Passive Knee Joint Proprioception Test in Normal Adults

Objective: To establish appropriate test angle of passive knee proprioception test and to compare with active knee proprioception test. Method: Thirty one healthy volunteers were tested in seated position on isokinetic machine. For passive test, the knee joints were placed in starting angle of 0 degrees, 30 degrees in flexion test and 90 degrees, 60 degrees in extension test. To memorize target angle, they were passively positioned to the target angle and left hold for 10 seconds, and returned to starting position. After these processes, knee joints were passively moved toward flexion and extension target angle. The subjects were instructed to press stop button when the memorized angles were reproduced. The tests were performed 3 times for each 6 different test angle. The active test were performed with the same memorized process but the subjects moved actively to reproduce target angles. The absolute angular errors (AAE) between target angle and produced angle were measured and compared. Results: In passive proprioception test, the AAEs were increased according to the test angle differences were increased from 30 degrees to 60 degrees. In the same target angle difference, there were no differences between starting positions. When the results of passive test were compared with active test, there were no significant differences in the flexion test, but larger angular error were measured in extension test. Conclusion: The passive knee proprioception test could be useful for patients with lower extremity weakness. Considering the possible error of large angular difference, the testing angular differences should be properly selected.