A study says young athletes' thinking abilities can be seriously hindered for years by two or more significant blows to the head.
And in professional soccer, the ball can travel at nearly 85 miles per hour.
Science Specialist Ed Yeates tells us more.
At that speed, the ball isn't so soft when it hits the head.
While professional soccer players train how to butt the ball, many amateur athletes don't!
When researchers reporting in the Journal of the American Medical Association tested players, they found the head does not react well to impacts. And in soccer, continual hits can come from both the ball and butting heads with other players.
Amateur athletes scored lower - especially in memory, attention span and visual perception.
Erik J.T. Matser, St. Anna Hospital, The Netherlands: "APPROXIMATELY THREE TIMES AS MANY SOCCER PLAYERS HAVE PROBLEMS WITH PLANNING AND FOUR TIMES AS MANY SOCCER PLAYERS HAVE PROBLEMS WITH MEMORY."
While the Netherlands Group did NOT look specifically at ball butting, it supported findings from other studies which show soccer players are more vulnerable to subtle cumulative brain injuries.
Doctors and trainers at Utah's Orthopedic Specialty Hospital - called TOSH - say the actual number of concussions may be underreported.
Vern Cooley/ TOSH Physician:
"THEY DON'T TELL THE COACH. THEY DON'T TELL THE TEAM PHYSICIAN. THEY DON'T TELL THOSE INVOLVED IN THEIR CARE THAT THEY'VE HAD A HEAD INJURY."
While physical therapists and trainers doubt ball butting will be banned in soccer - some see stronger rules for training - teaching players them how to butt the ball without rattling the brain.
Larry Monson/ TOSH Therapist, Trainer: "IF YOUR BODY IS IN ONE LINE AND YOUR BODY IS RIGHT UNDERNEATH YOUR NECK AND THE FORCE IS COMING RIGHT UP THROUGH THE BODY TO THE HEAD THERE'S NOT THAT FORCE KNOCKING YOUR HEAD OFF TO THE SIDE."
Animal research suggests that the youthful brain remains vulnerable after a first concussion for a longer time than a mature brain does, so a high school athlete may need a much longer recovery time from a concussion before returning to play.
Athletes who have had two or more concussions are also more likely to report continuing problems with headaches, sleep and concentration.
