What Causes Low Back, Hip, IT Band Pain With Muscle Spasms?

Seven months ago I had a chiropractic high velocity maneuver because my pelvis was out. I had immediate bad pain and have not gotten better. Before that I was walking 5 miles a day and needed a tune-up for pelvic rotation. I had a pulmonary embolism one year ago that was misdiagnosed by several has muscle pain. I have low back, hip and IT band pain and get severe muscle spasms in my mid and upper back. I am now getting cranio-sacral therapy, have gotten messages and have been doing stretches and started yoga. Since I have a family history of heart disease (which tests show I don't have at age 62, and I am slim and eat an almost perfect diet) I get very nervous about these spasms. Any thoughts?