High knee valgus in female subjects does not yield higher knee translations during drop landings: A biplane fluoroscopic study (original) (raw)
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Knee Surgery, Sports Traumatology, Arthroscopy, 2011
Purpose Passive anterior knee laxity has been linked to non-contact ACL injury risk. High deceleration movements have been implicated in the non-contact ACL injury mechanism, and evidence suggests that greater anterior tibial translations (ATT) may occur in healthy knees that are lax compared to a tight knee. The purpose of this study was to determine the relationship between anterior knee laxity scores and ATT during drop landings using biplane fluoroscopy. Methods Sixteen healthy adults (10 women; 6 men) performed stiff drop landings (40 cm) while being filmed using a high-speed, biplane fluoroscopy system. Initial, peak and excursions for rotations and translations were calculated and regression analysis used to determine the 6DoF kinematic relationships with KT1000 scores with peak ATT occurring during the landing.
Clinical Biomechanics, 2011
Background-Research has linked knee extensor moment and knee shear force to the noncontact anterior cruciate ligament injury during the landing motion. However, how these biomechanical performance factors relate to knee translations in vivo it is not known as knee translations cannot be obtained with traditional motion capture techniques. The purpose of this study was to combine traditional motion capture with high-speed, biplane fluoroscopy imaging to determine relationships between knee extensor moment and knee shear force profiles with anterior and lateral tibial translations occurring during drop landing in females athletes.
British Journal of Sports Medicine, 2011
Purpose: In vivo measurement of the forces and strains in human tissues is currently impracticable. Computer modeling and simulation allows estimates of these quantities to be obtained noninvasively. This paper reviews our recent work on muscle, ligament, and joint loading at the knee during gait. Methods: Muscle and ground-reaction forces obtained from a sophisticated computer simulation of walking were input into a detailed model of the lower limb to obtain ligament and joint-contact loading at the knee for one full cycle of gait. Results: Peak anterior cruciate ligament (ACL) force occurred in early stance and was mainly determined by the anterior pull of the patellar tendon on the tibia. The medial collateral ligament was the primary restraint to anterior tibial translation (ATT) in the ACL-deficient knee. ATT in the ACL-deficient knee can be reduced to the level calculated for the intact knee by increasing hamstrings muscle force. Reducing quadriceps force was insufficient to restore ATT to the level calculated for the intact knee. For both normal and ACL-deficient walking, the resultant force acting between the femur and tibia remained mainly on the medial side of the knee. The knee adductor moment was resisted by a combination of muscle and ligament forces. Conclusion: Knee-ligament loading during the stance phase of gait is explained by the pattern of anterior shear force applied to the leg. The distribution of force at the tibiofemoral joint is determined by the variation in the external adductor moment applied at the knee. The forces acting at the tibiofemoral and patellofemoral joints are similar during normal and ACL-deficient gait. Hamstrings facilitation is more effective than quadriceps avoidance in reducing ATT during ACL-deficient gait.