A 15-year prospective epidemiological account of acute traumatic injuries during official professional soccer league matches in Japan.

BACKGROUND: Few prospective epidemiological studies on soccer match injuries have collected continuous data using subjects from the same group. PURPOSE: To investigate long-term injury-induced changes during official matches in the professional Japanese soccer league. STUDY DESIGN: Descriptive epidemiological study. METHODS: Acute injuries during official matches among top-division Japanese professional soccer leaguers were prospectively collected from 1993 to 2007. Injuries preventing player participation for 7 days or more were defined as a reportable injury. Interseasonal variations of injury rate (IR: injuries/1000/player hours) and injury pattern (type, location, circumstances, severity, injury time, positional role, and relationship to weather) were analyzed. RESULTS: Throughout the study period, 2947 injuries from 3984 matches occurred. Mean annual IR was 21.77/1000 player hours, and annual variance showed gradual decrement throughout the study period. The proportion of injury type and location were not significantly changed. Sprain and contusion as injury type and thigh and ankle joint as location were the most common in every season. Contact-related injuries comprised 73.3% on average and were observed to occur more frequently during the last 15 minutes and extra time of match play. The proportion of foul play-related injuries showed a clear declining trend. The proportion of severe injury showed a sporadic increase from 2001 to 2004. The second, fifth, and sixth 15-minute match segments showed a higher IR. Goalkeepers had a lower IR versus other field players. Matches on rainy days resulted in a lower IR than did those held under other weather conditions. CONCLUSION: Long-term surveillance and statistical feedback of injury characteristics to organization members were considered effective in improving safer play awareness among players and for referees to reduce injury incidence, particularly foul play-related injuries.

Incidence of injury among adolescent soccer players: a comparative study of artificial and natural grass turfs.

OBJECTIVE: To investigate the incidence of acute injuries and soccer-related chronic pain from long-term training and during matches in adolescent players using natural grass turfs (NT) and artificial turfs (AT). DESIGN: Case-controlled prospective study. SETTING: Institutional-level Fédération Internationale de Football Association Medical Centre of Excellence. PARTICIPANTS: Youth soccer players (12-17 years of age) from 6 teams, with a predominant tendency to train on either NT or AT, were included. Of 332 players enrolled in this study, 301 remained to completion. INTERVENTIONS: Medically diagnosed acute injuries and chronic pain were recorded daily by team health care staff throughout 2005, and reports were provided monthly to the authors. ASSESSMENT OF RISK FACTORS: Noninvasive prospective study. INDEPENDENT VARIABLES: Age and turf type. MAIN OUTCOME MEASURES: Acute injuries per 1000 player hours on each surface and chronic complaints per 1000 player hours were evaluated according to frequency of surface used > or = 80% of the time. Incidence rate ratio (IRR) of acute injuries and chronic complaints during play on NT and AT was calculated. RESULTS: There was no significant difference in the incidence of acute injuries between the 2 surfaces during training and competition. However, the AT group showed a significantly higher incidence of low back pain during training (IRR, 1.62; 95% confidence interval, 1.06-2.48). Early adolescence and prolonged training hours were factors associated with an increased incidence of chronic pain in the AT group. CONCLUSION: Adolescent players routinely training on AT for prolonged periods should be carefully monitored, even on AT conforming to new standards.