If I have pain between my shoulder blades and lower back, the first thing I should do is to understand the causes of this pain. You can do it either by approaching a doctor, or by studying your symptoms (if you have some medical background, otherwise self diagnosis can be difficult or even wrong).
The most common cause of lower back and shoulder blades problems is incorrect posture. If your job involves long hour of sitting or standing, desk work, car rides, etc., you need to pay a closer attention to your posture. Being absorbed by our work we often forget about the posture we accept, and since we keep a wrong posture for long hours, gradually it affects the condition of our spine and accompanying muscles and nerves, leading to painful sensations.
The first step in treatment of your pain will be in watching your posture during your normal work day. Try to correct it as soon as you notice it changing towards a wrong side. If you do not keep yourself physically fit, keeping a proper posture may be difficult. The solution is to start doing regular exercises for at least half an hour every day. This will improve the state of your back and shoulder muscles and will let you keep a good posture easier. Also, a regular workout will help to reduce pain or even to get rid of it completely as it will tone your muscles and restore normal blood circulation.
Stress can be the cause of your shoulder blades and lower back pain; in this case you need to reduce the amount of stress you receive on the one hand, and learn how to relax on the other. Deep breathing practices as well as meditation can help you here.
Your pain can be caused by various health issues and disorders, but to address them properly you need to approach a doctor and receive an appropriate treatment. At least it is what I would do if I have pain between my shoulder blades and lower back, and I’m not sure about the cause of it.