Exploratory Examination of Knee Self-Efficacy in Individuals With a History of ACL Reconstruction and Sport-Related Concussion

Context: Knee self-efficacy and injury-related fear are associated with poor self-reported knee function and decreased physical activity (PA) after ACL reconstruction (ACLR). Limited research has explored contextual factors that may influence psychological responses in this population, such as history of sport-related concussion (SRC). After SRC, individuals may experience increased negative emotions, such as sadness and nervousness. However, it is unknown how SRC history may influence knee-self efficacy and injury-related fear in individuals with ACLR. The purpose of this study was to compare knee self-efficacy and injury-related fear in individuals after ACLR who present with and without history of SRC. Design: Cross-sectional study. Methods: Forty participants ≥1 year postunilateral ACLR were separated by history of SRC (no SRC = 29, SRC = 11). The Knee Self-Efficacy Scale (KSES) and subscales measured certainty regarding performance of daily activities (KSES-ADL), sports/leisure activities (KSES-Sport), physical activities (KSES-PA), and future knee function (KSES-Future). The Tampa Scale of Kinesiophobia-11 measured injury-related fear. Mann- Whitney U tests were used to examine between-group differences. Hedges g effect sizes and 95% confidence interval were used to examine clinically meaningful group differences. Results: Individuals with a history of ACLR and SRC demonstrated worse KSES-PA (7.5 [5.3]) compared with those without a history of SRC (8.1 [6.1], P = .03). No other statistically significant differences were observed. A medium effect size was present for the KSES-PA (0.62), KSES-ADL (0.42), KSES-Present (ADL + PA + Sport) (0.48), KSES-Total (0.53), and Tampa Scale of Kinesiophobia-11 (0.61) but must be interpreted with caution as 95% confidence interval crossed 0. Conclusions: This exploratory study indicated that individuals with a history of ACLR and SRC had worse knee self-efficacy for PA compared with those without history of SRC. Rehabilitation specialists should monitor knee self-efficacy deficits in the post-ACLR population and recognize the potential influence of cumulative injury history on rehabilitative outcomes.