Normative data of frontal plane patellar alignment in athletes

Abstract Objective The objective of this study was to provide normative data of frontal plane patellar alignment according to McConnell and Arno angles, verify the association between theses angles and identify the presence of patellar rotation in different sports. Design Cross-sectional. Participants Nine participants (18 knees) were assessed in a preliminary study to verify the intra and inter-examiner reliabilities of the patellar alignment measures. In the main study, 230 volleyball, basketball, gymnastics and soccer athletes (460 knees) were evaluated in order to obtain normative data of patellar alignment. Main outcome measures Frontal plane patellar alignment (McConnell and Arno angles) measured in standing position by means of photogrammetry. Results The standardized method demonstrated intra and inter-examiner reliability coefficients varying from .85 to .98. The mean McConnell and Arno angles were 2.05° (±5.9) and 2.89° (±7.57), respectively. A low association was observed ( r = .189, p