Comparison of proprioceptive acuity and lower limb functionality between individuals with patellofemoral pain syndrome and matched controls

Abstract

Introduction: Patients with patellofemoral pain syndrome (PFPS) present pain, functional limitation and alteration in knee proprioception. Few studies have investigated the proprioceptive acuity of the knee in people with PFPS, but none have analyzed the cortical proprioceptive representation and lower extremity functionality in combination with the knee proprioception. Objective: To compare proprioceptive acuity and lower extremity functionality among individuals with PFPS and controls. Methods: A case-control study was conducted in 48 patients with PFPS and 48 healthy participants. Patients with clinical diagnosis of PFPS and matched controls were included in the study. Patients completed a questionnaire with sociodemographic and clinical characteristics. Participants performed the proprioceptive evaluation using the active joint position sense test and the evaluation of cortical proprioceptive representation. The functionality analysis was performed with the Single Leg Triple Hop test, the Y-test and the Kujala questionnaire. The groups were compared using the T-test for independent samples. Results: The mean age of participants
was 31 years (ranging from 21 to 44), with 30 men (62.5%), and 45 right-handed dominance (93.80%). The right knee was tested in 26 (54.20%) participants from each group. Patients with PFPS had peripheral proprioceptive deficit in the knee in the SPA evaluation at 20 degrees (5.06 [3.53]) compared to controls (3.06 [2.46]) (P = 0.002). Differences were observed between the groups with statistical significance in reaching the anterior direction of the Y-test (patients with PFPS = 58.61 [6.58] versus Controls = 61.65 [5.90], p = 0.019). The other functional measures did not present differences between the two groups. Conclusion: Patients with patellofemoral pain syndrome presented a reduction in proprioceptive acuity in the evaluation of the active joint position sense at 20 degrees. The proprioceptive evaluation of the knee at 60 degrees and proprioceptive cortical representation were preserved in patients with patellofemoral pain syndrome. The anterior direction of the Y-test was the only functional measure impaired in comparison with matched controls.