The dial test is a test for the integrity of the posterolateral corner.
How to perform the dial test
The patient lies on their tummy, knees bent to 90 degrees, while the surgeon stands facing the patient's fee and 'dials' the feet outwards.
Evaluation of the reliability of the dial test for posterolateral rotatory instability: a cadaveric study using an isotonic rotation machine. Bae JH1, Choi IC, Suh SW, Lim HC, Bae TS, Nha KW, Wang JH. Arthroscopy. 2008 May;24(5):593-8. doi: 10.1016/j.arthro.2007.12.003. Epub 2008 Jan 25.