# Can we modify gait asymmetry after ACL reconstruction?

> **NIH NIH F31** · UNIVERSITY OF DELAWARE · 2021 · $46,036

## Abstract

PROJECT SUMMARY/ABSTRACT
More than a quarter of a million people in the US tear their anterior cruciate ligaments (ACL) each year, and
most subsequently undergo surgical reconstruction (ACLR). Despite extensive rehabilitation, individuals
persistently walk with asymmetrical knee joint mechanics after ACLR. Even years after ACL reconstruction,
long after they have returned to sporting activities, individuals walk with subtle gait asymmetries that are not
clinically detectable or perceived by the individual. These small asymmetries, nevertheless, directly contribute
to the development of early-onset, post-traumatic knee joint osteoarthritis. Post-traumatic knee joint
osteoarthritis develops 5-15 years after ACL injury and carries devastating implications for the individual. Early
osteoarthritis is directly associated with decreased sports and recreational participation, pain, and lower self-
reported quality of life. As the peak age of ACL rupture and reconstruction is 16 years old in girls and 17 years
old in boys, most are on track to develop knee osteoarthritis in young adulthood. The objectives of this
fellowship are to apply principles of motor learning to directly target the asymmetric knee joint mechanics in
individuals after ACLR. The potential to change walking mechanics short-term using a split-belt (one belt under
each foot moving at different speeds) treadmill has been demonstrated in neurologic and uninjured
populations. This fellowship will use a split-belt treadmill adaptation paradigm to understand how individuals
after ACL reconstruction adapt knee joint mechanics. Further, this work will assess the carry-over of a bout of
split-belt treadmill training on over-ground walking symmetry by quantifying changes in knee joint kinetics and
kinematics. Specifically, the proposal will determine the extent to which individuals after ACLR can adapt (Aim
1) retain (Aim 2), and overground transfer (Aim 3) improved knee joint mechanics compared to uninjured
individuals. This work will provide valuable insight into motor learning in individuals after ACLR, which is
necessary to correct detrimental walking mechanics. The long-term goal of this fellowship applicant is to
develop targeted interventions to optimize gait and ultimately reduce the rate of posttraumatic knee
osteoarthritis after ACLR. Findings from the proposed work will aid in the design of rehabilitation interventions
for early post-operative ACL rehabilitation. This research has potential to advance post-operative physical
therapy interventions and affect the development of early-onset knee osteoarthritis, potentially improving
activity levels and quality of life after ACLR. Further, this proposal will facilitate the applicant’s predoctoral
training, laying the foundation for a career as an independent clinician-scientist.

## Key facts

- **NIH application ID:** 10313330
- **Project number:** 1F31AR078580-01A1
- **Recipient organization:** UNIVERSITY OF DELAWARE
- **Principal Investigator:** Elanna Arhos
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $46,036
- **Award type:** 1
- **Project period:** 2021-06-28 → 2023-06-27

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10313330

## Citation

> US National Institutes of Health, RePORTER application 10313330, Can we modify gait asymmetry after ACL reconstruction? (1F31AR078580-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10313330. Licensed CC0.

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