Usually x-rays, ultrasounds and even the MRI's are completely normal. Occasionally abnormalities are found, in which case, it is possible to have more than one problem in the same shoulder. Often the frozen shoulder dominates the condition, hiding underlying problems.

The only investigation which can confirm the diagnosis (and frequently this is not necessary as it can be diagnosed clinically on history and examination at the time of the consultation0 is the arthrogram. In this investigation  a needle is introduced into the shoulder and a special dye, visible to x-rays, is injected into the shoulder. Normally the shoulder easily distends with the dye injection. In the presence of a frozen shoulder, the joint capsule is to tight to allow much fluid into the joint, and the absence of the lax redundant capsule at the bottom of the joint is absent.