The shoulder blade floats freely in a sling of muscle from the chest wall, apart from the strut of the collarbone which comes off the sternum anteriorly.  Minor or major injury can upset the brain’s automatic control of the shoulder blade on the chest wall.  A longstanding focus of irritability in the shoulder in particular can prevent the brain from providing the normal support for the postural muscles.  We see this frequently as a difference in position of the shoulder blade on the chest wall when compared to the normal side.  Correcting the source of irritation and then re-establishing the normal postural control of the shoulder girdle can be challenging.