Isokinetic peak torque and flexibility changes of the hamstring muscles after eccentric training: Trained versus untrained subjects

Özet

Objective: The aim of this study was to examine the effect of eccentric isotonic training on hamstringflexibility and eccentric and concentric isokinetic peak torque in trained and untrained subjects.Methods: Sixty healthy subjects (mean age: 21.66 ± 2.64) were divided into three equal groups, eachwith 20 voluntary participants. Two experimental groups (untrained and trained groups) participated ina hamstring eccentric isotonic strengthening program (five days/week) for a six-week period and onecontrol group that was not involved in the training program. The passive knee extension range of motionand hamstring eccentric and concentric isokinetic peak torque were measured at angular velocities 60and 120/s for all groups before and after the training period.Results: Two-way analysis of variance showed that there was a significant increase in the hamstringflexibility of the untrained and trained groups (25.65 ± 6.32, 26.55 ± 5.99, respectively), (p 0.05). Moreover, there was asignificant increase in eccentric isokinetic peak torque of both the untrained and trained groups(127.25 ± 22.60Nm, 139.65 ± 19.15Nm, 125.40 ± 21.61Nm, 130.90 ± 18.71Nm, respectively), (p 0.05) at both angular velocities. On the other hand, there was no significant increase in theconcentric isokinetic peak torque of the three groups (92.50 ± 20.50Nm, 79.05 ± 18.95Nm,92.20 ± 21.96Nm, 79.85 ± 18.97Nm, 100.45 ± 25.78Nm, 83.40 ± 23.73Nm, respectively), (p > 0.05) at bothangular velocities. The change scores in the hamstring flexibility (06.25 ± 1.86) and eccentric peaktorque of the untrained group (16.60 ± 4.81Nm, 17.45 ± 5.40Nm, respectively) were significantly higher(p 0.05).Conclusion: After a six-week period of eccentric isotonic training, the hamstring eccentric peak torqueand flexibility of trained and untrained groups improved without changes in the concentric peak torque.Moreover, the improvement of untrained subjects was higher than trained subjects. These findings maybe helpful in designing the hamstring rehabilitation program.