# Toward a Mechanistic Understanding of Optimization Principles Underlying Hemiparetic Gait

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2022 · $380,398

## Abstract

This project seeks to identify how motor impairments in stroke survivors contribute to mobility deficits through
the use of behavioral observations and computational models. Ultimately, this knowledge could be used to
design more effective interventions to improve walking ability, increase functional independence, and reduce
fall risk in individuals post-stroke. After a stroke, walking ability is affected by motor control deficits which are
often characterized by hemiparesis, or weakness on one side of the body. During walking, hemiparesis is often
associated with a visible limp that is due to differences in step lengths and stance times between the right and
left sides of the body. Reducing these right-left asymmetries are a common objective of rehabilitation, and
recently researchers have developed a number of approaches designed to reduce asymmetries such as
acoustic pacing, unilateral step training, and split-belt treadmill training. Despite the recent clinical focus on
reducing asymmetry, the potential functional benefits of improving symmetry have yet to be established. This
research will address this gap by answering two fundamental questions: 1) Do improvements in symmetry lead
to functional benefits such as a more efficient walking pattern or improvements in balance? 2) If stroke
survivors retain the capacity to walk more symmetrically why do they choose to do otherwise? Although
improvements in symmetry can no doubt reduce the potential stigma of walking with a limp, it is possible that a
symmetric walking pattern could be less efficient or put patients at a higher risk of falls if it requires that they
push the limits of their capacity. Alternatively, it is possible that, through repeated stepping practice, post-
stroke individuals have reinforced a suboptimal pattern due to insufficient experience with a more optimal,
symmetric pattern. Addressing these issues requires a thorough understanding of the processes by which
stroke survivors optimize their walking pattern. Here, these issues are addressed using behavioral approaches
to quantify tradeoffs between asymmetry and measures of walking ability such as stability and economy, and
computational methods to identify the causal relationships linking these variables. Ultimately, the knowledge
derived from this work will provide a mechanistic understanding of how the damaged brain optimizes
movement, and may also inform the way in which clinicians develop personalized rehabilitation objectives for
stroke survivors. Our findings may also inform cost/benefit analyses of walking in other patient populations
known to have asymmetric walking patterns such as amputees or individuals with Parkinson's disease.
Furthermore, providing a more mechanistic rationale for gait rehabilitation interventions could improve the
efficiency of physical therapy, reduce health care costs, and ultimately help to better reintegrate individuals
with neuromotor impairments into society by maximizing their mobility.

## Key facts

- **NIH application ID:** 10187612
- **Project number:** 5R01HD091184-04
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** James M. Finley
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $380,398
- **Award type:** 5
- **Project period:** 2018-08-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10187612

## Citation

> US National Institutes of Health, RePORTER application 10187612, Toward a Mechanistic Understanding of Optimization Principles Underlying Hemiparetic Gait (5R01HD091184-04). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10187612. Licensed CC0.

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