Alar Ligament Stress Test | Upper Cervical Spine Instability

Upper cervical spine instability has a prevalence rate of 0.6% according to Beck et al. (2004) and is associated with inflammatory conditions such as rheumatoid arthritis, ankylosing spondylitis, as well as trauma and congenital deviations such as Down’s syndrome or Marfan’s disease. In order to safely apply manual therapy techniques to the cervical area, it is necessary to screen for possible upper cervical instability.

In their systematic review, Hutting et al. (2013) found a sensitivity ranging from 69% to 72% and a moderate to high specificity ranging from 96% to 100%.

For this reason, the Alar Ligament Test has a moderate clinical value as a pre-manipulative screening test for upper cervical spine instability. The Alar Ligament test is designed to test the quality of side-bending and rotation between the occiput Atlas and axis. Insufficiency of the alar ligaments creates hypermobility in this area.

To perform the test according to the description of Mintken et al. (2008), have your patient in supine-lying position. Then the examiner grips and stabilizes the spinous process of C2 and bends the head and atlas to the side and assesses range of motion and end-feel. Repeat the process on both sides.

If the alar ligament is intact only little to no side bending to the opposite side can occur and the end-feel should be capsular.

Then the test is repeated with rotation of the head and atlas on the axis and end-feel and range of motion are assessed again.
Excessive range of motion compared to the other side or soft end-feel indicates a positive test.

Other orthopedic tests to assess upper cervical instability are:

• Transverse Ligament Test / Anterior Shear Test
• Upper Cervical Flexion Test
• Sharp Purser Test
• Lateral Shear Test / Lateral Displacement Test

Hutting N, Scholten-Peeters GG, Vijverman V, Keesenberg MD, Verhagen AP. Diagnostic accuracy of upper cervical spine instability tests: a systematic review. Physical therapy. 2013 Dec 1;93(12):1686-95.

Harry Von P, Maloul R, Hoffmann M, Hall T, Ruch MM, Ballenberger N. Diagnostic accuracy and validity of three manual examination tests to identify alar ligament lesions: results of a blinded case-control study. Journal of Manual & Manipulative Therapy. 2019 Mar 15;27(2):83-91.