Graduation Date

Spring 5-5-2024

Document Type


Degree Name

Doctor of Philosophy (PhD)


Medical Sciences Interdepartmental Area

First Advisor

Elizabeth Wellsandt PT, DPT, PhD, OCS


Anterior cruciate ligament reconstructions (ACLR) have increased in incidence worldwide. After ACLR, individuals are at higher risk for developing early onset knee osteoarthritis. Individuals after ACLR also participate in less physical activity (PA), contributing to an increased risk for early onset knee osteoarthritis and poor overall health outcomes.

The two goals of this work were to 1) determine the relationship between PA and knee health outcomes 18 months after ACLR and 2) determine the feasibility and acceptability of a PA intervention early after ACLR that considered participant thoughts and feelings.

Findings for the first goal suggest that there is no association between change in daily steps from six to 18 months after ACLR and structural or symptomatic signs of early onset knee osteoarthritis. However, there was an association with decreased morning sedentary time from six to 18 months after ACLR and improved symptoms related to knee health.

For the second goal, individuals were enrolled in a 12-week personalized progressive PA program within eight weeks of ACLR. The PA intervention was found to be safe, with good adherence to wearing a wrist-worn activity monitor and attending virtual visits demonstrated. However, individuals demonstrated difficultly reaching targeted PA levels. Qualitative analysis of post-intervention semi-structured interviews identified participant level theme (experience with sport, flexibility in schedule, and response to goals) that contributed to success in achieving PA targets, as well as programmatic themes (provide accountability and feedback, promote activity early, and measure all PA) to include in a future program to promote successful achievement of PA targets.

The results of my work add significant contributions to our knowledge about PA after ACLR. Although daily step counts were not associated with knee health outcomes 18 months after ACLR, decreasing sedentary time from six to 18 months was associated with better knee function. Beyond its impact on knee health, promoting PA after ACLR will likely also benefit overall health and wellness. My work establishing the feasibility of a PA program early after ACLR provides the foundation for further development and testing a PA intervention to promote recovery of healthy PA participation in individuals after ACLR.


2024 Copyright, the authors

Available for download on Saturday, April 11, 2026