The Effects of Patellofemoral Taping on Patellofemoral Joint Alignment and Contact Area

Purpose/Hypothesis: It is widely accepted that patellofemoral pain (PFP) is the result of excessive stress between the retro-patellar surface and the femoral trochlea. Elevated patellofemoral joint (PFJ) stress may be associated with a reduction in PFJ contact area resulting from patellar malalignment (e.g., lateral displacement, lateral tilt, or patellar alta and/or quadriceps imbalance). McConnell and Kinesio taping techniques are commonly used to address PFP and improve PFJ alignment. It has been theorized that PFJ taping can alter the PFJ alignment which may increase the patella’s contact area within the femoral trochlea, thereby resulting in a reduction in PFP. To date, the effects of these 2 taping approaches on PFJ contact area and PFJ alignment have not yet been studied thoroughly. The primary purpose of this study was to use magnetic resonance imaging (MRI) to examine the effects of patellofemoral taping techniques on PFJ alignment and contact area in persons with PFP at 3 knee joint angles (0°, 20°, and 40°). Number of Subjects: Fourteen female subjects with retropatellar pain and PFJ malalignment participated (age: 27.86 ± 5.95 years; weight: 72.15 ± 19.27 kg; height: 1.67 ± .08 m). Methods: Each subject underwent a pre-taping magnetic resonance imaging (MRI) scan session and 2 MRI scan sessions after the application of the 2 taping techniques aiming to correct lateral patellar displacement. Subjects were asked to report their pain using an 11- point numeric rating scale (NRS) while stepping down from a 23-cm step, before and after tape was administered. During each scan session, subjects were loaded with 25% of body weight on their involved/more symptomatic leg at 0°, 20°, and 40° of knee flexion. The outcome measures included patellar lateral displacement (bisect-offset (BSO) index), patellar mediolateral tilt (patellar tilt angle (PTA)), patellar position (Insall-Salvati ratio (ISR)), PFJ contact area, and NRS. PFJ alignment/contact area was compared among the 3 conditions (No tape, Kinesio, and McConnell) at 3 knee angles using a two-way ANOVA with repeated measures. Pain NRS was compared among the 3 conditions using Friedman test and post-hoc Wilcoxon signed-rank tests. Results: The results of the two-way ANOVAs revealed that neither McConnell nor Kinesio taping had significant effects on BSO index (p = 0.488), PTA (p = 0.558), ISR (p = 0.778), and contact area (p = 0.358) across the 3 knee flexion angles. Knee flexion angle had a significant effect on BSO index (p = 0.001) and contact area (p \u3c 0.001). The Friedman test revealed a significant difference in pain level among the 3 conditions. The post-hoc Wilcoxon signed-rank tests further demonstrated that there was a reduction in NRS during step-down test after the application of the Kinesio Taping technique (p=.007). Conclusions: In a weight-bearing condition, our results did not support the premise that applications of PFJ taping using a medial correction technique can alter the PFJ contact area or alignment of the patella. The reduction in pain, following the application of the Kinesio Taping technique performed in this study supports the previous literature on the use of Kinesio Taping techniques for pain management, although the underlying mechanism for the reduction of pain is unclear