Abnormal Interactions Between Arm and Leg Movements After Cerebral Stroke

Review Article

Abnormal Interactions Between Arm and Leg Movements After Cerebral Stroke

Sophie Blake¹* and Liam Robinson²

1Department of Medical Sciences, University of Sydney, Sydney, Australia
2Department of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia

Published: 19 May 2020

Abstract

Stroke is a leading cause of long-term disability, frequently resulting in motor impairments affecting both upper and lower limbs. While much research has focused on the independent deficits of the arm and leg, it is increasingly recognized that stroke disrupts the complex interplay and mutual influences between these limbs, critical for coordinated activities like walking, reaching, and maintaining balance. We discuss the neural substrates supporting interlimb coordination and how stroke-induced damage, particularly to descending motor pathways and cortical/subcortical networks, disrupts these mechanisms. The review explores observed abnormalities, including altered gait patterns influenced by upper limb support, changes in upper limb kinematics related to postural stability provided by the lower limbs, and the emergence of pathological coupling or synergies that constrain independent limb movement. Assessment methods for quantifying these interlimb dependencies are discussed, ranging from kinematic analysis during functional tasks to neurophysiological techniques. Finally, we consider rehabilitation strategies that implicitly or explicitly address interlimb coordination deficits, highlighting the importance of task-specific training that integrates upper and lower limb movements. Understanding these abnormal mutual influences is crucial for developing more effective, holistic rehabilitation approaches aimed at restoring functional independence after stroke.

Keywords: Stroke; Motor control; Interlimb coordination; Upper limb; Lower limb; Gait; Reaching; Functional connectivity; Rehabilitation; Motor recovery