DYNAMICAL SYSTEM THEORY

Dynamical System Theory

Dynamical System Theory

Introduction

Dynamical systems theory has emerged in the movement sciences as a viable framework for modeling athletic performance. From a dynamical systems perspective, the human movement system is a highly intricate network of co-dependent sub-systems (e.g. respiratory, circulatory, nervous, skeletomuscular, perceptual) that are composed of a large number of interacting components (e.g. blood cells, oxygen molecules, muscle tissue, metabolic enzymes, connective tissue and bone). In dynamical systems theory, movement patterns emerge through generic processes of self-organization found in physical and biological systems. (Bartlett, (1996)

Discussion

Dynamical systems theorists claim that the number of biomechanical degrees of freedom of the motor system is dramatically reduced through the development of coordinative structures or temporary assemblages of muscle complexes. The reduced dimensionality/complexity of the motor system encourages the development of functionally preferred coordination or "attractor" states to support goal-directed actions. Within each attractor region (the neighborhood of an attractor) system dynamics are highly ordered and stable, leading to consistent movement patterns for specific tasks. Variation between multiple attractor regions, however, permits flexible and adaptive motor system behavior, encouraging free exploration of performance contexts by each individual. The paradoxical relationship between stability and variability explains why skilled athletes are capable of both persistence and change in motor output during sport performance. Indeed, variability in movement behavior permits performers to explore task and environmental constraints in order to acquire stable motor solutions over time and enhance motor learning. He provides a more detailed explanation of the stability-variability paradox in skill acquisition.

(Sparrow, (1992)

Fast bowling has received considerable research attention during the past decade. Much of the existing literature has focused on factors that contribute to lower back injuries, but research on the basis of successful fast bowling performance is scarce. A good fast bowling technique is one that allows the fast bowler to bowl quickly with a low risk of injury (Bartlett, 1996). It is now well established that the “mixed” bowling technique, which is characterized by a counter-rotation of the shoulder axis relative to the hip axis during the delivery stride, is strongly related to lower-back injury. However, there is no consensus on the relative contributions of biomechanical, physiological, physical and anthropometric factors to ball-release speed.

Variable-variable plots have been used extensively to analyze the motion of one joint relative to the motion of another joint (angle-angle plot) and the angle of one joint relative to the angular ...