
Hi!
A typical winging of scapula is due to paralysis of serratus anterior muscle due to damage of long thoracic nerve due to infection, inflammation or injury. Treatment is by physiotherapy and maybe surgery.
Pain under the left shoulder blade is usually a referred pain from abdomen like stomach ulcers, acidity, pancreatitis, or ectopic pregnancy or from the chest like in heart attack, pericarditis, pleuritis, pneumonia, pulmonary embolus, and aortic dissection.