Relationship between hamstring flexibility (askling H-test) and isokinetic strength ratios in elite soccer players with prior hamstring strain injury: A cross-sectional study
Mary Kamal Nassif Takla, Mai Raouf Mohamed Rageh, Mohamed Aboalata Mohamed Aboalata, Elsaieed Ahmed AttiaBackground
Recurrent hamstring strain injuries are associated with deficits in eccentric strength and altered muscle-tendon extensibility, which may persist and contribute to reinjury risk.
Objective
To examine the relationship between hamstring flexibility, assessed by Askling H-test, and isokinetic strength ratios; concentric-to-eccentric (Con:Ecc) and hamstring-to-quadriceps (H:Q) in elite soccer players with previous hamstring strain.
Methods
Fifty-two male professional players (27 ± 5 years) with clinically confirmed prior hamstring injury completed the Askling H-test and bilateral isokinetic testing at 60°·s⁻ 1 (concentric) and 180°·s⁻ 1 (eccentric). The mean of three maximal efforts was used to calculate peak torques. Pearson correlations and multiple linear regression examined the relationship between flexibility, age, and strength ratios (α = 0.05).
Results
Mean ± SD Con:Ecc ratio was 86 ± 9% and H:Q ratio 63 ± 7%. Hamstring flexibility correlated inversely with the Con:Ecc ratio, moderately in the dominant limb (
Conclusions
Reduced hamstring flexibility is associated with a higher Con:Ecc ratio, indicating relatively reduced eccentric capacity, but is not related to H:Q balance. These findings highlight the role of flexibility in hamstring strength balance and warrant longitudinal investigation.