Patellofemoral pain syndrome (PFPS) is a common form of anterior knee pain caused by general overuse, muscular weakness or strength imbalances, and poor movement coordination leading to abnormal alignment or mal-tracking of the patella. Recent guidelines do not recommend the use of a knee orthosis due to a lack of evidence supporting their effectiveness. A new patellar support (NuNee, K-Neesio LLC.) which uses distraction force to relieve pressure placed on the patella, has been proposed. The purpose of this study was to examine the immediate effects of the NuNee patellar support on perceived pain, biomechanics, and function in individuals with patellofemoral pain while they perform the modified star excursion balance test. We hypothesized that the use of the NuNee would decrease perceived pain, increase knee flexion angles, decrease knee valgus angles, increase knee extensor moment, and improve knee extensor moment score in the anterior direction of the modified star excursion balance test.

Methods:​ Thirteen subjects with patellofemoral pain were recruited for this study. Subjects performed three successful trials of the modified star excursion balance test under various conditions (control, sham, and NuNee). Knee joint angles, knee extensor moments, and reach distances were calculated using a 3-D motion capture system and two force plates. Perceived pain was assessed using a visual analog scale following each successful trial. A repeated measures ANOVA was performed to examine differences in biomechanical variables between conditions. A Kruskal-Wallis analysis examined differences in self-reported pain between conditions.

Results:​ Although a pain level of ≥3 was a criterion for study participation, most subjects reported pain of <3 on a VAS during testing. Perceived pain had minimal decreases between the control and NuNee conditions (1.67 to 1.40). Knee flexion angle increased (-69.44 ±9.675° to - 71.62 ±9.731°), and knee valgus angle increased (0.1550 ±6.967° to 1.217 ±6.500°) between the control and NuNee condition. Knee extensor moment increased (1.216 ±0.6074 Nm/kg to 1.683 ±3.887 *+ Nm/kg) between the control and NuNee conditions. Anterior reach distance saw no change (62.06 ±6.054% to 62.83 ±6.025%) between the control and NuNee conditions. No statistical significance was found for any of the tested variables.

Conclusion:​ No significant differences were found between conditions for any of the tested variables. A larger sample size and increased perceived pain are needed to fully investigate the efficacy of the NuNee patellar support. Although not significant, our findings show enough promise that further research is warranted.