Mechanics is a key foundation topic for many engineering disciplines, the study of which usually constitutes a significant proportion of first and second year engineering undergraduate studies. Many engineering students experience substantial difficulties with introductory mechanics, and it is widely noted in the literature that pass rates in mechanics courses tend to be unacceptably low. This paper details the interim findings of, and issues arising from a literature search focusing on how engineering educators understand, describe, identify and deal with the causes of poor performance in introductory mechanics. The most striking conclusion drawn from this literature search is the lack of conclusive research into the more fundamental causes of difficulties for students studying mechanics