This is a comprehensive educational paper discussing the evaluation of those conditions that fall under the loose umbrella of Patellofemoral Pain Syndrome or PFPS. The article is 22 pages long, and illustrated. It is also easy to read, so I will only go over the key points here, because there is a link above to the free full text article.
The authors make the very good point that "(t)he seemingly simple design of the patellofemoral joint, is, in reality, a very complex articulation with contributing factors that are both intrinsic and extrinsic in nature, noncontractile and contractile, some of which include substantial interplay from other more distant sources, such as the hip or foot." They point out that the complaint may be non-specific in nature and symptoms may be traced to a variety of initiating circumstances.
They go through key points of the history, and then detail the clinical examination with illustration.