Hamstrings‐to‐quadriceps strength and size ratios of male professional soccer players with muscle imbalance

Summary The aim of this study was to determine the correlation between the concentric hamstrings/quadriceps muscle strength (H con :Q con ) and cross‐sectional area ratios (H csa :Q csa ) in professional soccer players with H con :Q con imbalance. Nine male professional soccer players (25·3 ± 4·1 years) performed five maximal concentric contractions of the knee extensors ( KE ) and flexors ( KF ) at 60 s −1 to assess H con :Q con . The test was performed using the dominant (preferred kicking), and non‐dominant limb with a 5‐min recovery period was allowed between them. Only players with H con :Q con  < 0·60 (range: 0·45–0·59) in both limbs were included in this study. The muscle cross‐sectional area ( CSA ) of KE and KF was determined by magnetic resonance imaging. The correlations between H con :Q con and H csa :Q csa in the dominant leg ( r  = −0·33), non‐dominant leg ( r  = 0·19) and in the both legs combined ( r  = 0·28) were not statistically significant ( P >0·05). Thus, the H con :Q con seems not to be determined by H csa :Q csa in professional soccer players with H con :Q con imbalance.