The effect of leg strength on the incidence of lower extremity overuse injuries during military training

This study examined the effects of strength, aerobic fitness, and activity profile on the incidence of overuse Injuries, particularly stress fractures , during military training. ti total of 136 military recruits were followed during 9 weeks of basic training. Maximal strength and aerobic fitness wer e determined by a one-repetition maximum leg press and a 2,000-m run, respe ctively, An activity profile was determined by the recruit's activity histo ry. Twelve recruits (8.8%) were diagnosed with stress fractures. Recruits w ho were 1 SD below the population mean in both absolute (98.4 +/- 36.6 kg) and relative strength (1.72 +/- 0.61 kg/kg of body weight) had a five times greater risk for stress fracture (p < 0.05) than stronger recruits. Poor a erobic fitness did not appear to be related to any increased incidence of s tress fracture. It appears that recruits with lower body strength levels, w ithin 1 SD of the population mean, have a reduced incidence of stress fract ures during military training.