The validity of clinical measures of patella position

Patellar taping is regarded as an important element of the treatment of patellofemoral joint pain. Key to the successful use of patellar taping is the assessment of patella position. The reliability and validity of the techniques used to assess patella position has been questioned. The aim of the study was to assess the validity of the clinical assessment technique of patella medio-lateral position and patella lateral tilt against the criterion measure of MRI. Twenty-four subjects eight females and 16 males had their patella position examined in the study (mean age 24.5+/-7.9 years, range 18-42 years). The study also assessed intra-tester reliability of the technique. A good correlation was found between the findings of the clinical test for medio-lateral position and the MRI measure (r=0.611, p=0.002). All of the subjects found to have a laterally tilted patella on clinical examination had a lateral patella tilt defined by PTA of greater than 5 degrees . Those subjects with a PTA of less than 5 degrees on clinical examination were assessed as having no degree of patella tilt. The study undertaken shows that when undertaken by an experienced manual therapist positional assessment of the patella can have strong criterion validity and intra-tester reliability.