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M. Kada1, M. Anan1
1Oita University, Graduate School of Welfare and Health Science, Oita, Japan
Background: Anterior cruciate ligament (ACL) injuries are relatively common and take a long time to heal enough to allow a return to sports. The rate of ACL injury is higher in females than in males, regardless of sport, and the majority of these injuries are of the non-contact type. In recent years, ACL injuries have increased with the increase in the number of female athletes. A previous study reported that non-contact ACL injuries were more likely to be caused by cutting, deceleration, and jump-landing motions. Therefore, motion analysis mainly focused on cutting motion. However, most of cutting motion in previous study were lateral cutting after straight-line running.
Purpose: The purpose of this study was to determine the differences in cutting without sufficient acceleration between ACL-injured and healthy individuals.
Methods: The subjects were 4 women with a history of ACL injury (5 knees in the ACL group) and 3 healthy individuals (6 knees in the control group). Three-dimensional motion analysis systems and force plates were used for measurements. Forty-five infrared-reflecting markers were attached to anatomical landmarks of the individual's body. Kinematics and kinetics data were measured using a three-dimensional motion analysis system and floor reaction forces. The subject stood on force plates and, after 3 steps, cut in the specified direction. The cutting was set in the lateral direction. The cutting direction was informed before the start of measurement. Subjects underwent the measurement procedure 3 times each. Knee angle (flexion and valgus, in degrees) and knee moment (flexion, valgus, and rotation, in Nm) were calculated at maximum on the cutting side. Each value was compared between groups. Corresponding t-tests were used for statistical analysis, with a significance level of < 5%.
Results: No significant differences were found for any of the measurements. The maximum valgus and rotation moment of the ACL group showed similar results. However, those values of the control group showed 2 patterns. One was similar to that of the ACL group, and the other was significantly larger than that of the ACL group (valgus: p=0.009, rotation: p=0.001).
Conclusion(s): This study showed 2 patterns in the control group. The knee angle was not significantly different. However, the knee moment of a few subjects in the control group was significantly higher than that of the ACL group. Individuals who showed similar results of the knee moment to those in the ACL group may perform cutting motion that prevents ACL injury. In this study, we measured the cutting motion with the direction informed before measurement. In future studies, it is necessary to consider the timing of directional announcements.
Implications: The findings of this study can lead to the assessment of people who may experience ACL injury. There is no clear method to prevent ACL injury. If a new assessment of ACL injury becomes clear, ACL injury can be prevented.
Funding, acknowledgements: This study was unfunded.
Keywords: ACL injury, cutting, motion analysis
Topic: Musculoskeletal: lower limb
Did this work require ethics approval? Yes
Institution: The Faculty of Welfare and Health Science, Oita University
Committee: The Ethics Committee of the Faculty of Welfare and Health Science
Ethics number: F200002
All authors, affiliations and abstracts have been published as submitted.
