head trauma

Can Headgear Halt Soccer Concussions?

JAMIE MALONEY, LINDA S. NIELD, MD, and MATHEW W. LIVELY, DO

Ms Maloney is a medical student and Dr Lively is professor of internal medicine and pediatrics at West Virginia University School of Medicine in Morgantown.

Linda S. Nield, MD––Series Editor:Dr Nield is associate professor of pediatrics at West Virginia University School of Medicine in Morgantown.

Parent Coach

A PARENT ASKS:

My 16-year-old daughter was diagnosed with a concussion after hitting her head against the ground during a soccer game. Her coach has recommended that I buy her a special sports headband that might prevent her from getting another concussion. Will this headband prevent another concussion?

THE PARENT COACH ADVISES:

No headband or headgear can prevent another concussion in this young athlete. Although some headgear products may decrease the force of the impact during a hit, they cannot eliminate the possibility of concussion.

Known as a sport associated with intricate footwork, speed, and well-timed passes, soccer also is classified as a high- to moderate-intensity contact/collision sport, with rates of head injury and concussion similar to those seen in football, ice hockey, lacrosse, and rugby.1,2 While the benefits of helmets and other head protection are more obvious in the latter sports, the role of headgear in soccer has been and still is unclear.

Does heading the ball cause injury? Discussion about the use of head protection in soccer took the spotlight after a 1991 study3 reported higher rates of electroencephalographic abnormalities among former professional soccer players in Norway.3-6 Because these players had headed the ball more than 2,000 times during their careers, heading was identified as a possible contributing factor to the development of chronic brain injuries similar to dementia pugilistica, a syndrome seen in boxers receiving numerous blows to the skull.4,5,7

Studies and critical reviews of literature published since then do not, however, support the idea that purposeful heading of the ball likely leads to acute or cumulative brain damage.1,5,6,8,9 A number of factors could explain the differences in findings over time, including the move away from using water-retaining leather balls (which increased in mass when wet, thus increasing the force of impact) to using synthetic, water-resistant materials.4,6 One study, for example, estimated that the average impact of purposefully heading a modern soccer ball measured well below the force necessary to generate a concussion.10 Further investigation is needed to determine whether head impacts with force deemed less than adequate to cause concussion produce neurologic or psychological consequences.1,11

Does headgear reduce the injury risk of heading? Concussion can result from an indirect force transmitted to the head, or from a direct force.8,12 These forces cause linear or rotational acceleration or deceleration injury, leading to an alteration in mental status or various other symptoms such as headache or dizziness.8 Research has explored only headgear’s possible attenuation of direct force but not indirect force.5,13-15

Delaney and colleagues2 showed that adolescent soccer players without headgear had an adjusted relative risk of 2.65 for concussion compared with players wearing headgear. This study is unique in that it showed a direct correlation between headgear use and concussion reduction.2 Other studies have examined decreasing peak impact force, rotational head acceleration, and linear head acceleration.5,14,15 Theoretically, a reduction in these areas translates into concussion prevention or reduction.16

Nevertheless, research suggests that although peak force of impact and peak acceleration at impact are diminished when wearing headgear, the results are significant only when the speed and force of the impact are high.5,14,15 When simulating the purposeful heading of a ball (associated with lower speed and force), little significant reduction in the interaction between the ball and the player’s head has been shown, suggesting that headgear may be more suited to reducing the impact from forceful blows during player-to-player or player-to-hard object contact as opposed to purposeful heading.5,15

Who is at greatest risk? Players who have sustained a previous concussion are more likely to experience a repeated incident.4,12,17,18 Each successive head trauma can be accompanied by longer and more severe periods of functional disability.4,18-21 Other high-risk groups are goalkeepers, children, and female soccer players. Goalkeepers, who are expected to stop oncoming balls kicked from short distances, are reported to be in the riskiest position. They have a higher risk of collision with a goalpost and of kicks to the head.4,11 Children are more susceptible to head injury because of their proportionately larger heads, weaker neck muscles, and thinner skulls. Younger players also lack the technical skills to properly head the ball in a way that allows the impact to dissipate away from the skull.1,4,11

Female athletes appear to be at much higher risk of head injury because of their comparatively smaller bodies and weaker neck muscles.1,2,8,11,12,14 Tierney and colleagues14 reported that while headgear-wearing male soccer players had reduced head acceleration when heading the ball, headgear-wearing female players had increased acceleration. They speculated that this could result from women athletes feeling they need to strike the ball harder or feeling safer while wearing headgear.

Obstacles to determining headgear’s effects. The numerous challenges in identifying the protective role of headgear in soccer begin with the inability of coaches, parents, and athletes to readily recognize and report concussion symptoms when they occur.2,8,11,12,17,22,23 This lack may be due in part to the fact that concussions cannot be “seen,” and that some athletes do not experience symptoms until hours or days after an injury.24 

Another challenge to defining any potential benefit of headgear is accounting for external variables (eg, ball speed, direction, and angle; location of cranial contact; player size and strength). The 4 main types of contact shown to contribute to concussions in soccer are unexpected head-to-ball contact, head-to-head contact in player collisions, head-to-ground contact in falls, and head-to-stationary object contact, such as with a goalpost.1,11,8,25 A study of collegiate athletes found that approximately 70% of concussions during soccer came from player-to-player contact.25

ASTM International has developed a standard for testing headgear during head-to-hard object contact.26 A product that satisfies the standard has the demonstrated ability to reduce the force of some of the head impacts (excluding head-to-ball impacts) that can occur during soccer.13,26 While studies have shown a reduction impact force during player-to-hard object collision when wearing ASTM-approved headgear, this translates into only a theoretic reduction in concussions.13,26,27 Because studies have insufficiently supported the protective effect of wearing headgear, the rules of the National Federation of State High School Associations, the United States Soccer Federation, and the Fédération Internationale de Football Association do not require players to wear headgear during games but do permit players to wear headgear if they so choose.28-30

Reducing soccer concussions. Coaches and parents should encourage safe player interactions regardless of safety gear. Heading the ball only should be taught to and used by players old enough to understand proper technique that allows dissipation of ball force.1,11,12 An appropriately sized ball that meets the age specifications of the players should be used.1,10 These suggestions, along with authoritative medical recommendations to increase the recognition of concussion symptoms (eg, the Centers for Disease Control and Prevention’s Heads Up initiative22) are important steps to protecting the health and safety of young soccer athletes.n

REFERENCES:

1. Koutures CG, Gregory AJM; American Academy of Pediatrics Council on Sports Medicine and Fitness. Injuries in youth soccer. Pediatrics. 2010;125(2):410-414.

2. Delaney JS, Al-Kashmiri A, Drummond R, Correa JA. The effect of protective headgear on head injuries and concussion in adolescent football (soccer) players. Br J Sports Med. 2008;42(2):110-115.

3. Tysvaer AT, Løchen EA. Soccer injuries to the brain: a neuropsychologic study of former soccer players. Am J Sports Med. 1991;19(1):56-60.

4. Delaney JS, Drummond R. Has the time come for protective headgear for soccer? Clin J Sport Med. 1999;9(3):121-123.

5. Naunheim RS, Ryden A, Standeven J, et al. Does soccer headgear attenuate the impact when heading a soccer ball? Acad Emerg Med. 2003;10(1):85-90.

6. Kirkendall DT, Garrett WE Jr. Heading in soccer: integral skill or grounds for cognitive dysfunction? J Athl Train. 2001;36(3):328-333.

7. Erlanger DM, Kutner KC, Barth JT, Barnes R. Neuropsychology of sports-related head injury: dementia pugilistica to post concussion syndrome. Clin Neuropsychol. 1999;13(2):193-209.

8. Meehan WP III, Bachur RG. Sport-related concussion. Pediatrics. 2009;123(1):114-123.

9. Jordan SE, Green GA, Galanty HL, Mandelbaum BR, Jabour BA. Acute and chronic brain injury in United States national team soccer players. Am J Sports Med. 1996;24(2):205-210.

10. Schneider K, Zernicke RF. Computer simulation of head impact: estimation of head-injury risk during soccer heading. J Appl Biomech. 1988;4(4):358-371.

11. Neidfeldt MW. Head injuries, heading, and the use of headgear in soccer. Curr Sports Med Rep. 2011;10(6):324-329.

12. Navarro RR. Protective equipment and the prevention of concussion—what is the evidence? Curr Sports Med Rep. 2011;10(1):27-31.

13. Standard Specification for Headgear Used in Soccer. West Conshohocken, PA: ASTM International; 2006, revised 2011. Standard F2439.

14. Tierney RT, Higgins M, Caswell SV, et al. Sex differences in head acceleration during heading while wearing soccer headgear. J Athl Train. 2008;43(6):578-584.

15. Broglio SP, Ju Y-Y, Broglio MD, Sell TC. The efficacy of soccer headgear. J Athl Train. 2003;38(3):220-224.

16. Halstead PD. Performance testing updates in head, face, and eye protection. J Athl Train. 2001;36(3):322-327.

17. Gerberich SG, Priest JD, Boen JR, Straub CP, Maxwell RE. Concussion incidences and severity in secondary school varsity football players. Am J Public Health. 1983;73(12):1370-1375.

18. Guskiewicz KM, McCrea M, Marshall SW, et al. Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. JAMA. 2003;290(19):2549-2555.

19. Gronwall D, Wrightson P. Cumulative effect of concussion. Lancet. 1975;2(7943):995-997.

20. Collins MW, Lovell MR, Iverson GL, Cantu RC, Maroon JC, Field M. Cumulative effects of concussion in high school athletes. Neurosurgery. 2002;51(5):1175-1181.

21. Iverson GL, Gaetz M, Lovell MR, Collins MW. Cumulative effects of concussion in amateur athletes. Brain Inj. 2004;18(5):433-443.

22. Heads up: concussion in youth sports. Centers for Disease Control and Prevention. http://www.cdc.gov/concussion/HeadsUp/youth.html. Updated May 24, 2013. Accessed June 18, 2013.

23. Kirkendall DT, Jordan SE, Garrett WE. Heading and head injuries in soccer. Sports Med. 2001;31(5):369-386.

24. Concussion in sports: how can I recognize a possible concussion? Centers for Disease Control and Prevention. http://www.cdc.gov/concussion/sports/recognize.html. Updated December 8, 2009. Accessed June 18, 2013.

25. Boden BP, Kirkendall DT, Garrett WE Jr. Concussion incidence in elite college soccer players. Am J Sports Med. 1998;26(2):238-241.

26. New soccer headgear standard to evaluate head protection products. ASTM Standardization News. March 2006. http://www.astm.org/SNEWS/MARCH_2006/
soccer_mar06.html. Accessed June 18, 2013.

27. Soccer headgear and ASTM product performance. National Federation of State High School Associations. http://www.nfhs.org. Accessed June 18, 2013.

28. U.S. Soccer Federation statement on use of padded headgear. United States Soccer Federation. http://www.ussoccer.com. Published August 25, 2005. Accessed June 18, 2013.

29. National Federation of State High School Associations (NFHS) Sports Medicine Advisory Committee (SMAC). Position statement regarding soccer headgear. National Federation of State High School Associations. http://www.nfhs.org. Revised and approved January 2012. Accessed June 18, 2013.

30. Law 4: the players’ equipment. Fédération Internationale de Football Association. http://www.fifa.com/mm/document/afdeveloping/refereeing/law_4_the_players_equipment_en_47415.pdf. Accessed June 18, 2013.