There are numerous reasons why you may be saddled with lower back pain, says Melanie Strassberg, PT, DPT, clinical director of Professional Physical Therapy in New Rochelle, New York: Muscle strains and spasms, a herniated disc, degenerative disc disease, spinal stenosis, and osteoarthritis are just a handful. Given the wide range of causes, your doctor will need to uncover the source during a medical examination before you can find the best lower back pain relief.