Avaliação do controle postural durante testes de desempenho funcional em mulheres com disfunção femoropatelar

Abstract

Introduction: Patellofemoral Dysfunction (PFD) is characterized by pain in the anterior or retropatellar region of the knee, of mild to moderate intensity, with a persistent characteristic and intermittent frequency. This condition affects physically active young women, with an incidence of 23% in the general population. Pain is generally reported during functional activities, especially those that require deceleration, such as descending steps and performing squats. Therefore, understanding biomechanical aspects and patient perceptions of functional aspects is important for a more assertive physical therapy assessment and, therefore, approaches involving these activities. One way to quantify these aspects is to include functional tests in the evaluations. Performing these tests is a quick, low-cost option that allows for the assessment of the activities of concern. Therefore, the objective of this study was to evaluate postural sway during functional tests in women with and without patellofemoral dysfunction. Method: This study evaluated the postural sway of 91 women (41 controls and 50 with patellofemoral pain), with a mean age of 24 years (23.6; 25.3) and active. These women underwent evaluation of the following functional tests: Vertical Jump and YBalance Test. To evaluate postural sway, the EMGSystem® force platform was used, with a sampling frequency of 500 Hz. The parameters evaluated for the Vertical Jump test were: peak ground reaction force, total displacement, mediolateral displacement, and anteroposterior displacement. These parameters were analyzed during the preparation and landing phase of the jump. Vertical Jump performance was collected for analysis. For the YBalance Test analysis, the parameters analyzed during the test execution were: total displacement, anteroposterior displacement, and mediolateral displacement. The YBalance Test performance was collected for analysis. For the analysis of isometric muscle strength, the following muscle groups were evaluated: hip lateral rotators, hip extensors, hip abductors, knee extensors, plantar flexors, and ankle evertors. The following instruments for reporting volunteer perception were applied: Visual Analog Scale (VAS), Anterior Knee Pain Scale (AKPS), and Patellofemoral Pain Syndrome Intensity Scale (PSS). Normality was tested by the Shapiro-Wilk test, with comparisons between groups performed by the Mann-Whitney U test when normality was not accepted, and by the Student's t-test for independent samples when normality was accepted. For both tests, significance was considered when p ≤ 0.05. The effect size was calculated by Cohen's d, being considered large (>0.8), moderate (0.4-0.7), and small (<0.3). Results: The DFP group presented greater sway during the preparation phase of the Vertical Jump, which could have contributed to poorer performance at jump height. In the YBalance Test, the DFP group presented less postural sway in the anterior direction, associated with poorer performance in the anteroposterior, posteromedial, and posterolateral directions. The DFP group presented lower isometric muscle strength in the Knee Extensors, Plantar Flexors, and Ankle Evertors. The DFP group presented higher levels of pain (VAS), worse perceived functioning (AKPS), and greater severity of pain in functional activities (PSS) when compared to the group without DFP. No significant differences were observed for the other parameters analyzed. Conclusion: The DFP group presented greater sway during the preparation phase of the Vertical Jump and poorer performance at jump height. In addition, it presented less postural sway in the anterior direction on the YBalance Test, as well as poorer performance in the anterior, posteromedial, and posterolateral directions.