Movement Variability and its Implications for Sports Scientists and Practitioners: An Overview

This overview paper presents results from the studies of the various research groups with which I have been involved over the last decade that clearly show the existence of movement variability. I then address the possible functionality of movement variability. The important issue, particularly for practitioners, of whether such variability can be assessed in the conditions that pertain in competition is a major focus of the paper. Unfortunately, current evidence suggests that we cannot measure movement variability in field conditions reliably or objectively, which prevents us from being able to address satisfactorily the possible implications that movement variability might pose for practitioners. Our major tasks, as sports biomechanists wishing to produce results that allow us to address issues that are relevant to coaches, are to develop accurate markerless tracking systems and to explore other measures of reliability that are more robust to measurement errors.