Bernstein's revolution in movement medicine: coordination disorders and the recovery of walking biodynamics after cerebrovascular injuries (1954)

On the concept of activity in the last papers of Nikolai Bernstein

In this paper, we analyze Nikolai Bernstein's notion of the activity of living organisms, which he introduced at the end of his career. Bernstein did not leave a systematic description of his last thoughts, but many remarks in his writing, especially in his last book [Bernstein, 1966], show that he thought deeply about the biological significance of the ideas that he developed while studying motor control. He accepted that negentropy (the tendency towards probabilistic determinacy, orderliness, free energy expenditure) is a hallmark of all life processes but wrote extensively about the insufficiency of this property and searched for a more complete definition of living organisms. This definition would include the goal-directedness of development, anticipation, persistence, tendency toward autonomy, initiative, and more. Thus, this paper is an attempt to present the definition of the activity of living organisms from Bernstein's later work to English-speaking readers.

Forward to Bernstein: Movement Complexity as a New Frontier

The paper attempts to demonstrate that the "old-school" approach in motor control studies suggested over a century ago by I. M. Sechenov (1866/1968, 1901) and, later, N. A. Bernstein (1923, 1929, 1940, 1961) remains valid and relevant. Their methodology was to study the motor "periphery" in order to determine "central" mechanisms of motor control. The approach, which can be termed "bottom-up," is contrasted with the "top-down" methodology of first making models of brain control and then investigating the functioning of muscles and joint torques. The earlier progress in motor control studies was, to a great extent, due to the fact that Bernstein developed procedures to register multiple degrees of freedom and thus to analyze in detail the structure of natural movement. The analysis of multi-joint goal-directed movement per se, in its own right, could be the starting point for productive studies of both muscular system functioning and its central control by the nervous system. The article reports on how, in some of his less well known works, Bernstein analyzed complex multi-joint movements. The article's main focus is on movements of the arm as a model example of multi-joint goal-directed movements. It reviews a body of research that follows the "bottom-up" tradition by summarizing contemporary research on two contrasting cases: (1) of a highly coordinated motor skill, as achieved in musical performance or in a precise stroke; and (2) of pathological arm movement in post-stroke neurological patients who have lost capacity as a result of damage to the central nervous system. The paper demonstrates the need for inclusive analyses of all existing degrees of freedom of the moving arm. In the first case, this is important in order to identify some features of learning skills. In the second case, it is important in order to adequately assess the restoration of movements in the process of rehabilitation. The paper concludes by arguing that the "bottom-up" approach in studying the nervous control of complex movements possess a heuristic potential that has not been exhausted.

Gait in patients with pregnancy-related pain in the pelvis: an emphasis on the coordination of transverse pelvic and thoracic rotations

OBJECTIVE

To quantify gait impairments in women with pregnancy-related pain in the pelvis which persisted post-partum.Design. Nine patients and nine healthy subjects were studied during treadmill walking at different velocities.

BACKGROUND

Walking problems in patients with pregnancy-related pain in the pelvis have been known to exist for a long time. To date, no quantitative gait studies have been conducted in this population.

METHODS

Maximum attainable walking velocity was determined, amplitudes of pelvic and thoracic rotations were calculated, and spectral analysis was used to assess the harmonicity of these rotations. Coordination between pelvic and thoracic rotations was characterized as mean relative Fourier phase and weighted coherence.

RESULTS

Maximum attainable walking velocity was highly variable between patients, but on average significantly lower than in healthy controls. Moreover, patients had a significantly lower mean relative Fourier phase (again, highly variable) and higher weighted coherence. The other parameters did not differ significantly between groups.

CONCLUSIONS

Coordination between pelvic and thoracic rotations in the transverse plane was affected in patients with pregnancy-related pain in the pelvis. Individual patients may apply different strategies during walking to cope with the underlying problems.

RELEVANCE

Pregnancy-related pain in the pelvis is poorly understood. Patients with this condition are known to have problems with locomotion. The present study reveals that gait coordination is altered. Theoretically, this underlines the importance of analysing coordination in pathological movement. Clinically, better understanding the gait problems of women with pregnancy-related pain in the pelvis may contribute to more appropriate treatments.