ACL ruptures are catastrophic injuries that are debilitating to athletes. Specific kinematic and kinetic variables observed in landing and cutting are associated with increased ACL injury risk. The drop vertical jump (DVJ) test has been established as an ideal task to evaluate neuromuscular control and simulate motions and moments that place athletes at risk for ACL injuries. A DVJ involves an athlete landing from a 31 cm drop followed by a maximal vertical jump and subsequent landing. This study aimed to examine kinetic and kinematic differences between the first and second landing of a DVJ. 239 middle and high school athletes each performed 3 trials of a DVJ task for a 10 camera motion analysis system while landing on AMTI force platforms. Kinematic variables demonstrated a decrease in peak hip and knee flexion, hip adduction, and knee abduction angles from the first to second landing. Kinetic variables demonstrated smaller peak knee flexion, knee abduction, and hip flexion moments in the second landing. Overall, the second landing exhibited mechanics characteristic of a higher intensity athletic task or lower neuromuscular control. The second landing may serve as a better screening tool for sagittal plane risk factors, while the first landing may prove optimal for the assessment of frontal plane control and injury risk.
Listed In: Biomechanical Engineering, Biomechanics, Physical Therapy, Sports Science