If your child is an avid soccer play, you may be wondering whether “heading” – where a player hits the ball with their head to move it in a certain direction – can cause neck, spine, and head injuries.
The bad news is that, according to a preliminary study by University of Delaware researchers, repetitive head impacts of soccer headers can have the potential to cause a subtle neurological deficit. The good news is that with proper technique and protective headgear, it’s possible to reduce your child’s risk.
“Soccer headers are repetitive sub-concussive head impacts that may be associated with problems with thinking and memory skills and structural changes in the white matter of the brain,” says study author John Jeka, Ph.D., a professor, and chair of the Department of Kinesiology and Applied Physiology in the College of Health Sciences. “But the effect of headers on balance control has not been studied.”
How the research was conducted
The researchers studied 20 recreational and club soccer players. The average player was 22 years old and reported heading the ball 451 times in the past year. Players were asked to walk on a foam pad with their eyes closed. They were tested under two conditions – one with electrodes placed behind their ears to make them feel like they were falling sideways and another without the stimulation. The electrodes make use of a tool called galvanic vestibular stimulation that stimulates the nerves in the inner ear and brain that affect balance.
The study found that players exposed to more repetitive head impacts were more affected by the vestibular stimulation while walking, suggesting subtle balance problems. For every 500 headers that a player reported, their foot placement and hip adduction responses slightly increased.
“At this point, it appears that frequent soccer heading may result in subtle balance impairments,” says Jaclyn B. Caccese, Ph.D., one of the authors of the study. “The question is, how do we get these really subtle effects and how do they manifest to later life complications?”
Because the balance problems are so subtle, there may be no outward indication of the impact from the repetitive head impact, says Fernando V. Santos, another study author.
“We are looking to understand the relationship between head impacts and concussion,” says Santos, who is a doctoral student in the biomechanics and movement science interdisciplinary programme. “These athletes, they’ve experienced head impact and they don’t show any signs.”
The researchers say that the next step is to gain a better understanding of how people use sensory information to maintain balance following a concussion and even mild head impact that does not result in acute symptoms of a concussion.