PhD Fellow Diego Martínez Echevarría

Knee osteoarthritis (KOA) is a complex, multifactorial disease affecting multiple structures at the joint. Pain is arguably the greatest concern in patients, as early stages of the disease­­­­­—with clear damage of the involved tissues—frequently go unnoticed until pain appears.

Pain clearly affects human motion. Induced pain in the knee is negatively correlated to joint loads in the involved leg. Intuitively, we understand that a person with pain will try to reduce the usage of a possibly injured limb. However, in the current literature, there is no model explaining how pain can cause these limping motions or a thorough description of the limping motion.

In his project, Diego will design predictive models of gait under pain. With Optimization and Control Theory, literature shows that it is possible to make predictions of normal gait based on assumptions of muscle activation and energy consumption, among others. The core idea of Diego’s project is to design a pain model that can be included in a similar framework, describing the connection between pain and limping mechanisms.

The project introduces two great challenges: the modelling and the computational. The former is the most conceptual, with the pain model relying on physical magnitudes (loads, muscle activations, etc.) and outputting a measure of pain that compares to the terms in the “normal gait” model.

On the other hand, the computational load associated with the optimisation problems can easily become unbearable due to its intrinsic nonlinearity and high dimensionality. Hence, thought and work is put into the application of efficient and reliable methods and algorithms.

The results of this PhD project have the potential to further our comprehension of pain and its effect on gait and characterise and explain limping motions, and produce reasonable joint load distributions for people experiencing pain.

Diego has a bachelor’s in Physics and a master’s in Mathematics and Computation. He can often be covered in chalk, shifting between the computer and the blackboard.

See Diego's profile on Aalborg University’s website.