title: [Consequences and prediction of hamstring muscle injury with concentric and eccentric isokinetic parameters in elite soccer players].
abstract: OBJECTIVE
  To know if isokinetic parameters identify previous hamstring (H) injury and predict a new muscle injury in high-level soccer player.
  
  
  METHODS
  Concentric (con) and eccentric (ecc) isokinetic torque was measured at the angular speed of 60 degrees /s in 28 elite soccer players (23 years +/- 3.3; 74 kg +/- 7.5; 178 cm +/- 6.5). First, 11 players, victims of 15 moderate or major hamstring injuries in the preceding 2 years, were compared with 17 players without previous hamstring injury. Comparisons were carried out from isokinetic knee flexors-extensors ratios [Hcon/Qcon and Hecc/Qcon] and bilateral knee flexors ratios [Hcon/Hcon and Hecc/Hecc]. Secondly, all the population was followed during 12 months and the isokinetic muscular profile of players who presented a recurrence or a new hamstring muscle injury was analysed.
  
  
  RESULTS
  A concentric ratio hamstring-to-quadriceps lower than 0.6 and a hamstring asymmetry of more than 10% do not allow to identify previous hamstring injury. On the other hand, the mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 represents the best indicator (probability: 77.5%). The rate of recurrence is 30% (three cases of 10) and the rate of new hamstring muscle injury is 31% (five cases of 16) (P > 0.05). One of the five injured soccer players presented a concentric ratio hamstring-to-quadriceps lower than 0.6 and no player presented a mixed ratio lower than 0.6. However, four of the five injured players presented a concentric and an eccentric asymmetry. But, it is the strongest side, which presented a new hamstring muscle injury.
  
  
  CONCLUSIONS
  The mixed ratio eccentric hamstring-to-concentric quadriceps lower than 0.6 identify a previous hamstring injury despite the resumption of competitive soccer. However, this ratio and the others isokinetic studied parameters do not predict a recurrence or a new hamstring muscle injury.
authors.affiliation: Pôle de médecine physique et réadaptation, hôpital Saint-Jacques, CHU de Nantes, 44035 Nantes 01, France. marc.dauty@chu-nantes.fr
authors.forename: M
authors.initials: M
authors.lastname: Dauty
authors.forename: M
authors.initials: M
authors.lastname: Potiron-Josse
authors.forename: P
authors.initials: P
authors.lastname: Rochcongar
mesh_terms: D000328:Adult; D015444:Exercise; D005544:Forecasting; D006801:Humans; D007869:Leg Injuries / Q000175:diagnosis / Q000473:pathology; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D011379:Prognosis; D012916:Soccer / Q000293:injuries*; D019415:Torque