title: Prevention of Hamstring Injuries in Collegiate Sprinters.
abstract: BACKGROUND
  No studies have been reported on how strength, agility, and flexibility training reduce the occurrence of hamstring injuries in sprinters. Therefore, a program for preventing hamstring injury in these athletes has not been established.
  
  
  OBJECTIVE
  To document the incidence of hamstring injuries during times when different prevention strategies were employed to see whether a particular prevention program reduced their occurrence.
  
  
  METHODS
  Descriptive epidemiology study.
  
  
  METHODS
  The study subjects were a total of 613 collegiate male sprinters trained by the same coach over 24 seasons. Tow training was used throughout the research period as a normal sprint training method. The hamstring injury prevention program evolved over time. From 1988 to 1991 (period 1), prevention focused on strength training alone; from 1992 to 1999 (period 2), a combination of strength and agility training was used; and from 2000 to 2011 (period 3), the program incorporated strength, agility, and flexibility training. The incidence of hamstring injuries was compared for each of the 3 prevention strategies.
  
  
  RESULTS
  The incidence of hamstring injuries per athlete-seasons was 137.9 for period 1, 60.6 for period 2, and 6.7 for period 3. A significant difference was observed in the incidence of hamstring injury according to the different prevention programs (χ2(2) = 31.78,P< .001, effect size: CramerV= 0.23, 1 - β = 0.999). Residual analysis showed that the number of hamstring injuries for period 1 was significantly greater than the expected value (P< .01), whereas that for period 3 was significantly lower than the expected value (P< .01).
  
  
  CONCLUSIONS
  The incidence of hamstring injuries in sprinters decreased as agility and flexibility were added to strength training.
authors.affiliation: Laboratory of Sports Science, Meikai University, Chiba, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Sugiura
authors.affiliation: Department of Health and Sports Science, Juntendo University, Chiba, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sakuma
authors.affiliation: Department of Health and Sports Science, Juntendo University, Chiba, Japan.
authors.forename: Keishoku
authors.initials: K
authors.lastname: Sakuraba
authors.affiliation: Laboratory of Sports Science, Chiba Institute of Technology, Chiba, Japan.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Sato
keywords: epidemiology; injury prevention; muscle injury; track/field