As the name Adhesive Capsulitis suggests, the shoulder capsule becomes sticky and swollen and then limits movement. Like a spider web that has too many layers. The more collagen is laid down, or the more spider web layers, the less elastic the capsule becomes.
Inflammation is our bodies’ way to facilitate healing, like the ambulance that gets help to an accident scene, after the paramedics are dropped off the ambulance can leave again. Inflammation gets everything needed to heal at the site of injury. It is a natural process and very much needed when there is an injury. Inflammation is not required when there is no acute injury.
In a frozen shoulder inflammation occurs within the joint space within the capsule. The cytokines, you can think of them as the guys who phoned the ambulance, sustain the unnecessary inflammatory response. He kind of has memory loss and keeps calling the ambulance even though there is no accident, too many vehicles in too little a space. This inflammation leads to fibrosis of the capsule where collagen (type I & III) is laid down. Collagen is present in all our connective tissues, but too much of it leads to tissue contraction or shortening.
As the capsule becomes stiffer the shoulder loses mobility.
After trauma, like shoulder dislocation, or surgery the risk for developing adhesive capsulitis is higher. Because of the trauma within the capsule, the ambulance is needed to facilitate healing. Any mistaken messages or sustained inflammation can lead to a frozen shoulder.