The Difference in a Clinical Measure of Patella Lateral Position Between Individuals With Patellofemoral Pain and Matched Controls

Lee Herrington

DOI: 10.2519/jospt.2008.2660

STUDY DESIGN: Cross-sectional matched-pairs design. OBJECTIVE: To investigate if differences existed in the medio-lateral position of the patella between subjects with patellofemoral pain (PFP) and matched controls. BACKGROUND: The assessment of patella position is often proposed as an essential aspect of clinical examination of individuals with PFP. To date, only 1 clinical method of assessing lateral patella position has been intensively investigated. Although there is a growing body of evidence on the reliability and validity of this method, no studies have investigated differences in patella position between patients with PFP and controls. METHODS AND MEASURES: Twelve female patients with PFP and 12 matched controls (mean ± SD age, 21.9 ± 2.6) had their medio-lateral patella position assessed in 20º of flexion. Differences between groups were investiged with independent-groups t tests. RESULTS: All subjects were found to have a laterally located patella. The mean ± SD lateral position for the individuals in the PFP group was 7.5 ± 2.6 mm compared to 3.8 ± 2.4 mm for the control group. This difference was statistically significant (P = .019). Intratester reliability of the measurement of patellar position, calculated using intraclass correlation model 3,1, was 0.86. CONCLUSION: Using this method of assessing patella position, the patella of individuals with PFP was significantly more laterally located than the patella of those in a matched control group.

J Orthop Sports Phys Ther. 2008;38(2):59-62, published online 16 October 2007. doi:10.2519/jospt.2008.2660

KEY WORDS: anterior knee pain, knee, patella, patellofemoral joint

The author investigates if differences existed in the medio-lateral position of the patella between subjects with patellofemoral pain (PFP) and matched controls.

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