what causes muscle spasms in upper back
A strain causes pain in the upper back between your shoulder blade and your spine. A spasm feels like a knot or tightness in the muscle. You may have pain when you move your shoulders or when you breathe.iew image. The rhomboid muscles in your upper back connect the inner edges of your shoulder blades to your spine. A rhomboid strain is a stretch or tear of these muscles. A rhomboid spasm is a sudden tightening of the muscle that you cannot control.