Prediction of hamstring injury in professional soccer players by isokinetic measurements.

OBJECTIVES

previous studies investigating the ability of isokinetic strength ratios to predict hamstring injuries in soccer players have reported conflicting results.

HYPOTHESIS: to determine if isokinetic ratios are able to predict hamstring injury occurring during the season in professional soccer players.

STUDY

DESIGN

case-control study;

LEVEL OF EVIDENCE: 3.

METHODS

from 2001 to 2011, 350 isokinetic tests were performed in 136 professional soccer players at the beginning of the soccer season. Fifty-seven players suffered hamstring injury during the season that followed the isokinetic tests. These players were compared with the 79 uninjured players. The bilateral concentric ratio (hamstring-to-hamstring), ipsilateral concentric ratio (hamstring-to-quadriceps), and mixed ratio (eccentric/concentric hamstring-to-quadriceps) were studied. The predictive ability of each ratio was established based on the likelihood ratio and post-test probability.

RESULTS

the mixed ratio (30 eccentric/240 concentric hamstring-to-quadriceps) <0.8, ipsilateral ratio (180 concentric hamstring-to-quadriceps) <0.47, and bilateral ratio (60 concentric hamstring-to-hamstring) <0.85 were the most predictive of hamstring injury. The ipsilateral ratio <0.47 allowed prediction of the severity of the hamstring injury, and was also influenced by the length of time since administration of the isokinetic tests.

CONCLUSION

isokinetic ratios are useful for predicting the likelihood of hamstring injury in professional soccer players during the competitive season.