Distinct Coordination patterns integrate Exploratory Head Movements with Whole-Body Movement Patterns during Walking

Abstract

Abstract Visual guidance of gait is an important skill for everyday mobility and for prevention of falls in older adults. While this has often been studied using eye-tracking techniques, recent studies have shown that visual exploration involves more than just the eye; head movement and potentially the whole body is involved for successful visual exploration. Here, we use Principal Component Analysis (PCA) to assess to what extend whole-body movement patterns are related to exploratory head movement during gait. Twenty-one (after exclusions) healthy young adult volunteers followed a treadmill walking protocol designed to elicit different types of head movements (no stimuli compared to stimuli requiring horizontal, vertical, and mixed gaze shifts). PCA was used to establish whole-body correlated patterns of marker movement (Principal Movements; PMs) related to the activity of the head. In total 37 higher order PMs were found to be associated with head movement, two of these showed significant differences between trials associated with strong head rotations in the horizontal and sagittal plane. Both of these were associated with a whole-body pattern of activity. It was found that an analysis of the higher order components was required to establish that exploratory head movements are associated with distinct movement patterns across the body. This shows that visual exploration can produce movement patterns that are at direct contrast with the alleged aim of the postural system (to minimize body movement as much as possible) since they could have a destabilizing effect on the body. These findings shed new light on established results in visual search research and hold relevance for fall and injury prevention.