This thesis aims to improve the theoretical modelling of compliant mechanisms. The conclusions drawn from this work will help designers understand sources of error associated with strain propagation when designing with lumped compliance. Compliant mechanisms have increased in popularity as they allow for designs that feature lower part counts, increased precision and reduced manufacturing costs. Although using theoretical models to design compliant mechanisms is a useful tool, there is an assumption that only the nodes in a compliant mechanism undergo strain. This is not the case. There is strain occurring outside of the node in a region called the preserve region. The preserve region’s impact on the theory is greatly under-explored in the literature. The preserve region’s size, shape, and impact were found and quantified for a range of critical node types. This was done through the use of FEA software by altering the model of a simple, compliant mechanism. The size of the preserve region changed based on the thickness and the fillet used, with an increase of thickness from 4mm to 8mm, causing the radius of the arc that encompasses the preserve region to grow from 8.5mm to 13mm. The shape was also found to be an ellipse, irrespective of the node’s geometry. The preserve region’s impact on the theoretical models was also quantified. It was found that the thickness has the most drastic effect on the compliance values of the node, increasing the error from 20.53% to 102.18% when the thickness was increased from 4mm to 8mm. This work shows the importance of considering the preserve region when creating theoretical models of compliant mechanisms. When properly considered, this research shows that the error between the theoretical and the FEA values can be greatly reduced.