Hi jacquelyn... Your stabbing pain is due to pectoral muscle...which would have got compressed while you roll..and activating a trigger or tender point. Since you aware of your loose ligaments..Spasm in the muscle would have arrested movements of shoulder girdle...resulting in sharp stabbing pain in shoulder Blade.... I recommend you to.... Ice your pectoral muscle and shoulder frequently... 15 mins 5-6 times in a day... Gently knead on the muscle belly...initially not on the pain ful area....once pain permits then move on to the painful area... Do strengthening exercises for setting up your shoulder and chest...as lack of strength and control of theses muscles lead to occasional outburst of pain during activity.... Gently stretch your Pecs lats and biceps after pain reduced... If you have a antiinflammatory medication prescribed to you previously have them.. Hope this is helpful for you... Revert back in case you need any further clarification...