THE SOCCER DOCTOR:
The Hazards of Heading

by Dr. Rocco Monto

A soccer header is one of the most unique and thrilling motions executed in sport. When delivered with the power and elegance that it demands, it can be the most efficient weapon in a soccer player's arsenal. Despite this, it has emerged as one of the most controversial issues in recent years. At the center of the debate remains the question of possible cumulative brain injury from heading. Recent comments by Dr. David Janda of the Institute for Preventative Sports Medicine in Ann Arbor, Michigan, have once again brought the soccer headball into the media spotlight. Concerned about heading in youth soccer, Dr. Janda has been quoted as saying, "WeÍre creating a bunch of little Muhammed Alis." Citing several European studies, he has recommended pre- and post-participation academic tests as well as the mandatory use of padded helmets for players.
While the vision of a helmeted soccer team may seem like heresy to the purist, the Institute's previous recommendation for padded goalposts was well-founded. There were 18 soccer fatalities from goalpost collisions in the United States between 1979 and 1992. The use of padded goalposts will likely dramatically lower this disturbing figure without noticeably affecting the quality of the play. Their concerns regarding heading, however, are based on far less reliable information and demand closer analysis.

The European studies cited by Dr. Janda originated in Norway in the late 1980's. These reports suggested that repeated heading might eventually result in deficiencies in memory, attention, concentration, and judgment as early as age 35. Changes similar to Alzheimer's disease were noticed on brain CAT scans in one third of a group of retired middle-aged soccer players. Additional studies documented abnormal EEG brain wave patterns in 16% of young, healthy soccer players. While flawed, this early research should not be casually dismissed.

A soccer player heads the ball an average of six times per match and many more times during training sessions. This can add up to several thousand head impacts over the course of a career. A plastic-coated leather soccer ball weighs about one pound, although older versions became much heavier when soaked with water on muddy fields. A soccer ball can be driven at speeds in excess of 74 miles per hour and can deliver enough force to fracture a cheekbone. The force of heading impacts in adults fall just within the force tolerance guidelines for safety used by the automobile industry for crash safety. These safety limits are exceeded in children when an adult-sized soccer ball is used.

A recent study has shown that as many as 89% of soccer players have had at least one painful head injury and more than 10% have sustained a concussion. Still, most players escape serious head injury and few show obvious long-term disability after years of repeated heading. The real question is if soccer heading is so dangerous, where are all its "little Mohammed Alis?" Intense new research has begun to answer this apparent paradox. Detailed bio mechanical studies now show that the forces sustained by the head during heading are probably much lower than previously estimated. The force transferred to the forehead at ball contact varies between 500 and 1200 Newtons. This force is then quickly dissipated and absorbed by the upper body and torso with proper heading technique. To put this into perspective, a single punch from a boxer delivers 6300 Newtons to the head and face. Unlike soccer players, the head and brain absorb the majority of this repetitive impact force. A recent combined clinical and MRI study has shown no evidence of brain injury from the cumulative effects of repeated heading.

How can we prevent serious head injuries without resorting to the rather dubious solution of helmets? After all, the use of helmets in American football did not prevent the continued risk of concussion and head injury. The answer in soccer lies in technique and equipment. Proper heading technique is critical to player safety and must be taught from an early age to be effective. It is no accident that the ball is most powerfully struck with the forehead while the neck and torso move rigidly together at impact. This utilizes the thickest portion of the skull for contact and prevents the neck from flexing or extending dangerously. It also allows the efficient dissipation of the impact force through the head, neck, and upper body. Another benefit of good technique is the rapid return of kinetic energy to the ball for a more lethal attack. This decreases the amount of energy that the head itself must absorb at impact, thus protecting the brain from injury.

Another way to protect the younger player is to avoid a potentially treacherous mismatch between ball weight and body size. By using a smaller, lighter soccer ball in youth leagues, impact force profiles can be kept well within safe limits. The development of waterproof coating for soccer balls has also dramatically decreased the risks of heading. It prevents the potentially dangerous water-weight gains once commonly seen during foul-weather play. The effects of the heavy, water-soaked ball once quite typical in Scandinavia may have contributed to the problems seen in the middle-aged players examined in the Norwegian studies. Several studies have also shown the advantage of stitched-seam balls over other varieties in shock absorption. They work by fractionally increasing the time the ball is spent in contact with the head so that the impact energy can be better absorbed.

While the danger of heading cannot be entirely removed, it can be minimized without diluting the quality of the sport. A team of helmeted players is certainly not the answer and might even create damaging new problems. And while it might make many goalkeepers quite happy, banning heading would only rob players and fans of soccer's most unique and exciting elements. The solution remains what it always has been: good technique, proper equipment, and common sense. Unfortunately, in soccer as in life, these qualities are not always present in abundance.

Dr. Rocco Monto is an orthopedic surgeon in Massachusetts at Martha's Vineyard Orthopedic Surgery and Sports Medicine.