Browsing by Author "Corrigan, Patrick"
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Item Achilles tendinopathy: the role of tendon structure in symptom and functional recovery(University of Delaware, 2019) Corrigan, PatrickAchilles tendinopathy is a debilitating overuse injury that is characterized by pain during loading activities, swelling, and impaired functional performance.1,2 The incidence rate in the adult population is 2.35 per 1000, with middle-aged adults (i.e. 30-50 years old) who are physically active being the most frequently affected.3 Throughout rehabilitation, patient-reported symptoms are commonly used to monitor recovery and tailor treatment. However, a rehabilitation program that solely focuses on symptoms may be problematic since the resolution of symptoms does not ensure the structure or function of the tendon has normalized.4,5 With 41% of patients continuing to have symptoms after 8 years and up to 29% undergoing surgery,6 a more comprehensive approach to rehabilitation is needed to improve long-term patient outcomes. Measures of tendon morphology and mechanical properties may provide critical information regarding the health of the tendon that can be used to supplement patient-reported symptoms. Before these measures can be implemented in clinical practice, there is a need to determine if tendon morphology and mechanical properties relate to the patient symptoms and function. Therefore, the purpose of this dissertation work was to determine if tendon morphology and mechanical properties play a critical role in recovery for patients with Achilles tendinopathy. ☐ The first aim of this dissertation work was to assess the reliability and validity of measuring in vivo mechanical properties with continuous shear wave elastography (cSWE) in healthy and degenerative Achilles tendons. Our findings support the use of cSWE for monitoring changes in tendon mechanical properties, with fair-to-excellent intrarater reliability for all properties.7 The second aim was to determine if tendon morphology and mechanical properties were associated with recovery of patient-reported symptoms and functional performance. This was performed by prospectively following a cohort of patients with Achilles tendinopathy for one year. The key findings were 1) greater tendon thickening was associated with worse symptoms and calf muscle function 2) patient-reported symptoms over the year depended on the initial shear modulus of the tendon and 3) worse calf muscle function was associated with lower viscosity. These results indicate that Achilles tendon morphology and mechanical properties are predictive of long-term symptoms and function in patients with Achilles tendinopathy. The goal of the third aim was to evaluate the immediate effects of laser-induced photobiomodulation therapy on Achilles tendon morphology and mechanical properties in healthy and degenerative tendons. Results demonstrated that laser therapy does not have immediate effects on the Achilles tendon,8 which suggests that laser therapy can be administered at any time during a treatment session without influencing other treatments. Lastly, in aim 4 we explored the relationships between patient-reported outcomes, tendon morphology, mechanical properties, lower leg function, pain, and running mechanics in patients with Achilles tendinopathy. We found that pain and lower leg functional performance were associated with Achilles tendon loading patterns while running, but patient-reported outcomes, tendon morphology and mechanical properties were not. ☐ Collectively, this dissertation work supports the use of cSWE for estimating tendon mechanical properties, identifies the importance of tendon morphology and mechanical properties in symptom and functional recovery, and elucidates aspects of tendon health that may be critical when progressing patients with Achilles tendinopathy from return-to-sport to return-to-performance.Item Tendon loading in runners with Achilles tendinopathy: Relations to pain, structure, and function during return-to-sport(Scandinavian Journal of Medicine and Science in Sports, 2022-04-30) Corrigan, Patrick; Hornsby, Samantha; Pohlig, Ryan T.; Willy, Richard W.; Cortes, Daniel H.; Silbernagel, Karin GrävareWe aimed to (1) compare pain, tendon structure, lower limb function, and Achilles tendon loads while running between limbs in runners with Achilles tendinopathy, and (2) explore the relations of pain, tendon structure, and lower limb function to Achilles tendon loads while running. Twenty runners with Achilles tendinopathy participated in this pilot study. Pain was assessed with questionnaires, quantitative sensory testing, and functional testing. Tendon morphology and mechanical properties were evaluated with ultrasound imaging, continuous shear wave elastography, and ultrasound imaging combined with dynamometry. Lower limb function was assessed with an established test battery. Achilles tendon loads were estimated from biomechanical data acquired during running. Compared to the least symptomatic limb, the most symptomatic limb had lower scores on the Victorian Institute of Sports Assessment – Achilles questionnaire and worse pain during drop countermovement jumping, hopping, and running. Tendon thickness and cross-sectional area were greater, and Young's modulus, drop countermovement jump height, and plyometric quotient during hopping were lower on the most symptomatic limb. Side-to-side differences in drop countermovement jump height were significantly associated with side-to-side differences in Achilles tendon peak forces and average loading rates during running. Various measures of pain, structure, and function differ between limbs in runners with Achilles tendinopathy during return-to-sport. Tendon forces, however, do not differ between limbs during comfortable running. In addition to measures that differ between limbs, measures of performance during drop countermovement jumping may aid in clinical decision-making during return-to-sport because they are associated with tendon forces while running.