Mobilisation of the nervous system is an approach to physical treatment of pain. The method relies on influencing pain physiology via mechanical treatment of neural tissues and the non-neural structures surrounding the nervous system. Previous descriptions of this method have not clarified the relevant mechanics and physiology, including interactions between these two components. To address this, a concept of neurodynamics is described. The body presents the nervous system with a mechanical interface via the musculoskeletal system. With movement, the musculoskeletal system exerts non-uniform stresses and movement in neural tissues, depending on the local anatomical and mechanical characteristics and the pattern of body movement. This activates an array of mechanical and physiological responses in neural tissues. These responses include neural sliding, pressurisation, elongation, tension and changes in intraneural microcirculation, axonal transport and impulse traffic. Because many events occur with body movement, in addition to tension, the term ‘neural tension' is incomplete and requires expansion to include both mechanical and physiological mechanisms. ‘Neural tension tests’ may be better described as ‘neurodynamic tests'. Pathomechanics and pathophysiology in neural tissues and their neighbouring structures may be regarded as pathodynamics.