Published papers

Background: A variety of athletic exercises are performed in sports training or rehabilitation after knee injuries. However, it remains unclear whether males and females exhibit similar joint loading during the various athletic motions. The purpose of this study was to identify gender differences in knee biomechanics during the athletic motions. Methods: Three-dimensional knee kinematics and kinetics were investigated in 20 recreational athletes (10 males and 10 females) while jumping rope, backward running, side running, side-to-side running, side-to-forward running, inside turning, and outside turning. The strengths of the quadriceps and hamstring muscles, the knee joint force, the knee joint angle, and the knee joint moment were compared between males and females using one-tailed t tests. Results: Peak knee anterior force was greater in female recreational athletes than in their male counterparts during jumping rope, side-to-forward running, inside turning, and outside turning. Female subjects displayed greater peak knee abduction angles and greater peak knee flexion moments while jumping rope compared to their male counterparts. There were no significant differences between the sexes in knee kinematics and kinetics in the frontal and transverse planes during running and turning motions. Conclusions: Female recreational athletes exhibited significantly different knee biomechanics compared with male counterparts during jumping rope and turning motions. © The Japanese Orthopaedic Association 2013.

Background: Our purpose was to clarify the differences of three-dimensional knee kinematics in anterior cruciate ligament (ACL)-deficient patients between with and without meniscal injury using gait analysis. Methods: A total of 72 knees in 36 young athletes with primary and unilateral ACL injury, with a mean age of 22. years, participated. Gait analysis was done before surgery. According to the arthroscopic findings, patients were divided into two groups. The patients with an unstable meniscal tear were allocated to the meniscal injury group (ACL + M group), and the patients without a meniscal tear were allocated to the no meniscal injury group (ACL group). In the gait analysis, three-dimensional knee kinematics was evaluated and compared. Results: The patients in both groups exhibited lower sagittal plane knee excursions and peak knee extension angles on the affected limb than on the unaffected limb during the mid-stance. In terms of the axial plane, a rotation angle was significantly smaller in the affected knees than in the unaffected knees in the ACL group. On the other hand, an opposite phenomenon was observed in the ACL + M group. Moreover, a significantly larger rotation angle in the affected knees during the stance phase and the whole gait cycle was observed in the ACL + M group than in the ACL group. Conclusion: Increased rotational motion during the gait was observed in the ACL-deficient knees combined with unstable meniscal injuries. Meniscal condition may be a key factor for compensatory gait mechanics to prevent rotatory instability in ACL-deficient patients patients. Level of evidence III