The term frozen shoulder already says a lot about the disease. There is a ‘freezing’ of the shoulder joint. This means that the shoulder joint becomes increasingly immobile and stiff. Often, a frozen shoulder is accompanied by pain. It results from a change/inflammation/thickening of the joint capsule tissue, which may involve shrinkage of the capsule.
The joint capsule surrounding the shoulder joint allows an extensive range of motion typically. The joint capsule is comparable to a bellows.
If you expand it, the material is stretched; if you compress it again, wrinkles are formed. The same happens with the joint capsule during movement.
In the case of a frozen shoulder, these wrinkles can stick together and shrink, with the result that you are no longer able to move your arm as usual. It is essential to mention here that the causes are often unknown. In most cases, these adhesions resolve after a certain period, and the shoulder becomes mobile again on its own.
Essentially, a frozen shoulder proceeds in 3 stages. The time of the stages can be very different for each affected person and can last between 6 and 24 months.
In the first stage (acute/inflammatory phase), the mobility of the shoulder/joint capsule is still given, but during this time, there is often inexplicable and severe pain. After a certain period, however, a restriction of mobility is frequently experienced.