Investigating the relationship between form and function in the ape shoulder

Erin Lee, Dr. Michael Rainbow

Our goal is to understand how variation in skeletal anatomy alters the mechanical function of the shoulder joint. Across ape species, large-scale differences in shoulder morphology alter joint mechanics to enable functional demands such as overhead suspension or terrestrial quadrupedalism. Within the human population, shoulder morphology is still highly variable and specific shape features are correlated with soft tissue injury, indicating that more subtle shape differences can also alter joint mechanics in a meaningful way. We investigate how bony morphology alters joint range-of-motion and soft tissue function using a combination of experimental imaging and computational modelling. Characterizing this relationship between form-and-function on a small scale (within humans) and a large scale (across apes) can inform patient-specific clinical treatment and improve our understanding of how we evolved our present-day shoulder anatomy.

Relevant publications: (Lee et al., 2020) 

Investigating the influence of passive structures in the foot and ankle on the coupling of arch-recoil and ankle flexion

Quinn Yetman, Dr. Michael Rainbow

Our goal is to understand how passive tissues transfer forces from the foot through the ankle joint complex. Recent work has shown that arch recoil is responsible for putting the talus into a more favourable position for push-off. The arch recoils, curling under the tibia, which causes the talus to rotate backwards keeping the tibio-talar articular surface upright and reducing dorsiflexion at the talocrural joint. Preliminary work has shown the timing of arch-recoil and ankle plantarflexion are synchronized, suggesting there may be a mechanism in the ankle joint complex facilitating this coupling. Using ArtiSynth, an open-source multibody and finite element modelling package, and state-of-the-art imaging techniques, we can see how force is transferred into and out of the talus over stance. This will allow us to answer fundamental questions about how passive tissue in the ankle joint complex contributes to the relationship between arch recoil and ankle motion. In the future, this model can be used to evaluate and improve upon talar and ankle replacements and as an input to a lower body musculoskeletal model to better understand the relationship between knee and ankle mechanics.

Relevant publications: ()

Why do we have patellas? Understanding optimal function and deviations in patellofemoral mechanics

Mitchell Wheatley, Dr. Michael Rainbow

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Relevant publications: ()