Purpose: The purpose of this study was to compare kinetic and knee kinematic measurements from male and female anterior cruciate ligament (ACL)–intact (ACLINT) and ACL-reconstructed (ACLREC) subjects during a jump-cut maneuver using biplanar videoradiography.
Methods: Twenty subjects were recruited; 10 ACLINT (5 men and 5 women) and 10 ACLREC (4 men and 6 women, 5 yr postsurgery). Each subject performed a jump-cut maneuver by landing on a single leg and performing a 45° side-step cut. Ground reaction force (GRF) was measured by a force plate and expressed relative to body weight. Six-degree-of-freedom knee kinematics were determined from a biplanar videoradiography system and an optical motion capture system.
Results: ACLINT female subjects landed with a larger peak vertical GRF (P < 0.001) compared with ACLINT male subjects. ACLINT subjects landed with a larger peak vertical GRF (P ≤ 0.036) compared with ACLREC subjects. Regardless of ACL reconstruction status, female subjects underwent less knee flexion angle excursion (P = 0.002) and had an increased average rate of anterior tibial translation (0.05%·ms−1 ± 0.01%·ms−1, P = 0.037) after contact compared with male subjects. Furthermore, ACLREC subjects had a lower rate of anterior tibial translation compared with ACLINT subjects (0.05%·ms−1 ± 0.01%·ms−1, P = 0.035). Finally, no striking differences were observed in other knee motion parameters.
Conclusion: Women permit a smaller amount of knee flexion angle excursion during a jump-cut maneuver, resulting in a larger peak vertical GRF and increased rate of anterior tibial translation. Notably, ACLREC subjects also perform the jump cut maneuver with lower GRF than ACLINT subjects 5 yr postsurgery. This study proposes a causal sequence whereby increased landing stiffness (larger peak vertical GRF combined with less knee flexion angle excursion) leads to an increased rate of anterior tibial translation while performing a jump-cut maneuver.
1Department of Orthopaedics, The Warren Alpert Medical School, Brown University and Rhode Island Hospital, Providence, RI; 2Center for Biomedical Engineering, Brown University, Providence, RI; 3Department of Surgery, The Warren Alpert Medical School, Brown University, Providence, RI; 4Biostatistics, Rhode Island Hospital, Providence, RI; and 5School of Engineering, Brown University, Providence, RI
Address for correspondence: Braden C. Fleming, Ph.D., Warren Alpert Medical School of Brown University, 1 Hoppin Street, Coro West, Suite 404, Providence, RI 02903; E-mail: firstname.lastname@example.org.
Submitted for publication July 2012.
Accepted for publication October 2012.
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