Reading through "Fascia" by Robert Schleip I came across a very interesting section about the link between hyper mobility and anxiety. It seems that people that are excessively mobile show a very large increase in anxiety, panic disorders and some GI disorders.
Through personal clinical history, it does seem that many of my hyper mobile patients are women and more often then not have dealt with anxiety disorders.
To start to address some of the hyper mobility issues, I started to implement a couple times a day of breathing exercises to try to gain better functionality out of the diaphragm. If breathing through the diaphragm produces greater rib movement, greater thoracic spine function is achieved. Mobility in the thoracic spine will produce stability in the shoulder/neck/lowback.
As a side note, anxiety is lessened. Schliep's chapter was very interesting to read after just having dealt with a few cases like this. If you know of someone dealing with anxiety, check for hyper mobility, if present, address it.