Proprioception of the knee joint in patellofemoral pain syndrome

Objectives: The importance of proprioception in the etiology, treatment, and prevention of sports injuries and joint diseases has become increasingly clear. The purpose of this study was to investigate knee proprioception in patients with patellofemoral pain syndrome (PFPS). Methods: The study included 28 patients (18 females, 10 males mean age 28 years: range 16 to 48 years) with a clinical diagnosis of unilateral PFPS and 27 normal volunteers (13 females, 14 males: mean age 26 years; range 19 to 32 years) without any complaint related to the knee. The mean duration of complaints was 35.8 weeks (range 2 weeks to 3 years). In both patient and control groups, proprioception of the knee was measured by means of active joint position sense at four different target angles (15 degrees, 30 degrees, 45 degrees, 60 degrees) with the use of a digital geniometer and the results were compared target angles Results: Proprioceptive errors were greater at all tar in the affected knees compared to those measured in the contralateral knees and both knees of the controls. Differences between affected knees and contralateral knees ranged from 1.01 +/- 0.250 to 1.65 +/- 0.43 degrees and were significant at three target angles (15 degrees, 30 degrees, 60 degrees; p<0.05). Comparisons between the affected knees and both knees of the controls also showed significant differences at all target angles ranging from 2.48 +/- 0.92 degrees to 3.87 +/- 2.46 degrees (p<0.001). Errors obtained in the normal knees of the patients were also significantly greater compared to those seen in both knees of the controls, exceeding, 2.7 degrees at some target angles (P<0.001). Conclusion: Our results show that patients with PFPS have impaired proprioception in the affected knee accompanied by significant losses in the proprioception of the contralateral normal knee. Based on these findings, proprioceptive rehabilitation techniques should be incorporated into the treatment of PFPS.