Table 2

Hamstring injury prevention: effect and grading the quality of evidence

OutcomesRR (95% CI)Effect size
Risk of injury
 Interventions including the Nordic hamstring exercise versus usual care*; n=5362, male/female football53 0.55 (0.34 to 0.89); I2=67.0%Moderate quality of evidence
 Mixed eccentric hamstring training versus usual care based*; n=1229, male football52 0.59 (0.24 to 1.44); I2=69.6%Low quality of evidence
 FIFA 11+ programme versus usual care;* n=3417, male/female football54 0.39 (0.24 to 0.64); I2=0.0%Moderate quality of evidence
 Nordic hamstring exercise protocol versus usual care;* n=1521, male football56 57 0.35 (0.22 to 0.54); I2=0.0%High quality of evidence
Individual studies
 Bounding exercise programme versus usual care; n=400, male football63 0.89 (0.55 to 1.44)Moderate quality of evidence
 FIFA 11+ programme performed pre-football and post-football versus FIFA 11+ performed pre-football; n=280, male football62 0.21 (0.05 to 0.95)Very low quality of evidence
 Modified FIFA 11+ with rescheduling of Part 2 versus standard FIFA 11+; n=806, male football64 0.86 (0.59 to 1.25)Moderate quality of evidence
 Balance board training versus usual care; n=140, female football65 0.18 (0.02 to 1.42)Very low quality of evidence
  • *Based on pooled data from meta-analysis. RR (risk ratio); I2 (heterogeneity in study results); The preventive effect is assessed as RR assessed as trivial (RR >0.78), small (0.78≥ RR >0.61), medium (0.61≥ RR >0.47) and large (RR ≤0.47).47