Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation


Health Sciences


Rehabilitation Sciences

First Advisor

Dr. Phillip A. Gribble

Second Advisor

Dr. Nathan F. Johnson


Lateral ankle sprains are the most common musculoskeletal injury among the general population and U.S. military personnel. Despite the common perception of being a minor injury, at least 1 out of 3 individuals with a previous ankle sprain will develop chronic ankle instability (CAI). This clinical phenomenon creates a significant barrier for patients to return to their prior level of physical function. Specifically, CAI is associated with reductions in physical activity level, leading to decreases in lower health-related quality of life and increase risk of developing of post-traumatic ankle osteoarthritis. Current evidence has largely focused on characterizing the mechanical and sensorimotor insufficiencies associated with CAI in adolescent and young-adult populations, with little attention on middle- and older-aged adults. This restricts our understanding of how these insufficiencies associated with CAI that develop in early adulthood progress over time and contribute to other chronic diseases such as post-traumatic osteoarthritis. Therefore, the overall objective of this study was to compare self-reported and physical function between three age groups: 1) young, 2) middle-aged, and 3) older-aged adults with and without CAI. We hypothesized participants with CAI would have age-related changes in self-reported and physical function compared to non-injured individuals across the lifespan.

The objective of this dissertation was to compare regional and global health- related quality of life (HRQoL), static and dynamic balance, spinal reflex excitability of the soleus muscle, open- and closed-kinetic chain dorsiflexion range of motion and spatiotemporal gait parameters between those with and without CAI across the lifespan. Her callIt was hypothesized that all self-reported and physical characteristics would be decrease with age, but significantly more in those with CAI compare to non-injured individuals.

Results from the first study demonstrated participants with CAI had worse regional HRQoL compared to healthy-controls as evidenced by the lower Foot and Ankle Disability Index scores. Likewise, participants with CAI reported having worse overall physical function and pain interference during activity compared to healthy-controls. There was no significant interaction for Injury (CAI and healthy-control) and Age group (young, middle, and old) for any dependent variable. In the second, it was determined that static and dynamic balance, spinal reflex excitability, ankle (dorsiflexion and plantarflexion) and hip extension torque were all lower in the older-aged participants compared to the younger-aged adults. In addition, it was determined that participants with CAI had decreased dorsiflexion range of motion, ankle (dorsiflexion and plantar flexion) and hip extension peak isometric torque compared to the healthy-control group. However, no significant interaction was found for Injury (CAI & healthy-control) and Age (young, middle, old) for any dependent variable. In the third study, there were no differences in spatiotemporal gait parameters between groups (CAI vs. healthy-controls) or age categories.

It can be concluded from this dissertation that regardless of the age, individuals with CAI have worse region-specific HRQoL, lower overall physical function, greater pain interference, limited dorsiflexion range of motion, and decreased ankle and hip peak isometric torque compared to healthy-controls. Several age-related observations were found including decreased static and dynamic balance, ankle and hip strength, and spinal reflex excitability. Though no relationship was found between CAI and age, several interactions were found to be trending towards significance. Therefore, future work is needed to better understand the consequences of CAI on middle- and older-aged adults.

Digital Object Identifier (DOI)