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  Identifying the Defective Muscle: Parks 3-Step Test

The technique of assessing movements of the eyes as the head is tilted successively toward one shoulder and then toward the other was introduced by Hoffmann and Bielschowsky but has since come to be known as the Bielschowsky head tilt test.[29] The manner in which this test is normally used in the clinical setting is referred to as the Parks 3-step test.

 Comparison of tests

This test can provide useful information to help determine the affected muscle in cases of known or suspected incomitancy. The test is useful in cases of paresis of any of the cyclovertical muscles, but the results are more dramatic when the oblique muscles are affected compared to when the vertical rectus muscles are involved. No additional equipment is required to perform this test. It offers the additional advantages in that the test is objective, allowing you to observe and measure the magnitude of any deviations without subjective responses from the …