The lower back is a complex area that connects the upper body (including the chest and arms) to the lower body (including the pelvis and legs) and is comprised of several vertebrae, soft cartilage discs, muscles, joints, ligaments, and nerve tissue. Lower back pain is extremely common for people of all ages, often triggered by some combination of overuse, strain, or injury. Heavy lifting, stretching and exercise can cause a strain, spasm or sprain of the lower back. Occasionally, a spinal disc may rupture or bulge outward, causing pressure on the nerves located in the lumbar region. Lower back pain may also be caused by sciatica or degenerative disorders like arthritis and osteoporosis, a disease characterized by thinning of the bones. Lifestyle factors such as lack of exercise, obesity, poor posture, stress, and bad work practices can also contribute to lower back pain.