Isokinetic muscle performance in healthy female handball players and players with a unilateral anterior cruciate ligament reconstruction

A total of 114 healthy female European team handball players in the elite to second division with no previous ACL injury, and the uninjured legs of 22 females with a unilaterally reconstructed ACL (the injury sustained while playing handball; mean time from reconstruction 15 months) were examined with a Biodex isokinetic testing device. Five extensions and flexions at lower speed (60°/s) and 15 repetitions at higher speed (240°/s) were performed. Gravity-corrected peak torque values for flexion and extension were obtained, and hamstrings-to-quadriceps ratios (H/Q) were calculated at both speeds. Compared with the control group, the uninjured legs of the injury group showed 8% weaker quadriceps muscles and 14% higher H/Q ratios at higher speed. The other between-group comparisons were not significant. These differences could have been developed by strength reduction after the injury in the noninjured limb due-to-insufficient rehabilitation, by a weaker musculature in the patient group already initially, or by both mechanisms. If the second option is true, the finding may indicate that weak quadriceps musculature is one of the risk factors for anterior cruciate ligament injuries. The study establishes additional normative data on hamstrings and quadriceps torque on high-level female handball players.