Hello Dr. Im having left flank intercostal pain. The pain feels like a burning sensation which can radiate to my left upper quadrant ( abdominal muscle) causing a spasm . My MD performed a 12 lead ekg , which looked great. noticed I was having active muscle spasms in his office, prescribed muscle relaxers and vicodin . again last night upon laying down I would have a burning pain which would get worse until unbearable and then I would stand up and the pain would go away after a couple of minutes. Originally the pain felt like a muscle was ripping apart from something. the started while sleeping on my side. Woke me up out of sound sleep.