Concussions. They’re a big deal in the news these days. For football players, hockey players, and even soccer players. And especially for young soccer players. Scary stuff. And my teenage son is a soccer player. So I couldn’t resist reigniting this blog with a post about concussions in soccer. If you’ve asked yourself the question “should I be worried about my son heading the ball”, this post is for you. We’ll start with some basic facts about the number of injuries and concussions that soccer players actually experience, followed by some information on the positions that are most prone to concussions and why, and end in a summary of what all of this means for you and your family. I should point out that this post does not go in to depth about the science of concussions, or the long-term damage that they can cause. This post is focused on answering your questions on the prevalence of concussions, and what you should know to avoid them.
This post has been written in a question/answer format, with the first question I asked myself being:
As a frame of reference, how many injuries (concussions and otherwise) are suffered by high school athletes?
The incidence (or rate) of injuries for high school athletes is between 1 and 3 injuries per 1,000 athletic events [9,17]. An athletic event is not exactly what you think it is and it’s an abstract number for sure. So let me provide some context, and I’ll provide that context in the realm of soccer because that’s the focus of this post.
For the average high-level soccer player who participates in five athletic events (practices and/or games) each week during an 11-month year and is on a 18-person team, an injury rate of 1-3 injuries per 1,000 athletic events would equate to the ENTIRE team experiencing five to eleven injuries during the year. So the average high school team would be forecast to experience 5 to 11 injuries per season. Keep in mind that’s all injuries (which would include concussions, sprained ankles, broken bones, etc) for all of the players combined. For teams who have shorter seasons, smaller rosters or fewer practices/games, the numbers would be smaller.
Now let’s whittle that down. How many concussions do high school athletes suffer?
The number of concussions experienced by the average high school athlete is reported to be approximately 2 to 4 per 10,000 athletic events [4,11].
In context: using the average team described above, that would equate to an incidence of approximately one or two concussions per year for the entire team.
How many concussions do high school soccer players suffer?
The incidence of concussions in high school soccer is approximately the same as that of other high school sports, namely 2 to 4 per every 10,000 athletic events [8,11,19].
In context: for a player on the team described above, the entire team would be forecast to have one to two concussions per year (or 11-month season).
It should be noted that female soccer high school players have a higher incidence of concussions than male soccer players [8, 11, 19]. That being said, a team of female soccer players similar to the one described above would be expected to experience two or fewer concussions per 11-month season.
Do soccer players suffer more concussions than other athletes in high school?
The incidence of concussions for male soccer players is approximately the same as that of other male athletes in high school. However, the incidence of concussions for female soccer players is higher than that of other girls’ sports in general. All of the numbers are summarized graphically in Figure 1 below. That being said, we should remember that the average high school soccer team would be forecast to have 1 to 2 concussions per year.
Do college soccer players experience more concussions than high school players?
The incidences of concussions in college soccer are slightly higher than those in high school [3, 11,15], averaging 4 to 5 concussions per 10,000 athletic events.
In context: for a player on a college team similar to that described above, the entire team would be forecast to have 2 concussions per 11-month season. Similarly, Boden et al. found that the incidence of concussion in college soccer was 0.96 concussions per team per season . Which is approximately the same as that of high school soccer players.
My soccer player is in elementary school or middle school. How prevalent are concussions in players of those ages?
Witol et al. have found that “the injury rate for the 14–17-year-old group was twice as high as that for the younger players” . Conversely, other studies have reported higher incidences of concussions for female middle school soccer players . Which is right? I’m not sure, and the lack of published studies focused on youth players makes it difficult to answer that question definitively. But I would estimate that the incidence is in the same ballpark of those discussed above.
How serious are the concussions when they do happen?
When researches analyzed the types of concussions sustained by college soccer players by concussion grade, 72% were grade 1 (also known as mild concussions), 28% grade 2 (or moderate concussions), and none were grade 3 (or severe) .
How do head injuries occur in soccer?
Most concussions are caused by the following (in decreasing order of incidence):
- Player/player collisions (such as contact with another player)
- Player/equipment collisions (such as collisions with goalposts)
- Player/Playing surface contact (such as striking the ground)
- A single hard blow from the ball
Repeated heading of the ball has also been associated loosely with head trauma or what some call "micro concussions", but data do not exist supporting that relationship .
If most of the concussions are caused by collisions, how many of the concussions are actually due to a head colliding with a ball?
18% of concussions have been found to result from the act of heading . However, that doesn’t mean that the culprit was actually a ball colliding with a head. In fact, none of the references reviewed documented a concussion resulting from head-to-ball contact during the intentional heading of the ball [1,3,14,16].
That being said, concussions have been caused by a collision of the ball with the temporal area of the head (the side of the head above the ear) [8, 16]. Why? Because the head whips around in a rotational movement when the ball contacts the side of head. Kirkendall et al. stated “in soccer, head injury from ball contact is mostly due to rotational impacts from accidental contact of the ball to the head. Head-ball contacts on the side of the head of an unprepared player can obviously lead to rotational impacts. Preparation of the head cannot be understated: strike an unprepared player on the forehead, and linear forces (pushing the head posteriorly) can be coupled with transverse rotation (as in a whiplash injury)” .
So when a concussion is caused by contact between a head and the ball, the ball was not being headed properly but had either accidentally collided with the head and caused the head to whip around, or had been headed improperly.
Are there areas of the field where injuries occur more frequently?
Kirkendall et al. found that “the penalty area (where players compete for a cross-corner kick) and the collision of an onrushing forward and goalkeeper are the most likely circumstances for a head injury” . “Near the midfield line, where players compete for airballs (eg, punts, goal kicks), is another troublesome place on the field.” It was also reported that goalpost collisions are possible but not common. So the penalty area, the midfield line, and the areas around goalposts are the most likely places in which concussions occur.
Are certain player positions more prone to concussions?
Research has shown that “those players directly involved in attack or defense are those most likely to be injured” . Those players include the center back, the center forward, full-backs and the goalkeeper, who combined accounted for 86% of the medical treatments needed .
What’s important when correctly heading the ball?
“Correct heading involves use of the frontal bone to contact the ball, the neck muscles to restrict head motion, and the muscles of the lower body to position the torso in line with the head and neck to increase the resistant mass and decrease acceleration of the head” .
Why is this technique so important? Because “studies have shown that concussion is induced with difficulty when the head is held in a fixed position but more easily when the head is allowed to move freely” . Which is why concussions are caused by balls accidentally hitting the head and causing it to whip around, and not when the ball is being intentionally headed by a player.
Would the presence of an athletic trainer or physician onsite decrease the severity of concussion symptoms?
No. Research has shown that “there were no significant associations between having a medical professional on site at the time of injury and duration of symptoms or timing of return to play” .
What about those reports linking repeated heading to brain trauma in older soccer players?
All of us have probably heard about those studies and read those magazine articles. “Older soccer players reported to have neurological deficits”. I’ve studied some of those publications and the results were scary but not conclusive (in my humble opinion). In fact, the researchers themselves concluded that the results did not provide “unambiguous evidence that ball-to-head contacts are responsible for impaired functioning” . Why? Because in the few neurological measurements where differences were seen, those differences were either insignificant, significant but not large, or the measurements obtained was different but still within the normal range. Does that mean that repeated heading is completely safe? No. But studies are inconclusive at this point.
What do the experts recommend to mitigate any potential harm of heading?
Researchers and experts had several recommendations for mitigating the harm of heading in soccer. Those suggestions include:
EDUCATION. “Education should be enhanced to increase awareness of the potential for injury from heading a soccer ball” . Researchers have suggested “with better data comes an improved understanding of the types of actions and activities that typically result in concussions”. So a better understanding of how concussions take place (namely player/player contact or player/equipment contact) and which areas of the field are most important (such as the penalty area and the midfield line) is invaluable to preventing future concussions.
TRAINING. “Correct heading technique must be emphasized and promoted” . This should be accompanied by emphasizing the importance of avoiding unnecessary player/player or player/equipment contact whenever possible.
RULES. “Rules that protect players should be enforced by referees and supported by coaches, parents, and fans” . These include rules to protect the goalie and to deter reckless player/player contact.
TREATMENT. “Physicians should continue to appreciate the potential for brain injury from heading” . This includes understanding the symptoms of concussions and making sure that players are not allowed to return to play too quickly after a concussion. For example, researchers recommend athletes take "approximately 1 week after becoming asymptomatic to return to the normal level of sports activity” .
So what should we conclude about heading and concussions?
Based on the research reviewed, my conclusion is that concussions are scary but infrequent, and are generally caused by impact with other players or objects, not by the act of intentionally heading the ball. That being said, head-to-ball contact can cause a concussion when the ball collides with the side of the head or forces the head to whip around quickly during accidental contact.
So what should we do? Well, we should educate ourselves (and perhaps other soccer moms and dad) and realize that the act of heading the ball in itself maybe shouldn't be of highest concern. But the collisions that can occur while trying to head the ball should be. And although these collisions may be unavoidable, we can be more knowledgeable about them. Especially for soccer players playing in the positions that are most prone to concussions.
We should also make sure that we’re aware of the symptoms of a concussion (loss of consciousness, headache, dizziness, nausea, amnesia, etc.) and make sure that any players suspected of having a concussion are seen by a medical professional and withheld from activity until those symptoms have abated for a sustained period of time.
But perhaps most importantly, we should contextualize the importance of concussions and understand how frequently they occur, which is actually infrequently. Concussions are scary, especially for parents watching their child play a sport where concussions can happen. But hopefully some of your questions have been answered and you now know with confidence how best to educate your player about the incidence of concussions.
- Heading the Ball in Soccer: What's the Risk of Brain Injury? Asken MJ, Schwartz RC. Phys Sportsmed. 1998 Nov;26(11):37-44.
- Concussion history in elite male and female soccer players. Barnes BC, Cooper L, Kirkendall DT, McDermott TP, Jordan BD, Garrett WE Jr. Am J Sports Med. 1998 May-Jun;26(3):433-8.
- Concussion incidence in elite college soccer players. Boden BP, Kirkendall DT, Garrett WE Jr. Am J Sports Med. 1998 Mar-Apr;26(2):238-41.
- The child and adolescent athlete: a review of three potentially serious injuries. Caine D, Purcell L, Maffulli N. BMC Sports Sci Med Rehabil. 2014 Jun 10;6:22.
- Sports and recreation related injury episodes in the US population, 1997-99. Conn JM, Annest JL, Gilchrist J. Inj Prev. 2003 Jun;9(2):117-23.
- Sex Differences and the Incidence of Concussions Among Collegiate Athletes. Covassin T, Swanik CB, Sachs ML. J Athl Train. 2003 Sep;38(3):238-244.
- Helmets and mouth guards: the role of personal equipment in preventing sport-related concussions. Daneshvar DH, Baugh CM, Nowinski CJ, McKee AC, Stern RA, Cantu RC. Clin Sports Med. 2011 Jan;30(1):145-63
- The epidemiology of sport-related concussion. Daneshvar DH, Nowinski CJ, McKee AC, Cantu RC. Clin Sports Med. 2011 Jan;30(1):1-17
- Epidemiology of severe injuries among United States high school athletes: 2005-2007. Darrow CJ, Collins CL, Yard EE, Comstock RD. Am J Sports Med. 2009 Sep;37(9):1798-805.
- Epidemiology of knee injuries among U.S. high school athletes, 2005/2006-2010/2011. Swenson DM, Collins CL, Best TM, Flanigan DC, Fields SK, Comstock RD. Med Sci Sports Exerc. 2013 Mar;45(3):462-9.
- Concussions among United States high school and collegiate athletes. Gessel LM, Fields SK, Collins CL, Dick RW, Comstock RD. J Athl Train. 2007 Oct-Dec;42(4):495-503.
- Epidemiology, trends, assessment and management of sport-related concussion in United States high schools. Guerriero RM, Proctor MR, Mannix R, Meehan WP 3rd. Curr Opin Pediatr. 2012 Dec;24(6):696-701.
- American Academy of Pediatrics. Clinical report--sport-related concussion in children and adolescents. Halstead ME, Walter KD; Council on Sports Medicine and Fitness. Pediatrics. 2010 Sep;126(3):597-615.
- American Medical Society for Sports Medicine position statement: concussion in sport. Harmon KG, Drezner J, Gammons M, Guskiewicz K, Halstead M, Herring S, Kutcher J, Pana A, Putukian M, Roberts W; American Medical Society for Sports Medicine. Clin J Sport Med. 2013 Jan;23(1):1-18.
- Epidemiology of collegiate injuries for 15 sports: summary and recommendations for injury prevention initiatives. Hootman JM, Dick R, Agel J. J Athl Train. 2007 Apr-Jun;42(2):311-9.
- Heading in Soccer: Integral Skill or Grounds for Cognitive Dysfunction? Kirkendall DT, Garrett WE Jr. J Athl Train. 2001 Sep;36(3):328-333.
- A prospective study of injury incidence among North Carolina high school athletes. Knowles SB, Marshall SW, Bowling JM, Loomis D, Millikan R, Yang J, Weaver NL, Kalsbeek W, Mueller FO. Am J Epidemiol. 2006 Dec 15;164(12):1209-21.
- PREVENTION OF SPORTS INJURIES: Systematic review and meta-analysis of randomized controlled trials. Masters Thesis by Mari Leppänen.
- Epidemiology of concussions among United States high school athletes in 20 sports. Marar M, McIlvain NM, Fields SK, Comstock RD. Am J Sports Med. 2012 Apr;40(4):747-55.
- Trends in concussion return-to-play timelines among high school athletes from 2007 through 2009. McKeon JM, Livingston SC, Reed A, Hosey RG, Black WS, Bush HM. J Athl Train. 2013 Nov-Dec;48(6):836-43.
- Assessment and management of sport-related concussions in United States high schools. Meehan WP 3rd, d'Hemecourt P, Collins CL, Comstock RD. Am J Sports Med. 2011 Nov;39(11):2304-10
- A profile of pediatric sports injuries at three types of medical practices. Naughton, G.; Broderick, C.; Van Doorn, N.; Lam, L.; Browne, G. December 2007. Acta Kinesiologiae Universitatis Tartuensis;2007 Supplement, Vol. 12, p147
- Concussion among female middle-school soccer players. O'Kane JW, Spieker A, Levy MR, Neradilek M, Polissar NL, Schiff MA. JAMA Pediatr. 2014 Mar;168(3):258-64.
- Head injuries in youth soccer players presenting to the emergency department. Pickett W, Streight S, Simpson K, Brison RJ. Br J Sports Med. 2005 Apr;39(4):226-31
- Injury patterns in selected high school sports: a review of the 1995-1997 seasons. Powell JW, Barber-Foss KD. J Athl Train. 1999 Jul;34(3):277-84.
- An epidemiologic comparison of high school sports injuries sustained in practice and competition. Rechel JA, Yard EE, Comstock RD. J Athl Train. 2008 Apr-Jun;43(2):197-204.
- Sports-Related Concussions in Youth: Improving the Science, Changing the Culture. Committee on Sports-Related Concussions in Youth, Board on Children, Youth, and Families, Institute of Medicine, National Research Council; Graham R, Rivara FP, Ford MA, Spicer CM, editors. Washington (DC): National Academies Press (US); 2014 Feb 04.
- Personality Traits Relate to Heading Frequency in Male Soccer Players. Webbe, F. M., & Ochs, S. R. (2007). Clinical Journal of Sport Psychology, 1, 379-389.
- Soccer heading frequency predicts neuropsychological deficits. Witol AD, Webbe FM. Arch Clin Neuropsychol. 2003 May;18(4):397-417.
- Amateur soccer: injuries in relation to field position. Hunt M, Fulford S. Br J Sports Med. 1990 Dec;24(4):265.