Measurement of coronal plane patellar mobility in normal subjects

This study evaluated an instrument for measuring patellar mobility in the c oronal plane in normal subjects, established baseline quantitative data and compared with methods of measurement described in the literature. This dat a can be used as a baseline for clinical assessment of patellar mobility. T he findings suggest that 8-20 mm displacement is normal patellar mobility i n the coronal plane. Displacement less than 8 mm may be considered as retin acular tightness and displacement greater than 20 mm considered as abnormal retinacular laxity.