What is it? : 

Immune response (essentially the body’s defence system attacking itself) that triggers an initial period of inflammation in the shoulder (particularly the ligament in red) and changes in the cells within (Rangan, 2020). Increased cells are created, reducing space and stretch in the tissue- imagine filling up all the holes in a waffle.

Why does it happen? : 

Can occur without cause or be associated with an initial period of immobilisation caused by injury or disuse, older age . Contributing factors include cardiovascular disease, type two diabetes, thyroid disease, depression and increased stress which all contribute to the triggering immune response above (Gibson, 2020).

What do I do about it? : 

Recent research suggests the concept of phases that involve stiffening (freezing) followed by gradual loosening (thawing) may be outdated and less well defined than previously thought (Wong, 2017). It also indicates that the greatest improvement occurs earlier rather than later. Because of this, waiting for a natural improvement with time (1-4 years) may not be the best approach as it doesn’t always occur. For this reason, there’s no reason to delay getting moving and physiotherapy, involving strengthening and flexibility exercises for the shoulder, has been shown to be effective in the long term (Rangan, 2020).

References 

Gibson, Jo. Physio Edge Podcast 2020

Rangan, A., Brealey, S. D., Keding, A., Corbacho, B., Northgraves, M., Kottam, L., Goodchild, L., Srikesavan, C., Rex, S., Charalambous, C. P., Hanchard, N., Armstrong, A., Brooksbank, A., Carr, A., Cooper, C., Dias, J. J., Donnelly, I., Hewitt, C., Lamb, S. E., McDaid, C., … UK FROST Study Group (2020). Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial. Lancet, 396(10256), 977–989.

Wong, C. K., Levine, W. N., Deo, K., Kesting, R. S., Mercer, E. A., Schram, G. A., & Strang, B. L. (2017). Natural history of frozen shoulder: fact or fiction? A systematic review. Physiotherapy, 103(1), 40–47.