Background In Japan, sports-related concussions have been a subject of active research in recent years. Among sports played in Japan, concussions occur most frequently in rugby football.

Objective The purpose of this study was to investigate the status of concussions in high school rugby players, with the intent of prevention.

Design Subjects were Japanese high school rugby players.

Setting The subjects were evaluated at a clinic in Sugadaira, a revered venue for rugby training in Japan, attended by teams from all over the country. Subjects were 178 high school rugby players who were diagnosed with concussion within 2 hours of injury. Information about the concussion was obtained from the injured player and a witness. Symptoms and disturbances of consciousness after concussion were evaluated using the Sport Concussion Assessment Tool 3 (SCAT3), in an interview format.

Results A total of 93% of subjects has been injured during a match, and 43% had a history of concussion. The contact site was the head in more than 90% of cases, with the forehead in 38%, the side of the head in 30%, the back of the head in 21%, the top in 5%, and an unknown site in 6%. The concussion occurred while performing a tackle in 61% cases, and when being tackled in 30%; the cause was uncertain in 9% cases. Symptoms were present in 94% of the subjects on SCAT3 evaluation. The most common symptom was headache (84%). Loss of consciousness occurred in only 15%, but 72% had some loss of memory.

Conclusions The most common circumstance of concussion involved head contact was when tackling an opponent. Concussion was associated with subjective symptoms and the loss of memory more often than the loss of consciousness.