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Background: Collegiate athletes with prior sports-related concussion (SRC) are at increased risk for lower extremity (LE) injuries; however, the biomechanical and cognitive mechanisms underlying the SRC-LE injury relationship are not well understood. Purpose: To examine the association between cognitive performance and LE land-and-cut biomechanics among collegiate athletes with and without a history of SRC and to determine the association among multiple cognitive testing batteries in the same athlete cohort. Study Design: Controlled laboratory study. Methods: A cohort of 20 collegiate athletes with prior SRC (9 men, 11 women; mean ± standard deviation [SD] age, 20.5 ± 1.3 years; mean ± SD time since last SRC, 461 ± 263 days) and 20 matched controls (9 men, 11 women; mean ± SD age, 19.8 ± 1.3 years) completed land-and-cut tasks using the dominant and nondominant limbs. LE biomechanical variables and a functional visuomotor reaction time (FVMRT) were collected during each trial. Athletes also completed the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) and Senaptec Sensory Station assessments. Results: In the SRC cohort, Pearson correlation coefficients indicated slower FVMRT was moderately correlated with decreased dominant limb ( r = –0.512) and nondominant limb ( r = –0.500) knee flexion, while increased dominant limb knee abduction moment was moderately correlated with decreased ImPACT Visual Memory score ( r = –0.539) and slower ImPACT Reaction Time ( r = 0.515). Most computerized cognitive measures were not associated with FVMRT in either cohort ( P > .05). Conclusion: Decreased reaction time and working memory performance were moderately correlated with decreased sagittal plane knee motion and increased frontal plane knee loading in collegiate athletes with a history of SRC. The present findings suggest a potential unique relationship between cognitive performance and LE neuromuscular control in athletes with a history of SRC injury. Last, we determined that computerized measures of cognitive performance often utilized for SRC management are dissimilar to sport-specific cognitive processes. Clinical Relevance: Understanding the relationship between cognitive performance and LE biomechanics in athletes with prior SRC may inform future clinical management strategies. Future research should prospectively assess cognitive and biomechanical measures, along with LE injury incidence, to identify mechanisms underlying the SRC-LE injury relationship.

Context Fear has been cited as the primary barrier to return to sport (RTS) by athletes after anterior cruciate ligament reconstruction (ACLR). Understanding the neural factors that contribute to fear after ACLR may help us to identify interventions for this population. Objective To characterize the underlying neural substrate of injury-related fear in patients after ACLR versus healthy matched control individuals during a picture imagination task (PIT) consisting of sport-specific images and images of activities of daily living (ADL). Design Case-control study. Setting Research laboratory. Patients or Other Participants A total of 24 right-hand–dominant participants (12 with left-sided ACLR and 12 control individuals) were enrolled. Participants underwent full-brain functional magnetic resonance imaging. Main Outcome Measure(s) Functional data were acquired using blood oxygen level–dependent (BOLD) echoplanar imaging. Independent t tests were conducted to identify between-groups differences in BOLD signal changes during all images of the PIT. Paired t tests were computed to examine differences in BOLD signal change between sport-specific and ADL images in the ACLR group. Results Increased activation in the inferior parietal lobule and the mediodorsal thalamus was observed during PIT in the ACLR group. An inability to suppress the default mode network in the ACLR group was noted. The ACLR group exhibited increased activation in the cerebellum and inferior occipital regions during the sport-specific images versus the ADL images, but no other regions of interest demonstrated differences. Conclusion After ACLR, patients may be more predisposed to fear, anxiety, and pain during sport-specific activities and ADLs. Psychosocial interventions may be warranted after ACLR to reduce injury-related fear and mitigate potentially maladaptive neuroplasticity.