Effect of Different Knee Angles on Active Joint Position Sense in Patients with Patellofemoral Pain Syndrome

Abstract
Background: Patellofemoral pain syndrome is a common, painful musculoskeletal condition that affects physically active young adults and adolescents. During assessment of joint position sense, the different positions of the knee may affect the internal structures of the knee differently. Therefore, examining the differences in the two positions between both males and females may shed light on the effect of muscle activation.
Aim of Study: To examine the differences between 20 and 60 angles of knee extension on knee joint position sense as well as to examine the differences in knee joint position sense between males and females in patient with patellofemoral pain syndrome.
Material and Methods: Thirty nine participants (11 men, 28 women) participated in this study. With a mean age of 18 to 35 years with mean age (24.25±3.40) years, mean weight (68.71±16.01) Kg, and mean height (164.07±10. 14) cm. All subjects were assessed by the same examiner via the Isokinetic Dynamometer Device (IKD) at angles 20º and 60º with angular velocity 2º/sec to determine which angle has more angular error.
Results: The results revealed that the 20 angle position had a significantly greater absolute reposition error than the 60 angle position (p=0.039). There was no significant differ-ence in joint position sense between males and females at angle 20 (p=0.829), and angle 60 (p=0.833).
Conclusion: The results indicate that there is a significant difference in knee joint position sense between position of 20 degrees of extension and 60 degrees of extension. Specif-ically, as the knee becomes more extended proprioceptive acuity was heightened. Therefore, future research is still needed to discern exactly whether the heightened propriocep-tive acuity comes from the differences in gravitational torque or the differences in the anatomical structures of the knee between the two positions.