Effects of the application of a fatigue protocol in the trunk and lower limb kinematics during a landing from a single-leg drop jump: comparison between genders

Abstract

One of the most common injuries during sports is the rupture of the anterior cruciate ligament (ACL). Women are four to six times more exposed to ACL injuries than men when compared to the same sports activity. The excessive knee dynamic valgus (knee abduction and adduction and hip internal rotation), especially during the landings of single-leg jumps, has been considered as an important mechanism of ACL injury. The position of the knee proximal joints such as the hips and trunk can result in excessive dynamic valgus. Another risk factor for ACL injury is muscle fatigue. Fatigue causes biomechanical changes, loss of performance of the lower limbs, which may increase the risk of ACL injury during jump landing. The aim of this study is to compare between men and women, the effect of fatigue on frontal plane kinematics of the trunk, hip, and knee during single-leg drop jump landing. Participate in the study, 10 men and 10 women active and healthy, aged between 18 and 30 years. A kinematic analysis of the trunk, hip, and knee will be performed during a single leg drop jump from 31cm height, before and after a fatigue protocol. The fatigue protocol will include series of 10 squats, 2 vertical jumps, and 20 steps. Will be considerate for analyses the peak angles of adduction/abduction of the knee and hip and ipsilateral/contralateral trunk lean, before and after a fatigue protocol. To compare the kinematic variables before and after application of the fatigue protocol and verification of interaction between the sexes will be applied ANOVA - two-way (mixed model) for repeated measures. For all comparisons will be considered a significance level of 5%. (AU)