Another simple test of first rib dysfunction is simply LF C/S L and R while palpating the top of the first rib. In normal motion, you will feel the rib move inferiorly e.g. Left 1st rib moves inferiorly when C/S LF L.

Abnormal motion is seen as the rib not moving down during sideflexion. The first rib is usually fixated superiorly and a simple MET will help move it.