During the transverse ligament stress test, a PA glide is performed on which vertebra?

The transverse ligament stress test specifically assesses the integrity of the transverse ligament of the atlas (C1). During the test, a posterior-anterior (PA) glide is applied to the first cervical vertebra, which is C1. This test aims to determine if there is an excessive displacement of the atlas in relation to the axis (C2), which could indicate instability.

In clinical practice, the transverse ligament is crucial in stabilizing the atlas, particularly against anterior translation. By applying a PA glide directly to C1, the clinician can evaluate if the transverse ligament is maintaining the appropriate bony alignment and preventing excessive movement. If the ligament is compromised, the atlas may shift significantly, potentially leading to neurological issues or other complications. Thus, performing the PA glide on C1 directly evaluates the function of the transverse ligament.