Using the vault hold, the examiner exerted a gentle force over the occipital squama and great wings of the sphenoid concurrently. This force was directed caudal and was applied by his paired index and fifth fingers. The thumbs were in contact with each other and furnished proprioceptive and kinesthetic cues so that the examiner's force was applied as symmetrically equal as possible. After the cranium responded to the initiating force (of approximately 5.0 grams or less), the examiner became passive and followed the cranial motion to its restricted end point. This was the test for flexion. Restriction against this examiner-induced motion was then rated and reported after comparison with restriction encountered when testing for extension, next. To test for extension, a similar bilaterally equal force was applied by the examiner in a cephalad direction. The testing was then repeated until the examiner gained a reliable impression as to the relative ease/restriction of these reciprocal motions.