**Preface to "Neuroscience, Neurophysiology and Symmetry"**

Human movements and posture often show lateral asymmetries in healthy, young, older, frail and pathological subjects. Why are there asymmetries in motor behaviour? These asymmetries have not been fully identified and are likely to stem from different components of motor function, such as the sensory (perception), central (central integration) and motor (movement command and control) components. The neural mechanisms involved are also not yet understood at different neurological levels (peripheral, spinal, subcortical and cortical). Therefore, exploratory research is needed in order to understand symmetry or asymmetry in terms of human movement and posture. This Special Issue, "Neuroscience, Neurophysiology and Symmetry", presents experimental or theoretical data that provide answers to these questions, focusing mainly on asymmetry in human movement and posture.

> **Thierry Paillard and Sandeep Kumar Singh** *Editors*
