Effects of Soccer Heading on Brain Structure and Function

Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of six to twelve incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety guidelines that could help to minimize the risk of possible adverse effects of soccer on brain structure and function

Concussion in Women’s Soccer: A Prescriptive Analysis of Force Loading During Heading

Women’s soccer has the highest incidence of concussion among female sports. However, there has been relatively little research investigating the immediate and cumulative effects of soccer heading on brain injury, especially among youth. In an effort to better understand concussion in the often-underserved population of women high school soccer players, we investigated, both quantitatively and qualitatively, the nature of force loading during heading of a soccer ball. Data was collected from the Oxford High School Women’s Varsity Soccer Team using X2 Biosystems’ xPatch, which measures force loading magnitude and direction with six degrees of linear and rotational freedom using a 3-axis gyroscope and a high-G 3-axis accelerometer. Analysis included skill set differentiation, baseline assessment of heading skill, live-play data collection, and comparative analysis of player-by-player technique. Heading type impact data was analyzed to find if a correlation exists between the types of header (passing, shooting, clearing) and force loading. The distance, velocity, and angle of the incoming ball were varied to examine how players alter form in response to changes in these variables. In addition, form and force-loading data was contrasted for headers performed while stationary versus headers performed while moving. Player-by-player analysis included differentiation of position (defender, midfielder, forward) to assess if correlations could be made regarding form/force loading and player position. The overall goal was to provide prescriptive analysis and recommendation of form in relation to force loading of soccer headers with minimum training obtrusiveness and maximum player benefit. This study serves as a broad overview of the varying types of headers and the relations between those header types, player profiles, and heading impact profiles. As such, no definitive conclusions were made. This study does, however, show that useful quantitative and qualitative correlations can be made and evaluated in regards to heading and impact profile