“…The original studies of thorax-pelvis relative phase in different forms of pathology [4,7] stemmed from inspiration by Bernstein's 1935 concept of ''coordination'' [17][18][19], combined with the idea, from the theory of dynamical systems [20], that somehow thoraxpelvis phase relationships are self-organised [11]. In general, there is hardly any doubt that self-organisation plays an important role in walking [21,22], but above a certain speed, the passive dynamics of the system are insufficiently powerful to produce a further speeding-up [23].…”