Date of Completion


Embargo Period



ACLR, neurocognitive, physical function, post-operative outcomes

Major Advisor

Lindsey K. Lepley

Co-Major Advisor

Lindsay J. DiStefano

Associate Advisor

Adam S. Lepley

Associate Advisor

Marc L. Cormier

Associate Advisor

Robert A. Arciero

Field of Study



Doctor of Philosophy

Open Access

Open Access


Traumatic knee injuries, such as anterior cruciate ligament (ACL) sprains detrimentally impact long-term health by initiating a cycle of chronic pain, inactivity, and disability. Neural activity alterations have been suggested as a large contributor to numerous aspects of reduced physical function including but not limited to persistent quadriceps strength deficits, aberrant biomechanical movement patterns and reduced self-reported function after ACL reconstruction (ACLR). Emerging evidence strongly points to the notion that psychological deficits also hinder recovery. Notably, neural impairments observed following ACLR may initiate psychological dysfunction, a process defined as learned helplessness (LH). This project will innovatively investigate the constructs of commonly affected after ACLR, including constructs of quadriceps strength, biomechanics, neural activity and psychological function, specifically focusing on establishing LH in this cohort. The central tenet of this work will establish the framework that after ACL injury and ACLR, patients experience alterations in afferent neural drive due to loss of mechanoreception, pain, and swelling, leading to subsequent alterations in central nervous system neural activity. This change in neural activity can either acutely foster an environment of uncontrollability promoting LH or persist, leading to a cyclical pattern of muscle inhibition and weakness, altered joint biomechanics, depressed self-reported and psychological function that generates the construct of LH in these patients; conversely, the change in neural activity can be restored, placing patients on the path to more positive outcomes. The negative psychological responses that ensue likely can further exacerbate the negative neural responses, creating a cyclical pattern that results in decreased overall quality of life in these patients. A natural extension of our need to comprehensively care for the patient after ACLR is to firstly continue to further understand the relationship between common post-operative outcomes and secondly to more thoroughly consider psychological health during ACL rehabilitation and to recognize LH as a potential barrier to successful recovery. By elucidating these relationships, we can begin to develop future evidence-based interventions capable of promoting both physical and psychological health and improved long-term quality of life.

Available for download on Monday, October 21, 2019