Understanding the role of the triceps surae muscle-tendon unit during rehabilitation from Achilles tendinopathy (PhD academy award)

My PhD aimed to gain insights in the relationship between triceps surae muscle force-sharing, Achilles tendon properties, and changes in pain, tendon structure and functioning during rehabilitation in patients with Achilles tendinopathy. The long-term aim of this work was to identify new outcomes that could optimise and improve rehabilitation strategies. We identified differences in force-sharing between patients with Achilles tendinopathy and healthy controls, assessed Achilles tendon property changes over time, compared responders from non-responders throughout rehabilitation and investigated the impact of incorporating Achilles (sub)tendon characteristics into musculoskeletal models. ### Why did I do it? The Achilles tendon is connected to, and loaded through force production of the three triceps surae muscle forces: the soleus (SOL), the gastrocnemius lateralis (GL) and medialis (GM). Tendon remodelling occurs due to repetitive, high or unusual loads as internal tendon strains will increase, leading to microtrauma, where the arrangement of collagen fibres within the tendon gets disorganised. This common overuse injury, known as Achilles tendinopathy, affects both competitive and recreational athletes. Various structural and functional changes in the tendinopathic tendon are observed compared with healthy tendons, for example, increased volume and cross-sectional area, and decreased stiffness, …