.
In article      
 
[61]  Hollis SJ, Stevenson MR, McIntosh AS, et al. Compliance with return-to-play regulations following concussion in Australian schoolboy and community rugby union players. Br J Sports Med 2012; 46 (10): 735-740.
In article      View Article  PubMed
 
[62]  Sye G, Sullivan SJ, McCrory P. High school rugby players’ understanding of concussion and return to play guidelines. Br J Sports Med 2006; 40 (12): 1003-1005.
In article      View Article  PubMed  PubMed
 
[63]  White PE, Newton JD, Makdissi M, et al. Knowledge about sports-related concussion: Is the message getting through to coaches and trainers? Br J Sports Med 2014; 48 (2): 119-124.
In article      View Article  PubMed
 
[64]  Mueller BA, Cummings P, Rivara FP, et al. Injuries of the head, face, and neck in relation to ski helmet use. Epidemiology 2008; 19: 270-6.
In article      View Article  PubMed
 
[65]  Tierney GJ, Lawler J, Denvir K, McQuilkin K, Simms CK. Risks associated with significant head impact events in elite rugby union. Brain Inj. 2016; 30 (11): 1350-61.
In article      View Article  PubMed
 
[66]  Slobounov, S., & Sebastianelli, W. (2006). Foundations of Sport-Related Brain Injuries (Google eBook), (January 2006), 502.
In article      
 
[67]  French, L., McCrea, M., & Baggett, M. (2008). The military acute concussion evaluation. (MACE). Journal of Special Operations Medicine, 8(1), 68-77.
In article      
 
[68]  Gardner AJ, Iverson GL, Quinn TN, Makdissi M, Levi CR, Shultz SR, Wright DK, Stanwell P. A preliminary video analysis of concussion in the National Rugby League. Brain Inj. 2015; 29: 1182-5.
In article      View Article  PubMed
 
[69]  McCrea M, Kelly JP, Randolph C. Standardized Assessment of Concussion (SAC): Manual for Administration, Scoring and Interpretation. Waukesha, WI: CNS Inc; 1996.
In article      
 

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Wangui Anthony Muchiri, Oloo Micky Olutende, Issah W. Kweyu. Concussion: A Growing Concern in the Rugby Fraternity. American Journal of Sports Science and Medicine. Vol. 7, No. 1, 2019, pp 10-15. http://pubs.sciepub.com/ajssm/7/1/2
MLA Style
Muchiri, Wangui Anthony, Oloo Micky Olutende, and Issah W. Kweyu. "Concussion: A Growing Concern in the Rugby Fraternity." American Journal of Sports Science and Medicine 7.1 (2019): 10-15.
APA Style
Muchiri, W. A. , Olutende, O. M. , & Kweyu, I. W. (2019). Concussion: A Growing Concern in the Rugby Fraternity. American Journal of Sports Science and Medicine, 7(1), 10-15.
Chicago Style
Muchiri, Wangui Anthony, Oloo Micky Olutende, and Issah W. Kweyu. "Concussion: A Growing Concern in the Rugby Fraternity." American Journal of Sports Science and Medicine 7, no. 1 (2019): 10-15.
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[1]  Raftery M. Concussion and chronic traumatic encephalopathy: International Rugby Board’s response. Br J Sports Med. 2014; 48(2): 79-80.
In article      View Article  PubMed
 
[2]  Gardner, A. J., Iverson, G. L., Williams, W. H., Baker, S., & Stanwell, P. (2014). A systematic review and meta-analysis of concussion in Rugby Union. Sports Medicine, 44(12), 1717-1731.
In article      View Article  PubMed
 
[3]  Chermann, J. F., Klouche, S., Savigny, A., Lefevre, N., Herman, S., & Bohu, Y. (2014). Return to rugby after brain concussion: A prospective study in 35 high level rugby players. Asian Journal of Sports Medicine, 5(4).
In article      View Article  PubMed  PubMed
 
[4]  McCrory, P., Meeuwisse, W., Johnston, K., Dvorak, J., Aubry, M., Molloy, M., & Cantu, R. (2009). Consensus statement on concussion in sport 3rd international conference on concussion in sport held in zurich, november 2008. Clinical Journal of Sport Medicine, 19(3), 185-200.
In article      View Article  PubMed
 
[5]  Guskiewicz, K. M., Marshall, S. W., Bailes, J., Mccrea, M., Harding, H. P., Matthews, A., ... Cantu, R. C. (2007). Recurrent concussion and risk of depression in retired professional football players. Medicine and Science in Sports and Exercise, 39(6), 903-909.
In article      View Article  PubMed
 
[6]  Burger, A. N., Abrahams, S., Brown, J., Hendricks, S., Mcfie, S., Patricios, J., & Burger, N. (n.d.). Long-term effects of concussion in rugby union versus other contact sports, 1-21.
In article      
 
[7]  Pearce, A. J., Rist, B., Cohen, A., & Maller, J. J. (n.d.). Neurophysiological and cognitive impairment following repeatedsports concussion injuries in retired professional rugby league players., 1-25.
In article      
 
[8]  Feigin, V. L et.al (2013) Incidence of traumatic brain injury in New Zealand: a population-based study, The Lancet Neurology, Volume 12, Issue 1, Pages 53-64, ISSN 1474-4422.
In article      
 
[9]  England Professional Rugby Injury Surveillance Project: 2015-2016 Season Report. http://www.irbplayerwelfare.com/ pdfs/RFU_Community_Rugby_Injury_Surveillance_Report_10 _11_EN.pdf. Accessed May 20, 2017.
In article      
 
[10]  Mc Fie S, et al. (2016) Incidence and Factors Associated With Concussion Injuries at the 2011 to 2014 South African Rugby Union Youth Week Tournaments. Clinical Journal of Sport Medicine.
In article      
 
[11]  Willigenburg N, W. et al (2016) Comparison of Injuries in American Collegiate Football and Club Rugby: A Prospective Cohort Study. m J Sports Med.44(3): 753-60.
In article      View Article  PubMed
 
[12]  McCrory P, Meeuwisse WH, Aubry M, et al (2012) Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012 Br J Sports Med 2013; 47: 250-258.
In article      
 
[13]  Patricios JS, Makdissi M. (2014) The sports concussion picture: fewer ‘pixels', more HD Br J Sports Med 2014; 48: 71-72.
In article      View Article  PubMed
 
[14]  Wadesportspin, B. A., Wadeemailprint, W., Adam, C., Cup, R. W., Black, A., Woodcock, T., … Cup, R. W. (n.d.). Rugby needs to get serious about concussions: Study.
In article      
 
[15]  Koh JO, Cassidy JD, Watkinson EJ. Incidence of concussion in contact sports: a systematic review of the evidence. Brain Inj 2003; 17: 901Y917.
In article      
 
[16]  Kemp SP, Hudson Z, Brooks JH, et al. The epidemiology of head injuries in English Professional Rugby Union. Clin J Sport Med 2008; 18: 227Y234.
In article      
 
[17]  Roberts SP, Trewartha G, England M, et al. Epidemiology of time-loss injuries in English community-level rugby union. Br Med J. 2013; 3(11): e003998.
In article      
 
[18]  Davidson RM. Schoolboy rugby injuries, 1969-1986. Med J Aust. 1987; 147(3): 119-20.
In article      PubMed
 
[19]  Lee AJ, Garraway WM. Epidemiological comparison of injuries in school and senior club rugby. Br J Sports Med. 1996; 30 (3): 213-7.
In article      View Article
 
[20]  Fuller C, Sheerin K, Targett S. Rugby World Cup 2011: Inter- national Rugby Board Injury Surveillance Study. Br J Sports Med. 2013; 47(18): 1184-91.
In article      View Article  PubMed
 
[21]  Fuller CW, Taylor A, Raftery M. Epidemiology of concussion in men’s elite Rugby-7s (Sevens World Series) and Rugby-15s (Rugby World Cup, Junior World Championship and Rugby Trophy, Pacific Nations Cup and English Premiership). Br J Sports Med.
In article      
 
[22]  Marshall SW, Spencer RJ. Concussion in rugby: the hidden epidemic. J Athlet Train. 2001; 36 (3): 334-8.
In article      PubMed  PubMed
 
[23]  Holtzhausen LJ, Schwellnus MP, Jakoet I, et al. The incidence and nature of injuries in South African rugby players in the rugby Super 12 competition. S Afr Med J. 2006; 96 (12): 1260-5.
In article      PubMed
 
[24]  Kerr ZY, DeFreese JD, Marshall SW. Current physical and mental health of former collegiate athletes. Orthop J Sport Med. 2014; 2: 1-9.
In article      View Article  PubMed  PubMed
 
[25]  Gardner AJ, Kohler RMN, Levi CR, Iverson GL. Usefulness of video review of possible concussions in National Youth Rugby League. Int J Sports Med. 2016.
In article      View Article
 
[26]  Savage J, Hooke C, Orchard J, Parkinson R. The incidence of concussion in a professional Australian rugby league team, 1998-2012. J Sports Med. 2013.
In article      View Article  PubMed  PubMed
 
[27]  Aubry M, Centu R, Dvorak J, et al Summary and agreement of the First International Conference on Concussion in Sport, Vienna 2001. Recommendations for the improvement of safety and health of athletes who may suffer concussive injuries, Br J Sports Med 2002; 36: 6-10.
In article      View Article  PubMed  PubMed
 
[28]  Bruns J Jr., Hauser WA. The epidemiology of traumatic brain injury: A review. Epilepsia 2003; 44(Suppl 10): 2-10.
In article      View Article  PubMed
 
[29]  Tagliaferri F, Compagnone C, Korsic M, Servadei F, Kraus J. A system- atic review of brain injury epidemiology in Europe. Acta Neurochir (Wien) 2006; 148: 255-268.
In article      View Article  PubMed
 
[30]  McCrory PR, should we treat concussion pharmacologically? BrJ Sports med 2002: 36: 3-5.
In article      View Article  PubMed  PubMed
 
[31]  Choe, M. C. (2016). The Pathophysiology of Concussion. Current Pain and Headache Reports, 20(6), S359-S368.
In article      View Article  PubMed
 
[32]  Hovda DA, Lee SM, Smith ML, et al. The neurochemical and metabolic cascade following brain injury, lancet 2004; 2: 605-9.
In article      
 
[33]  Katayama Y, Becker DP, Tamura T, et al. Massive increases in extracel- lular potassium and the indiscriminate release of glutamate following concussive brain injury. J Neurosurg 1990; 73: 889-900.
In article      View Article  PubMed
 
[34]  Xiong Y, Gu Q, Peterson PL, Muizelaar JP, Lee CP. Mitochondrial dysfunction and calcium perturbation induced by traumatic brain injury. J Neurotrauma 2007; 14: 23-34.
In article      View Article  PubMed
 
[35]  Nicholls DG, Budd SL. Mitochondria and neuronal glutamate excito- toxicity. Biochim Biophys Acta 1998; 1366: 97-112.
In article      View Article
 
[36]  Khodorov B, Pinelis V, Storozhevykh T, Vergun O, Vinskaya N. Dom- inant role of mitochondria in protection against a delayed neuronal Ca2 overload induced by endogenous excitatory amino acids follow- ing a glutamate pulse. FEBS Lett 1996; 393: 135-138.
In article      View Article
 
[37]  Zoratti M, Szabò I. The mitochondrial permeability transition. Biochim Biophys Acta 1995; 1241: 139-176.
In article      View Article
 
[38]  Schinder AF, Olson EC, Spitzer NC, Montal M. Mitochondrial dysfunc- tion is a primary event in glutamate neurotoxicity. J Neurosci 1996; 16: 6125-6133.
In article      View Article  PubMed
 
[39]  Noakes T, Du Plesis M, Common Rugby injuries, including anatomical sites and mechanisms of injury, in: Noakes T, du Plesis M, eds. Rugby Without Risk, Cape Town: J L van Schalk, 1996: 45-86.
In article      
 
[40]  Goldberg LD, Dimeff RJ. Sideline management of sport-related concussions. Sports Med Arthrosc 2006;14:199Y205.
In article      
 
[41]  Makdissi M, Darby D, Maruff P, et al. Natural history of concussion in sport : markers of severity and implications for management. Am J Sports Med 2010;38:464Y471.
In article      
 
[42]  Mansell JL, Tierney RT, Higgins M, et al. Concussive signs and symptoms following head impacts in collegiate athletes. Brain Inj 2010; 24: 1070Y1074.
In article      
 
[43]  IRFU (2007) Irish Rugby Football Union Annual Report 2006/2007.
In article      
 
[44]  Baker, J. F., Devitt, B. M., Green, J., & McCarthy, C. (2013). Concussion among under 20 rugby union players in Ireland: Incidence, attitudes and knowledge. Irish Journal of Medical Science, 182 (1), 121-125.
In article      View Article  PubMed
 
[45]  Boffano, P., Boffano, M., Gallesio, C., Roccia, F., Cignetti, R., & Piana, R. (2011). Rugby players’ awareness of concussion. Journal of Craniofacial Surgery, 22(6), 2053-2056.
In article      View Article  PubMed
 
[46]  Walker, S. P., & Psych, M. C. (2015). Concussion knowledge and return-to-play attitudes among subelite rugby union players. South African Journal of Sports Medicine, 27(2), 50-54.
In article      View Article
 
[47]  Patricios JS, Kohler RMN, Collins RM. Sports-related concussion relevant to the South African rugby environment: A review. S Afr J Sports Med 2010; 22(4): 88-94.
In article      View Article
 
[48]  Tierney, G. J., & Simms, C. K. (2017). Concussion in Rugby Union and the Role of Biomechanics. Res Medica, 24(1), 87-95.
In article      View Article
 
[49]  Graham R, Rivara FP, Ford MA, et al., editors Committee on Sports-Related Concussions in Youth; Board on Children, Youth, and Families; Institute of Medicine; National Research Council; . Washington (DC): National Academies Press (US); 2014 Feb 4.
In article      
 
[50]  Concussion in Sport Group. (2013). Pocket Concussion Recognition Tooltm. British Journal of Sports Medicine, 47 (5), 267.
In article      PubMed
 
[51]  Teasdale G, Jennett B. Assessment of coma and impaired consciousness: A practical scale. Lancet. 1974; 2(7872): 81-84.
In article      View Article
 
[52]  McCrea M, Kelly JP, Randolph C. Standardized Assessment of Concussion (SAC): Manual for Administration, Scoring and Interpretation. 2nd ed. Waukesha, WI: CNS Inc; 2000.
In article      
 
[53]  McCrea M. Standardized mental status assessment of sports concussion. Clin J Sport Med 2001; 11: 176-81.
In article      View Article  PubMed
 
[54]  DVBIC (Defense and Veterans Brain Injury Center). MACE: Military Acute Concussion Evaluation. 2012. [September 17, 2018]. https://www.jsomonline.org/TBI/MACE_Revised_2012.pdf.
In article      
 
[55]  Riemann BL, Guskiewicz KM, Shields E. Relationship between clinical and forceplate measures of postural stability. Journal of Sport Rehabilitation. 1999; 8 (2): 71-82.
In article      View Article
 
[56]  Neurocom. Sensory organizing test. 2013. [September 23, 2013]. http://resourcesonbalance.com/neurocom/protocols/sensoryImpairment/SOT.aspx.
In article      
 
[57]  Galetta KM, Brandes LE, Maki K, Dziemianowicz MS, Laudano E, Allen M, Lawler K, Sennett B, Wiebe D, Devick S, Messner LV, Galetta SL, Balcer LJ. The King-Devick test and sports-related concussion: Study of a rapid visual screening tool in a collegiate cohort. Journal of the Neurological Sciences. 2011; 309(1-2): 34-39.
In article      View Article  PubMed
 
[58]  Eckner JT, Kutcher JS, Richardson JK. Pilot evaluation of a novel clinical test of reaction time in National Collegiate Athletic Association Division I football players. Journal of Athletic Training. 2010; 45 (4): 327-332.
In article      View Article  PubMed  PubMed
 
[59]  Eckner JT, Kutcher JS, Broglio SP, Richardson JK. British Journal of Sports Medicine. 2013. Effect of sport-related concussion on clinically measured simple reaction time. (Published online first: January 11).
In article      
 
[60]  Johnston KM, McCory P, Mohtadi NG, Meeuwisse W, Evidence-Based review of sport-related concussion: clinical science. clin J Sport Med 2001; 11: 150-9.
In article      
 
[61]  Hollis SJ, Stevenson MR, McIntosh AS, et al. Compliance with return-to-play regulations following concussion in Australian schoolboy and community rugby union players. Br J Sports Med 2012; 46 (10): 735-740.
In article      View Article  PubMed
 
[62]  Sye G, Sullivan SJ, McCrory P. High school rugby players’ understanding of concussion and return to play guidelines. Br J Sports Med 2006; 40 (12): 1003-1005.
In article      View Article  PubMed  PubMed
 
[63]  White PE, Newton JD, Makdissi M, et al. Knowledge about sports-related concussion: Is the message getting through to coaches and trainers? Br J Sports Med 2014; 48 (2): 119-124.
In article      View Article  PubMed
 
[64]  Mueller BA, Cummings P, Rivara FP, et al. Injuries of the head, face, and neck in relation to ski helmet use. Epidemiology 2008; 19: 270-6.
In article      View Article  PubMed
 
[65]  Tierney GJ, Lawler J, Denvir K, McQuilkin K, Simms CK. Risks associated with significant head impact events in elite rugby union. Brain Inj. 2016; 30 (11): 1350-61.
In article      View Article  PubMed
 
[66]  Slobounov, S., & Sebastianelli, W. (2006). Foundations of Sport-Related Brain Injuries (Google eBook), (January 2006), 502.
In article      
 
[67]  French, L., McCrea, M., & Baggett, M. (2008). The military acute concussion evaluation. (MACE). Journal of Special Operations Medicine, 8(1), 68-77.
In article      
 
[68]  Gardner AJ, Iverson GL, Quinn TN, Makdissi M, Levi CR, Shultz SR, Wright DK, Stanwell P. A preliminary video analysis of concussion in the National Rugby League. Brain Inj. 2015; 29: 1182-5.
In article      View Article  PubMed
 
[69]  McCrea M, Kelly JP, Randolph C. Standardized Assessment of Concussion (SAC): Manual for Administration, Scoring and Interpretation. Waukesha, WI: CNS Inc; 1996.
In article