Date Available


Year of Publication


Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation





First Advisor

Dr. Susan K. Frazier


The purpose of this dissertation was to explore the physical and psychological responses to the combination of major trauma (Injury Severity Score [ISS] > 15) and variable periods of immobility. Specific aims were to: 1) develop a conceptual model that illustrates physiological and psychological alterations that occur after injury and subsequent immobility, and their association with skeletal muscle responses and recovery; 2) evaluate daily measures of skeletal muscle strength (bicep and quadricep) using dynamometry and skeletal muscle (rectus femoris and biceps brachii) muscle thickness measured with ultrasound in patients after major trauma; and 3) assess the predictive ability of anxiety and depressive symptoms after traumatic injury on delayed ambulation (> 48 hours) following hospital admission.

Specific Aim 1 was addressed by development of a conceptual model to describe the association between injury responses, immobility and skeletal muscle after trauma based on a comprehensive review of the state of the science. This model guided the research reported in Aims 2 and 3. The second specific aim was addressed with the conduct of an observational study in which we evaluated daily skeletal muscle strength with dynamometry and muscle thickness with ultrasound to evaluate the impact of trauma and immobility on skeletal muscle in patients after major trauma (n = 19). Participants with delayed ambulation after trauma (more than 48 hours immobility) demonstrated significantly less muscle strength compared with those who had early ambulation (bicep: delayed ambulation 12.9 ± 3.8, early ambulation 17.7 ± 4.7, p = 0.004; quadriceps: delayed ambulation 9.9 ± 3.1, early ambulation 17.1 ± 4.6, p = 0.001). Muscle thickness was unchanged over time in those with delayed ambulation; however, in those who ambulated early, muscle thickness significantly increased by 0.17 cm (p = 0.008) from baseline to day 5. The third specific aim was addressed with data collected during the same observational study of patients after trauma (n = 19). Participants provided measures of anxiety and depressive symptoms at baseline. Anxiety was not a predictor of delayed ambulation; however, depressive symptoms increased the likelihood of delayed ambulation by 67% (Odds Ratio [OR]: 1.67, 95% CI: 1.02 – 2.72, p = 0.041).

Early ambulation was associated with significantly greater muscle strength and thickness as determined by dynamometry and muscle ultrasound, and depressive symptoms significantly increased the likelihood of delayed ambulation. Systematic evaluation of the association between trauma injury, immobility, skeletal muscle function and structure, and psychological state will provide an opportunity for the appropriate evaluation after injury and development of effective, tailored interventions to improve short- and long-term physiological and psychological recovery.

Digital Object Identifier (DOI)

Funding Information

The Robert Wood Johnson Foundation, Future of Nursing Scholars program (2015 - 2018)

UK HealthCare Nursing Research Fellowship (2017 - 2019)