Techniques for measuring the static and dynamic properties of the patella

An electrogoniometric method was used together with a new standardized radiographic technique to accurately determine the rotation of the patella during knee flexion of both normal subjects and patients referred for retropatellar pain. A preliminary study using these techniques shows that retropatellar pain is very much a multi-factoral clinical problem and that combinations of patello-femoral articulation abnormalities, patellar shape and mechanical influences are present in all forms of the painful patella.