# Improving physical activity and gait symmetry after total knee arthroplasty

> **NIH NIH R21** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2021 · $100,313

## Abstract

Total knee arthroplasty (TKA) is one of the most common surgical procedures performed in the U.S., and rates
are rising rapidly. TKA results in decreased pain, increased range of motion, and improvements in some
aspects of physical function for most patients. However, accumulating evidence shows that patients have
persistent deficits in other critical outcomes following TKA. First, the majority of patients do not substantially
increase physical activity beyond levels prior to TKA, remaining well below recommended levels. This has
negative implications for both joint health and overall health. Second, gait asymmetries are common following
TKA, such that patients often continue to load the non-surgical leg more heavily during walking, even when the
post-surgical leg is pain free, placing the contralateral limb at risk for developing or worsening osteoarthritis.
Our long-term objective is to improve post-TKA outcomes, particularly overall physical activity and joint
loading symmetry, through implementation of a rehabilitation process that directly addresses these core
domains. The objective of the proposed study is to conduct an exploratory trial of a novel Physical Activity
and Symmetry (PAS) intervention, which addresses these persistent post-TKA deficits in the context of routine
post-TKA physical therapy. The study specifically aims to obtain preliminary data on the efficacy of the PAS
intervention, with respect to changes in: 1) objectively assessed physical activity and 2) peak load symmetry
during gait using a novel insole device. The study will also assess the feasibility and acceptability of the PAS
intervention. The trial will involve 72 patients enrolled during the course of routine post-TKA physical therapy
who will be randomized either to the PAS intervention or an attention control group. The PAS intervention will
be initiated by the treating physical therapist during the final visits of traditional in-person PT and will be
continued via a phone call after four weeks and an in-person visit after eight weeks to monitor progress,
address barriers to engagement, and advise on exercise modifications. The PAS intervention will utilize
evidence-based strategies of brief motivational interviewing, goal-setting and connection with appropriate
resources to assist participants with progressively increasing overall physical activity levels. Tailored balance
exercises will be used to address joint loading asymmetries. Outcomes will be assessed at baseline, eight
weeks (following completion of PAS), and 6 months. This exploratory study will provide essential information to
guide a larger, multi-site randomized controlled trial of the PAS intervention.

## Key facts

- **NIH application ID:** 10144005
- **Project number:** 5R21AR074149-03
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Kelli D. Allen
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $100,313
- **Award type:** 5
- **Project period:** 2019-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10144005

## Citation

> US National Institutes of Health, RePORTER application 10144005, Improving physical activity and gait symmetry after total knee arthroplasty (5R21AR074149-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10144005. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*