It may be due to muscle spasm or nerve problems at cervical spine..it needs neurological examination and imaging to confirm the diagnosis..consult a neurosurgeon and follow his advice

Hi there...have you been doing excercises in spite of the pain? Pain below the left shoulder blade could be due to many reasons like muscle tear/strain, neuropathy, pancreatitis, etc. It will need clinical examination. Try cold compresses and take paracetamol 650 mg if you have severe pain. Also visit a orthopedic for further evaluation.