Diferenças cinemáticas e eletromiográficas de membros inferiores durante o salto horizontal em corredoras amadoras com e sem valgo dinâmico de joelho

Abstract

Running can be characterized as a sequence of jumps, and forward jumping could simulate single-leg landing and reveal excessive knee valgus, especially in women. The aim of this study was to compare the kinematic and electromyographic patterns of the main lower limb muscles in amateur female runners with and without dynamic knee valgus (DKV). A total of 38 amateur female runners aged between 20 and 25 years were evaluated, divided into a group with DKV (n= 17) and a non-DKV group (NDKV, n= 21). The presence or absence of DKV was determined through visual analysis of the Step-Down Test. Participants were also assessed for isometric strength of the lower limb and trunk muscles. A forward jump test was performed, and during execution, kinematic variables (linear and angular displacement) and electromyographic activity of the main lower limb muscles were recorded. An independent Student's t-test was used to compare variables between groups, with a significance level set at 5%. No differences were found between groups regarding anthropometric data, maximal isometric strength, or EMG activity. However, the DKV group showed greater hip adduction (pelvic drop) (p = 0.048) and greater knee valgus (p = 0.042) in the frontal plane. Therefore, it is concluded that amateur female runners with DKV clearly demonstrate the condition during landing in a forward jump, which may have important implications for the development of lower limb injuries.