I am a 44 year old female and have been suffering from lower back-ache for past 8 months. It started with raising a leg to put on lower garment. It was very severe in the beginning. There was no apparent problem with X_Ray. Doctor had prescribed painkillers and ointment at the time. I have managed it with hot packs, gels and some general self acupressure. I have been taking Calcium for last 6 months. Vitamin D is low. I now frequently experience a bad back (sometimes upper, sometimes lower) and think its something with the muscles. Could someone suggest ways to strengthen back muscles. Thanks in advance.