Angle-Specific Eccentric Hamstring Fatigue After Simulated Soccer

Purpose: To evaluate the effect of simulated soccer on the hamstrings eccentric torque-angle profile and angle of peak torque (APT(ecc)H), and on the hamstrings:quadriceps torque ratio at specific joint angles (H-As(ecc):Q(con)). Methods: The authors assessed dominant-limb isokinetic concentric and eccentric knee flexion and concentric knee extension at 120 degrees/s in 9 semiprofessional Male soccer players immediately before and after they completed the Loughborough Intermittent Shuttle Test (LIST). Results: The LIST resulted in significant decreases in eccentric hamstrings torque at 60, 50, and 10 and a significant (21.8%) decrease in H-As(ecc):Q(con) at 10 degrees (P < .05). APT(ecc)H increased from 7.1 +/- 1.0 to 18.8 +/- 4.2 (P < .05). Eccentric hamstrings peak torque significantly declined from 185.1 +/- 70.4 N.m pre-LIST to 150.9 +/- 58.5 N.m post-LIST (P = .002), but there were no significant changes in hamstrings or quadriceps concentric peak torque (P = .312,.169, respectively). Conclusions: Simulated soccer results in a selective loss of eccentric hamstrings torque and hamstrings-to-quadriceps muscle balance at an extended joint position and a shift in the eccentric hamstrings APT to a shorter length, changes that could increase vulnerability to hamstrings injury. These findings suggest that injury-risk screening could be improved by evaluating the eccentric hamstrings torque-angle profile and hamstrings strength-endurance and that the development of hamstrings fatigue resistance and long-length eccentric strength may reduce injury incidence.