Table 3

Exposure and hamstring injury data in teams in which all players performed the Nordic hamstring exercise (NHE) (n=5) and teams in which only some players performed NHE (n=11)

Team training (n=5)Individual training (n=11)P value
Training exposure hours, median (IQR)4710 (4535 to 4860)4785 (3513 to 4863)0.743
Match exposure hours, mean (SD)1030 (162)1024 (110)0.925
Total exposure hours, median (IQR)5722 (5648–5742)5742 (4515–5972)0.827
Training hamstring injuries, mean (SD)3 (2)4 (2)0.336
Match hamstring injuries, mean (SD)2 (1)7 (3)0.005
Total hamstring injuries, mean (SD)5 (2)11 (4)0.008
Hamstring injury burden, mean (SD)12 (4)35 (14)0.003
Lay-off days following training hamstring injuries, mean (SD)29 (20)82 (44)0.024
Lay-off days following match hamstring injuries, mean (SD)38 (14)103 (47)0.011
Lay-off days absence following all hamstring injuries, mean (SD)67 (26)184 (69)0.003
  • Data are presented as team averages with corresponding SD for normally distributed variables and as medians with IQR for non-normally distributed variables.

  • Hamstring injury burden is expressed as the number of lay-off days per 1 000 player hours.