Assessment of Achilles Tendon Injury in Adolescents - PROJECT SUMMARY/ABSTRACT The incidence of Achilles tendon injury in youth sports has increased, yet Achilles tendon pathology in adolescents has been poorly investigated. While the overuse injury of Achilles tendinopathy is clinically diagnosed by pain with loading and loss of function in adults, the same symptoms in adolescents are instead considered a growth plate disorder called calcaneal apophysitis. Calcaneal apophysitis and Achilles tendinopathy may onset at different times during musculoskeletal growth in adolescents who consistently overload their tendons. However, the involvement of Achilles tendon pathology amongst adolescents with general heel pain is unknown. Further, the etiology of Achilles tendon injury has yet to be determined in the adolescent population. It is speculated that an overdevelopment of triceps surae muscle alters Achilles tendon structure (i.e., morphology and mechanical properties), resulting in heel pain during loading and loss of function. With no clear clinical diagnostic delineation between apophysitis and tendinopathy for patients under 18 years old with heel pain, overlooking Achilles tendon pathology may result from an assumed diagnosis of calcaneal apophysitis. Misdiagnosis and subsequent misaligned treatment of Achilles tendon injury in adolescents can reduce quality of life and may impede the development of a physically active lifestyle into adulthood. The growing incidence rates of lower limb tendinopathies in adolescence, and premature retirement from youth sports due to debilitating injury, stress the need for adequate understanding of Achilles tendon injury. Yet, Achilles tendon pathology research is disproportionately focused on the adult population, potentially leaving the pediatric population at risk of long-term health issues. The objective of this proposal is to investigate the effect of heel pain on adolescent Achilles tendon health and lower limb biomechanics. Specifically, this study will evaluate Achilles tendon symptoms and lower limb impairments (Aim 1), Achilles tendon structure and triceps surae muscle strength alterations (Aim 2), and Achilles tendon loading profiles (Aim 3) of adolescents with complaints of heel pain compared to healthy adolescents. This work will contribute valuable evidence for establishing the pathoetiology of adolescent heel pain, which is necessary to properly diagnosis and treat adolescents with heel pain so they can maintain physically active lifestyles into adulthood. The long-term goal of this fellowship applicant is to investigate mechanisms of musculoskeletal injury and improve clinical rehabilitation. The interdisciplinary training this applicant will receive from expert biomedical researchers and clinical collaborators at the University of Delaware during the proposed fellowship will make her a valuable investigator, with proficiencies in clinical testing, innovative imaging techniques, and novel computational modeling. Further, this proposal will facilitate the applicant’s postdoctoral training, laying the foundation for a career as an independent clinical scientist and strong advocate for diversity in health science fields.