I have eds3 my 1st rib keeps pinching down on nerves on the right side. Exercises to help keep it in place?

THORACIC OUTLET. You likely have thoracic outlet symptoms due to compression by 1st rib. Typically can be handled by physical therapy techniques focused on postural shoulder arrangements. This can be seen associated with connective tissue disorders. See a physical therapist who is experienced in TOS syndromes, and learn the specific approaches (Feldenkreis is one approach)