Abstract
Injury is an inevitable consequence to physical activity (PA). Healthcare providers main goal is to help individuals safely return to their PA following injury, minimizing risk of re-injury and detrimental psychological impact. While physical markers (e.g., range of motions, restored muscle strength) are more easily and commonly measured to guide return to PA, psychological factors (e.g., psychological readiness, gratitude) are less commonly measured but are of equal importance to guide a safe return to PA. In order to capture psychological states, patient-reported outcome (PRO) instruments are needed. PROs must be reliable and valid in order for them to be utilized in research; therefore, the primary purpose of this dissertation was to further establish the psychometric properties of the Injury Psychological Readiness to Return to Sport Scale (I-PRRS) and the Gratitude Questionnaire (GQ-6) in an injured physically active population. A one-factor model was confirmed for the I-PRRS, demonstrated redundancy (α = 0.91 and = 0.91), and demonstrated invariance between groups and across time. No group differences were found between sex and injury type; however, group differences were found for age and PA status with adolescents and competitive athletes scoring the highest on the I-PRRS. Statistically significant, weak to moderate correlations were found between the I-PRRS, pain, disablement, function, and QOL (r = -0.15 to 0.61, p < .001). LGM demonstrated an increase in all variables over time, and those who showed worse levels at baseline, improved at faster rates. Results from LGM also demonstrated that initial scores on disablement and function predicted the rate of change of psychological readiness, but psychological readiness did not predict the rate of change of disablement or function.
A 5-item model was confirmed for the GQ-5, demonstrated adequate internal consistency (α = 0.89 and = 0.89), potential ceiling effects, adequate test-retest reliability (ICC (2,1) = 0.87), and demonstrated invariance between groups and across time. No group differences were found between sex, age, injury type, PA status, or across time. However, LGM analysis revealed that scores on the GQ-5 for the sample did not change over time, but rate of change was different for individuals and those who scored low on the GQ-5 increased at faster rates over time. Additionally, LGM analysis revealed that gratitude predicted rate of change in pain and QOL and pain and disablement predicted the rate of change in gratitude. Further, bivariate correlations demonstrated moderate to strong relationships between pain and disablement, but negligible correlations between gratitude and pain and disablement. Our overall analysis demonstrated the structural validity of the I-PRRS and GQ-5, confirming their use in an injured physically active population.