Muscle recruitment and co-contraction when walking in young women with chronic lumbar pain

Abstract Introduction: The lumbar pain is the main musculoskeletal complaint reported by the active population, and it prevents daily activities such as walking. Objective: To assess muscle recruitment and the co-contraction of the trunk muscles during different walking speed in individuals with and without chronic lumbar pain. Method: Thirty-four sedentary young women attended the study, in which 18 belonged to the lumbar pain team (LPT) and 16 to the team without lumbar pain (WLP). We assessed the electromyography activity of the internal oblique (IO) local muscle and lumbar multifidus (MUL), and global external oblique (EO), abdominal rectus (AR) and lumbar iliocostalis (LIC), during walking. The electromyography analysis was performed from the average of the linear envelope value, normalized by the peak of muscle activation. The muscle co-contraction (IO/MUL, EO/LIC, AR/LIC, IO/EO, and the abdominal/paravertebral muscle groups) was calculated with the Falconer and Winter formula. The Shapiro-Wilk test, Multivariate Analysis, mixed Variance Analyses with Bonferroni post-hoc, and Pearson (p