Individual Coordenative Structures During Single-Legged Stance Present Lateral Asymmetry

Abstract

The study investigated the coordination of joint and segmental angles for preferred (right) and non-preferred (left) lower limb movement for a single-legged postural task. Nineteen healthy youngers (8 women and 11 men), aged between18-40 years (M = 25.11 years, SD = 6.61), the mean height of 169.30 cm (SD = 10.23), mean weight of 71.18 kg (SD =16.87) participated in this experiment. The angular variability was assessed by analyzing the first and second principal components. The crosscorrelation between the principal components and the angles showed that specifically the thorax and pelvis segment, as well as the neck and spine joints, participate actively in the coordination of postural control during single-legged stance. As a main result, it was found that the coordinative structures differ between preferred and non-preferred lower limbs, but show high inter-subject variability (among participants) in the angular and segmental coordination strategies adopted to maintain unipodal postural control. Findings show that intersubject variability represents motor abundance, which prioritizes various kinematic solutions through joint and segmental degrees of freedom to maintain vertical postural control. Intersubject variability may be an underlying mechanism of laterality that takes advantage of kinematic motor abundance.