Sensory Augmentation Methods in Stroke

Development of Sensory Augmentation Methods to Improve Post-stroke Gait Stability

Many chronic stroke survivors have poor walking balance, contributing to an increased risk of falls and fear of falling. One factor contributing to these balance deficits is a reduced ability to place the feet appropriately when walking. This study investigates whether enhancing the sensory information available to chronic stroke survivors while they walk improves their foot placement accuracy and balance.

The objective of this project is to test a method of providing real-time augmentation of hip proprioceptive feedback during post-stroke walking. The sensory information available to participants will be augmented by providing vibration of the hip abductor musculature that is scaled to the near-real-time mechanical state of their body. The central hypothesis is that augmented proprioception will improve participants' perception of their body's motion, thus increasing the mechanics-dependent modulation of foot placement, an important gait stabilization strategy. This clinical trial will establish the safety, feasibility, and efficacy of a rehabilitation intervention centered on repeated exposure to sensory augmentation during gait. Specifically, participants in the experimental group will complete training sessions twice a week for four weeks in which they receive sensory augmentation during ~30 minutes of treadmill walking. Participants in the activity-matched control group will perform the same task, except the hip vibration will be randomly delivered, not linked to the body's actual mechanical state. Changes in walking balance and foot placement accuracy will be quantified over the course of the intervention.

Inclusion Criteria:

• Experience of a stroke 6 months prior to participation
• Gait speed of at least 0.2 m/s
• Ability to walk on a treadmill without a cane or walker
• Provision of informed consent

Exclusion Criteria:

• Evidence of cerebellar damage
• Resting blood pressure higher than 220/110 mm Hg
• History of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during activities of daily living
• Preexisting neurological disorders or dementia
• Legal blindness or severe visual impairment
• History of DVT or pulmonary embolism within 6 months
• Uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions
• Orthopedic injuries or conditions (e.g. joint replacements) in the lower extremities with the potential to alter the gait pattern