Movement Systems as Dynamical Systems

Abstract

In recent years, concepts and tools from dynamical systems theory have been successfully applied to the study of movement systems, contradicting traditional views of variability as noise or error. From this perspective, it is apparent that variability in movement systems is omnipresent and unavoidable due to the distinct constraints that shape each individual's behaviour. In this position paper, it is argued that trial-to-trial movement variations within individuals and performance differences observed between individuals may be best interpreted as attempts to exploit the variability that is inherent within and between biological systems. That is, variability in movement systems helps individuals adapt to the unique constraints (personal, task and environmental) impinging on them across different timescales. We examine the implications of these ideas for sports medicine, by: (i) focusing on intra-individual variability in postural control to exemplify within-individual real-time adaptations to changing informational constraints in the performance environment; and (ii) interpreting recent evidence on the role of the angiotensin-converting enzyme gene as a genetic (developmental) constraint on individual differences in physical performance. The implementation of a dynamical systems theoretical interpretation of variability in movement systems signals a need to re-evaluate the ubiquitous influence of the traditional 'medical model' in interpreting motor behaviour and performance constrained by disease or injury to the movement system. Accordingly, there is a need to develop new tools for providing individualised plots of motor behaviour and performance as a function of key constraints. Coordination profiling is proposed as one such alternative approach for interpreting the variability and stability demonstrated by individuals as they attempt to construct functional, goal-directed patterns of motor behaviour during each unique performance. Finally, the relative contribution of genes and training to between-individual performance variation is highlighted, with the conclusion that dynamical systems theory provides an appropriate multidisciplinary theoretical framework to explain their interaction in supporting physical performance.

Kinematic measures and stroke rate variability in elite female 200-m swimmers in the four swimming techniques: Athens 2004 Olympic semi-finalists and French National 2004 Championship semi-finalists

“…In the dynamic systems theory, movement is considered as an emerging property that results from the interaction between the self-organization capacity of the neuromusculoskeletal system, represented in our study by individual skill or standard, and the task requisites, represented in our study by the four swimming events (Schöner and Kelso, 1988;Newell and Corcos, 1993;Brisswalter and Mottet, 1996;Davids et al, 2003). The measures stroke length, stroke rate and speed were considered as control characteristics that correspond to a specific coordination pattern (Seifert et al, 2004a, b).…”

Utilising GPS Data to Quantify Torso Range of Motion in Field Hockey Athletes

“…The high variability seen in these results is somewhat limiting to establishing statistical significance in any of these measures, and is likely due to the variability seen in the performance of actions [13]. Research needs to be conducted including more matches and a variety of playing positions.…”

Complexity, Regularity and Non-linear Behaviour in Human Eye Movements: Analysing the Dynamic of Gaze in the Virtual Sailing Programs

“…These characteristics are related to a functional behaviour of the NCS based on complexity and stability, and in addition have associated with the aptitude of the human to adapt to the environment [14].…”

“…It is possible to state that the complexity in a temporary series is related to the functional behaviour of the system from which the signal is extracted [7]. Thus, biological signals with high levels of irregularities or complexities seem to be cues as to the motor skill performance and functional, exploratory or adaptive motor behaviours [8,9,10,11] of the cardiovascular system, [12], the motor performance and functional, exploratory or adaptive behavior [8,13,14].…”