Epidemiological patterns of musculoskeletal injuries and physical training

Purpose: The purpose of this study was to identify rates of diagnosis-speci fic musculoskeletal injuries in U.S. Marine Corps recruits and to examine t he association between patterns of physical training and these injuries. Me thods: Subjects were 1,296 randomly selected male Marine recruits, ages 17 to 28 yr, who reported to Marine Corps Recruit Depot San Diego for boot cam p training between January 12 and September 14, 1993. Recruits were followe d prospectively through 12 wk of training for injury outcomes. Injury patte rns were examined in relation to weekly volumes and types of vigorous physi cal training. Results: The overall injury rate was 39.6% (number of recruit s injured/population at risk), with 82% of injuries occurring in the lower extremities. Overuse injuries accounted for 78% of the diagnoses. The most frequent site of injury was the ankle/foot region (34.3% of injuries), foll owed by the knee (28.1%). Ankle sprains (6.2%, N = 1,143), iliotibial band syndrome (5.3%, N = 1,143), and stress fractures (4.0%, N = 1,296) were the most common diagnoses. Injury rates were highest during the weeks with hig h total volumes of vigorous physical training and the most hours of running and matching. Weekly injury rates were significantly correlated with hours of vigorous physical training (overuse injuries r = 0.667, P = 0.018; acut e injuries r = 0.633, P = 0.027). Conclusions: The results of this controll ed epidemiological investigation indicate that volume of vigorous physical training may be an etiologic factor for exercise-related injuries. The find ings also suggest that type of training, particularly running, and abrupt i ncreases in training volume may further contribute to injury risk.