Walking Stability Control in Chronic Stroke: Differences Between the Paretic and Non-Paretic Limb

• Brooke Milnor, Biological Sciences, University of Delaware

• Jeremy Crenshaw, Kinesiology and Applied Physiology, University of Delaware

Stroke is the leading cause of long-term disability in the US. Chronic stroke is defined as those six or more months post-stroke with ongoing impairments. People with chronic stroke experience both balance and walking impairments, which likely contribute to a higher fall risk. This is due to weakness in the affected side, also known as the paretic side. Chronic stroke reduces push-off force in the paretic limb and the accuracy with which paretic steps are placed. These post-stroke motor problems can lead to inefficient, compensatory walking and limited independent walking outside the home. Studying the difference in foot placement and push-off contributions to stability between the paretic and non-paretic limb enables us to investigate how stroke affects walking stability control. This pilot study aimed to explore the impact of the paretic limb on balance control mechanisms. This may allow us to advance our understanding of how stroke affects balance, potentially influencing further research into post-stroke rehabilitation. Two participants with chronic stroke wore a full-body motion capture marker set and walked on a dual-belt treadmill instrumented with force plates to measure ground reaction forces during walking under individual limbs. We determined push-off and foot placement contributions to lateral stability from the location of the whole-body center of mass, as well as the location and magnitude of the vertical ground reaction force under each foot. We expected that both push-off and foot placement contributions would be lower in the paretic limb compared to the non-paretic limb. Our initial data did not support these expectations. We will continue this study by investigating those with more paretic limb impairment, and we will explore how compensatory strategies are used to enhance the push-off and foot placement contributions of the paretic limb.