Lower limb kinematic alterations during drop vertical jumps in female athletes who have undergone anterior cruciate ligament reconstruction.

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL-R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non-injured age, sex, and activity matched control group. Fourteen ACL-R and 14 non-injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time-averaged angular displacements were quantified and utilized for between-group analysis. The ACL-R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL-R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time-averaged, following landing. The ACL-R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre-dispose ACL-R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits.