Diagnostic value of the hamstring to quadriceps ratio in monitoring of the effectiveness of supervised 6-month physiotherapy in males after Anterior Cruciate Ligament Reconstruction (ACLR)

Purpose: The aim of the study was to assess the usefulness of isometric torque (IT) and peak torque (PT) of the hamstring to quadriceps muscles ratio (H/Q ratio) in monitoring the effectiveness of physiotherapy (PH) in males after ACLR. Hypothesis: The H/Q ratio is a diagnostic tool for monitoring of the effectiveness of the 6- month PH after ACLR. Methods: Twenty males 6 months after ACLR (ACLR group) and 20 male controls underwent IT and PT (60°/s and 180°/s) bilateral measurements of H and Q muscles. The IT and PT were normalized to body mass, and expressed as relative IT (RIT) and relative PT (RPT). The RIT and RPT H/Q ratios, and Limb Symmetry Index (LSI) were calculated. Results: In the ACLR group, the RIT for the H and Q, the RIT for the H/Q ratio and most of the RPT, as well as the H/Q ratio, ROM and LSI values of the operated knee, were not significantly different (NSD) than those of the non-operated side (NOS) or the control group. The between-group comparison of the H/Q ratio for RIT and RPT weren’t NSD. The isokinetic test at 180°/s showed lower RPT, H/Q ratio and LSI values for the Q muscle than those of the NOS (p = 0.042, p = 0.001). Conclusions: The H/Q ratio, in combination with the RIT, RPT and LSI, is a useful diagnostic tool for monitoring the effectiveness of 6-month PH after ACLR. Restoring the correct H/Q ratio can reduce the risk factor for ACL graft rupture.