Osteopaths are musculo-skeletal specialists and should go through a very thorough examination after their history taking. Frozen shoulder is the lay man term for Adhesive Capsulitis.
This is a very common medical diagnosis for any kind of pain in the shoulder. A generic diagnosis if that make sense.
There are three distinct stages to this self limiting condition. A freezing stage were your shoulder movement gets more and more restricted and very painful. This can last up to 9 months. This is worst part of the process, as it can be refractory to even allopathic medication. The frozen stage is when the shoulder joint is literally completely restricted mobility wise, no way you can comb your hair or reach with your affected shoulder for that cup of tea. This phase again can last in the region of 9 months. And finally, for no apparent reasons the shoulder joint regains its almost full mobility (90 or 95%) after another 9 month period.
From an osteopathic point of view the initial part is when treatment can be the most effective. But it is not for the faint hearted as the approach we use here can be very painful, but would potentially decrease the length of this pathological process.